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Alpha Magnetic Spectrometer: The Tools

Season 1Episode 119Nov 21, 2019

Heather Bergman, Justin Cassidy, and Drew Hood discuss how unique tools were developed to complete the on-orbit repair of the Alpha Magnetic Spectrometer (AMS), a space particle detector that’s hot on the trail of dark matter and dark energy. This is part three of a three-part series on AMS. HWHAP Episode 119.

AMS: The Tools

AMS: The Tools

If you’re fascinated by the idea of humans traveling through space and curious about how that all works, you’ve come to the right place.

“Houston We Have a Podcast” is the official podcast of the NASA Johnson Space Center from Houston, Texas, home for NASA’s astronauts and Mission Control Center. Listen to the brightest minds of America’s space agency – astronauts, engineers, scientists and program leaders – discuss exciting topics in engineering, science and technology, sharing their personal stories and expertise on every aspect of human spaceflight. Learn more about how the work being done will help send humans forward to the Moon and on to Mars in the Artemis program.

On Episode 119, Heather Bergman, Justin Cassidy, and Drew Hood discuss how unique tools were developed to complete the on-orbit repair of the Alpha Magnetic Spectrometer (AMS), a space particle detector that’s hot on the trail of dark matter and dark energy. This is part three of a three-part series on AMS. This episode was recorded on October 23, 2019.

Houston, we have a podcast


Pat Ryan (Host): Houston, we have a podcast. Welcome to the official podcast of the NASA Johnson Space Center. This is Episode 119, “Alpha Magnetic Spectrometer, The Tools.” I’m Pat Ryan. On this podcast, we talk with scientists, engineers, astronauts, and other folks about their part in America’s space exploration program. And today, we’re going to talk about a typically NASA sort of thing — how we develop unique tools to complete the on-orbit repair of an amazing space particle detector which is hot on the trail of dark matter and dark energy. Yeah, it’s what we do. In 1994, Nobel Laureate Professor Samuel Ting from MIT proposed the Alpha Magnetic Spectrometer. You’ll hear us call it the AMS. He had in mind a particle physics detector to be deployed on the International Space Station, which itself wasn’t even flying yet, and which would gather information about cosmic particles traveling through space. He was searching for antimatter, and dark matter, and keys to the origins of the universe. It was delivered to the International Space Station on the next-to-last space shuttle mission in May of 2011, and it’s been gathering and gathering more than 146 billion cosmic ray events, give or take. Check out our podcast Episode 117, with space station Assistant Program Scientist Brandon Reddell for more on the science of the AMS. Well, the AMS today is ready for some upgrades to extend its life. That means spacewalks by station astronauts. The thing is, AMS was not designed to be repaired on orbit, or have its parts replaced in space, as was the case for another iconic piece of NASA science hardware, the Hubble Space Telescope, and those on-orbit upgrades and repairs worked out really well. So the spacewalk experts at the Johnson Space Center here in Houston tagged in some colleagues at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, the home of Hubble, to figure out how to do this job. In the process of the figuring out, they realized they didn’t have the tools they needed for all the work. No one had them. They didn’t exist. So they created them, and that’s our story today. I got a chance to talk with three of the engineers involved — Justin Cassidy from Goddard, and Heather Bergman and Drew Hood from Johnson — about the development, and fabrication, and testing of more than 20 brand-new tools to allow spacewalking astronauts to keep AMS in business for as long as the station keeps flying. OK then, here we go.

[ Music ]

Host: From the “one of these things does not belong with the other department” is, in this case, me, because I am not a spacewalk engineer, or an engineer of any kind, frankly, and I don’t play one on television. And I didn’t even stay in a special hotel chain last night, but I really get turned on by stories about how machines work. So I’m really excited to get to talk to all of you today. Heather Bergman and Drew Hood work here at NASA’s Johnson Space Center in the — and why do we do this to ourselves? In the [Extravehicular Activity] EVA and Advanced Exploration Tools Office, which is a part of the Tools, Equipment, and Habitability Systems Branch of the Crew and Thermal Systems Division. Good for you guys. And Justin Cassidy works in the Satellite Servicing Project Division at Goddard Space Flight Center, and he’s been involved in planning and execution of most of the Hubble Space Telescope repair missions. So by way of introduction, I wanted to ask if each of you would just tell me a little about yourself, about your own background, how you got to NASA, maybe some of what you’ve been working on before, and how you got involved in the Alpha Magnetic Spectrometer spacewalk project. Heather?

Heather Bergman: I’m Heather Bergman. For the past four years, I’ve been the JSC EVA tools Project Manager for the AMS repair tools. I started mechanical engineering at the University of Toledo in Ohio. I started co-oping in the car industry. I always wanted to design sports cars, and after spending a semester doing that, I realized that world was too political for me. So oddly, I came to work for the government [laughter]. I worked at Glenn Research Center, NASA Glenn Research Center in Cleveland, Ohio, and after graduating, I worked there for a year before I moved down here. I started working shuttle repair tools, return-to-flight for STS-114, and did that through the end of the Space Shuttle program, and then moved over to ISS tools. So International Space Station — anything that goes out the door, any of our new builds comes through our office. So worked that for a while, so when AMS showed up, we were the office that was — went through first, I guess. And we’ve been working AMS since the beginning, since they decided that they needed to go outside and do the repair on a spacewalk.

Host: Did you say four years you’ve been working on this?

Heather Bergman: Four years for AMS.

Host: My goodness. We’ll find out why here in a minute.

Heather Bergman: Yes.

Host: Drew Hood, tell me about your —

Drew Hood: Yeah, my name’s Drew Hood. I studied mechanical engineering at Purdue University, and I honestly had no idea what even the last A in NASA stood for [laughter]. I was interested in biomedical engineering. So I was going to Purdue, and as a freshman, I got introduced to the co-op program, as Heather mentioned earlier, where you go to school a semester, work a semester. So I was focused on trying to land a job in the Midwest with a biomedical company, and thankfully, my dad said, “Hey, why don’t you interview with NASA as well, just to kind of round out your interview session?” And so, thankfully, I did that, and five years and six co-op tours later, I landed a full-time job here at NASA.

Host: Man.

Drew Hood: And so, I came into the tools group that I currently work in today, and really, really enjoy that work. So I’ve worked on a lot of different projects from NEEMO, [NASA extreme environment mission operations] which is an underwater exploration analogue off the coast of Florida, where astronauts go down and do some training, building hardware for that, to certifying a GoPro camera for the crew to take out, and take good video, and for the International Space Station. But the last — Heather said, the last four of my ten years here at NASA as a full-time employee have been focused on AMS.

Host: My goodness. Justin Cassidy, you’ve been involved in spacewalking for longer than that.

Justin Cassidy: It certainly has that. So I’m Justin Cassidy. I’ve been with NASA for over 30 years, so I’m going to age myself there. Like — I’m an engineer as well, mechanical engineer. I went through school at — in Washington, D.C., a Catholic University, and that is just down the street from NASA Goddard Space Flight Center in Maryland, just across the line. So it was always my desire to go up the street, if you would, and find employment at NASA Goddard, and I did. And I worked a couple of early development programs at NASA. I started working on this thing that people were kind of getting together called space station. So I worked really, really early days of pre-planning with what our contribution was to that. I worked another program called the Flight Tower Robotic Service, which was basically putting a robotic arm in the shuttle cargo bay, and showing what you could do robotics-wise. So I do have a tie to robotics. I had a great opportunity back in 1994 to work on this program called Hubble Space Telescope after they had discovered that there was an issue with the mirror on Hubble. And conducting that — that servicing SM1 repair, it definitely was something interested– I had availability to get a part of that team. And so, I worked Hubble — four out of five servicing missions for Hubble, much in a systems role supporting that project, also supporting the EVA folks developing critical tools, I would say, for servicing Hubble. Basically, Hubble was meant to be serviced, visited by astronauts, and upgraded, so we did that over a number of years. And the beauty about having Hubble Space Telescope, and its ability to be upgraded, was – is that as technologies mature, those upgraded components could be replaced over the years. So better instruments, better cameras, better tape recorders —

Host: Or replacements for things that broke.

Justin Cassidy: — or replacements for things that failed before they were expected to last. So that became a very great opportunity for myself. The last servicing mission, SM4, was very unique in that we went beyond the — what they call ORU box level change-out. We actually were having astronauts open up instruments and do technician-level work, replacing a board about the size of 8-1/2 x 11 sheet of paper. And that was totally something new that helped us — what we’re going into.

Host: You said it was four years ago that somebody said, “Oh, you, come talk about the AMS.” At the point that this first presented itself, what was the problem? What was going on with AMS that spacewalks were needed for it?

Heather Bergman: Well, they — they started out having some spikes on their pumps. So the pumps are — they move cooling fluid through AMS. So they keep things cool that are supposed to be cool. They keep things warm that are supposed to be warm, and it just moves things around. Think of it as the air conditioning for the system.

Host: And it has — it — both directions, because the thing is mounted on the outside of the International Space Station, so it’s going through times where there’s sun and times when they’re in dark. So it’s got to maintain a steady level temperature.

Heather Bergman: Correct. So it was starting to have trouble maintaining those temperatures. So they wanted to go out and fix that, so they started with putting a little extra blanket up near those — some sections to keep it a little warmer in there, and that didn’t quite do everything. So they started to look more and more into what needed to be done, and they decided that the pumps that moved that fluid throughout AMS needed to be replaced. And AMS was not designed to be serviced like Hubble was. It was designed to go up for maybe three years or so, get some science, and then be done. Well, nine years later, it’s getting such amazing science that they want to keep going. So even though it’s well past its life, they’ve asked us to go do a spacewalk and fix something that was not meant to be fixed.

Host: Well, and it’s still got more to do, because the scientists behind it are still not publishing their final findings yet. So they still want to gather more data. So I guess this was not just another assignment.

Heather Bergman: No.

Drew Hood: No, for me, definitely not. I was — as I said earlier, I’ve only been here ten years full-time, and four of that have been worked on AMS. So I was brought in as a pretty green engineer. I had had a lot of experience in, like, the development world, doing kind of quick-and-dirty development projects, but not the rigors of a full-flight project. So I was brought in, and kind of shadowed Heather here, and have grown over the past four years, which have been awesome.

Host: It would seem to me, not knowing any of this that you guys do, that you have two problems, and it’s the one that we’ve mentioned, the fact that this was not designed to be worked on in this way, in space. And it’s also not here for you to play with, right? I mean, its 250 miles up, and moving pretty fast.

Heather Bergman: Yeah.

Host: What do you do in a situation like that? How do you start to approach this problem?

Heather Bergman: So we just finished a series of spacewalks replacing something that was meant to be replaced on space station. We just replaced the BCDUs, a battery, something —

Host: Charge-Discharge Unit—

Heather Bergman: Yes. So these weren’t meant to do that. So you go in, and we’ve looked at — we looked at all of the drawings, and all the pictures. We looked at hundreds of pictures and drawings to try to figure out the best way to get inside of AMS. AMS has a nice hard shield on the outside of it to protect anybody from getting into these things. You don’t want any micrometeoroids to puncture anything that is important. So it’s shielded. So we had to go find a way to get inside, and you look at all of these photos, and videos, and drawings to try to figure out the best way to get inside, and talk to all the people who made it.

Justin Cassidy: So, Pat, there’s a very large lesson learned, going back to — so I’ll talk about often is the Hubble, Hubble space servicing, basically. And we — the division I report to at Goddard Space Flight Center has invested significant amount of efforts to work through all the Hubble servicing missions for success, and we are now also relying on proving that you could do the same thing as an astronaut with a robot. So we’ve — we have put some experiments up onto space station with specialized robotic tools for performing servicing repair, to show that, yes, a robot and an astronaut can do it. Maybe one is better than the other, but certainly, the capability is there. And we have been working a lot with satellite operators and vendors creating satellites, basically saying that the most important thing you could do is take photographs of your hardware. That is of utmost importance. So when you get there, there is no surprise, or less surprise when you need to do the work on that particular repair.

Heather Bergman: And when you think at home, you measure twice and cut once, right?

Host: That’s what I’ve heard.

Heather Bergman: Well, I hope we measured twice before we launched AMS, because there’s no more measuring to be done.

Host: Right.

Drew Hood: And one of the best things that we were able to do was to use spare parts, and build some mockups. So we actually decided to build — of what we had around, we were able to piece part together — I think they call it Woody [laughter]. It’s a half-wooden, half-metal mockup over in building nine that we —

Host: But its parents love it just the same. [Laughter]

Drew Hood: Yeah, they do. They do. So it’s — we were able to train some astronauts on it, and we were able to actually look at it to develop some of our tools. We went over as engineers at the beginning and said, “Hey, what do we think we can use to get into some of this worksite, and do some of this challenging stuff?” So while we may not have the real one here, there were some spare parts, and we were able to create a — one that we could play with.

Host: And just to make sure I understand — because, Justin, you mentioned the possibility of a robotic — of robots being able to make repairs. Is that being used in this case?

Justin Cassidy: Certainly not in this case.

Host: OK.

Justin Cassidy: Just a reference for similarity between repairs. No matter what you’re trying to work on, photo documentation is certainly a very large precedence that we’d like to put out there, that is very, very important, as well as drawings, and CAD [Computer aided design] models, and having spare parts are really critical and essential for reducing your risk for any potential issue we’d have during a repair.

Host: And it sounds like you guys had lots of cooperation from the AMS people, who provided you the tools, or the toys, in order to figure out how to do the repair that had to be done.

Heather Bergman: Absolutely. We’ve gone and — since we don’t have the actual hardware here to go measure, we’ve looked at all the paperwork they put together over the years that they were building it, and looked at any measurement they made, any picture they took, and anything we can use in there to make sure that our hardware is going to fit properly when it gets up there. We’ve done everything we can to look at all that paperwork, to make sure it happens.

Host: How long were you working at this before you started to come to the realization that you didn’t have all the hardware that you needed for this, that it didn’t exist, that there were things that you — that you wanted to get at that you didn’t have tools for, or didn’t have tools in space for?

Justin Cassidy: Pat, let me ask Heather.

Host: Yeah.

Justin Cassidy: During the — since we’ve been doing this so long, during the course, the actual worksite changed —

Host: Yes, it did.

Justin Cassidy: Three times, at least, for where our target was, where we were going to adapt into the system in order to create this life extension for AMS.

Host: The AMS didn’t move.

Heather Bergman: No, but where we were going to repair it moved. So there are a couple of cooling loops, and we’re going to repair one of them. So we started off on the port side of AMS, and that was a very challenging worksite. And as we were working with the AMS project office, and their collaboration, they were able to come up with some other places that we could go in and look. So after we had thought about how do we get into this place, and spent some time looking at that, we completely changed our worksite to the starboard side of AMS, which is a little —

Host: As your access point?

Heather Bergman: — mm-hmm, is a little more open, still not open from what we would normally want to have, but much more open than the previous area. So yeah, we’ve moved around a couple of times, and changed the general repair scenario.

Host: Was there any thought given to, “well, let’s just pick it up off the truss and hold it out here so that we could get at it”?

Heather Bergman: Absolutely, yeah, we thought about that as well. We can’t fly a new one anymore, because we don’t have the capabilities of shuttle to fly something that large, but everything was on the table. Maybe we need to pick it up and hold it up for a while, while we give the crew good access. We thought about it all.

Host: Install foot restraints, so that they could go up to it and get at any side of it.

Heather Bergman: Yeah, we thought about it.

Host: But we’re not going to do that this time.

Heather Bergman: No.

Justin Cassidy: I mean, one thing was very for certain — that they approached us. Could we actually come up with methodologies for getting to the worksite, to open the worksite, perform the worksite? We couldn’t come back with, “oh, no, we can’t do it.” So we had to find a solution. There was no “no” in this condition. We had to find a way, and by the end, we all found a very great way, I think.

Heather Bergman: And I think as tool engineers, kind of our job is to not say no. They come to us when things become really difficult, and say, “OK, can you make a tool to do this?” And that’s one of my favorite things, is being able to create a tool to do the impossible.

Host: If it was easy, they’d have asked me. [Laughter]

Drew Hood: And I guess I want to say one of the robots we are using on this mission, though, is the robotic arm. So the robotic arm — you mentioned foot restraints. So that is a big, key component to get to this worksite, because we need to be able to position people in the right spot. Because this worksite was never meant to be worked on. So there aren’t the convenient handrails in all the places that you normally find on station. Like, on station, the handrails are numbered. Like, there’s a — they have a number on them, and you can actually walk down the station. They plan out exactly where they’re going to put their hands. On this one, they —

Host: And one handrail at a time.

Drew Hood: One handrail at a time, yes. And so, we didn’t have that on the side of AMS where we’re working, and so, we had to use the robotic arm, and the foot restraint to get the crew in the spots where they could actually do the tasks that are needed.

Host: What kind of things were you finding that you — that made you say, “We don’t have the tool to do this”? Can you give me an example of what — what kind of things were you encountering?

Heather Bergman: Well, Drew was just talking about handrails being all over station. Without gravity to hold you in place, you’ve got — you need something to grab onto. Well, there’s no handrails, so Drew and I worked on the team that built three new handrails to attach to things that are not meant to have handrails attached to them. So after Justin’s team removed some of the debris shield to get us access into the cavity, we tried to look at any little feature that we could grab onto, to put a handrail on. And when you put a handrail on, it’s not just something that needs to take five or ten pounds. It’s 125 pounds minimum. So it’s — you need to find some beefy structure, which may or may not be there, so you have to get creative with how you’re going to grab onto things.

Host: Well, I mean, it’s got to take the weight not only of the astronaut, but the suit that the astronaut is wearing, plus any other hardware they may have with them, right? That’s 500 pounds.

Heather Bergman: The loads that they’ve put into it — well, they don’t weigh anything in space. They do have some mass.

Host: Mass — thank you.

Heather Bergman: But they move around, and so, generally, we say that 125 pounds is a kick load. So if they kind of push off of something, or bump into it, 125 pounds is kind of where we aim for, for most of our hardware. Handrails tend to go a little higher, especially if the crew’s going to be — their safety on them, but —

Justin Cassidy: So Pat, without these crew rates that Heather and Drew have been talking about, it would be very difficult for the crew member to do their work at the worksite, unrestrained, without being in the foot restraints. So it gives them a lot more control, using the tools that we have created for them in order to conduct the repair.

Host: In general, without talking about — again, maybe not one particular tool, but what kind of process do you have to go through? I am assuming, just because I’ve been around here for a while, that it’s going to be really detailed, and every step of the way’s got to be documented, and there are 1000 people you never heard of who are here to tell you how you should change what you wanted to do, that it’s a really difficult process to get through. Right?

Heather Bergman: Yeah, absolutely. On our side —

Host: Give me a sense of it.

Heather Bergman: — so we — some of the things we’re looking at — we’re — so we’re doing plumbing. We’re replacing the pumps and fixing the air conditioning system. So there are tools out there that can be used to cut into stainless steel lines, and to swage back onto those lines, and do these things. They’re just not friendly for an astronaut in a spacesuit. So where we started with a lot of our tools is, “Is there an easy tool that I can go buy at the store that might do this job?” And even if I can’t buy something that’ll do this job, can I get an idea of what — the industry’s already gone off and found the best widget to do this. Can I take that widget and redesign it so that it can be used in a spacesuit?

Host: Did you find any you could buy?

Heather Bergman: We found ones that we could use some of [laughter], but even if you can use some of — we had some bolt-cutters that are — half of them are something that we were able to buy, but the other half — you need to put nice, friendly handles on them for the crew to use, and —

Host: Just would’ve been easier.

Heather Bergman: — most tools that you buy in a store don’t have a tether point on them.

Host: What?

Heather Bergman: Yeah [laughter]. So we want to make sure none of that hardware floats away if the crew member lets go of it. So at a bare minimum, we almost always have to add a tether point.

Host: In working through that process, does — it strikes me that that’s something that sounds like it’s got all sorts of opportunities for you to be frustrated, in trying to get this to work. I mean, it — because you’re trying to figure out something really difficult, and then you’ve got — not difficult? You’re shaking your head.

Drew Hood: No, it is difficult. I would say the frustration is usually on the back end, trying to get all the paperwork in order. Like, solving the problem up front is the fun, exciting part. Like, that’s the blast, and then checking all the boxes, dotting your T’s, crossing all your I’s — oh, other way around, yeah. You know what I meant [laughter]. That’s — like, see, that’s the challenging part, the paperwork.

Host: Already — it occurs to me to ask that, in the course of doing this, that it might be helpful for you to not only be working with all the other engineers that you know who have developed tools for other missions, but to talk to astronauts who have used the actual tools in actual space to do this stuff. Did you have a lot of access, a lot of help from the astronaut office in working through this stuff?

Heather Bergman: Absolutely. This — especially with this — not with every EVA, we don’t necessarily have a lot of access to the astronauts, but with this one in particular, we knew from the beginning that this was going to be a challenging set of EVAs. And we were going to need to design the tools to be used by probably a more particular crew than usual. A lot of our hardware is designed to be built by any crew member, on any day, and the crew members are all very capable of using them. But this was such a difficult repair idea that we thought it was going to be intricate and difficult enough that we were probably going to have to have somebody that trained on it, more like on a Hubble mission, where they’d seen the hardware and played with the hardware in the worksite on more than one occasion. Because it was just going to be too much to do based on reading through the procedures, and too much to pick up and just — just real quick.

Host: We hear astronauts talk about how they receive skills training when they’re getting ready for an International Space Station mission, because they don’t know what spacewalk they’re going to do, if any, but they know how to do the skills things. But what I understand you saying is that this was different. There was a very specific set of skills that were going to be needed here that weren’t needed in other — for other tasks, in other spacewalks.

Heather Bergman: Yeah, well, we tried to go find tools from industry to be able to use. We weren’t successful in most cases, so most things had to be built from the ground up. And there are nuances of how you use them. There are very particular things that you have to know, to do step A before you do B, and it took a lot of training for the crew that’s up there right now to be able to use those — I think anybody could use them, but to try and use them efficiently, so that we can get through a very long series of EVAs in as short a time as possible. It took them a lot of time to get used to using the hardware.

Host: Justin, you looked like you were about to join in.

Justin Cassidy: Heather’s words were, of course, fantastic, spot-on [laughter].

Host: She seems to agree.

Justin Cassidy: Yeah, I think so [laughter]. I think so. It is very — the requirement for the training for the crew members that were going — brought to us to evaluate and test our tools before the final flight crew was selected — they were definitely very seasoned veterans of astronauts, and they’ve used tools before. And they know how to use them, generic skill training. Some of the tools that we used during the repair are pretty generic tools. There are screwdrivers. They’re pretty easy to operate. But when you combine that with all the worksite factors that you’re dealing with, having a specialized knowledge of how that tool works, what to go, what to count, how hard to turn, where your body position — really did require the specialized training at the NBL [Neutral Buoyancy Laboratory] in our Argos [Active Response Gravity Offload System] facilities in order to accommodate and create that comfort level for them to work proficiently, if that makes sense.

Host: Yeah. In listening to a previous podcast where we talked with the folks who helped develop the timelines for these repairs, I got the sense that, in the process of working all of this out, you found out some things about the spacewalking suits that astronauts use on the International Space Station. That may — I don’t know if it was that you didn’t know before, or just that worked into what you were doing here. What — tell me about what those things were.

Heather Bergman: I thought that this was cemented what we knew about the suit. I mean, it’s a spacecraft all in itself. It’s an amazing piece of hardware, but it has its limitations. There are reach limitations for how far you can go into something. It’s very bulky and large, and we’re going into a small cavity. So there are definitely some reach limitations, and I don’t know that those were surprising to us. But I feel like I’m more surprised at how much we’re able to do — not that we’re limited, but there are things that we can do that I’m almost surprised that we can do. Because normally, we would’ve — I would’ve thought we couldn’t get into an area like this.

Host: But you found that, in fact, you — how big an area are we talking about that you mentioned? I mean, how big a workspace inside the AMS are these astronauts going to be dealing with? I don’t mean an exact number, but —

Heather Bergman: I think it’s about 18 inches deep.

Drew Hood: Yeah, it’s the shape of Nevada. So if you think of the state of Nevada —

Host: — I’m sorry, what? It’s the shape of Nevada.

Drew Hood: Yeah, it looks like the state of Nevada. That’s the shape of it, and I’d say it’s probably —

Host: And it’s 18 inches deep?

Drew Hood: 18 inches deep.

Justin Cassidy: Drew’s doing hand gestures for those who are listening —

Drew Hood: What do you think, three, maybe four feet tall, and three feet wide?

Justin Cassidy: — maybe a little larger on the wide.

Drew Hood: Maybe a little larger, but yeah.

Justin Cassidy: The VSB [Vertical support beam] tray — sure.

Drew Hood: Yeah, yeah. So, yeah. Climbing down in that cavity when you’re in a giant spacesuit —

Justin Cassidy: And it could be dark.

Drew Hood: — yeah.

Host: Well, it will be, for at least part of it. Are they going to bring lights?

Justin Cassidy: That’s right?

Heather Bergman: They will be bringing lights, but they’ve also got a tool belt. Their workstation is on the front of them, so that means — when you’re working at home, you just — you belly right up to the workspace. They can’t necessarily do that, because they’ve got their work belt that’s in the way. And so, that leaves them just a little farther out of the worksite, so —

Host: And covers up at least part of the reach of their own arms.

Heather Bergman: — mm-hmm.

Host: So keeping them from getting that much further inside to the workspace —

Heather Bergman: Yeah, Luca’s long arms will come in handy.

Host: Will help.

Justin Cassidy: I mean, we had certain new tools that we provided, but we also leveraged on building tool stack-ups of existing tools that already were in the arsenal of the EVA community. So that enabled us to have a further reach for where they actually can touch.

Host: Give me an example.

Justin Cassidy: We would use a bit that’s six inches long, and that was certainly not going to make the reach, so we put a socket extension on there. And now, you’ve got an 18-inch reach.

Host: So not essentially different than the ratchet set I have at home —

Justin Cassidy: That’s correct.

Host: — But, more expensive [laughter]. But just common sense kind of — of ways to make existing tools do the work that you need them to do, which is what you guys do all the time anyway, right?

Heather Bergman: Yeah.

Drew Hood: And starting at the beginning — you asked about kind of like the process we had. So we used these facilities, and a lot of 3D-printed concepts. So we would take a — go print up an idea of just volumetrically — here’s what we think we want to use. Now, get a crew member into a facility, and see if he can reach in there, and envision himself being in a spacesuit, and saying, “Oh, yeah, I think I can do this task,” or, “Oh, wait, how I do that — I actually bump up against this. I don’t think this tool’s going to work in this form factor.” And so, we went through a lot of iterations of just dummy, solid, 3D-printed shapes to progress to then prototypes that were semi-functional, and then flight-like engineering development units. And that spanned multiple — a year, year and a half on some of the tools because of their complexities. We want to make sure we got it right at the end, and we spent a lot of time up front.

Host: Is 3D printing things faster and less expensive than developing —

Drew Hood: Very less expensive. So I can 3D print a widget just the size of, like, a water bottle for about 35 to 40 cents of material. Now, granted, there’s electricity costs, and the cost of the unit, but —

Host: — I’ll cover the electricity for you, but —

Drew Hood: — yeah, exactly.

Host: — I mean — but assuming you’ve already bought your 3D — you already have the 3D printer —

Drew Hood: We have the — yep.

Host: — you can knock out a —

Drew Hood: Overnight. We start it when I leave, and it’ll be there in the morning when I get back. It literally sits on my desk in the office, so —

Host: — Drew, you made reference to some facilities that you used. Tell me about the different — the different stuff here — the places where astronauts train for spacewalks that you used in the process of developing these tools.

Drew Hood: — yeah, so one of those is called Argos, stands for the Active Response Gravity Offload System. That’s a little bit of a mouthful, but —

Heather Bergman: Which is why we use acronyms, by the way.

Drew Hood: — yeah [laughter], Argos. So it is a system that incorporates a crane, that crane that basically — you attach it to a crew member, and say you weigh 200 pounds, and you want to make it feel like you weigh 100. This crane will offload 100 pounds, and it sits there and senses with a load cell. If you jump, it realizes, oh, wow, I’m only offloading 80 pounds. Now I better pick the guy up, so it lifts you up. And then, as you start to fall, it says, “Oh, man, this guy’s weighing 120 pounds. I better let him down.” And it does this real-time, very rapidly, and so it also moves in the horizontal plane, the X-Y direction. And it has a little sensor that measures the angle of that cable that you’re being suspended from. So you can walk around, and jump in parabolas just like you’re in any gravity environment, whether that’s micro-gravity, or lunar gravity, or Martian gravity. We can simulate all of those in a mechanical crane-like system.

Host: You’re still attached to this crane, so you can’t fly, but you can float-ish.

Drew Hood: Float, yep. It doesn’t do your appendages very well. So, like, your arm still feels like you’re in 1G. Your legs still feel like you’re in 1G, so we have to do some things to help with those artifacts. But, we actually lay the mockup down on its back, and the crew member can actually fly over in a spacesuit, and be floating around like he would be in micro-gravity.

Host: And in this 1G environment, it sounds like they’re floating above it.

Drew Hood: They’re floating above it, and he’s horizontal. And he can work down in the cavity, and we actually have a foot restraint, like I mentioned earlier, that we can roll in. It’s like on a little crane arm, and it’s not robotic. We can’t position it with, like, a robot, but we can roll it around and lock it in place. And we can do the best job we can to simulate where he would actually be at in real life, on the space station. The second place is the NBL, the Neutral Buoyancy Lab. So that one was where we have a full-size mockup of the International Space Station submerged underwater. And so, that mockup is a little bit simplified, because it’s made out of stainless steel and some plastic. We don’t have all the intricate details on that mockup, because it has to live in the water environment. But it gives them another layer of training. So we use both of those in tandem.

Host: And does that mean that you — when you’re developing tools, you have to develop them not only — or some version of it, ultimately, will have to be able to work where there’s no oxygen, but the training method has to be able to work underwater, has to be able to get wet.

Drew Hood: It does, and we do some work — the biggest thing there is to actually make it feel neutrally buoyant. So sometimes, we have to swap things out so they don’t float or sink. So, like, if I take my —

Host: Balsa-wood screwdriver, or —

Drew Hood: — exactly. Actually, there’s some pretty great plastics, though, that you can — like, say if you just had a simple knob that it’s not going to take a bunch of load. I’m going to use aluminum for my flight, you know, but aluminum sinks really well in water. So I need to swap it out for a plastic that’s neutrally buoyant, so I’ll make some changes, and try to make that tool float — well, be neutrally buoyant as close as possible. Because you don’t want that — a boat anchor. That’s not positive to training.

Host: So then it — for the astronaut who’s training, it feels like it would feel when they are —

Drew Hood: Correct.

Host: — were on orbit.

Heather Bergman: And that can be challenging, when you get heavier hardware that is required to be tough enough — when you get handrails, and some of our other hardware that it really needs to be able to take load, and plastics don’t tend to do that very well. So sometimes, we’ll do what Drew calls arts and crafts, where we’ll try to attach little plastic or foam to areas that they don’t have to touch, that’ll help make it a little lighter, so that it’ll float a little more.

Host: Just — and again, get weight of it in other ways that are not —

Drew Hood: Yep.

Host: — that don’t impact its use.

Heather Bergman: And every once in a while, we take too much weight off, and it floats to the surface.

Host: Away —

Heather Bergman: And we have to pull it out of the pool skimmer, but [laughter] —

Drew Hood: Or sometimes we’ll actually build a whole separate tool. Like I mentioned 3D printing — we’ll 3D-print a volumetric one that they can take out in a bag, and they can go through the tasks of tethering it, and handing it off to each other, and getting set up in the worksite. And then, we do what’s called the magic swap. A support diver comes up and gives them the heavy one, and takes away the lightweight one, and they do their task. And then the diver comes back and gives them the lightweight one, nonfunctional one, and they can proceed with stowing it again.

Host: — that they swapped out.

Drew Hood: And so, we do that a lot in training as well.

Host: A hundred years ago, I used to dive at the NBL running cameras, and would watch that happen all the time, where, you know, they would take out a plastic thing, and practice maneuvering it around, and getting it where they needed to be. And then a diver would come up, take it away, and give them a machine that would allow them to actually turn a bolt in a thing.

Drew Hood: — yeah.

Drew Hood: And the great thing — now we can just 3D-print them, and so, they’re pretty cheap now. And I just start them before I go home, and they’re ready to go the next morning. And if they break, I print another one.

Host: Let’s get to some examples of tools. I think they said there were 20-something new — brand-new tools, and I don’t know that you need to tell me all 20. But give me some examples of these brand-new tools that are, or are about to, be on board the International Space Station so that these astronauts will have them to use to keep AMS running well. Want to start, Justin?

Justin Cassidy: So the tools that we altered from — as a Hubble tool are specialized in that they — our task that — that JSC has, has asked us to participate for this repair was to help take apart things. Take apart things are actually fun and easy. It’s putting them back together, or actually even better putting things back together — the tools are not necessarily specialized. And what they need to do, basically, is to remove a screw, and allow you to then remove a cover. It’s how we remove it, and how we control that screw that potentially could become loose, and this screw has a washer as well. So we want to minimize losing that screw and washer in a space environment, because it could be detrimental to ISS. If one gets away, that is acceptable, but our going-in plan is, we want to capture all hardware, control it, and put it away.

Host: I mean, in those cases, don’t you need it to put the thing back together again, too?

Justin Cassidy: We have a very fortunate path forward that they are not required to put this cover back on. We are being — closing out that worksite with a tent, basically, an MLI [Multilayer insulation] tent.

Host: I don’t want to distract. Go ahead. You’re talking about developing the tool.

Justin Cassidy: So, yeah — so developing the tool — basically, these are screws. They’re called socketed cap screws. They are number 10 in size. They are about an inch long in thread, and they are OK and easy to remove. But again, what we bring from our investment in working with Hubble, and its repair, and controlling foreign object debris, screws and washers becoming loose — because Hubble was an optical instrument, while astronauts were working inside of Hubble, you didn’t want one of these washers or screws getting in the optical path, hence compromising the science.

Host: Right.

Justin Cassidy: So we’re going in with the same kind of plan, because we want to control these screws. So we have tools that we have brought, and provide to the astronauts for releasing screws, and capturing them, and putting them away in an appropriate way that saves them from becoming FOD.

Host: Cool. Give me another example. Give me another new tool.

Heather Bergman: So one of my favorites is the new zip-tie cutter. We — Justin was talking about not wanting foreign object debris, FOD, floating around. You don’t want to let anything get loose. You don’t want it to — space station’s moving 17,500 miles an hour. If that comes back around and hits you, that’s going to sting. So even something like a plastic zip-tie is not something we want to let go. So there are a lot of zip-ties. They bundled all this up real nice before they launched it, and now we need to go break into all of it. So we need to pull all those out. So you could use scissors, or any number of EVA tools that we have now.

Host: I was thinking that doesn’t sound like a — like it would be too complicated a tool.

Heather Bergman: Yeah, you could, but they’re really tight, and so, it’s — because sometimes, it’s hard to get the scissors in there. And again, we’re 18 inches down in there, and so you can’t necessarily get in there. So this tool — we actually work with a group called Micro G Next here, where they go out, and they present challenges to the college students in the country, and say, “Hey, we’ve got a problem. We’d like to see — get your take on this problem.” And so, they bring forward proposals, and they get to design their tools, and bring them out here, and test them in the NBL. And our group reads those proposals, and helps those students out a lot, and one of them — the proposals — maybe — I think it was one last year was a zip-tie cutter. And one of the teams brought that forward, and we took it over to show one of the astronauts. And he was like, “Oh, this thing’s amazing. We need to fly this.”

Host: We need what?

Heather Bergman: We need to fly this. This needs to be on AMS. It needs to happen, and we were like, I — you mean AMS, the hardware we’re delivering here in just a few months, that AMS? Yeah, that one. So our team took what the students had done, and we modified that tool to be more flight — to follow the flight requirements that we had, to make sure it was going to meet the load requirements, and all the safety requirements. We modified that, and so that’ll be flying here shortly. So it cuts the zip-tie. There’s a little tiny foot on it that’ll slide underneath a zip-tie, and — almost regardless of how tight it is, and then you push a button, and it’ll cut the zip-tie, but it’ll also — when you cut it, a little foot comes down and grabs the zip-tie, and holds onto it. And then you can move the cutter over into the trash can, and — or their little trash bag, and when you hit a different button, it’ll let the zip-tie loose, and release it into the trash.

Host: So it’s holding onto it, so that nothing floats away.

Heather Bergman: Yep.

Drew Hood: Another big concern is, these tight zip-ties are wrapped around a ribbon cable that is kind of like a spinal cord of data for AMS. So if you just go out there willy-nilly with your scissors and start hacking at it, you could end the EVAs really quickly if you damage that cable.

Host: You want to cut zip-ties and only zip-ties.

Drew Hood: Yeah, only zip-ties, so yeah, we had to — the cool features of that zip-tie cutter is that it has that foot that slips underneath that zip-tie, and protects that ribbon cable.

Host: What other are — new tools can we look forward to seeing being used?

Drew Hood: I really like the clean-cutter. We kind of talked about that earlier, that it’s kind of a combination of various features you find in the industry. So if you ever just cut a tube, whether it’s PVC, [Polyvinyl chloride] or a piece of copper, or a stainless-steel tube — a brake line, you usually have a tool where you make one revolution, you tighten it, you make one revolution, you tighten it, and you go through that process until you finally get through your tube. And then usually, the tube’s then scrunched down. You might have to ream it out, or clean it up for you to connect. And so, that process — we wanted to simplify that for the crew member. And so, there were some tools in industry that ratchet, that you only tighten it down once, and then the head spins. And there were different styles of that, so we ended up tailoring what we found in industry to cut a four-millimeter line specifically. So you wouldn’t just go sell this on a shelf, because there’s only one specific line diameter with one specific wall thickness that this tube cutter works with, but it does it repeatedly, every single time, leaving behind a clean, round tube that is ready for the connection for the repair. And so, that was one of my favorite things of picking things out from industry, and then repackaging it to solve this very unique problem.

Host: And in this case, these tubes that you’re cutting, if I understand right, is to allow you to remove the old pump or pumps —

Drew Hood: Yep.

Host: — which are then going to be replaced with new hardware, but somehow have to be reconnected to those same lines that you just cut.

Drew Hood: Yeah. Yep. I kind of like to think of this whole thing as kind of like — my biomedical side comes out a little bit, and it’s kind of like you’re working on a patient here. So we have to get behind the rib cage. We’re going to do a heart transplant, really. So Justin has designed tools to remove that debris shield. That’s opening up the rib cage.

Host: Rib cutters.

Drew Hood: Yep, rib cutters. Take off the rib cage. Now, we’re going to get down — we have that — we have that spinal cord there that we need to move out of the way, that data cable, so we use a zip-tie cutter, and we move that out of the way. And then we have these eight stainless-steel tubes that are kind of like the veins and arteries, because some of the supply lines going to out to the radiators, and some of the return lines. So we have to cut into those, but we have to cut into them and remember which ones they are. Because if you mix up your arteries and your veins, that’s a bad day.

Host: Yeah.

Drew Hood: And so —

Host: Are they all the same size?

Drew Hood: — they’re all the same size, all the same color, yep, yep, yep. So when we cut them, we actually have to label them. So we have a little tool that —

Host: That’s what I was thinking. Like, you know, Post-It notes of different colors.

Drew Hood: — kind of like — kind of like Post-It notes, but our Post-It notes — you cut them, and you bend them up towards you, and you put this little cap on. It’s kind of like a finger trap, where you can snap it on, but you can’t pull it off. So as they cut one, they label it. They cut one, they label it. Then you end up with all these tubes sticking up out of the worksite with the labels on the end. So now, you have to come back and clean cut it with the clean-cutter I just described to prep that tube, so you can connect it. So once we do that, you hang the new heart on the outside of the box. There’s this pump box that you — that we bring up. This is the repair box. So that’s the new heart, with the new CO2 gas, the new blood, the new lifeblood for the vehicle, for AMS. So now, you have to connect those veins, as you were just mentioning. So we go through and use a special swage fitting to actually reconnect those veins to — and then you have to open up the new heart, get the blood flowing, and then close everything back up. So it’s kind of like a — kind of like a patient repair.

Host: Little surgery —

Heather Bergman: That’s a good analogy.

Host: — yeah.

Drew Hood: It is, yeah.

Host: Tell me about more tools. What other things did you guys help create that are going to get pressed into use here?

Drew Hood: One of the simplest ones I kind of like is just the puller. So the puller, as I mentioned —

Host: A puller, Gracie?

Drew Hood: — yeah [laughter], a brake puller, actually.

Heather Bergman: It was designed off a brake puller.

Drew Hood: Off a brake puller — so we just needed a way — we talked about that reach. We’re 18 inches down in this cavity. They’re trying to reach down for these stainless-steel tubes and pull them up to their — to them — to the worksite, and they’re very close together. And so, we looked through, and someone said, “Hey, what about a brake puller?” We literally brought in a brake puller from Ace, or Home Depot, or somewhere, and had them try it out. And they’re like, oh, this actually works pretty good. So we had to flight-ify, and change materials, but it’s literally a metal hook with a bend on the end. And it’s simple, but it does the job.

Host: And it’s easier to make something simple than it is to make something complicated.

Drew Hood: Yep.

Host: Others? Other tools that are your favorites?

Heather Bergman: Favorites? No, we have more least-favorites. [Laughter]

Host: We love all of our tools equally?

Heather Bergman: No, not even a little. [Laughter]

Justin Cassidy: I could probably give you an example.

Host: Yes, Justin?

Justin Cassidy: So we have something called a capture cage that we developed, and I’m sorry, again — go back to Hubble, but we —

Host: Don’t apologize.

Justin Cassidy: — had something called a —

Host: Did good work.

Justin Cassidy: — a fastener capture plate. So we had a repair on Hubble, and it had over 100 screws on it. And we didn’t want to risk losing these 100 screws, so what we basically did is put a large cover on top of these, and release the little screws. And they would float around in these little pockets, so we called it the fastener capture plate. So you release it. The screw would float around this little pocket, but it could not get out. Yet how you release it was a bit that went through a little hole, so the bit can go in, but the screw cannot go out the hole. And then we’d removed that entire thing. So what we did for AMS is, we have three difficult screws in the IPA [Interface panel A] area, which is a three — area designated for three fasteners that we need to remove. We made little, tiny fastener capture plates, basically a five-sided box. When you install it, when you install it against the cover that becomes your sixth side. So it’s then trapped box. A screwdriver would reach in there, release the screw, and both the washer and the screw would float around in the cage, and then you would remove the cover.

Host: Wow. Nice.

Heather Bergman: I think I have one more. So the — we have a tool board. So when you — when you’re doing a repair at your house, you have a bunch of tools. You set them down next to you. Well, we can’t set anything down next to us. We’ve got a second crew member who will be helping hand things back and forth, but he’s only got so many hands as well. So one of the things we made was a tool board. It’s — think of it as the pegboard in your garage. It’s got places for them to take some of the tools that they use regularly and put it on the board, and take out something new, and then, when they’re done with that one, they can put it back. So it holds four or five different tools, so they can go back and forth regularly without having to dig through a bag, and untangle things in the bag.

Host: And presumably, the things that they are using most frequently at any particular point, so that they’re handy.

Heather Bergman: Correct.

Host: You — and is this the tool suite that you mentioned in the note that you sent me before we got here?

Heather Bergman: Yeah. So everything together becomes this new AMS tool suite. This is such a specialized set of repairs that most of this hardware won’t be able to be used for other tasks. We’re already looking — the zip-tie cutter — we’re actually working right now to close up a certification to allow that to stay on space station and be used on other spacewalks, but this tool board is specifically holding a four-millimeter clean-cutter. And there’s just not that many four-millimeter lines on station. So most of the rest of this hardware won’t be able to necessarily be used in its current format for other spacewalks, so this suite is really special to AMS. And it’s there just for this particular task.

Host: In developing these special tools for this particular task, as we’ve said, you got some inspiration, if not some more practical guidance, from developing the tools to repair the Hubble Space Telescope — not only to make repairs, but also to change out some of its instruments, things that were intended to do. Justin, you did the work on Hubble, and developing tools. How did this compare?

Justin Cassidy: Some of the — well, when we replaced large-box instruments on Hubble, their major interface was a 7/16ths double hexagon bolt. I mean, it was very simple, so that’s a very standard large power tool with a socket extension, with a 7/16ths socket at the end. And you drive a bolt, you release the instrument, and the astronaut would remove it and put a new one in. So that’s pretty straightforward, and this is definitely what is still maintained up to ISS today, is using that type of interface. Our last servicing mission is where — I mentioned before is when we actually started performing mini or microsurgery, replacing circuit cards. That involved turning the astronaut into basically a ground technician, removing covers, and getting to the circuit board, and replace those, and everything is sharp all over the place. So those became quite challenging tasks in themselves in aspects of sharp edges, creating FOD, ESD concerns generated during the repair, and then, as difficult as that was, it is fun and easy and takes a long time to remove and get down to where you need to take the repair. But putting it back together actually is the easier part, because it’s easy. And, for example, when we took apart one of the instruments on Hubble called the STIS, we took the radio cover off, took over an hour to get that cover off. When it came to — after the new board was put into it, the new cover went on in less than five minutes. It simply went on, two latches were thrown, and it was done.

Host: Didn’t have to redo each of the little screws.

Justin Cassidy: We did not. So the major reason for that is, everything that we build on the ground is going to be launched into space. So it needs to survive the launch environment. So it’s vibrated very heavily during launch, and we do testing on the ground to make sure that things are going to survive launch. But now we’re doing — we’re pairing space. So, don’t necessarily have to put 100 screws back in. You may only have to put a fraction of that in because there are no large un-orbit lows that can be put into that box.

Host: They’re not going to have to go through that same sort of —

Justin Cassidy: Exactly, exactly. So, you’re really trying to replace a carbon that this case is restoring the thermal path in order — because this is a raider that we’re removing. Restore that thermal path, you need a lot of screws, two latches, and we’re done.

Host: As a public service, we’ll put STIS in the transcript. It’s Space Telescope —

Justin Cassidy: Imaging Spectrograph.

Host: OK. Well, I won’t have to. And FOD is, Foreign Object Debris?

Justin Cassidy: Yes.

Heather Bergman: Things that are floating around.

Host: Heather you said earlier that you had worked in — in shuttle times. Makes it sound like that’s 100 years ago. [Laughter]

Heather Bergman: At least it feels like it.

Host: Developing tools. And I think that was for the — the tile repairs that we had to do after the loss of Columbia. They were being developed to figure out how to make those kind of repairs in the future if it — if it came to that point again. Did that work compare to what you were doing here?

Heather Bergman: In that they’re very challenging and it’s a very specialized set of tools. We weren’t just going to find something on the shelf that could fix that. We were repairing both the — the RCC [Reinforced carbon-carbon], the leading edge of the wing where Columbia’s main damage was, and — and the tiles themselves. You’re in a very challenging workspace. For the shuttle — you weren’t allowed to touch anything, because while you were trying to repair this damage, you didn’t want to do damage to anything else. You were trying to, you know, stay back away. You didn’t have any handrails. So very similar from that perspective. We — we still — this workspace is — wasn’t meant to be a workspace. Once we take this debris shield off, there are lots of areas behind the debris shield that were not tested to make sure they were not sharp. We want — we’re very careful to make sure that we’re not going to do anything to cut the gloves of the spacesuit or any other part of the spacesuit.

Host: Right.

Heather Bergman: So, before we button any piece of hardware up, before we launch it, we test it to make sure there are no sharp edges and if there are, we file those down, make them safe. Well, once we pull this cover off, everything behind that, hasn’t been tested for that. So, we’ve done a lot of work to find out where we might still have some areas that might be sharp. So, those do exist back there and it’s one of the reasons why we want this crew to be very trained so that they are careful and are aware of where those sharp edges are without us having to constantly remind them, hey, don’t touch that, don’t touch that, don’t touch that.

Host: Right.

Heather Bergman: So, they can’t touch much while they’re in there either. They don’t have any handrails. Neither of those tasks were trivial and you — people are very passionate about both tasks for different reasons. So, you get into strong personalities and —

Host: Oh really?

Heather Bergman: And difficult — some difficult conversations as you try to weigh the options out and make sure everybody’s getting what they want while everybody’s still being safe.

Host: Yeah. Drew did you have experience before working on AMS tools that — that helped you in doing this task?

Drew Hood: Yeah, I did. I would say this was obviously a very new challenge for me. As I mentioned earlier, I kind of spent a lot of time in the development world where it’s kind of the quick and easy solutions we look for. We are trying to make trainers on a shoestring budget do some tasks with crew members for future missions, like looking way in the future. So, it was really neat to kind of bring that mindset of the quick and easy solution to this really complicated challenge and say, what about this? Why does it need to be that complicated? So, we really need to do that? And I really enjoyed that of trying to look at it kind of from a different perspective of coming with very little knowledge and actually having the opportunity to — a chance to speak up about that stuff. Instead of just kind of learning the old way, it was hey, we have this problem. Let’s see how we can solve it a different way. And coming together and finding the middle ground.

Host: Not just because it’s the way we’re always done it.

Drew Hood: Yep.

Host: That Sort of thing. You’ve developed all these great tools. Did you have any problems in getting them to the worksite? Getting them to space.

Heather Bergman: Well, we’ve — we — some of the hardware is rather large. I mean the new box that they’re launching is 400 pounds. So that — I think that can fit in one vehicle that we have right now.

Host: Yeah.

Heather Bergman: Some of our handrails are rather large. So — and we also wanted to get most of these up in fairly short period of time, prior to the EVAs. Because we don’t want them sitting on station taking up space for a year prior to — space there is — is –pretty important.

Host: Because you had it all ready to go a year ago?

Heather Bergman: No, not even a little. [Laughter] But as we get closer to the date that we have the crew that we want ready to go, we definitely had to look — we had to talk with our logistics people who were in charge of weighing what goes up, and what doesn’t, and making sure that we had the hardware ready on the day they needed it. Because most the time it was a bit of a challenge to get it ready by that day. To get it up on this specific vehicle. Because there wasn’t necessarily going to be a second shot to get it up there.

Host: Right.

Heather Bergman: And still have the trained crew use it.

Drew Hood: You know, and I think for those that keep a close eye on space launches, some of our hardware was on HTV [H-II Transfer Vehicle], that had a little bit of a launchpad fire and a delay, so some of our hardware was on there and we had a few nail bitters of — when that got delayed of when that was going to launch, but thankfully it successfully made it to the station and delivered I think nearly the last. We’ve got one more launch.

Heather Bergman: One more.

Drew Hood: One more launch.

Heather Bergman: And NG-12 should be the last of the hardware.

Host: Right. I am looking forward a lot to seeing these spacewalks and see how all your work turns out.

Heather Bergman: And I’d be — I’d be remiss if I didn’t say, it’s not just the three of us working on this by any means. There is a small army behind us that is —

Host: And behind them there’s a bigger army.

Heather Bergman: Exactly, so that is — you know, we’re the people that kind of get to go talk to people about what the team has done, but we’re by no means the only people doing work on this side. It’s been — it’s been a huge effort across agencies. Within the NASA agency to Goddard, and a number of other places. So, it’s —

Justin Cassidy: Pat, I want to mention Drew touched on the two training facilities, the ARGOS and the NBL.

Host: Right.

Justin Cassidy: So, these are fantastic assets that we leverage on in order to train crew. I’d also like to say it also – is a tremendous [tool] that it also trains us as well. So, both at Argos, all three of us participated in that, and for divers, Heather and I both dived in the NBL. So we have spent tens — of hours watching different crews do the repair, such that I feel very prepared that when the mission is being conducted, and we have camera view of what they’re doing, we know where they are, we know — we’ve seen this and we know if something’s going off nominal, and how to respond to that with the team.

Heather Bergman: Yeah, and we’re actually right now, while we lead up to these EVAs, which will hopefully happen here shortly, we’re doing simulations of those EVAs. So if somebody has gone through and planned out the EVA and they throw little snafus in there for us and we have to figure out what we can do, what we can do real-time to get the crew to get back on track and make sure that they’re safe, but that we still maintain the EVA if at all possible.

Host: Sim Sup my old friend. [Laughter]

Heather Bergman: Yes, so we’ve been running through sims and we’ll say, enjoying that.

Host: Great. Heather Bergman, Justin Cassidy, Drew Hood, thank you very much for sharing the story. Look forward to seeing it all go well.

Host: Thank you.

Drew Hood: Thank you.

Justin Cassidy: Thank you for having us.

[ Music ]

Host: At last report there would be four spacewalks done to complete the repairs to the Alpha Magnetic Spectrometer. First, to remove shields to gain access to the worksite. A second to cut stainless steel tubing to remove old pumps and then put the AMS on temporary life support until the third spacewalk, which will be to install the system of new pumps and connect that tubing. And then fourth, to verify that there aren’t any leaks at the installation site. Make any repairs if they’re needed. And then reinstall the shielding and the insulation to get AMS back to the business of searching for evidence of the origins of the universe. You’ll be able to follow along with all of the spacewalks on NASA TV and online at Also, there’s a very interesting story about the history of the development and the deployment of the Alpha Magnetic Spectrometer. We didn’t even begin to get into that in these episodes. But you can. The story is called “AMS: The Fight for Flight.” You can access it on and other online sites. I’ll remind you that you can go online to keep up with all things NASA at And you can follow us on Twitter, Facebook, and Instagram at all the NASA JSC accounts. When you go to those accounts, use the hashtag #AskNASA to submit a question or suggest a topic for us. Make sure to indicate that it’s for Houston, we have a podcast. You can find the full catalogue of all our episodes by going to and scrolling to our name. You can also find all the other exciting NASA podcasts right there at the same spot where you can find us Very convenient. This episode was recorded on October 23, 2019. Thanks to Alex Perryman, Beth Weissinger, Gary Jordan, Norah Moran, and Belinda Pulido for their help with the production. To Rachel Barry and Erin Anthony and the International Space Station Program Science Office team, and to our guests Heather Bergman, Drew Hood, and Justin Cassidy for explaining it all. We’ll be back next week.