221 - Fire experiments at the ISS (SoFIE-MIST) with Michael Gollner

Transcript

Space Fire Safety Returns Why Fire Risks Dominate Spaceflight NASA Calls, History, And Prior Experiments SOFT—Solid Fuel Focus And Goals Atmospheres, Oxygen, And Pressure Tradeoffs Why Rods, Not Flats Or Spheres The Combustion Integrated Rack Constraints PMMA As The Benchmark Fuel Microgravity Flame Physics 101 Extinction Limits And Surprising Thresholds Opposed Vs Concurrent Flame Spread Measuring Heat Release Without Gravity Inside The ISS Test Apparatus Live Operations, Links, And Dead Zones

WEBVTT 00:00:00.320 --> 00:00:02.799 <v Wojciech Wegrzynski>Hello everybody, welcome to the Fire Science Show. 00:00:02.799 --> 00:00:10.160 <v Wojciech Wegrzynski>Today I'm taking you to the space and we're gonna do space fire safety, space fire science once again. 00:00:10.160 --> 00:00:21.120 <v Wojciech Wegrzynski>I've invited Professor Michael Gollner from Berkeley to discuss some recent fire experiments that have been carried at the International Space Station called the Sophie Mist. 00:00:21.120 --> 00:00:40.640 <v Wojciech Wegrzynski>So uh well, we'll talk more about what that acronym means and what goes into the experiments, but the general overview is that they are testing the flame extinction limits in different conditions in microgravity to answer a very, very simple and fundamental question. 00:00:40.640 --> 00:00:46.799 <v Wojciech Wegrzynski>Can this burn and can this keep burning in conditions that are present? 00:00:46.799 --> 00:00:50.960 <v Wojciech Wegrzynski>It's about little flames, little fires. 00:00:50.960 --> 00:00:56.799 <v Wojciech Wegrzynski>So it's about really testing out the flame behavior at the incipient stage of a fire. 00:00:56.799 --> 00:01:00.640 <v Wojciech Wegrzynski>If you have followed Fire Science show, we already had um space episodes. 00:01:00.640 --> 00:01:18.799 <v Wojciech Wegrzynski>I had David Urban in the podcast from NASA, and we've discussed about how big fires look on spacecraft, and we had unfortunately we had some in the past and they were all catastrophical, and uh yeah, we're doing everything we can uh to not have fires in the spacecraft and space station. 00:01:18.799 --> 00:01:30.000 <v Wojciech Wegrzynski>Therefore, studying uh the incipient stage of fires is the highest importance because if we can detect it early, if we can understand when something burns, we can perhaps create conditions at which it cannot. 00:01:30.000 --> 00:01:36.640 <v Wojciech Wegrzynski>And if we understand how the fires grow at early stage, we may be better at detecting them and removing them. 00:01:36.640 --> 00:01:43.040 <v Wojciech Wegrzynski>So while it is a fundamental research, it has also a lot of practicality to it. 00:01:43.040 --> 00:01:48.480 <v Wojciech Wegrzynski>And it is just so much fun to run your experiment in the space. 00:01:48.480 --> 00:01:56.079 <v Wojciech Wegrzynski>If you ever wondered how it looks like to set up a fire on the International Space Station, Michael will tell you how. 00:01:56.079 --> 00:01:58.480 <v Wojciech Wegrzynski>So that's the episode today. 00:01:58.480 --> 00:02:00.400 <v Wojciech Wegrzynski>I hope you will enjoy it. 00:02:00.400 --> 00:02:02.640 <v Wojciech Wegrzynski>I loved it as a space geek. 00:02:02.640 --> 00:02:06.799 <v Wojciech Wegrzynski>It's always uh fun to discuss space fire safety. 00:02:06.799 --> 00:02:10.479 <v Wojciech Wegrzynski>And I I hope you share the passion and you share the same views. 00:02:10.479 --> 00:02:13.439 <v Wojciech Wegrzynski>Uh let's spin the intro and jump into the episode. 00:02:13.439 --> 00:02:20.000 <v Wojciech Wegrzynski>Welcome to the Fireside Show. 00:02:20.000 --> 00:02:23.599 <v Wojciech Wegrzynski>My name is Voyage Viginsky, and I will be your host. 00:02:23.599 --> 00:02:45.919 <v Wojciech Wegrzynski>This episode is brought to you in partnership with OFR Consultants, the UK's leading independent fire engineering consultancy. 00:02:45.919 --> 00:02:56.800 <v Wojciech Wegrzynski>With a multi-award-winning team and offices across the country, OFR are experts in fire engineering committed to delivering pre-eminent expertise to protect people, property, and the planet. 00:02:56.800 --> 00:03:01.680 <v Wojciech Wegrzynski>Applications for OFR's 2026 graduate program are now open. 00:03:01.680 --> 00:03:08.240 <v Wojciech Wegrzynski>If you're ready to launch your career with a supportive forward-thinking team, visit OFRconsultants.com to apply. 00:03:08.240 --> 00:03:14.479 <v Wojciech Wegrzynski>You will join a worldless organization recognized for its supportive culture and global expertise. 00:03:14.479 --> 00:03:19.199 <v Wojciech Wegrzynski>Start your journey with OFR and help shape the future of fire engineering. 00:03:19.199 --> 00:03:20.319 <v Wojciech Wegrzynski>Hello everybody. 00:03:20.319 --> 00:03:23.360 <v Wojciech Wegrzynski>I am joined today by Professor Michael Gollner from Berkeley. 00:03:23.360 --> 00:03:24.000 <v Wojciech Wegrzynski>Hey Michael. 00:03:24.000 --> 00:03:25.039 <v Wojciech Wegrzynski>Hey, how are you doing? 00:03:25.039 --> 00:03:26.159 <v Wojciech Wegrzynski>All good, all good. 00:03:26.159 --> 00:03:29.439 <v Wojciech Wegrzynski>Let's let's fly to the spaceman with your crazy experiments. 00:03:29.439 --> 00:03:36.960 <v Wojciech Wegrzynski>I'm really happy that again on the podcast I'm able to talk about uh spacecraft fire safety and general fires and microgravity. 00:03:36.960 --> 00:03:43.919 <v Wojciech Wegrzynski>It's a thing that's uh very interesting to me as an amateur astrophotographer and a space nerd in general. 00:03:43.919 --> 00:03:59.280 <v Wojciech Wegrzynski>Anyway, let's perhaps start with uh I know that there's a long history of Berkeley doing work with NASA, so maybe you can introduce the listeners about how the NASA collaboration began at Berkeley and how did you turn into the current round of experiments? 00:03:59.280 --> 00:04:00.879 <v Wojciech Wegrzynski>Maybe that's an interesting thought. 00:04:01.120 --> 00:04:09.120 <v Michael Gollner>Well, I definitely don't know the whole history, but um, you know, Professor Carlos Fernandez Pello, who fortunately, you know, has not been able to join the podcast. 00:04:09.120 --> 00:04:11.759 <v Michael Gollner>I hope we're going to twist his arm to get on here someday. 00:04:12.080 --> 00:04:14.000 <v Wojciech Wegrzynski>The more people twisting, the easier it's gonna be. 00:04:15.039 --> 00:04:22.000 <v Michael Gollner>But yeah, so he he's been leading microgravity experiments with NASA for many years. 00:04:22.000 --> 00:04:32.240 <v Michael Gollner>Actually, you know, for anyone that comes to our lab, which I'm running now, it's it's really cool because we have at least two or three apparatus that have all been on space shuttle, been space hanging around. 00:04:32.240 --> 00:04:33.759 <v Michael Gollner>You can touch them, you can see them. 00:04:33.759 --> 00:04:35.360 <v Michael Gollner>So there's a lot of history. 00:04:35.360 --> 00:04:40.000 <v Michael Gollner>He led the smoldering experiments that were done on the space shuttle. 00:04:40.000 --> 00:04:45.199 <v Michael Gollner>There's still the samples, I believe Jose Torrero and many others worked on those. 00:04:45.199 --> 00:04:52.639 <v Michael Gollner>So there's a long history, and even this current experiment, the material ignition and spread test, it has a long history, right? 00:04:52.639 --> 00:04:59.759 <v Michael Gollner>Like it, I was not around when it was initiated, and so it's been going for quite a long time. 00:04:59.759 --> 00:05:07.920 <v Michael Gollner>It it's not easy to actually conceptualize, put it in the thing, have it planned, and actually getting it up. 00:05:07.920 --> 00:05:12.720 <v Michael Gollner>It's this incredibly long process before it actually flies and is run. 00:05:13.519 --> 00:05:19.279 <v Wojciech Wegrzynski>That's exactly why you are on the podcast because it just summed up the contents of this podcast episode to come. 00:05:19.279 --> 00:05:20.879 <v Wojciech Wegrzynski>Tell me, tell me all about it. 00:05:20.879 --> 00:05:24.000 <v Wojciech Wegrzynski>So, first let's talk about the idea. 00:05:24.000 --> 00:05:30.319 <v Wojciech Wegrzynski>Does the idea come from the needs of NASA, or is it something you as a researcher come with an idea to NASA? 00:05:30.319 --> 00:05:34.240 <v Wojciech Wegrzynski>Is there an open bid for like, hey, anyone wants to do a space stuff? 00:05:34.399 --> 00:05:36.399 <v Michael Gollner>Uh both, both, right? 00:05:36.399 --> 00:05:41.199 <v Michael Gollner>So spaceflight, there's been a need for fire safety research. 00:05:41.199 --> 00:05:46.480 <v Michael Gollner>When you talk about the hazards that you have in microgravity, fire is one of the greatest. 00:05:46.480 --> 00:05:55.439 <v Michael Gollner>Obviously, in launch and in re-entry tend to be the highest risks because there's a lot that can happen that goes wrong during launch, and we've seen those critical failures. 00:05:55.439 --> 00:05:59.199 <v Michael Gollner>The same thing for re-entry, a damaged tile can lead to destruction. 00:05:59.199 --> 00:06:06.639 <v Michael Gollner>But I think in terms of current space flight, fire is one of the most risky hazards that are that are out there. 00:06:06.639 --> 00:06:10.560 <v Michael Gollner>And so they're very concerned about fire safety. 00:06:10.560 --> 00:06:15.040 <v Michael Gollner>And fire behaves differently in microgravity, which we'll talk about. 00:06:15.040 --> 00:06:20.000 <v Michael Gollner>But because of this, there's always been this research program going on the side. 00:06:20.000 --> 00:06:25.199 <v Michael Gollner>So I think going in NASA Glen, and David Urban, you know, who runs that program would know better. 00:06:25.199 --> 00:06:30.560 <v Michael Gollner>But I believe he said like the drop tower started for microgravity research. 00:06:30.560 --> 00:06:34.720 <v Michael Gollner>So they got like a five seconds of microgravity drop, started around the Apollo program. 00:06:34.720 --> 00:06:39.120 <v Michael Gollner>And there were a lot of other things they were testing too, and they started to look at fire safety. 00:06:39.120 --> 00:06:52.720 <v Michael Gollner>You know, Apollo one was this critical failure and disaster on the pad where high oxygen environment, which makes some things easier, and we'll talk about that, led to a spark, which which then the astronauts couldn't get out. 00:06:52.720 --> 00:06:56.480 <v Michael Gollner>So there were door failures, and then there was this fire and led to their death. 00:06:56.480 --> 00:07:00.639 <v Michael Gollner>Fire safety has always been an issue since then, or at least it's been highlighted. 00:07:00.639 --> 00:07:11.759 <v Michael Gollner>There's been an accident on Mir, there's been a lot of close calls, the space shuttle and even space station, you know, nothing really severe has happened, but that's also because a lot of effort is put into mitigating these hazards. 00:07:11.759 --> 00:07:18.959 <v Michael Gollner>And we still don't understand everything about microgravity, fire safety, which is why the research program continues to emphasize. 00:07:18.959 --> 00:07:31.759 <v Michael Gollner>And so I think you see NASA, well, they rarely have calls for spaceflight experiments, but when they have for combustion, there's been like fundamental combustion and then kind of fire safety, and then fundamental combustion and then fire safety. 00:07:31.759 --> 00:07:39.600 <v Michael Gollner>And so it is a big priority beyond just the science for us to actually try to make sure that you can do long-duration spaceflight safely. 00:07:39.920 --> 00:07:54.240 <v Wojciech Wegrzynski>On uh Sophie Mist website, it even says that it's kind of triggered by the future missions to moon to the Mars, which are very long-duration events, and of course, uh a fire could be a catastrophical failure in such a mission. 00:07:54.240 --> 00:07:58.800 <v Wojciech Wegrzynski>I actually had David in the podcast a long, long time ago, uh, 2022. 00:07:58.800 --> 00:08:06.879 <v Wojciech Wegrzynski>And oh that I'll link the episode in the show notes if if the listeners have not have missed it one, it's joy as well, uh, one of my favorite all-time episodes. 00:08:06.879 --> 00:08:08.800 <v Wojciech Wegrzynski>So there are calls. 00:08:08.800 --> 00:08:11.680 <v Wojciech Wegrzynski>Do they I wonder how it is awarded? 00:08:11.680 --> 00:08:16.160 <v Wojciech Wegrzynski>Like, uh do they have favorite people to work with or or do you fight for it? 00:08:16.160 --> 00:08:18.800 <v Wojciech Wegrzynski>Like, I'm really curious about the the technicalities of that. 00:08:19.040 --> 00:08:23.279 <v Michael Gollner>Yeah, so I came on as a co-PI after this was already started. 00:08:23.279 --> 00:08:27.279 <v Michael Gollner>This so typically NASA has calls for proposals. 00:08:27.279 --> 00:08:42.399 <v Michael Gollner>I mean, this there may not be any more given the ISS's retirement coming up, but they have calls basically when there's openings for experiments, and then there's some things that have come through what's called cases, which is like a sidearm into kind of commercial operations. 00:08:42.399 --> 00:08:47.120 <v Michael Gollner>The NSF, the National Science Foundation, the US, has had small experiment additions. 00:08:47.120 --> 00:08:53.200 <v Michael Gollner>And so uh I've had I've had some that were approved by that, but then they came back and said, Ah, actually, we don't have time. 00:08:53.200 --> 00:08:56.320 <v Michael Gollner>And so we never got to do any new things. 00:08:56.320 --> 00:08:59.759 <v Michael Gollner>But this program was long before I was a faculty. 00:08:59.759 --> 00:09:01.679 <v Michael Gollner>Uh, they had a call for experiments. 00:09:01.679 --> 00:09:03.519 <v Michael Gollner>It actually goes back further. 00:09:03.519 --> 00:09:06.320 <v Michael Gollner>I believe a lot of this idea originated. 00:09:06.320 --> 00:09:13.600 <v Michael Gollner>So there was a an older experiment, the flame ignition and spread test, Fist, which used heaters on a sample uh as it was blowing. 00:09:13.600 --> 00:09:15.440 <v Michael Gollner>And that experiment was planned. 00:09:15.440 --> 00:09:18.720 <v Michael Gollner>I think Sarah McAllister did her thesis on it and some others. 00:09:18.720 --> 00:09:23.679 <v Michael Gollner>And then it never went to space flight because of changes in the administration in the government. 00:09:23.679 --> 00:09:29.679 <v Michael Gollner>So that program was canned, and then a new program later came where MIST was proposed. 00:09:29.679 --> 00:09:46.720 <v Michael Gollner>And as I recall, it may not have been this one, but one of the other projects, the one that Jim Quintiri worked on with the um fuel emulator, I think Carlos and Quintiri, uh Jim Quintiri worked on together, but it wound up that only one PI was, you know, Jim was leading it. 00:09:46.720 --> 00:09:54.960 <v Michael Gollner>Um, but in this case, it was sort of like an adaptation of what was going to happen on Fist, but adapted to the new call. 00:09:54.960 --> 00:10:01.759 <v Michael Gollner>So this call was for material ignition, and all of the experiments are solid fuels, so solid fuel experiments. 00:10:01.759 --> 00:10:08.159 <v Michael Gollner>And the real change in our experiment missed from all the others was that heat is added. 00:10:08.159 --> 00:10:13.759 <v Michael Gollner>So if you're anyone working on material inflammability, external heating is like a core of fire science. 00:10:13.759 --> 00:10:14.559 <v Michael Gollner>That's what we always do. 00:10:14.559 --> 00:10:16.960 <v Michael Gollner>But you pretty much don't find that ever on the space station. 00:10:16.960 --> 00:10:20.879 <v Michael Gollner>It's pretty hard to add here, and there's lots of problems with it. 00:10:20.879 --> 00:10:23.600 <v Michael Gollner>So that's something unique that was added in this experiment. 00:10:23.600 --> 00:10:28.320 <v Michael Gollner>There were a series of other investigations in the same lineup, not all of which have completed. 00:10:28.320 --> 00:10:35.120 <v Michael Gollner>But that addition of external heating is supposed to make this somewhat unique compared to previous experiments. 00:10:35.120 --> 00:10:42.559 <v Michael Gollner>Although it's no longer the flat configuration from Fist, this one is a cylindrical configuration. 00:10:42.559 --> 00:10:47.679 <v Michael Gollner>So, you know, depending on the requirements, things change, but there's a lot of things that can be investigated. 00:10:47.919 --> 00:10:59.360 <v Wojciech Wegrzynski>Yeah, I have some questions regarding the details of the experiment, but first let's maybe give a far field introduction to the uh missed experiment itself and maybe the SOFI program, in which it's it's a part. 00:10:59.360 --> 00:11:07.120 <v Wojciech Wegrzynski>So if you could give a high-level summary of what SOFI was missed, and what is the first uh and main uh research question in those. 00:11:07.440 --> 00:11:12.399 <v Michael Gollner>Yeah, so Sophie's main research question, right, is to look at solid fuel flammability. 00:11:12.399 --> 00:11:18.720 <v Michael Gollner>You talked about long duration spaceflight, and we know that flammability and microgravity is a little different. 00:11:18.720 --> 00:11:25.759 <v Michael Gollner>And some of that's because buoyancy is gone, and so that makes things interesting, but there's still some airflow. 00:11:25.759 --> 00:11:29.519 <v Michael Gollner>There's HVAC or heating ventilation air conditioning on the space station. 00:11:29.519 --> 00:11:38.559 <v Michael Gollner>We assume it's about 10 centimeters per second, so it's pretty slow, but it's there, and that can cause conditions potentially for materials to burn where they couldn't on Earth. 00:11:38.559 --> 00:11:45.759 <v Michael Gollner>They're not going to burn as intensely necessarily, but creeping flames that keep growing still present a huge hazard and can grow over time. 00:11:45.759 --> 00:11:47.120 <v Michael Gollner>It's an interesting mix. 00:11:47.120 --> 00:11:56.799 <v Michael Gollner>So Sophie is designed to look at the fundamentals of that, and in particular, a lot of the experiments are focused on the ignition and extinction limits. 00:11:56.799 --> 00:12:04.399 <v Michael Gollner>So this also ties into another interesting question, which is that we don't always keep the same atmosphere in space as we have on Earth. 00:12:04.399 --> 00:12:09.039 <v Michael Gollner>So we like our one atmosphere, 21% oxygen at sea level. 00:12:09.039 --> 00:12:14.080 <v Michael Gollner>Um, in space, if you want to go into a spacesuit at that pressure, it doesn't move. 00:12:14.080 --> 00:12:17.759 <v Michael Gollner>So you want to reduce the pressure, but then you don't have enough oxygen to breathe. 00:12:17.759 --> 00:12:20.720 <v Michael Gollner>So just like going up Everest, you pump in more oxygen. 00:12:20.720 --> 00:12:22.799 <v Michael Gollner>So you have a higher percentage of oxygen. 00:12:22.799 --> 00:12:25.840 <v Michael Gollner>That potentially adds a high risk. 00:12:25.840 --> 00:12:33.279 <v Michael Gollner>And it takes time for for your body because of the way you know the nitrogen bubbles were, it's gonna take time to adjust to the higher oxygen environment. 00:12:33.279 --> 00:12:40.559 <v Michael Gollner>So you can really speed things up by keeping lower pressures and higher oxygen concentration on what's called the normoxic curve. 00:12:40.559 --> 00:12:46.639 <v Michael Gollner>So it's basically says you have to keep the same partial pressure of oxygen, you have to keep enough oxygen for your body to breathe. 00:12:46.639 --> 00:12:49.679 <v Michael Gollner>Even at a lower pressure, you're gonna have a higher percentage of oxygen. 00:12:49.679 --> 00:12:51.759 <v Michael Gollner>So your body gets enough. 00:12:51.759 --> 00:12:59.759 <v Michael Gollner>And if you start, you know, with a lower pressure but higher oxygen, you're gonna have a lot less time to get into and out of a spacesuit. 00:12:59.759 --> 00:13:04.000 <v Michael Gollner>You're also gonna have to have less material for the structural integrity of the spacecraft. 00:13:04.000 --> 00:13:06.639 <v Michael Gollner>So there's a lot of reasons and it makes space flight easier. 00:13:06.639 --> 00:13:15.440 <v Michael Gollner>But potentially, even though lower pressures and microgravity make things less flammable in general, higher oxygen makes it more flammable. 00:13:15.440 --> 00:13:25.440 <v Michael Gollner>So this experiment for all the investigations varies pressure, oxygen, and then each one does a little bit different flavor. 00:13:25.440 --> 00:13:35.840 <v Michael Gollner>So in mist, we're looking at flame spread along a rod, and then we look at extinction limits as well as the flame spread process for different rods. 00:13:35.840 --> 00:13:42.720 <v Michael Gollner>And then, as I mentioned, the really unique aspect compared to any of the other investigations is we do add external heating. 00:13:42.720 --> 00:13:50.960 <v Michael Gollner>So there's already like Jim Tien uh led an experiment uh with a cylinder where they're looking at ignition extinction, and it's a really nice, very fundamental flow. 00:13:50.960 --> 00:13:55.360 <v Michael Gollner>So you can get like one D in the tip of the cylinder, and so there's a lot that you can learn from that. 00:13:55.360 --> 00:14:01.759 <v Michael Gollner>And then for modeling, Sandy Olsen from NASA led another, and that you know, so there were there are a bunch of investigations, each taking their angle. 00:14:01.759 --> 00:14:07.759 <v Michael Gollner>And I think the unique part about the mist experiment was that we get to do this with external heating. 00:14:08.000 --> 00:14:09.919 <v Wojciech Wegrzynski>What's about the shape of the fuel? 00:14:09.919 --> 00:14:10.960 <v Wojciech Wegrzynski>Why a rod? 00:14:10.960 --> 00:14:13.279 <v Wojciech Wegrzynski>Is it like experimental setup specific? 00:14:13.279 --> 00:14:16.799 <v Wojciech Wegrzynski>Is it like a real-world representative for space fuels? 00:14:16.799 --> 00:14:17.919 <v Wojciech Wegrzynski>It's a great question. 00:14:18.159 --> 00:14:20.000 <v Michael Gollner>I don't know the true answer. 00:14:20.000 --> 00:14:22.320 <v Michael Gollner>You know, I'll tell you, I don't know. 00:14:22.320 --> 00:14:26.559 <v Michael Gollner>And I'm not saying the rod's a problem, there are lots of different ways to configure this, right? 00:14:26.559 --> 00:14:31.039 <v Michael Gollner>So the cylinder is not perfectly uniform everywhere. 00:14:31.039 --> 00:14:37.360 <v Michael Gollner>So I get why the sphere would be very nice in the very fundamental aspect, but it's very impractical. 00:14:37.360 --> 00:14:42.799 <v Michael Gollner>A flat piece would be good, though that was already proposed on the fist and then canceled. 00:14:42.799 --> 00:14:44.320 <v Michael Gollner>Not sure if that could be done again. 00:14:44.320 --> 00:14:46.000 <v Michael Gollner>I don't know how much that's the reason. 00:14:46.000 --> 00:14:57.600 <v Michael Gollner>But also part of it is by doing a rod, you can do 360 heating and you can do different size rods, so we can get thinner and thicker, and we do do three different diameters. 00:14:57.600 --> 00:15:03.360 <v Michael Gollner>There's complications in that, but then there's some benefits that you sort of get more thermal thickness testing. 00:15:03.360 --> 00:15:08.159 <v Michael Gollner>The other thing is with a flat sample, I mathematically prefer the flat sample a little bit. 00:15:08.159 --> 00:15:11.039 <v Michael Gollner>Maybe I just don't like cylindrical coordinates on an issue. 00:15:11.039 --> 00:15:11.679 <v Michael Gollner>Oh god. 00:15:11.679 --> 00:15:19.919 <v Michael Gollner>But it but an issue with the flat sample is that how do you ramp up so that you can do three of them in a test? 00:15:19.919 --> 00:15:20.240 <v Michael Gollner>Okay. 00:15:20.240 --> 00:15:31.120 <v Michael Gollner>So the way it is actually designed is that they put the astronaut refills the gas canisters, clean things, closes it up, and then we run three experiments in a row robotically. 00:15:31.120 --> 00:15:34.000 <v Michael Gollner>And then they'll do the switch out a week later and we do another set. 00:15:34.000 --> 00:15:37.200 <v Michael Gollner>So that way they don't have to sit there for eight hours while we're trying to run it. 00:15:37.200 --> 00:15:41.279 <v Michael Gollner>It's all being done robotically, controlled by Earth. 00:15:41.279 --> 00:15:46.480 <v Michael Gollner>And it's pretty hard to do that with a flat sample and fit that in the apparatus. 00:15:46.480 --> 00:15:48.720 <v Michael Gollner>And I maybe you should talk about the constraint. 00:15:48.720 --> 00:15:53.279 <v Michael Gollner>There is um fabulous apparatus called the Combustion Integrated Rack, the CIR. 00:15:53.279 --> 00:15:58.879 <v Michael Gollner>This apparently flew on the space shuttle and has been on the space station for years. 00:15:58.879 --> 00:16:03.440 <v Michael Gollner>It did all the droplet experiments like Flex with the cool flame discovery. 00:16:03.440 --> 00:16:06.240 <v Michael Gollner>It's done the previous Spire investigations. 00:16:06.240 --> 00:16:15.279 <v Michael Gollner>Maybe the only exception would be Sapphire, which was was pretty cool, and I'm sure David Urban talked about where they they used the resupply craft to do some bigger experiments. 00:16:15.519 --> 00:16:16.480 <v Wojciech Wegrzynski>And they were quite large, right? 00:16:16.480 --> 00:16:17.360 <v Wojciech Wegrzynski>For the space stuff. 00:16:17.600 --> 00:16:29.039 <v Michael Gollner>Like they were they were they were when it was not attached to people, so that's how they were but in terms of something attached while people are on board, the CIR has been the main vehicle for doing that. 00:16:29.039 --> 00:16:32.720 <v Michael Gollner>And I we we may have been the last in that apparatus, which is a little sad. 00:16:32.720 --> 00:16:34.000 <v Michael Gollner>It has been shut down. 00:16:34.000 --> 00:16:38.159 <v Michael Gollner>I don't know if it'll be turned back on, but you know, ISS is getting towards retirement. 00:16:38.159 --> 00:16:43.279 <v Michael Gollner>But we're constrained by how much space, how much gas, how much resources can be put in there. 00:16:43.279 --> 00:16:46.000 <v Michael Gollner>And so that also constrains a lot. 00:16:46.000 --> 00:16:59.759 <v Michael Gollner>Another thing, for instance, we were planning on higher heat fluxes, but you can only burn something so much, and halogen lamps, which would provide higher heating, sound like a real safety risk when the flight engineers take a look. 00:16:59.759 --> 00:17:09.519 <v Michael Gollner>And so they had to switch to more ceramic heaters, which don't achieve as high heat fluxes, but should be better surviving on launch. 00:17:09.519 --> 00:17:18.640 <v Michael Gollner>And so that was and they they did survive, they put they broke once, they flew new ones, but the halogen lamps obviously, you know, they're worried about floating like broken glass. 00:17:18.640 --> 00:17:28.640 <v Michael Gollner>So there are there are unique constraints to running these experiments, but the missed experiment was this next round in in Sophie, where we actually got to test the rods. 00:17:28.640 --> 00:17:32.240 <v Michael Gollner>We did a round last year and another round this year. 00:17:32.240 --> 00:17:35.279 <v Michael Gollner>We just concluded a couple weeks ago, and it was pretty neat. 00:17:35.279 --> 00:17:40.880 <v Michael Gollner>We were actually able to ignite fires in space, watch them, see it extinguish, learn something new. 00:17:40.880 --> 00:17:43.200 <v Michael Gollner>It was amazing to get that opportunity. 00:17:43.680 --> 00:17:49.039 <v Wojciech Wegrzynski>I I would just send a gas burner, but my career in space uh science would end very quickly, I guess. 00:17:49.359 --> 00:17:57.519 <v Michael Gollner>Hey, you know, you Jim Quintiri led that experiment, Peter Sutherland and the group, and then John DeRist joined like was ever everybody was on that. 00:17:57.519 --> 00:18:00.240 <v Michael Gollner>Um that burner, they used a burner in space. 00:18:00.240 --> 00:18:03.200 <v Michael Gollner>That was if you're Quintiria, you're allowed to use burner in space. 00:18:03.200 --> 00:18:04.240 <v Michael Gollner>Hey, I'm not. 00:18:04.240 --> 00:18:06.319 <v Michael Gollner>It was very tiny, right? 00:18:06.319 --> 00:18:12.480 <v Michael Gollner>I remember I was in Maryland, you know, watching the grad students and calibrating the tiniest heat flex gauge in there. 00:18:12.480 --> 00:18:13.920 <v Michael Gollner>It was it was still cute. 00:18:13.920 --> 00:18:29.119 <v Michael Gollner>Um, but they that was it, it was a really neat idea to use a gas burner to emulate solid fuels, and that whole experiment, the acne project was focused on gas burners, and that everything was configured for gas, and then this is all configured for solid fuel. 00:18:29.200 --> 00:18:37.440 <v Wojciech Wegrzynski>Yeah, uh, in in terms of materials, what what the roads were made of, did I or you just use PMMA as as just one single material? 00:18:37.440 --> 00:18:40.079 <v Wojciech Wegrzynski>Polymethylmethacrylate, of course, right? 00:18:40.400 --> 00:18:42.559 <v Michael Gollner>Hooper's anything else than fire. 00:18:42.559 --> 00:18:48.319 <v Michael Gollner>Yeah, but the most realistic fire of them uh of them all, like the default uh fuel, you know. 00:18:48.319 --> 00:18:56.160 <v Michael Gollner>So there are arguments before and against, and you know, my PhD, I use PMMA too, so yeah, that sweet methyl methacrylate smell. 00:18:56.160 --> 00:19:11.440 <v Michael Gollner>So one, you know, you can argue, well, they make make windows out of it, there's some plastic, but I think a reality is one, we have a large data set of PMMA already, and two, it is a really fundamental good material to work with. 00:19:11.440 --> 00:19:21.440 <v Michael Gollner>It bubbles and vaporizes and burns, it doesn't char, it doesn't tend to release any toxic gases, which is nice. 00:19:21.440 --> 00:19:30.160 <v Michael Gollner>It is uniform, it's accessible, it can be made in different shapes, it can be made in different colors without affecting its properties. 00:19:30.160 --> 00:19:36.480 <v Michael Gollner>It's just a really nice material to work with, and it tends to just you know continuously. 00:19:36.480 --> 00:19:45.039 <v Michael Gollner>There is a little bubble layer which is slightly off, but otherwise it it's a pretty uniform material which makes it easier to model, easier to work with. 00:19:45.039 --> 00:19:46.640 <v Michael Gollner>And so I like that. 00:19:46.640 --> 00:20:04.000 <v Michael Gollner>I understand why we use that, and when you have so few materials that you're actually able to test in space, it's good to test on something you know, and then we're focused more on other aspects happening in the gas phase and that interaction rather than this material property, that material property. 00:20:04.240 --> 00:20:14.000 <v Wojciech Wegrzynski>Also, I I assume because it's studied so much, you also have easy access to the best numerical models for for that uh compared to other complex fuels. 00:20:14.160 --> 00:20:19.759 <v Michael Gollner>Uh so uh yeah, I mean there's better there's better solid-phase kinetic models for for PMMA. 00:20:19.759 --> 00:20:22.640 <v Michael Gollner>Not that that's been used an awful lot in this work. 00:20:22.640 --> 00:20:35.519 <v Michael Gollner>We're looking more at this uh at well, extinction limits and spread, but it enables everyone to go back and model this and compare it to years of studies on the ground and in space. 00:20:35.519 --> 00:20:39.279 <v Michael Gollner>So everything we did was done on the ground and in space. 00:20:39.680 --> 00:20:44.079 <v Wojciech Wegrzynski>Okay, well, here you talk here you take one of the questions I had for later, but thank you. 00:20:44.079 --> 00:20:46.400 <v Wojciech Wegrzynski>Okay, another another question about fuels. 00:20:46.400 --> 00:20:54.480 <v Wojciech Wegrzynski>Uh perhaps uh well, you're clear that it's just PMMA for mist, but were like foam materials, porous materials also tested in in space? 00:20:54.559 --> 00:21:00.640 <v Michael Gollner>Or no, I mean, not that they don't have fire hazards, but that wasn't part of this uh experiment. 00:21:00.640 --> 00:21:07.599 <v Michael Gollner>You know, the real goal of these experiments was to look at those extinction limits and particularly oxygen extinction. 00:21:07.839 --> 00:21:08.160 <v Wojciech Wegrzynski>Yeah, yeah. 00:21:08.160 --> 00:21:09.759 <v Wojciech Wegrzynski>Let's move there. 00:21:09.759 --> 00:21:10.960 <v Wojciech Wegrzynski>I I like this. 00:21:10.960 --> 00:21:19.839 <v Wojciech Wegrzynski>When you you say that fire behaves differently in space, could you like give uh again a high-level summary to a fire engineer who's just interested in that? 00:21:19.839 --> 00:21:22.720 <v Wojciech Wegrzynski>What exactly do you mean by by different behavior? 00:21:22.960 --> 00:21:23.359 <v Michael Gollner>Sure. 00:21:23.359 --> 00:21:28.079 <v Michael Gollner>In space, we're dealing with tinier flames, right? 00:21:28.079 --> 00:21:29.599 <v Michael Gollner>If you let's start with a candle. 00:21:29.599 --> 00:21:33.039 <v Michael Gollner>Candle on Earth, you get tall yellow flame. 00:21:33.039 --> 00:21:34.480 <v Michael Gollner>Why is that happening? 00:21:34.480 --> 00:21:38.880 <v Michael Gollner>The wax diffuses up, vaporizes. 00:21:38.880 --> 00:21:47.839 <v Michael Gollner>Gravity, because it's lower density hot air, hot gases, pulls it up as it reacts with the air, and you get that long stretched flame. 00:21:47.839 --> 00:21:50.319 <v Michael Gollner>And it doesn't mix perfectly, it's not pre-mixed. 00:21:50.319 --> 00:21:55.920 <v Michael Gollner>So that diffusion flame generates soot, which glows yellow and orange, and you get a nice flame. 00:21:55.920 --> 00:22:00.480 <v Michael Gollner>In space, there's no buoyancy, no stretchy, no pull. 00:22:00.480 --> 00:22:02.799 <v Michael Gollner>It's a bubble, it's a beautiful blue bow. 00:22:02.799 --> 00:22:04.480 <v Michael Gollner>And it's interesting. 00:22:04.480 --> 00:22:23.440 <v Michael Gollner>If I took a candle and I made that beautiful blue bubble and it grew and it grew and it grew, eventually the heating from the blue flame would not be sufficient to keep vaporizing the fuel, and we'd reach a radiation-dominated extinction limit. 00:22:23.440 --> 00:22:25.519 <v Michael Gollner>And pop, there it goes. 00:22:25.519 --> 00:22:29.839 <v Michael Gollner>So we see that with a droplet flame experiments, you can do it with a candle. 00:22:29.839 --> 00:22:31.839 <v Michael Gollner>So in space, it's different. 00:22:31.839 --> 00:22:32.720 <v Michael Gollner>It is different. 00:22:32.720 --> 00:22:37.200 <v Michael Gollner>The feedback process, I mean, all the physics is the same, but you remove gravity. 00:22:37.200 --> 00:22:43.359 <v Michael Gollner>If I also took a flame in space, I could I could take and ignite that flame and then I could blow on it. 00:22:43.359 --> 00:23:03.759 <v Michael Gollner>And if I blow and blow and blow fast enough, I at high enough oxygen concentrations, the flame's gonna get thinner and hotter, and eventually there's gonna be insufficient like convective feedback, and there's gonna be too many convective losses on the surface, and it's gonna go out, and that's gonna be kind of like a thermal or kinetic blow-off limit. 00:23:03.759 --> 00:23:08.480 <v Michael Gollner>So there are there are two limits for extinction that are gonna occur in space. 00:23:08.480 --> 00:23:12.640 <v Michael Gollner>And the big thing is that is that they're they'll be a little different than on Earth. 00:23:12.880 --> 00:23:21.039 <v Wojciech Wegrzynski>Yeah, but but still, like uh you maybe not have buoyancy, but you're gonna have like thermal expansion of the gas because of change in density. 00:23:21.039 --> 00:23:31.440 <v Wojciech Wegrzynski>So the fumes are not like escaping this area of the of the flame or or or the region of the they'll just stay there and create a growing bubble. 00:23:31.440 --> 00:23:32.559 <v Wojciech Wegrzynski>Is that what you meant? 00:23:32.799 --> 00:23:33.119 <v Michael Gollner>Right. 00:23:33.119 --> 00:23:40.319 <v Michael Gollner>So that is what's going to happen unless we are giving it a little bit of wig. 00:23:40.319 --> 00:23:41.119 <v Michael Gollner>Okay. 00:23:41.119 --> 00:23:49.440 <v Michael Gollner>And that's what really happens on any human spaceflight, is that there's always some ventilation because you need the air to mix, right? 00:23:49.440 --> 00:23:52.960 <v Michael Gollner>You need oxygen in there, and there's no buoyancy to keep it going. 00:23:52.960 --> 00:23:54.240 <v Michael Gollner>So there's always small. 00:23:54.240 --> 00:24:04.000 <v Michael Gollner>We it they say it's about like 10 centimeters per second that the HVAC system is blowing air through the space station or other spaceflight vehicles. 00:24:04.000 --> 00:24:09.680 <v Michael Gollner>So that is going to provide some velocity over the fuels, but not much. 00:24:09.680 --> 00:24:12.480 <v Michael Gollner>But there isn't the buoyancy that we have here. 00:24:12.480 --> 00:24:14.960 <v Michael Gollner>These extinction limits happen on Earth. 00:24:14.960 --> 00:24:22.400 <v Michael Gollner>So, like a tiny flame, buoyancy can almost help blow itself out on Earth, which won't happen in space. 00:24:22.400 --> 00:24:30.000 <v Michael Gollner>It can just creep and creep and creep along very small, where it would never be stable on Earth. 00:24:30.000 --> 00:24:41.440 <v Michael Gollner>And that makes an interesting situation where in theory you can have flames that exist and persist in microgravity that wouldn't exist and persist on Earth gravity. 00:24:41.440 --> 00:24:47.519 <v Michael Gollner>So the true limits of flammability are different in space than they are on Earth. 00:24:47.519 --> 00:24:58.160 <v Michael Gollner>And if you are designing protection systems, if you're picking those materials, you can get into a safety scenario where you think something is safe and non-flammable, but it is. 00:24:58.160 --> 00:25:05.759 <v Michael Gollner>And as we know, when you kick up external heating, that changes the flammability of a material too. 00:25:06.160 --> 00:25:11.759 <v Wojciech Wegrzynski>We'll go to the the heating uh in a second, but uh there's a lot of physics we still need to cover. 00:25:11.759 --> 00:25:16.640 <v Wojciech Wegrzynski>There's not many opportunities to talk about physics in space, so I need to be thorough in this. 00:25:16.640 --> 00:25:18.880 <v Wojciech Wegrzynski>The the the concentration of oxygen. 00:25:18.880 --> 00:25:29.839 <v Wojciech Wegrzynski>In my uh boring earthly systems, uh in the terrestrial fire engineering, I I do 15% oxygen concentration, and I'm pretty much done if I want to protect the space. 00:25:29.839 --> 00:25:35.440 <v Wojciech Wegrzynski>Usually, you said that in the space it's not about percentage really, but about partial pressures. 00:25:35.440 --> 00:25:37.519 <v Wojciech Wegrzynski>Could could you tell me how that actually works? 00:25:37.519 --> 00:25:43.759 <v Wojciech Wegrzynski>Because I'm I'm so used to the concept of just you know concentration and everything that uh it's it's it's kind of uh yeah. 00:25:43.839 --> 00:25:56.079 <v Michael Gollner>Well, it does change with pressure, but it you know, we we still often call it like a limiting oxygen concentration, but it's it's actually like a limiting oxygen volume fraction, would be a more proper term. 00:25:56.079 --> 00:26:02.880 <v Michael Gollner>So this this with you know, when I was mentioning this, it depends it's really important when we talk about breathing. 00:26:02.880 --> 00:26:06.720 <v Michael Gollner>You need enough oxygen in the air uh to breathe. 00:26:06.720 --> 00:26:20.000 <v Michael Gollner>And so there are issues when you're lowering the pressure, which is done for those reasons for external vehicular activities, EVAs, and um just the structure of the spacecraft. 00:26:20.000 --> 00:26:23.680 <v Michael Gollner>Those lower pressures require higher oxygen for people to breathe. 00:26:23.680 --> 00:26:42.400 <v Michael Gollner>And the higher oxygen concentration, even though even though you have the same volume fraction, which is what you need to breathe, the flame has a higher percentage in terms of this limiting oxygen oxygen concentration, and and it it's going to behave differently. 00:26:42.400 --> 00:26:52.400 <v Michael Gollner>The oxygen concentration to keep you breathing, having that higher oxygen concentration actually affects the flame more strongly than the lower pressure does. 00:26:52.400 --> 00:26:55.279 <v Michael Gollner>Like lower pressures are gonna make the flames weaker. 00:26:55.279 --> 00:27:01.119 <v Michael Gollner>When we want to mimic microgravity flames on Earth, we lower the pressure in the chamber. 00:27:01.119 --> 00:27:01.519 <v Michael Gollner>Okay. 00:27:01.519 --> 00:27:07.599 <v Michael Gollner>It will make them bluer, it will make them rounder because there's less gas, so there's less buoyancy effects. 00:27:07.599 --> 00:27:17.359 <v Michael Gollner>But it's actually fascinating that just the little bit of oxygen in there extra, even at that lower pressure, does tend to overcome a lot of those pressure effects. 00:27:17.359 --> 00:27:23.680 <v Michael Gollner>So the higher oxygen concentration has a big influence uh and is very important consideration when we talk about flammability. 00:27:23.680 --> 00:27:32.720 <v Michael Gollner>So if you're designing a hotel, you know, in the Himalayas, and you want everyone to breathe nicely, you're gonna have a big flammability problem. 00:27:32.720 --> 00:27:36.880 <v Michael Gollner>Just the same as if you do that in aircraft or if you do that in spacecraft. 00:27:37.359 --> 00:27:42.400 <v Wojciech Wegrzynski>Now I need some fire engineers from Colorado to discuss the high-altitude fire engineering. 00:27:42.400 --> 00:27:50.799 <v Wojciech Wegrzynski>I found a very interesting uh write on uh Engineering Berkeley about the NASA funded projects and uh by Marnie Ellery. 00:27:50.799 --> 00:28:01.519 <v Wojciech Wegrzynski>And uh in that text, there's like a quote from Car from Carlos who says in normal gravity the limit oxygen concentration, which materials are flammable, is approximately 18%. 00:28:01.519 --> 00:28:09.680 <v Wojciech Wegrzynski>But we're finding that in uh the spacecraft environment is about 15, and then there's uh we're expecting that it would be lower, but not that low. 00:28:09.680 --> 00:28:17.839 <v Wojciech Wegrzynski>So I understand uh okay, the partial pressure, so so you keep it more or less like on in the end, it's more or less like in normal atmosphere. 00:28:17.839 --> 00:28:24.000 <v Wojciech Wegrzynski>So the fact that you have higher oxygen concentration doesn't translate to that more vigorous fires, or maybe it does. 00:28:24.319 --> 00:28:29.359 <v Michael Gollner>Well, so first off, the experiments on on mist are not all on the normoxic curve. 00:28:29.359 --> 00:28:39.119 <v Michael Gollner>Okay, we methodically change the pressure and the oxygen concentration to understand the process, which some hit on the normoxic curve and some don't. 00:28:39.119 --> 00:28:45.359 <v Michael Gollner>So it's not like we've done papers and things where we just follow that curve, but that that's not the case here. 00:28:45.359 --> 00:28:53.359 <v Michael Gollner>It's not only following that curve because we really want to understand what's more strongly influencing is it the pressure, is it the oxygen, is it the heating? 00:28:53.359 --> 00:29:01.200 <v Michael Gollner>And we can only do so much because we're limited in the number of experiments, but yeah, we've had experiments that are lower than 15. 00:29:01.200 --> 00:29:16.960 <v Michael Gollner>So the limit is getting close to 14 oxygen concentration, which you just uh you just won't find PMMA burning at 14 point something oxygen concentration on Earth. 00:29:16.960 --> 00:29:19.279 <v Michael Gollner>It's just it's not happening. 00:29:19.279 --> 00:29:22.319 <v Michael Gollner>Um, but it does happen in microgravity. 00:29:22.640 --> 00:29:25.519 <v Wojciech Wegrzynski>And have you had a short on explaining why why that is? 00:29:25.519 --> 00:29:28.880 <v Wojciech Wegrzynski>Is it like a heat transfer phenomenon, radiation? 00:29:29.279 --> 00:29:33.119 <v Michael Gollner>I think the majority of this all centers around the buoyancy, right? 00:29:33.119 --> 00:29:41.279 <v Michael Gollner>So uh the buoyancy is not blowing off the flame, some of it's geometric in the way the flow is going around and where it's centered. 00:29:41.279 --> 00:29:44.160 <v Michael Gollner>We actually interestingly found two limits. 00:29:44.160 --> 00:29:55.119 <v Michael Gollner>So there's a first limit, which is a little bit higher oxygen concentration where the flame stops spreading, and then it sits there and it burns still, but it no longer spreads. 00:29:55.119 --> 00:29:59.759 <v Michael Gollner>And then there's a second limit where it actually stops burning and goes out. 00:29:59.759 --> 00:30:00.400 <v Michael Gollner>Out. 00:30:00.400 --> 00:30:03.519 <v Michael Gollner>And you know, limits are complicated. 00:30:03.519 --> 00:30:08.480 <v Michael Gollner>It there's fluid mechanics occurring and the flow because it's it's a cylinder geometry. 00:30:08.480 --> 00:30:12.640 <v Michael Gollner>There's the heat transfer effects, which depend on the thickness. 00:30:12.640 --> 00:30:14.240 <v Michael Gollner>That's why we have different thicknesses. 00:30:14.240 --> 00:30:17.759 <v Michael Gollner>We don't change materials, but the thickness makes a big influence there. 00:30:17.759 --> 00:30:24.240 <v Michael Gollner>And then there's a chemical kinetic effects, which is going to affect the temperature of the flame and the heat feedback. 00:30:24.240 --> 00:30:26.079 <v Michael Gollner>So these are all coupled. 00:30:26.079 --> 00:30:31.200 <v Michael Gollner>So none of the results are perfectly translatable to everything. 00:30:31.200 --> 00:30:41.200 <v Michael Gollner>But universally, it's it's fairly universal configuration and fuel that we would then expect this to happen to most other materials, right? 00:30:41.200 --> 00:30:43.279 <v Michael Gollner>The limits may be slightly different. 00:30:43.279 --> 00:30:48.400 <v Michael Gollner>There may be even more, but we're trying to understand that influence and we see that pretty strongly. 00:30:48.720 --> 00:30:50.799 <v Wojciech Wegrzynski>I wanted to ask about the flame spread. 00:30:50.799 --> 00:31:04.240 <v Wojciech Wegrzynski>So if anyone wants to learn about flame spread, there's like Jose on Princeton lectures, and somewhere between the fifth and ninth uh hour of lecture, there's like two hours on opposed and concurrent flame spread and everything about it. 00:31:04.240 --> 00:31:07.440 <v Wojciech Wegrzynski>Do those things change in microgravity as well? 00:31:07.440 --> 00:31:08.960 <v Wojciech Wegrzynski>They do and they don't. 00:31:08.960 --> 00:31:09.359 <v Wojciech Wegrzynski>Okay. 00:31:09.599 --> 00:31:09.920 <v Michael Gollner>Right? 00:31:09.920 --> 00:31:12.799 <v Michael Gollner>So opposed flame spread is what we're doing. 00:31:12.799 --> 00:31:17.680 <v Michael Gollner>Um, and maybe after this, let's let's focus on the and I'll walk through how the experiments run. 00:31:17.680 --> 00:31:20.640 <v Michael Gollner>So opposed flame spread when it's going against the flow. 00:31:20.640 --> 00:31:34.720 <v Michael Gollner>So it's flowing one way and it's trying to go the other, um, is more similar in microgravity than and Earth because it is focused on the small-scale effects from the tip of that flame where it's anchored, and it's heating the material surface ahead. 00:31:34.720 --> 00:31:41.200 <v Michael Gollner>And so a lot of the heating tends to be radiation from the flame or it could be conduction through the solid. 00:31:41.200 --> 00:31:50.160 <v Michael Gollner>The flame isn't extended to unburned materials, it's centered over what's already burning and then heating what's not burned, and it propagates. 00:31:50.160 --> 00:31:57.119 <v Michael Gollner>Concurrent flame spread is where the flame laps over the area that hasn't burned yet and heats it. 00:31:57.119 --> 00:32:00.000 <v Michael Gollner>So concurrent flame spread is faster. 00:32:00.000 --> 00:32:06.640 <v Michael Gollner>It's very dominated by buoyancy or by flow, and where you see the flames in front. 00:32:06.640 --> 00:32:10.559 <v Michael Gollner>So upward flame spread or wind-driven flame spread, that's concurrent. 00:32:10.559 --> 00:32:12.720 <v Michael Gollner>And it's almost always flat faster. 00:32:12.720 --> 00:32:14.880 <v Michael Gollner>It's also acceleratory, right? 00:32:14.880 --> 00:32:19.920 <v Michael Gollner>So it doesn't ever get linear unless it's through a very thin fuel. 00:32:19.920 --> 00:32:26.319 <v Michael Gollner>And yeah, so countercurrent flame spread is much more fundamental. 00:32:26.319 --> 00:32:33.599 <v Michael Gollner>It goes back to like John DeRis in 1969's paper with the first theory for a post-flow flame spread. 00:32:33.599 --> 00:32:43.039 <v Michael Gollner>And theoretically, it's it's easier to deal with, it's also smaller, and so for configuration like this, that's kind of what you want to do. 00:32:43.039 --> 00:32:51.920 <v Michael Gollner>Sapphire did some concurrent flame spread, but for these small experiments, you really need to work with the small countercurrent flames. 00:32:51.920 --> 00:32:57.920 <v Michael Gollner>Hypothetically, if you have no flow, like well, what would it look like? 00:32:57.920 --> 00:32:59.920 <v Michael Gollner>In microgravity or on Earth? 00:32:59.920 --> 00:33:00.720 <v Michael Gollner>In microgravity. 00:33:00.720 --> 00:33:06.319 <v Michael Gollner>In microgravity, if we had no flow ignite at the tip, uh, it is possible that it could spread. 00:33:06.319 --> 00:33:08.720 <v Michael Gollner>It could be way slow, right? 00:33:08.720 --> 00:33:10.960 <v Michael Gollner>Because the flame wouldn't grow as much. 00:33:10.960 --> 00:33:17.440 <v Michael Gollner>We would probably have a very small burning region that would propagate. 00:33:17.440 --> 00:33:27.359 <v Michael Gollner>So it would look a little more like the extinction limit, which, you know, could still be interesting in some ways, but it's not going to achieve that kind of flame spread over time. 00:33:27.359 --> 00:33:31.519 <v Michael Gollner>Ultimately, when we think about flammability, there are a lot of parameters that are important. 00:33:31.519 --> 00:33:36.160 <v Michael Gollner>Ignition, which is not something studied as much here, because we're not controlling it. 00:33:36.160 --> 00:33:39.440 <v Michael Gollner>You have uh flame spread, the rate at which the fire grows. 00:33:39.440 --> 00:33:42.720 <v Michael Gollner>You have the heat release rate, which is also something that we capture. 00:33:42.720 --> 00:33:48.079 <v Michael Gollner>Uh, and then you you have sort of like the, you know, in this case here, extinction suppression. 00:33:48.079 --> 00:33:52.640 <v Michael Gollner>So those are different aspects of flammability that would be tested. 00:33:52.960 --> 00:33:54.720 <v Wojciech Wegrzynski>How do you capture heat release rates? 00:33:54.720 --> 00:33:56.720 <v Wojciech Wegrzynski>Do you have oxygen colorimetry in the experiment? 00:33:56.799 --> 00:34:00.160 <v Michael Gollner>Or there is a lot of oxygen sensors throughout the experiment. 00:34:00.160 --> 00:34:08.239 <v Michael Gollner>And you know, in the past that wasn't being done on Earth, so we added oxygen concentration measurements on Earth so we can do heat release there. 00:34:08.239 --> 00:34:21.599 <v Michael Gollner>But you know, PMA, again, going back to simple, it's all about timing because you're measuring oxygen in different parts, but you you you can get the heat release rate, and yeah, you can't weigh it, there's no gravity. 00:34:21.920 --> 00:34:24.480 <v Wojciech Wegrzynski>Yeah, that's that's probably true. 00:34:24.480 --> 00:34:29.679 <v Wojciech Wegrzynski>I mean, but as a trade-off, you don't need any sample holders. 00:34:29.679 --> 00:34:32.400 <v Wojciech Wegrzynski>You do, you can what's time? 00:34:32.800 --> 00:34:34.239 <v Michael Gollner>Can we talk about like how this works? 00:34:34.239 --> 00:34:35.119 <v Michael Gollner>Yeah, yeah, yeah. 00:34:35.119 --> 00:34:38.000 <v Michael Gollner>So if you go online, you look at the experiment. 00:34:38.000 --> 00:34:46.079 <v Michael Gollner>So the the experiment is in this big cylinder, and inside is essentially stuck a little square, uh, rectangular wind tunnel. 00:34:46.079 --> 00:34:50.880 <v Michael Gollner>And so it's a very simplistic wind tunnel, and it can blow faster. 00:34:50.880 --> 00:34:53.440 <v Michael Gollner>What size is like shoebox, uh bigger? 00:34:53.440 --> 00:34:57.199 <v Michael Gollner>It's like two shoeboxes, maybe two and a half. 00:34:57.199 --> 00:34:58.559 <v Michael Gollner>It's not super big. 00:34:58.559 --> 00:35:10.719 <v Michael Gollner>I mean, the plastic samples are you know seven centimeters-ish, something like centimeter wide, and then there's three diameters up to what uh was it nine millimeters. 00:35:10.719 --> 00:35:18.400 <v Michael Gollner>So they're not they're not that big because we can't get that big of a fire and heat it and do everything we want to it. 00:35:18.400 --> 00:35:27.440 <v Michael Gollner>Okay, so inside that apparatus are three holders which are robotically controlled, and then there's an arm that has an igniter. 00:35:27.440 --> 00:35:46.719 <v Michael Gollner>And so on a test day, we start off and we have they the we don't do this, but while we're talking to them, the you know, contractors that that run this are then positioning the sample in the duct and then positioning the igniter and the wire close to it. 00:35:46.719 --> 00:35:52.320 <v Michael Gollner>And you gotta be really careful because if you knock it, you're gonna break the igniter or you're gonna bend something, and then nothing will work. 00:35:52.320 --> 00:35:59.199 <v Michael Gollner>Do we have like a live view of that happening or sort of so you have a live view while it's in range? 00:35:59.199 --> 00:36:11.199 <v Michael Gollner>So this gets to a fun part where when you're running an experiment, they're prepping the day and they're gonna predict when they have signaled and internet, but then sometimes things are out. 00:36:11.199 --> 00:36:17.679 <v Michael Gollner>So there's a series of satellites around the earth that are bouncing off of the space station and then beaming it back. 00:36:17.679 --> 00:36:26.639 <v Michael Gollner>There are dead spots and there are good spots that are sending the internet back, and sometimes some of them the connection breaks, and they're constantly working on this. 00:36:26.639 --> 00:36:33.599 <v Michael Gollner>And so it's really interesting where you go and you're like, okay, we got a window for an hour and they're positioning and then oh, they're like, okay, next window in 20 minutes. 00:36:33.599 --> 00:36:35.199 <v Michael Gollner>Wait, no, it happened in 15. 00:36:35.199 --> 00:36:35.920 <v Michael Gollner>Oh, let's go. 00:36:35.920 --> 00:36:44.400 <v Michael Gollner>You know, so they know a lot more about this, and they're constantly in contact with Johnson Space Center, which is controlling the ISS um to manage this. 00:36:44.400 --> 00:36:48.960 <v Michael Gollner>But we you're on pins and needles waiting, hoping this works. 00:36:48.960 --> 00:36:51.119 <v Michael Gollner>But they have a real system for this. 00:36:51.119 --> 00:36:59.920 <v Michael Gollner>When you see the live view, we have multiple camera angles, we have all the sensors, and so they're they're fiddling with this to see where it is. 00:36:59.920 --> 00:37:05.360 <v Michael Gollner>Of course, every time an astronaut opens up the chamber, they reinstall stuff, everything shifts a bit. 00:37:05.360 --> 00:37:09.280 <v Michael Gollner>So you've got to readjust everything and hope it all fits and how it lines up. 00:37:09.280 --> 00:37:21.360 <v Michael Gollner>And it can be challenging, it can take them hours to twist around and rearrange without breaking because if you hit a wire, you break something, no one's you know, astronaut time is the most valuable commodity. 00:37:21.360 --> 00:37:26.880 <v Michael Gollner>So we can sit for two hours repositioning and it's hard. 00:37:26.880 --> 00:37:33.599 <v Michael Gollner>Once it's all positioned, that igniter comes up to there and basically heats up. 00:37:33.599 --> 00:37:38.400 <v Michael Gollner>We usually sometimes we do it on a lower flow, depending on what the oxygen and the pressure is. 00:37:38.400 --> 00:37:42.480 <v Michael Gollner>So, like low pressure, low oxygen, be really hard to ignite. 00:37:42.480 --> 00:37:47.440 <v Michael Gollner>Lower flow means there's gonna be a bigger buildup of gases, it's easier to ignite. 00:37:47.440 --> 00:37:52.159 <v Michael Gollner>And then you you ramp up the wind and you can like blowing on it like a fire, right? 00:37:52.159 --> 00:37:55.199 <v Michael Gollner>You shield it from the wind, you get it going, then you blow on it. 00:37:55.199 --> 00:38:05.199 <v Michael Gollner>So there's some fiddling and playing to get it ignited sometimes, and then that flame is gonna spread against the wind, so a post flow from the tip across. 00:38:05.199 --> 00:38:18.880 <v Michael Gollner>And what's really unique, the experiment was first designed that we were going to take the oxygen concentration and we were gonna pulse nitrogen in to drop it and see at which nitrogen concentration it goes out. 00:38:18.880 --> 00:38:37.920 <v Michael Gollner>When we've built a mock wind tunnel here in the lab, so originally our wind tunnel, the lab, blows whatever pressure and oxygen concentration you want through the sample, and we have a little straightener and wind tunnel in the lab and a pressure chamber, and we can test the samples here, and which is great. 00:38:37.920 --> 00:38:46.480 <v Michael Gollner>It's closed, it is it's it's sealed, and we realize that we were always testing where we're just blowing it the whole time. 00:38:46.480 --> 00:38:53.920 <v Michael Gollner>So we tried sealing it and using a fan, and you realize the oxygen concentration builds up pretty quick, which is fine. 00:38:53.920 --> 00:38:57.360 <v Michael Gollner>You can add the nitrogen, you can pulse it. 00:38:57.360 --> 00:39:05.519 <v Michael Gollner>But it turns out the way in which you purge over pressure kind of tweaked the experiment. 00:39:05.519 --> 00:39:14.239 <v Michael Gollner>The whole plan originally was that we're gonna add nitrogen and then we'll bleed a little bit of gas from the chamber to keep the pressure the same. 00:39:14.239 --> 00:39:30.000 <v Michael Gollner>But the rate at which you add nitrogen and the rate at which you bleed is not perfectly timed, and so it winds up having kind of step and the pressure jumps up and down, and then it's really hard to find an extinction limit because you're like affecting the flame. 00:39:30.000 --> 00:39:41.760 <v Michael Gollner>And just by testing it, it turned out if we just let it burn, CO2 builds up really quickly in the chamber, and oxygen goes down, and oxygen goes down, and it puts itself out. 00:39:41.760 --> 00:39:52.719 <v Michael Gollner>So on some things where you start on a high oxygen, yeah, you can pulse nitrogen once or twice in the beginning, and then you bleed a little bit to keep the pressure right, and then you can just let it go. 00:39:52.719 --> 00:40:15.039 <v Michael Gollner>The most important thing is at the extinction limit that you're not adding impulse in which might wiggle and might affect the plane, and then at the end, you can get really close, and then actually the accuracy of that extinction point you can get to like a 0.2%, 0.1% rather than like a single percent, because that change in pressure was really affecting it. 00:40:15.519 --> 00:40:17.199 <v Wojciech Wegrzynski>How do you maintain pressure while doing that? 00:40:17.199 --> 00:40:18.480 <v Wojciech Wegrzynski>Do you have some relief? 00:40:18.559 --> 00:40:22.079 <v Michael Gollner>Uh I mean, I assume the error is a relief valve on the space station. 00:40:22.079 --> 00:40:25.440 <v Michael Gollner>It's it's you know, I believe it's relieved in space. 00:40:25.440 --> 00:40:38.000 <v Michael Gollner>So there's only so much you can do at a time, and it has to be controlled, and those limits make it so that it's like, you know, when you open it, it does it and it closes, and it's just it's just jerky for our experiments. 00:40:38.400 --> 00:40:43.280 <v Wojciech Wegrzynski>Once you ignore it, you you can only sit down and observe pretty much like any fire experiment. 00:40:43.280 --> 00:40:45.360 <v Wojciech Wegrzynski>Or do you do you get to do things to it? 00:40:46.159 --> 00:40:47.840 <v Michael Gollner>We do get to do things to it. 00:40:47.840 --> 00:40:51.280 <v Michael Gollner>Okay, they really hate if we don't tell them what we're gonna do in advance. 00:40:51.280 --> 00:40:53.119 <v Michael Gollner>Yeah, they're wonderful. 00:40:53.119 --> 00:41:05.519 <v Michael Gollner>It was it used to be called Zinn, now I think it's part of Sierra Lobo or something, but there's a company in Ohio that supports this experiment, built the apparatus that was flown up, uh, and they're just wonderful to work with. 00:41:05.519 --> 00:41:13.039 <v Michael Gollner>And then there's folks from NASA Glen, and they're all on site at NASA Glen in Ohio, um, running it, and we're remotely logged in. 00:41:13.039 --> 00:41:17.039 <v Michael Gollner>I mean, there's some of them where some of us uh flew in to join with them. 00:41:17.039 --> 00:41:27.360 <v Michael Gollner>Most of the time we're remotely directly connected, and we also have the same live stream when it works, um, viewing the cameras and viewing all the instrument data. 00:41:27.360 --> 00:41:32.800 <v Michael Gollner>And we have options to do things like we can say, Oh, pressure's getting high. 00:41:32.800 --> 00:41:34.639 <v Michael Gollner>Can you please bleed it for a little bit? 00:41:34.639 --> 00:41:36.480 <v Michael Gollner>You know, and that they can do that live. 00:41:36.480 --> 00:41:40.320 <v Michael Gollner>They can change the camera angle, they can change the lighting. 00:41:40.320 --> 00:41:47.679 <v Michael Gollner>We started at the very end to position the sample during the burn. 00:41:47.679 --> 00:41:50.719 <v Michael Gollner>We didn't do that in the beginning, it was never in the plan. 00:41:50.719 --> 00:42:02.239 <v Michael Gollner>Um, but one of the students, there's two two students, grad students, who who helped prepare most of these experiments when it was in space, Christina Liverto and Jose Rivera. 00:42:02.239 --> 00:42:03.840 <v Michael Gollner>And Jose came up with the idea. 00:42:03.840 --> 00:42:09.840 <v Michael Gollner>He's like, wait, we're always positioning, and sometimes the flame starts spreading away from the heater. 00:42:09.840 --> 00:42:12.239 <v Michael Gollner>Can we just scooch it to the heater? 00:42:12.239 --> 00:42:13.119 <v Michael Gollner>Why not? 00:42:13.119 --> 00:42:17.599 <v Michael Gollner>You know, then it stays heated longer because sometimes it just burns longer than we expected. 00:42:17.599 --> 00:42:24.880 <v Michael Gollner>And that was me, because then when you get closer to that lower 14% extinction limit, um, because it stays heated. 00:42:24.880 --> 00:42:29.679 <v Michael Gollner>And there are things we can do, they just they like to know a little bit in advance. 00:42:29.679 --> 00:42:36.320 <v Michael Gollner>There are limits depending on how much gas is prepped and what we're doing, but it's it is a live process. 00:42:36.960 --> 00:42:46.400 <v Wojciech Wegrzynski>Do you have like a mock-up of the like you said, you have wind tunnel, but do you have like an exact copy of the experiment in the space in your lab to like play fine-tune or no? 00:42:46.480 --> 00:42:47.840 <v Michael Gollner>We don't have an exact mock-up. 00:42:47.840 --> 00:42:58.000 <v Michael Gollner>I think uh I think the lab at NASA Glen or the Zen team has a mock-up because they calibrated the wind tunnel using that, uh, but we do not. 00:42:58.320 --> 00:43:04.960 <v Wojciech Wegrzynski>And uh do the people so so well, technically you can fiddle, but it's true a third-party engineers. 00:43:04.960 --> 00:43:08.000 <v Wojciech Wegrzynski>Like, uh, what's their comprehension of experiment? 00:43:08.000 --> 00:43:11.360 <v Wojciech Wegrzynski>Do you have to brief them of on what you're doing, on the science of it? 00:43:11.360 --> 00:43:13.599 <v Wojciech Wegrzynski>Like how how how much do they know? 00:43:13.920 --> 00:43:17.119 <v Michael Gollner>I mean, they know a lot, but they're not the scientists. 00:43:17.119 --> 00:43:18.079 <v Michael Gollner>It's interesting. 00:43:18.079 --> 00:43:24.960 <v Michael Gollner>So they do have a lot of experience, which is great because they've done a lot of microgravity experiments and they're very close to the NASA engineers. 00:43:24.960 --> 00:43:28.159 <v Michael Gollner>So, this you know, the planning for this project goes back many years. 00:43:28.159 --> 00:43:31.119 <v Michael Gollner>I, you know, Carlos originally did the application. 00:43:31.119 --> 00:43:34.719 <v Michael Gollner>I was actually part of the first science review team. 00:43:34.719 --> 00:43:49.039 <v Michael Gollner>So when I was a new professor at Maryland, I was unaffiliated with this, and they asked me with a bunch of other much more well-known um people to come and evaluate the science and whether they were ready. 00:43:49.039 --> 00:43:52.880 <v Michael Gollner>And this was the projects were already selected, like in the grant. 00:43:52.880 --> 00:43:56.000 <v Michael Gollner>But is this ready to like go for space? 00:43:56.000 --> 00:44:01.760 <v Michael Gollner>Um, which it was, you know, we made some suggestions and changes, like, oh, add this too. 00:44:01.760 --> 00:44:02.800 <v Michael Gollner>Why aren't you doing this? 00:44:02.800 --> 00:44:06.960 <v Michael Gollner>Or, you know, and then there was another review whether it was technically ready. 00:44:06.960 --> 00:44:11.280 <v Michael Gollner>Is the design, does everything sound like it's feasible to do a space? 00:44:11.280 --> 00:44:14.320 <v Michael Gollner>Cast this was baby, like it felt like 10 years ago. 00:44:14.320 --> 00:44:19.840 <v Michael Gollner>I don't know exactly, but it was it was a while ago till it's actually flown and and done. 00:44:19.840 --> 00:44:29.440 <v Michael Gollner>But it was only years after that process that then Carlos was talking to me about joining the project from my work on flame spread and needing help. 00:44:29.440 --> 00:44:32.239 <v Michael Gollner>But this was after I was you know, all the reviews were over. 00:44:32.239 --> 00:44:47.360 <v Michael Gollner>It takes a long time to make sure that everything comes together, and there are many changes along the way because you have to fit what's going to happen in there for all the different investigators over time, stay within budget, and there's a lot of NASA rules, right? 00:44:47.360 --> 00:44:54.320 <v Michael Gollner>For you can use this, you can't use that, this camera's allowed, that's not, it hasn't been certified. 00:44:54.320 --> 00:44:57.360 <v Michael Gollner>They have to pass a flame spread test, these sorts of things. 00:44:57.440 --> 00:45:00.320 <v Wojciech Wegrzynski>So does your PMA pass a flame spread test? 00:45:00.800 --> 00:45:03.119 <v Michael Gollner>Uh I wouldn't think it does. 00:45:03.119 --> 00:45:05.599 <v Michael Gollner>So the NASA actually adds a flame spread test. 00:45:05.599 --> 00:45:10.239 <v Michael Gollner>It's uh what is it, NASA 6000, like 6001 test. 00:45:10.239 --> 00:45:21.920 <v Michael Gollner>It's an interesting standard, but it's it's basically you know a rod, you ignite it in whichever pressure oxygen and see whether it yeah it's or not. 00:45:21.920 --> 00:45:23.760 <v Michael Gollner>It's it's not very advanced. 00:45:24.000 --> 00:45:25.119 <v Wojciech Wegrzynski>Uh another question. 00:45:25.119 --> 00:45:26.480 <v Wojciech Wegrzynski>Uh the heater. 00:45:26.480 --> 00:45:30.239 <v Wojciech Wegrzynski>So the twist in this experiment you said is is the heat feedback. 00:45:30.239 --> 00:45:35.679 <v Wojciech Wegrzynski>So given the previous experiments, what does the heater change? 00:45:35.679 --> 00:45:39.920 <v Wojciech Wegrzynski>And and how how did you introduce the heater to the to the experiment? 00:45:39.920 --> 00:45:44.559 <v Wojciech Wegrzynski>I assume it's 360 degrees, it's like uh a tube to which you put the sample? 00:45:44.559 --> 00:45:45.840 <v Wojciech Wegrzynski>Or how the how does it work? 00:45:46.079 --> 00:45:46.880 <v Michael Gollner>Don't be wish. 00:45:46.880 --> 00:45:47.599 <v Michael Gollner>No, okay. 00:45:47.599 --> 00:45:49.760 <v Michael Gollner>Uh it's three rods, three row rounds. 00:45:49.760 --> 00:45:50.480 <v Michael Gollner>Okay. 00:45:50.480 --> 00:45:54.559 <v Michael Gollner>Um, originally there were more, but there were three that were allowed. 00:45:54.559 --> 00:46:02.639 <v Michael Gollner>Um and there are reflectors, rounded reflectors on the back to try to even that out as much as possible over the sample. 00:46:02.639 --> 00:46:05.840 <v Michael Gollner>It's not perfectly uniform, but it's not that bad. 00:46:05.840 --> 00:46:12.960 <v Michael Gollner>Um so yeah, the apparatus, the rod is pushed into that wind tunnel, and around are the three heaters. 00:46:12.960 --> 00:46:13.199 <v Michael Gollner>Okay. 00:46:13.199 --> 00:46:27.760 <v Michael Gollner>Ceramic rod, or whether not ceramic, they're ceramic, they're like flat rectangular heaters with a that shiny foil reflector behind them to try to then reflect that over the surface so they overlap a bit. 00:46:27.760 --> 00:46:30.000 <v Michael Gollner>And they're they're it's fairly good. 00:46:30.000 --> 00:46:32.239 <v Michael Gollner>It's not perfect, but it's a fairly good coverage. 00:46:32.239 --> 00:46:38.800 <v Michael Gollner>Originally it was supposed to be halogens, which are much more controllable, but there's issues with power and with that chattering. 00:46:38.800 --> 00:46:52.000 <v Michael Gollner>So when we run the heaters, so the first set of tests last year was without heaters, and this year, it's not that we really got to an incredibly new lower oxygen concentration. 00:46:52.000 --> 00:46:58.000 <v Michael Gollner>Um, but generally the experiments could achieve lower oxygen concentration. 00:46:58.000 --> 00:47:06.639 <v Michael Gollner>You know, so it's not like the back's limit changed, but the same conditions that were not getting down are getting lower with additional heating. 00:47:06.639 --> 00:47:08.639 <v Michael Gollner>It it hasn't been a dramatic change. 00:47:08.639 --> 00:47:14.719 <v Michael Gollner>I I should caution too, the heat fluxes are one to three kilowatts per meter squared. 00:47:14.719 --> 00:47:15.199 <v Michael Gollner>Okay. 00:47:15.199 --> 00:47:16.400 <v Michael Gollner>Sunny day. 00:47:16.400 --> 00:47:22.400 <v Michael Gollner>It's uh very three kilowatts is is a little more than a sunny day, but yeah, it's very sunny day. 00:47:22.400 --> 00:47:31.599 <v Michael Gollner>Yeah, so it is not the 20 kilowatts per meter squared that we think of in fire testing on Earth, but these are very tiny flames, and we're doing them in space. 00:47:31.599 --> 00:47:33.360 <v Michael Gollner>And I mean, there is a change. 00:47:33.360 --> 00:47:40.960 <v Michael Gollner>If three kilowatts per meter squared, you see longer flames and it spreads faster, and it it changes because it it's heating the sample. 00:47:40.960 --> 00:47:49.760 <v Michael Gollner>Countercurrent spread, those those flames take time, and heating up the sample is also going to help it spread faster. 00:47:49.760 --> 00:47:53.360 <v Michael Gollner>So there's a lot of effects that are kind of all tying it together. 00:47:53.760 --> 00:47:57.519 <v Wojciech Wegrzynski>How does this relate to real engineering problems on the spacecraft? 00:47:57.519 --> 00:48:00.480 <v Wojciech Wegrzynski>Wouldn't you expect like much higher heat focuses? 00:48:00.480 --> 00:48:08.000 <v Wojciech Wegrzynski>Or it's actually quite representative because you have this very sophisticated smoke detection with the with the suction. 00:48:08.000 --> 00:48:12.639 <v Wojciech Wegrzynski>Like, I guess it's very early detected the fires in space. 00:48:12.639 --> 00:48:17.039 <v Wojciech Wegrzynski>You don't like wait until it's a megawatt, it would be the disaster, right? 00:48:17.519 --> 00:48:17.920 <v Michael Gollner>Right. 00:48:17.920 --> 00:48:28.880 <v Michael Gollner>So, I mean, it's not representative of everything going awry where things are spreading and falling apart. 00:48:28.880 --> 00:48:39.760 <v Michael Gollner>This is representative of the early incipient stages, and I think that's where the goal is is that you don't want things that can get to that stage and propagate further. 00:48:39.760 --> 00:48:46.480 <v Michael Gollner>So it really is focused on the early stage fires and the ignitability limits. 00:48:46.480 --> 00:48:49.119 <v Michael Gollner>Could this really burn and keep burning? 00:48:49.119 --> 00:48:53.440 <v Michael Gollner>And we're trying to understand those limits, and that's the focus. 00:48:53.440 --> 00:48:58.480 <v Michael Gollner>I you know, for long duration of space flight, there's a different level of safety. 00:48:58.480 --> 00:49:19.119 <v Michael Gollner>I mean, astronauts wear cotton shirts and people freak out on the safety end, but they're still gonna allow it because it's just something the astronauts really want for their comfort, but at the same time, most other things are held really stringently to just not allow a lot of flammable materials in living spaces. 00:49:19.119 --> 00:49:23.119 <v Michael Gollner>It's just really trying to reduce that as much as possible to lower the risk. 00:49:23.119 --> 00:49:25.920 <v Michael Gollner>It's a different kind of safety considerations. 00:49:26.559 --> 00:49:52.159 <v Wojciech Wegrzynski>I wonder what like I mean, observing the the space market, let's say, I wonder how it's gonna evolve because perhaps one day we'll you you'll have like a cargo missions which will be tolerating a larger level of risk but both needing oxygen on boards, and you could just send a bunch of stuff there, and you could have like this VIP uh passenger vehicles, which would be crazy control, like like uh early detections and stuff. 00:49:52.159 --> 00:49:56.719 <v Wojciech Wegrzynski>Do you think uh that there will be uh work for uh space fire engineers? 00:49:56.719 --> 00:49:59.199 <v Wojciech Wegrzynski>I wonder if that's gonna be a thing in the future. 00:49:59.599 --> 00:50:11.519 <v Michael Gollner>I I do really worry about what is going to come when things are a lot less regulated, because things have been so regulated. 00:50:11.519 --> 00:50:29.280 <v Michael Gollner>It's just, you know, I it's not like, oh, this is the specific risk, but obviously, you know, we worry about how an unregulated environment for something that is traditionally very risky and unique, and how that's going to change the the system. 00:50:29.280 --> 00:50:35.199 <v Michael Gollner>I think I think we do worry about that, and I don't think we know exactly how that's going to change. 00:50:35.199 --> 00:50:44.639 <v Michael Gollner>NASA, for all aspects, has had that approach of just super over-engineering design within limits to try to be as safe as possible. 00:50:44.639 --> 00:51:02.960 <v Michael Gollner>We've already seen that change in the space flight industry, you know, it's evolved with the NFTA on the spaceport safety standards, and that kind of evolved because we're now taking the off of a military base and we're putting it into a you know private thing, where now a county inspector is inspecting. 00:51:02.960 --> 00:51:04.159 <v Michael Gollner>And what did they do? 00:51:04.159 --> 00:51:05.760 <v Michael Gollner>That's really complicated. 00:51:05.760 --> 00:51:15.119 <v Michael Gollner>Yeah, it's gonna be the same in space flight, but right now I think NASA maintains a lot of the inspection and a lot of the safety rules, but you know, it might change. 00:51:15.119 --> 00:51:17.519 <v Michael Gollner>So it's the space flight's never routine. 00:51:17.760 --> 00:51:21.920 <v Wojciech Wegrzynski>Yeah, one more question that I that I had in mind before uh I forgot to ask. 00:51:21.920 --> 00:51:25.199 <v Wojciech Wegrzynski>You said the astronauts' time is the most expensive commodity. 00:51:25.199 --> 00:51:29.440 <v Wojciech Wegrzynski>How much do astronauts really physically do with those experiments? 00:51:29.440 --> 00:51:37.119 <v Wojciech Wegrzynski>It's not that an astronaut is sitting and observing your flame through a window, but what's actually their part on the experiment? 00:51:37.360 --> 00:51:40.559 <v Michael Gollner>Yeah, I mean, I think they spend, you know, an hour to a few hours. 00:51:40.559 --> 00:52:01.599 <v Michael Gollner>So when we would typically run once per week, be an all-day test day, unless something went wrong, we have a makeup, and we'd do three test points to prep for that, or at the end of that, an astronaut would come in, they'd open it up, they'd replace some gas cylinders, they might replace a filter, they take the fuel rods out and they'd replace them every other week. 00:52:01.599 --> 00:52:05.039 <v Michael Gollner>So we'd re-burn them if they weren't too badly damaged. 00:52:05.039 --> 00:52:07.039 <v Michael Gollner>They might replace an igniter tip. 00:52:07.039 --> 00:52:12.000 <v Michael Gollner>You know, these extra materials were flown up with the experiment, and then they close it all up again. 00:52:12.000 --> 00:52:18.159 <v Michael Gollner>So they the contractors would give them a list of what to do, and they they were trained and they went in there and did that. 00:52:18.159 --> 00:52:22.719 <v Michael Gollner>And you know, it's always neat to see the pictures back when you see like the but it used to be on Twitter. 00:52:22.719 --> 00:52:24.400 <v Michael Gollner>Now you see it on their LinkedIn, yeah. 00:52:24.400 --> 00:52:33.760 <v Michael Gollner>And uh, you know, so like Johnny Kim, who's a famous astronaut, is is in our apparatus, you know, going changing our experiment, putting things in. 00:52:34.000 --> 00:52:37.280 <v Wojciech Wegrzynski>And the communication with the astronauts, it goes through the third party. 00:52:37.280 --> 00:52:45.599 <v Wojciech Wegrzynski>Did you uh have to train them, or you just made an explicit instructions on what's gonna happen, or that's the the company from Ohio doing that. 00:52:46.559 --> 00:52:50.159 <v Michael Gollner>The company and then NASA are doing most of that coordination. 00:52:50.159 --> 00:52:56.079 <v Michael Gollner>Obviously, NASA Johnson Space Center Mission Control is doing the direct communication with the astronaut. 00:52:56.079 --> 00:53:03.920 <v Michael Gollner>This is very interesting the way this process works as the PIs, you know, we're proposing and we're planning. 00:53:03.920 --> 00:53:08.320 <v Michael Gollner>We work together with the NASA scientists who are fabulous. 00:53:08.320 --> 00:53:19.679 <v Michael Gollner>I mean, their experience, you know, so was Sandy Olson and Paul Stracool and Dennis Stalker are always someone is always there supporting us. 00:53:19.679 --> 00:53:36.719 <v Michael Gollner>And they've done decades of experiments, and they actually see you know the company as they're building it, and they're like, no, no, no, no, no, you know, so so they are very, I mean, we're involved too, and we're constantly in calls and checking, and we're flying at, but but not to the level that they are. 00:53:36.719 --> 00:53:38.639 <v Michael Gollner>Um, and they do have a lot of experience. 00:53:38.639 --> 00:53:47.840 <v Michael Gollner>It's not the first fire experiment they built, they built a lot of them, and so that's you know, and they know what astronauts can do, what they can't do. 00:53:47.840 --> 00:53:52.239 <v Michael Gollner>We have no idea about that, and so it helps tremendously. 00:53:52.239 --> 00:53:54.159 <v Michael Gollner>That's really just part of that process. 00:53:54.159 --> 00:53:56.559 <v Michael Gollner>And NASA contracts with them to build it. 00:53:56.559 --> 00:53:58.480 <v Michael Gollner>We just run the science part. 00:53:59.039 --> 00:54:02.480 <v Wojciech Wegrzynski>The decades of experiments, I guess you can say it never gets old. 00:54:02.480 --> 00:54:17.039 <v Wojciech Wegrzynski>And I can I can I can only imagine like the joy of a student who gets to do their master's or PhD like experiment in a space station, like like we had a you know, so you know, Mari Thompson worked on this. 00:54:17.199 --> 00:54:23.360 <v Michael Gollner>There's another student, Andy, it's a postdoc Charles and Luca all worked on MIST. 00:54:23.360 --> 00:54:30.320 <v Michael Gollner>And it hadn't flown yet, it was going to, it was delayed and delayed and delayed and the delayed, you know, right? 00:54:30.320 --> 00:54:40.960 <v Michael Gollner>They got rid of the spatial, they moved to the space, and then this happened, that happened, and then yeah, Jose and Christina just and me lucked out flying. 00:54:40.960 --> 00:54:43.599 <v Michael Gollner>Like, wow, this is happening. 00:54:43.599 --> 00:55:02.079 <v Michael Gollner>I didn't believe it was ever gonna happen, you know, and then um and then we spend weeks getting the computer to connect through Alabama to the space station so you can see the video, and then we, you know, I mean, like we spent months getting the IT stuff so that we could see it in real time. 00:55:02.079 --> 00:55:05.119 <v Michael Gollner>I had to get my NASA ID so I could install it. 00:55:05.119 --> 00:55:10.159 <v Michael Gollner>Like there's silly little things to make it happen, but it was a really neat experience. 00:55:10.480 --> 00:55:12.239 <v Wojciech Wegrzynski>I I guess uh you would do it again. 00:55:12.239 --> 00:55:16.159 <v Wojciech Wegrzynski>Like you look like someone who would do it again if if if got the proposal tomorrow. 00:55:16.480 --> 00:55:17.760 <v Michael Gollner>Yeah, yeah, of course. 00:55:17.760 --> 00:55:24.960 <v Michael Gollner>I mean, you know, we've applied for other things, but I'm afraid that a lot of the programs are gonna be are gonna be shutting down now, which is sad. 00:55:24.960 --> 00:55:41.599 <v Michael Gollner>I I looking at the emails, you know, the folks who supported us, you know, they put out some nice commemorative kind of like posters about everything that ran in the combustion integrated rack and the kind of like a good buy. 00:55:41.599 --> 00:55:48.400 <v Michael Gollner>Because they've been supporting it for well over a decade, and um, and I guess we closed it out. 00:55:48.400 --> 00:55:49.840 <v Michael Gollner>So it's a little sad. 00:55:49.840 --> 00:55:55.440 <v Michael Gollner>Maybe it'll come back again, but yeah, at the moment, I don't know if anything else is planned. 00:55:55.760 --> 00:56:02.480 <v Wojciech Wegrzynski>I I hope that after uh some downs there comes the ups, and uh like you understand everything about fire in space. 00:56:02.480 --> 00:56:08.079 <v Wojciech Wegrzynski>Well, there's still fire experiments on the moon to be done, fire experiments on Mars to be done. 00:56:08.320 --> 00:56:10.880 <v Michael Gollner>There are now there are some, there are some planned. 00:56:10.880 --> 00:56:17.280 <v Michael Gollner>I know, you know, NASA Glen and I think, and um Ya Ting Lao, I believe, at Chase Western. 00:56:17.280 --> 00:56:18.480 <v Michael Gollner>Uh she's part of a group. 00:56:18.480 --> 00:56:21.840 <v Michael Gollner>I believe they are planning a small experiment on the moon. 00:56:21.840 --> 00:56:25.920 <v Michael Gollner>That partial gravity will be really exciting and interesting at the moment. 00:56:25.920 --> 00:56:31.360 <v Michael Gollner>The only way to do it is while dropping in a drop tower for five seconds and spinning it. 00:56:31.360 --> 00:56:33.840 <v Michael Gollner>So you got a lot of distortion effects. 00:56:33.840 --> 00:56:44.320 <v Michael Gollner>And actually, you know, some of the previous studies have shown that partial gravity may be riskier than you're on Earth. 00:56:44.559 --> 00:56:52.000 <v Wojciech Wegrzynski>Well, in that case, uh, we will not run out of topics uh for the space fire science show uh episodes in the future. 00:56:52.000 --> 00:56:57.760 <v Wojciech Wegrzynski>And I am really looking forward uh to hear some news uh from from this industry. 00:56:57.760 --> 00:57:01.679 <v Wojciech Wegrzynski>Anyway, Michael, well, I didn't even notice, but it was it's already an hour. 00:57:01.679 --> 00:57:02.159 <v Wojciech Wegrzynski>Wow. 00:57:02.159 --> 00:57:07.360 <v Wojciech Wegrzynski>Uh thank you, thank you so much for coming to the fire science show and sharing all of this. 00:57:07.360 --> 00:57:12.480 <v Wojciech Wegrzynski>It it was a pleasure, and uh my uh space geekness is satisfied right now. 00:57:12.639 --> 00:57:28.079 <v Michael Gollner>I'm glad it was you know, I I have to say it uh one of the coolest things was not just I mean it's amazing seeing your first ignition and watching it might because it always happens at a weird way too early or late. 00:57:28.079 --> 00:57:37.039 <v Michael Gollner>You know, my kid was there, was like, you know, then an extent, you know, everyone was we were all excited, cheering, you know, watching it through a screen. 00:57:37.039 --> 00:58:02.559 <v Michael Gollner>And but when you realize the level of support for even any of those experiments, you know, you've got support staff, people are doing things in a lab, but to put something in space, I mean, there is a massive team supporting space station, but just for this experiment, there is a huge group of those contractors who are designing the experiment, checking, someone's making sure the data is working, someone's making sure the arm is working, someone's watching the gases and doing that. 00:58:02.559 --> 00:58:04.800 <v Michael Gollner>There's NASA scientists there checking. 00:58:04.800 --> 00:58:05.679 <v Michael Gollner>We're doing that. 00:58:05.679 --> 00:58:09.760 <v Michael Gollner>Someone at Johnson's making sure the astronauts had all this prep, they had to do it. 00:58:09.760 --> 00:58:15.599 <v Michael Gollner>It's such a massive undertaking for those few moments of you know gathering science. 00:58:15.599 --> 00:58:17.760 <v Michael Gollner>It's it's really incredible. 00:58:17.760 --> 00:58:21.920 <v Michael Gollner>And uh it's it's just an amazing privilege to be part of it. 00:58:21.920 --> 00:58:39.599 <v Michael Gollner>And I'm hoping that there'll be more opportunities and more researchers in the future get to do this because it it's a it's really a neat experience, and it provides some valuable information that you just can't get on Earth, and the discoveries are not done. 00:58:39.599 --> 00:58:42.000 <v Michael Gollner>We just finished a couple weeks ago. 00:58:42.000 --> 00:58:46.719 <v Michael Gollner>We've got mounds of data to go through, and we're just starting all the analysis. 00:58:46.719 --> 00:58:51.920 <v Michael Gollner>So we're gonna learn a lot in the next year from all of that data that we collected. 00:58:52.239 --> 00:58:52.880 <v Wojciech Wegrzynski>And that's it. 00:58:52.880 --> 00:58:54.239 <v Wojciech Wegrzynski>Thank you for listening. 00:58:54.239 --> 00:59:02.960 <v Wojciech Wegrzynski>So much stuff we still don't know, uh, so much stuff that we still need to learn about uh fires in microgravity and fires in space in general. 00:59:02.960 --> 00:59:08.239 <v Wojciech Wegrzynski>And at the same time, it's not that we can learn those things uh at the surface of Earth. 00:59:08.239 --> 00:59:12.719 <v Wojciech Wegrzynski>So, yeah, still plenty of uh science to do in space. 00:59:12.719 --> 00:59:18.400 <v Wojciech Wegrzynski>I hope uh the world ends up a little bit more optimistic than uh Michael is worrying about. 00:59:18.400 --> 00:59:37.440 <v Wojciech Wegrzynski>I hope that those experiments in space continue and we find new ways to put interesting stuff at uh representative scales in the space environment and get a little more fire researchers to get this excitement of having you know their first ignition outside of uh planet Earth, I think. 00:59:37.440 --> 00:59:39.199 <v Wojciech Wegrzynski>That that that must be a thing, right? 00:59:39.199 --> 00:59:42.079 <v Wojciech Wegrzynski>To start your first first experiment in the space. 00:59:42.079 --> 00:59:46.960 <v Wojciech Wegrzynski>I can just imagine the amount of joy and excitement that that accompanies that. 00:59:46.960 --> 00:59:58.480 <v Wojciech Wegrzynski>If we look at the practical side of things, you know, fire engineers, I I think there is some space for fire engineering in space pun intended. 00:59:58.480 --> 00:59:59.840 <v Wojciech Wegrzynski>I think uh maybe. 00:59:59.840 --> 01:00:02.559 <v Wojciech Wegrzynski>It's not gonna be a huge industry. 01:00:02.559 --> 01:00:15.679 <v Wojciech Wegrzynski>I mean, if you look at aircrafts and air travel, there is a lot of foreign engineering to be done in relationship with aircrafts and in the same way as we have space travel. 01:00:15.679 --> 01:00:26.639 <v Wojciech Wegrzynski>I mean, when I was a kid, you know, there was NASA, there were Russians, they were sending stuff to space with those governmental funded rockets through governmental companies. 01:00:26.639 --> 01:00:27.760 <v Wojciech Wegrzynski>That was it. 01:00:27.760 --> 01:00:48.719 <v Wojciech Wegrzynski>And today you have those billionaire big boys who are playing with rockets, and there's more and more companies that actually go into this industry as a commercial project and they're actually building very large vessels, very large vehicles, like SpaceX is running the biggest vehicles right now. 01:00:48.719 --> 01:00:59.519 <v Wojciech Wegrzynski>So it appears that once we enter the era of interplanetary travel, maybe more missions to the moon, perhaps missions to Mars. 01:00:59.519 --> 01:01:08.079 <v Wojciech Wegrzynski>If what Elon Musk says he means that we will be able to send a whole fleet of ships to the Mars. 01:01:08.079 --> 01:01:12.480 <v Wojciech Wegrzynski>In not so far from now, maybe 20, maybe 30 years, who knows? 01:01:12.480 --> 01:01:18.480 <v Wojciech Wegrzynski>But but it's definitely in the foreseeable future that we we should have the capacity to do that. 01:01:18.480 --> 01:01:39.280 <v Wojciech Wegrzynski>At that point, you will need a lot of fire engineering to make those missions safe and to to figure out ways in how you provide those people amenities for months of travel in the space, and you will need to find ways to to make uh their destination safe, you know, the Martian colonies safe, the lunar colonies safe. 01:01:39.280 --> 01:01:42.559 <v Wojciech Wegrzynski>We've already had a brainstorm in the fire science show some episodes ago. 01:01:42.559 --> 01:01:53.519 <v Wojciech Wegrzynski>I think it was a very interesting episode where we've just sat down and and thought like if we want to make a Martian uh Martian-based fire safe, what would it look like? 01:01:53.519 --> 01:02:00.719 <v Wojciech Wegrzynski>It was a very interesting and exciting task, and I highly encourage any fire site engineer to actually do such a brainstorm. 01:02:00.719 --> 01:02:02.800 <v Wojciech Wegrzynski>How would you make a Martian-based safe? 01:02:02.800 --> 01:02:05.920 <v Wojciech Wegrzynski>Because it opens up some pathways you wouldn't think they exist. 01:02:05.920 --> 01:02:08.000 <v Wojciech Wegrzynski>So yeah, I would I would highly recommend it. 01:02:08.000 --> 01:02:18.000 <v Wojciech Wegrzynski>But anyway, a lot of fundamental science and a lot of practicality that I see in in research like that, and I hope you've seen that as well. 01:02:18.000 --> 01:02:21.440 <v Wojciech Wegrzynski>Thank you very much for being here with me in the fire science show. 01:02:21.440 --> 01:02:26.800 <v Wojciech Wegrzynski>And next week I'm gonna bring you more fire science, terrestrial fire science this time. 01:02:26.800 --> 01:02:28.960 <v Wojciech Wegrzynski>So see you here next week. 01:02:28.960 --> 01:02:31.039 <v Wojciech Wegrzynski>Uh same same time, same place. 01:02:31.039 --> 01:02:31.760 <v Wojciech Wegrzynski>See you there. 01:02:31.760 --> 01:02:32.159 <v Wojciech Wegrzynski>Bye.

221 - Fire experiments at the ISS (SoFIE-MIST) with Michael Gollner

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