From Earth orbit to the Moon and Mars, explore the world of human spaceflight with NASA each week on the official podcast of the Johnson Space Center in Houston, Texas. Listen to in-depth conversations with the astronauts, scientists and engineers who make it possible.
On episode 398, acting vehicle integration office manager for NASA's Orion Program Chris Edelen discusses the spacecraft that will carry astronauts around the Moon on Artemis II. This episode was recorded August 6, 2025.
Houston, We Have a Podcast. Welcome to the official podcast of the NASA Johnson Space Center, Episode 398: Artemis II: The Orion Spacecraft. I'm Kenna Pell, and I'll be your host today. On this podcast, we bring in the experts, scientists, engineers and astronauts, all to let you know what's going on in the world of human spaceflight and more.
Built to take humans farther than they've ever gone before, Orion is NASA's spacecraft capable of crewed flight to deep space and high-speed reentry from the vicinity of the moon on the Artemis II mission, Orion will be tested for the first time in space with humans on board it'll send NASA astronauts Reid Wiseman, Victor Glover and Christina Koch and Canadian Space Agency astronaut Jeremy Hanson around the moon and bring them home safely.
This deep space capsule is built upon everything learned from NASA's past 50 plus years of human space flight missions, and uses new and advanced technologies to enable it to travel farther into space than any other crewed spacecraft in history. On this episode, we bring in Chris Edelen, the acting manager of the Orion program's office, responsible for the spacecraft systems integration and analysis. He'll tell us all about the spacecraft and what we can expect from humanity's return to the moon aboard Orion.
Let's hear about your journey to NASA, and let's start from the beginning. Where are you from, and did you have an interest in space or NASA as a kid?
Yeah, I'm from a small town in southwestern Virginia called Martinsville, and grew up there and was interested in space and aviation from an early age. One of my earliest memories is during the Apollo missions. I can remember seeing, you know, seeing the the TV coverage, and walking outside the house and looking up to the moon, and just my mind was blown that, you know, thinking, wow, there's two people on the moon and another person orbiting the moon. So I was sort of hooked at an early age, and that sort of set my path for the for the future.
Okay, wow, full circle, speaking of going around the moon and now working in the Orion Program. What did you So, what did you go to school for?
Yeah, so as I was growing up, you know, again, just reading everything I could get my hands on about aviation, space flight, I got my pilot's license when I was 17, and in when I was in high school, the Space Shuttle launched and so followed closely with all those missions, and decided then that I was going to try to pursue a degree in aerospace engineering. So I got accepted into Virginia Tech and went to school there and my freshman year on a help wanted bulletin board. They the Chief Scientist for NASA Langley Research Center was going to be coming to Blacksburg to interview people. So I was like, Oh, wow, I've got to, got to get my resume ready. And I applied for that. And then imagine my excitement when I got hired. And so I was 19 years old, the fall of my, you know, the beginning of my sophomore year, I was working part time at NASA Langley in Hampton, Virginia. So cooperative education is where you alternate, you know, a semester of school with a semester of work. So take an extra year to graduate to do that. But really enjoyed doing that, and again, learned a lot more about space and aviation, and decided while I was in school that I would try to get on with Johnson Space Center out here in Houston, because I wanted to be part of the space shuttle flight operations. And so that's what I did.
Super cool. I didn't realize, we talked before this, I didn't realize you were at Langley before.
Yeah. So when I came out to JSC after, right after graduation, I started as a checklist book manager for the shuttle ascent checklist, and then within, within a couple years, I'd worked my way into the Mission Control Center, which is where I really wanted to be. I was working in the one of the multi purpose support rooms, or the back rooms for the Flight Dynamics Officer or FDO. And after a couple years in the back room, I worked my way up to the front room. And so yeah, I found myself supporting about, over the years, about, let me think about 40 missions or no, 34 missions as a FDO during the shuttle program. And, you know, just thinking back to being that high school kid watching the shuttle launch for the first time, and then being in Mission Control, sending up commands, you know, to uplink the state vector for the space shuttle, or guiding it into rendezvous with the space station or or bring it back to the runway, you know, first, you know, runway landing at Kennedy Space Center or Edwards Air Force Base. Yeah, that was just, it was, it was literally a dream come true for me,
So how did you transition from being a FDO to flight director and then ultimately your position now?
Yeah, as like, as I became more experienced as a FDO, I served as a lead flight controller on several missions, and so every, every every console, every discipline in the control center, has a lead that works starting, you know, a year or two in advance of the mission, working with the lead flight director to plan, what are the objectives of the mission, what are the unique requirements? Do we need new procedures, special hardware, or analysis to accomplish the mission? And then we work closely with the astronauts, what the what the shuttle program at the time to, you know, to plan that mission and bring it into being. And then you go and you train during simulations and go fly it. So it's a great experience to be a lead. And so doing that, you know, I worked more and more closely with the Flight Directors, and I became interested in doing that job. So, you know, I learned a lot through their leadership on these missions. And then so you know, decided, hey, that would, that would be even cooler than being a FDO would be to be a Flight Director. So I applied, and was selected in 2007, and so I was able to work two shuttle flights as a Flight Director. And then I've supported space station operations for about 14 years. And it was just, again, an amazing experience. The best part of it was just all the different people you got to work with. You know, as an individual console, like a FDO, you're sort of specialized in one area, but as a Flight Director, you're sort of, you know, you have to be quite, quite familiar with all the systems and all the operations, whether it's, you know, the part that I was most familiar with, orbital rendezvous and burns, you know, doing maneuvers in space. But you also have to know space walks, robotics systems, repair of equipment on board the space station. So and you know, all the, all the different power, life support and avionics on the space station. So that was a really fun part, was to again, to get that broad understanding of how the whole vehicle works, and then to go be a part of the exciting missions on the space station, and especially looking out the window and of the space station from the video, to come into the mission control and seeing this amazing machine that we built 250 miles up in the sky.
And so each Flight Director has a call sign. There's usually a description or story behind that. What is yours?
Mine is Venture Flight. And so I chose that name to to sort of capture the spirit of adventure that goes into space flight, and also that a venture is any kind of risk that you take, some kind of endeavor that you do where there's a there's a great risk, but there's also a great payoff.
I love that. We're gonna have to go look up the symbol, put it here in the show notes.
Oh, there's a patch to go with the symbol too. So, you know, at NASA, we've got to have patches for everything.
Absolutely. Okay. So after flight director, you are now the acting manager of the Orion program's vehicle Integration Office. Can you explain how that fits into the program as a whole and what your office is responsible for?
Sure! Yeah, before I do that, let me explain my transition. So, yeah, after about 14 years working ISS as a flight director, I was starting to think, hey, what's the what would be the next phase of my career? And I was really interested in being playing a bigger role in the Artemis program to return humans to the moon. And so again, I saw another help wanted ad, this time in the JSC RoundUp. And I said, Oh, the Vehicle Integration Office, it was for the deputy of that office. And I said that that sounds like something I'd be really interested in. So applied for that job. And yeah, they again, look, they were also interested in my experience in operations and technical integration. So I started with Orion about four years ago, as first as Deputy of Vehicle Integration, and now as the acting manager. So but yeah, to describe for you what what role VIO plays, and again, that's vehicle integration. Integration means the sum of all the parts, and that's essentially what we do. We take all the all the individual systems of the Orion spacecraft and determine, you know what their constraints and operating limitations? What kind of missions can we fly? So for example, you know what how much power can we generate on a given launch date? What kind of propellant do we have available to use for the burns in space? How much air and water will the crew need on a particular mission? In fact, we come. With the manifest everything that goes into the crew cabin, to make sure that that all fits inside of Orion to last for in the case of Artemis II, a 10 day mission, but even longer for Artemis III, out you know, which is going to eventually land astronauts on the moon. So so our in vehicle integration, we perform the analysis to determine what kind of missions Orion can fly. We also, as part of our team, have our systems engineering and integration or SE&I team, and they the systems engineering is essentially making sure that we're meeting all of the requirements that are imposed upon us. So as you can imagine, there are 1000s of requirements to make sure that Orion can execute the mission safely, and so we have to prove that before we fly. We have to make sure we've done the analysis or the testing to show that each requirement is met. In some cases, you know, we might have come up short. Is that acceptable or not? So we have to process any of the waivers on those requirements, and then our systems engineering team also leads the entire program through our run up to flight readiness review now for Artemis II that'll happen in December, but there's already starting reviews of each of the systems, and we will build up and again, making sure that every single system is ready to go so and then there's a third part of our vehicle integration team, and that is our Guidance, Navigation and Control, and in engineering, we call that GN&C so we developed the algorithms essentially to determine where Orion is in space. So there's no GPS out at the moon, so we have to do that through inertial navigation with our inertial measurement units and also radiometric tracking with the comm system. And then once you know where you know where you are, you need to figure out, well, how do I get to where I want to be? How do I fly around the moon, you know, at the right altitude? How do I get back to the Earth's atmosphere at just the right speed and the right angle? So that's, that's the guidance. And so again, as you can imagine, very complex mathematics and orbital mechanics go into the into, you know, preparing those algorithms, and then the guidance computes when to fire the engines, how long to burn, what direction that's the control. So that's GN&C and that team prepares all of the software. Works closely with our prime contractor, Lockheed Martin, to get those algorithms loaded into the software. And as well, they do the analysis to make sure when we have the mission plan ready, they fly those out and make sure that, yeah, we're not violating any constraints on the vehicle, like the g loads during entry or using too much propellant that we wouldn't, you know, that we will not be able to accomplish the mission. So that's, that's the big picture of what vehicle integration does for the Orion program.
That was fantastic. I'm here taking a whole bunch of notes and so many full circle moments in your career. You know, you mentioned that VIO or Vehicle Integration Office is the sum of all parts. I like that, and kind of similar to what you did as flight director. So speaking of just overall integration, how would you say that? So we're gearing up for Artemis II, right? But it doesn't mean we aren't preparing for future missions. So Artemis III, and how does your role integrate with programs of the future? So think Artemis III with the Human Landing System and things like that.
Yeah. Actually, that's a that's a very important part of our systems engineering and integration team that that I'd like to go into a little bit of detail on. So we have a cross program integration team within vehicle integration, and they are responsible for establishing and negotiating the interfaces between the Orion spacecraft and the other programs. So for example, for Artemis II, Orion is going to be riding into space on top of a Space Launch System, an SLS rocket. So we need to make sure that the computers are speaking the same language to each other and exchanging data. So our cross program integration team is responsible for doing that work, and when we fly Artemis III, Orion will dock with a human lander, an HLS lander built by SpaceX, so we'll dock out in lunar orbit. And again, as we're approaching and rendezvousing, we need to make sure that we've jointly agreed where we're going to rendezvous, what distance, what closing rate, who's going to do, which burns to dock? Are there any limitations on attitude or the timeline for the rendezvous? And then again, can the radios speak to each other? Can the computer, once we get docked, make sure that the computers can send messages and data back and forth and telemetry to the ground. So that's, that's everything that our cross program integration team does. And you know, sort of the dry part is, it's all captured in interface control documents. So there's a lot of documentation, as you can imagine. The pictures look pretty on TV, but there's a lot of detailed engineering that goes on in the background, and that's what our cross program team does.
Got it. Okay! Can you tell us about your role during Artemis I and what that entailed?
Yeah, Artemis I was that was the first full up mission of an Orion spacecraft with our European Service Module, first ride that we took on the Space Launch System, and that was back. In November 2021, and my role supporting that mission was lead of the Mission Evaluation Room, or MER. So everyone's familiar with Mission Control, right? The flight control team that you see on TV. And you know, if you've seen the Apollo 13 movie, you know, you know when "Houston, we have a problem," that's the team that answers that call. So again, as flight director, I was very, very experienced working on that side of Mission Control, but most people probably don't know that there's supporting mission control. The flight ops team is the MER, and the MER is made up of the engineers from the program. So in the case of Artemis one, we built up a team. It was a total team it was a total team of about 190 people. These were all the engineers and software developers from both NASA and Lockheed Martin and other contractors that had literally designed and built all the systems. They coded the software they, you know, were there for the 1000s of hours of testing, so they knew in intimate detail each of the components. So in the MER, you know, they're there to watch and see how the vehicle performs, to make notes of things we need to go look into or correct for next time or make better. And also to be there in case of problems. And we did have some anomalies, some mostly minor, but things during Artemis I that The MER worked closely with the flight ops team and the Mission Control. Actually, we were just right across the hall, and we're on the same loops, looking at the same displays and working cooperatively to accomplish the mission successfully. So the way I like to describe the MER is if, if Mission Control, if the flight ops team is the help desk, the MER is who the help desk calls when they need help.
That is so good and a great way to describe this. Okay, so Artemis I mission, uncrewed mission, first full up mission of Orion. Now, what about for Artemis II? What will you be doing for the mission coming up here shortly?
Yeah, so for Artemis II, now, I'm on the management team there. You know, I will not be part of the MER, per se, but I'll be participating with our Orion management team as we prepare each day for the daily Artemis Mission Management Team, or MMT meetings. So the flight director is in charge in real time of the mission to execute according to the flight plan and the flight rules. The flight director has authority to do whatever is necessary, along with the crew commander, to keep the crew safe. But for slowly developing issues, or maybe we need to consider changing up, you know, what we're going to do tomorrow, or what the rest of the mission looks like, for like, I say, for more slowly developing issues that will be brought up to the management team. And this has been done since, you know, Apollo and space shuttle as well, that you know there's a management team overseeing the operations. So the Orion Program Manager will have, it will have a seat at the at the MMT, and again, my role will be to assist with the other Orion managers to prepare our program manager, Howard Hugh, to support the meeting and to be ready to make recommendations and decisions about how Artemis II will be conducted.
Okay. Can you explain your role in a way that would make sense to someone who isn't familiar with Artemis or maybe isn't a space enthusiast?
So for Artemis II, the day in the life of Artemis II will be again the flight ops team and Mission Control is overseeing the vehicle, planning the day's activities, advising the crew as they go through the timeline. The MER, the Mission Evaluation Team, will be, again, monitoring the data, looking for any funnies. Is there a current maybe for a motor that's a little higher than it should be? Is there some software bug that that has caused a computer to flake out? So we'll be looking at all those problems, and then the MER team will then bring those to the Orion Management Team, of which I'm a, I'm a member, and we'll bring those issues, and we'll determine whether we need to change anything for the flight, whether there's any additional risk that we've got to sign up to, or if we should change the you know, if we should bring the crew back early, or if we should continue on. So we will discuss within internally, within Orion, at a meeting each day to prepare for again, that mission management team meeting, which will ultimately make the decisions regarding how we conduct Artemis II and that MMT is chaired by the Deputy for the Moon to Mars program.
Well, there's a lot of unfinished business from Apollo. We learned a lot about the geology of the moon and the history of the moon. The moon actually came from the earth during a collision with a large Mars sized body, we believe so. So we learned a lot on Apollo, but there's a lot more to be learned. One thing we've discovered since Apollo is that there's evidence of ice in the South Pole region of the moon and permanently shadowed craters. So these are craters that have not seen sunlight for billions of years. And so we believe that that comets and maybe other orbital bodies from the beginning of the solar system have deposited water essentially on the south pole of the moon, so that, if that's true, that will become one of the most valuable pieces of real estate in the solar system, because water is like gold in space. You can, of course, you can use it to drink, or you can use you can split the water into hydrogen and oxygen, and that, of course, is rocket fuel, like the shuttle manages used hydrogen and oxygen and also oxygen to breathe. So we want to go to the South Pole the moon is a very difficult region to get to, very rugged terrain, but we want to find if there's these resources we can use on the moon in order to support a human habitation. And also, why do you go back to the moon eventually, NASA's goal is to take humans out into the solar system and eventually the stars. And so in order to, for example, to be able to live and work on Mars, we first it's much safer and easier to do it on a relatively close by Orbital body, the moon. So let's that's the benefit of going to the moon. Just like if you were going to run a marathon, you wouldn't put on your running shoes and immediately go out and run 26 miles. You would probably start one probably start with a run a mile and then run a 5k and a half marathon. So let's say going to the moon is our half marathon to get ready to go for Mars.
Okay, well, let's get into the spacecraft itself, not literally. Let's talk about it. We're recording this episode in August of 2025 and just last week, the crew suited up and went inside the spacecraft for the first time in their suits to test all the interfaces. So, missions coming up early next year, can you give our listeners the high level elevator description of the spacecraft? So how many passengers can can it carry for how long, size comparison, things like that. And you can pretend this is a really tall building, and it doesn't have to be just a few floors. It can be a couple floors, it doesn't have to be that quick!
All right. Well, so Orion is essentially America's deep space crew transportation vehicle. So it's going to ride on top of a Space Launch System or SLS rocket from the launch pad up into Earth orbit, and then the Space Launch System will the upper stage will send it on its way to the moon, and so the crew will be riding in Orion. Four crew members can fit inside the spacecraft. It's about 60% larger than Apollo. It's the same shape as Apollo because, again, the physics have not really changed since the 1960s. So that's that's an efficient shape, lightweight and minimizes the area that we have to protect of the thermal protection system. So the crew will ride, in the case of Artemis II, it's about about a four day trip out to the moon. It could be longer. For some of the later missions, they will ride in Orion and rendezvous in lunar orbit, eventually on Artemis III with the lander, and so the lander will take the crew down to the lunar surface, where they'll spend about a week down, doing Moon walks and conducting experiments on the moon. Meanwhile, Orion will be in remain in orbit around the moon, with two of the crew members doing experiments and making observations of the moon. And then when the lander comes back up again about a week later, it will rendezvous with Orion in lunar orbit. The crew will transfer back to all four crew to Orion, and then Orion will depart lunar orbit and head back to the Earth. So again, about a for Artemis II about a four day trip back to the earth, and then the last important role of Orion is to provide a safe re entry and landing, just like Apollo under parachutes in the Pacific Ocean. In this case, it'll be off the coast of San Diego.
Okay, really informative elevator ride. Thank you for that overview of the spacecraft itself. So let's dive a little more quote "under the hood" and talk about the spacecraft's three main components, and let's go from top to bottom. So let's start with the Launch Abort System. Can you tell us more about that?
Yeah, we call that the LAS so that's a it's a solid rocket motor that's mounted on top of the capsule, and it's designed if there's a problem with the rocket in the first about the first three minutes of the launch, or even on the launch pad, if there was, for example, a fire or the rocket was losing control, rates or attitude goes out of limits that there's an emergency detection system, the software will automatically abort the mission. The crew also has an abort switch that they can engage manually, and so that that LAS is like a very fast rocket ride away from your rocket to take the crew away from whatever bad things are happening back on the SLS, and it will take them away and then release the capsule, and then the parachutes will come out, and Orion would land safely in the ocean. So it's a similar system to what we had with Apollo. The Russians have actually used this on their Soyuz before. So they had a fire before a launch, and they did a safe LAS type abort. So it's definitely an improvement over what we had on the space shuttle in terms of providing a safe abort option for the crew.
You mentioned, almost like a rocket launch in itself. And I remember, were you down in Florida for Ascent Abort-2 or AA-2?
Oh my gosh! I was not expecting that to be as big as it was, right? So going down from- Okay, launch abort system on the top, then going down to the middle, so to speak. So the crew module, that's the pressurized part, sometimes called the capsule. Can you talk about that?
So that's where the crew is going to ride. I mentioned earlier. It's about 60% larger than Apollo I was looked up the the cubic feet. It's about the size of a small camper van, if you've seen one of those on on a video. So it's, it's small for four people. It's going to be, you're going to you're going to be pretty getting to know each other very well. But the nice thing is, you know, in microgravity, you you can use the ceiling and the walls, so you're not just limited to the floor. So inside the capsule or the four seats that the crew will ride during launch and landing, they'll stow those. When they're done, they'll take their their suits, their launch and entry suits, off, and stow those as well. So create a little. Bit extra room. There's storage compartments for all their food and clothes and and extra tools that might be needed. There's a water distribution system. So they'll be eating food similar to what the crew eats on the space station. So just sort of like being on a camping trip, that kind of, that kind of thing. There's an exercise a flywheel. So essentially, it's a box with a, again, a flywheel. They can do, they can do curls, they can do squats, so any number of exercises, again, to get the heart rate going while they're flying around the moon. And also to, you know, keep their, keep their strength up, and, you know, sort of to avoid some of those debilitating effects of microgravity. And there's also a toilet. We call it the Universal Waste Management System, or UWMS, we have an acronym for everything, as you know. So it's a it's located on the in the floor of Orion. It's in one of the compartments. So actually, it's about the size of a small phone booth for the for the listeners that remember what phone booths were back in the day, but you open that door and go down into the floor, and there's a little bitty, really small toilet that it uses a pump to provide some suction, to do the things that gravity does for us here on Earth. And then there's a fecal can that holds the solid waste, and that'll, you know, once, once that's filled up, that'll be sealed off and just returned to Earth with the crew. But that's, that's how the toilet works. And let's see, what other systems should I describe? I guess there's sleeping bags that the crew will sleep in at night and all the other things you would expect to have in a spacecraft to do the human hygiene and, you know, little tablet computers to monitor the flight plan, and, of course, all the displays and controls that are needed to fly the spacecraft. And four big windows to enjoy the view.
Cool. Okay, and then moving on to the service module. Can you tell us about that?
Yeah, that's another really exciting part of the Orion Program, is that it's not just the US. You know, just as we have with the International Space Station, we have a large component of international partners working with us. So for the European Service Module for Orion, it's actually built in in Germany by the European Space Agency. And so it provides the power through four solar arrays, and the propulsion through a main engine and eight auxiliary thrusters, and then about 24 auxiliary thrusters, or RCS thrusters on the on the ESM, in order to steer Orion and keep it pointed in the right direction so that we can get sunlight on our arrays. So, again, manufactured by the European Space Agency. So we have an office within the Orion program that does all the interfacing for the for the ESM, and it also provides our heat rejection capability. So the ESM is sort of the utilities to keep the crew safe and comfortable.
Okay, that was a great overview of the three main components. So the Launch Abort System, the crew module and the European Service Module. Where are all these components manufactured? You talked about it a little bit with the service module, but what other agency, centers and contractors are involved?
Yeah, so our prime contract contractor is Lockheed Martin, so their their headquarters for Orion is out in Denver, Colorado, so that's where a lot of the engineering and some of the early components are built up. But the spacecraft itself is assembled at Kennedy Space Center and and so the parts come together from all over the country, and, as I mentioned earlier, all over the world, really. So there's many, I don't know have the exact number, but there's many subcontractors that provide parts. In terms of the NASA centers that are participating, the Glenn Research Center up in Cleveland, Ohio, is where our European interface office is located, that interfaces for the European Service Module. So that's where our propulsion experts reside. And then at Langley, that Langley helped lead the Launch Abort System Development, along with Marshall Space Flight Center in Alabama. And Marshall has also done a lot of our life support system development. Of course, Kennedy Space Center is where it all comes together and where we launched. And then finally, at Ames Research Center out in California, we've used their arc jet test facility to test our heat shield materials. So it's a it's definitely a joint effort throughout the country and indeed, the world.
Okay, and so, of course, Artemis I was uncrewed. What did we learn about the spacecraft?
Yeah, Artemis I was the first time that we had flown the the entire, you know, integrated Orion with the service module and the LAS on top of a space launch system. So it was the first, first, first flight of that integrated stack. And so the first thing we learned was that the SLS worked great, and overall, the vehicle control, computers, telemetry, communication, all of that worked fantastic. So a lot of good results coming out of Artemis I, there were a few little glitches, like on one of our our power conversion distribution units that passes power from the solar rays to the to the spacecraft. It had some glitches where these essentially solid state switches would occasionally trip open. And so, of course, we had redundant power so we didn't lose any critical systems. But we need, definitely needed to understand why that was happening. And so that was, that was an example of case where the MER, the Mission Evaluation Room was heavily involved in terms of psyching out that problem. And we've determined that it was actually caused by radiation hits on some of the some of the electrical components within that that that box. So that's, we've, we're gonna fix that for Artemis three, and we've put in fault detection software for Artemis II that will that will more quickly recover from that if we if we see that occur again. So that was just an example of the type of glitches we saw during the mission. The probably one that some of the listeners are familiar with is our what we learned about our heat shield performance on the landing. So one difference between Orion and Apollo is that Apollo did a direct entry. So essentially, wherever you know whatever point you're going to impact with the ocean or land on the ocean is fixed when you leave the moon. There's very little control of that. The Apollo and the Orion do not have wings like a space shuttle, so you can't steer you know left or right or up range or down range very well. So not a lot of ability to avoid a storm if you're coming back. And so one thing we a new capability with Orion is we've got the ability to do what's called a skip entry, where we sort of bounce off the atmosphere a little bit and skip further down range and then come into our desired landing site. So sort of like taking a flat rock and skipping it across a pond. So what, so, and the reason we do that, of course, is so we can skip over any bad weather and sort of pick down range where we want to land again for safety for the crew. But what we found with Artemis I was that in doing that, skip it. It created a char layer on the sort of a burned layer on the outside of the heat shield during the cooler part of the entry, relatively cooler part. And it allowed gasses, heat to build up inside the heat shield as we descended back in the second time. And that that excess heat, in some cases, caused little chunks of the heat shield to pop off. Now, fortunately for Artemis I, you know, that char loss was was not significant enough to cause any excess heating of the structure. The spacecraft landed perfectly fine, but it's definitely something that we we needed to understand. So again, we it. We did extensive arc jet testing, heat testing of the heat shield material in order to create this problem. And once we were able to create it on the ground and through analysis, modeling with simulations, then we knew we had understood the problem, and it matched very well with what we observed on Artemis I. So what we're doing for Artemis II, the heat shield was already built. So we're going to fly Artemis II with the heat shield as is, but we're going to go back to doing sort of an Apollo style entry. We're going to do a direct entry. We do have a little bit of capability to vary that landing site up range or down range if we have to avoid any any weather systems, but we will not do the full up. You know, up to 4800 nautical miles is what capability we eventually want to have with Artemis III. Artemis III will that heat shield is being manufactured now, and we've adjusted the, essentially, the recipe for that avcoat material so that we don't have this problem on Artemis III and beyond.
Okay? And so for Artemis II, it would not so direct entry is not that flat rock skipping across.
We're not skipping we're going straight in, yeah, that was a great way to describe that. Okay? And by going straight in, we'll allow the heat to bleed off steadily, and we won't build up those pockets of heat.
Let's talk about demonstrating the spacecraft's capabilities, this time with crew on board. But first episode 394, we did look at a detailed look at the mission, but for our listeners here, can you provide a quick overview of the mission profile?
Yeah, Jeff Radigan did a great job describing the mission in that episode, but yeah, just a quick recap. So the Space Launch System, SLS, will launch Orion and the crew up to a 1200 nautical mile apogee, right off the bat, which is amazing, because again, Space Station orbits about 250 miles up, so SLS has got lots of power to spare. And so about 1 hour 45 minutes later, the upper stage of SLS is called the ICPS, for Interim Cryogenic Propulsion Stage. It will boost the apogee, or the high point of the orbit, up to about 39,000 miles. So now we're we're really way up. The crew is going to get a great view up there. So and So Orion will separate from the ICPS, and then about three hours into the mission, will perform a proximity operations demonstration. We call it prox ops demo. And what they'll do is essentially, as they're separating from that upper stage, they'll stop the opening rate, turn around and point the nose back to that stage, and then they'll fly in and practice maneuvering around that stage, get, you know, basically flying the stick to exercise the- and, you know, to see how the handling characteristics of the capsule match what we've modeled in simulations. So once we're done with that, then the crew will be will separate finally, from the ICPS, it'll be disposed of, you know, in the ocean. Orion will continue up for about one day on what we call the high Earth orbit or HEO. A few hours after that demo, they'll go to sleep. And in the meanwhile, in mission control and in the mission evaluation room, the MER, we will be closely monitoring their systems to determine is everything working okay? So that we can commit to send the crew to the moon. So that commit decision is about one day in one hour. It's the TLI, or Trans Lunar Injection burn, and that's where we'll fire the main engine on the European Service Module that will give Orion that final boost to leave the earth and head out to the moon. And in the case of Artemis II, we will not orbit the moon. We're going to be on a free return trajectory. So we'll we'll pass about about 5000 miles behind the moon and and then start falling back to Earth. And again, about after, after about nine days of the mission, will reenter the earth and come in for that landing off the coast of San Diego.
Great. Okay, now with crew on board for the mission, what elements are we testing that differ from Artemis I? You did talk about prox ops a little bit. Let's start with that. So what new pieces of hardware were added to Orion for this?
Yeah, so we're gonna be flying our docking camera, and so the crew will install that on the there in Orion. I didn't mention it earlier, but there's an overhead hatch, as you would expect, because to transfer from Orion to the lunar lander, you've got to, just like an Apollo, you've got to pass through a hatch into the other vehicle. So there's a window on that hatch, and they will mount a camera that is going to be used for to provide a sort of a nose on view of the ICPS, and for Artemis III of the docking target on the lunar lander. And we'll also be flying a compact flight computer, or CFC, that's going to interface with that docking camera and that will display that will allow the camera imagery and the overlays, which are sort essentially grids on the crew display. So the crew will have all the information right there in front of them on their control panel as they're flying around the ICPS. So that's what we'll that's what we'll exercise as part of that prox ops demo.
Okay. And then, of course, with humans on board, life support systems are very important. Can you tell us more about that?
Yeah. So the the piece of hardware that everyone's going to be watching the most closely will be our Atmosphere Revitalization system. So for Artemis I, we had a pressure control system that maintained, you know, habitable temperatures within the cabin. But for Artemis II, we're flying new hardware to this time to, you know, to provide CO2 removal and humidity removal for the, for the for the crew. So our the box is called the CHC, carbon dioxide humidity controller. There's three CHCs, and they are regenerative, CO2 removal systems. So with shuttle and Apollo, we used non renewable systems, essentially canisters of lithium hydroxide or LiOH, LiOH canisters, and we would pass air over those, and it would chemically react with the CO2, remove that from the atmosphere. And then the crew would, you know, breathe easy, but, but again, it's, it's not reusable. So you, as you use them up, they, you know, they create space and waste, right, and more weight. So for Orion, again, to have longer capability of flying, we wanted a regenerative system. So we've tested this technology. It's in a mean swing bed, carbon dioxide adsorption bed. So essentially, I think of it as a molecular sponge, where it you flow air over it. It grabs the CO2 and the humidity out of the air, and then once it, you know, after a certain period of time, once it's saturated, you expose it to the vacuum of space, and that CO2 and humidity are relieved overboard. And so you can just switch back and forth between two beds, one absorbing and one regenerating continually. And it will, you know, keep the air clean for the for the crew to again, to not have excess levels of CO2, And hat tip to the space station, because we test a lot of this technology over the years onboard the space station. So we'll be watching very closely how that, how the CHCs work, especially in the first rev, that high Earth orbit. Well, you know we, if things are not going well, you know, we're always thinking, what's. What do we do? What if, right? What if, if they're not working, we can bring the crew back safely. We've got, we are flying enough contingency LiOH canisters, actually old shuttle canisters, that can get us through the first day. So if we do have problems, we can bring them back safely from that high Earth orbit using the old school technology. But again, we we've done a lot of testing with the CHCs, and assuming they are working right, we will press on with our trans lunar injection burn about one day into the mission.
And so that the ECLSS system also introduces some, some, some new problems for us, the venting. I mentioned how that, that the CO2 is vented overboard. We're also going to what the toilet, the UWMS, the urine dumps. We have a urine tank, so we'll vent that overboard. So all those things, my FDO friends, and all the trajectory, people hate the they hate the venting and the dumping overboard, so it's going to perturb the trajectory somewhat. So that's another thing we're going to be watching closely. Is tracking the orbit and doing orbit correction burns, we've got at least one per day budgeted throughout the mission in order to correct the trajectory, make sure that we are staying on track to again, to hit the right speed and an angle when Orion contacts the atmosphere.
Okay. And so with crew on board prox ops, life support systems. What about communication systems?
Yeah, so we're flying the same communication system as we did in Artemis I with one exception. We actually have a, an emergency comm system, which is totally separate from our S band system. We have two, two strings, two independent S bands, and then we have a third, fully independent emergency com system. It doesn't provide telemetry, but it's voice only, and it will be used if both of the radio the prime radios fail, at least the crew will be able to talk to Earth, and we can again uplink by voice any information they need to get them back safely, and if that were to fail, we've got yet another system. We've got an optical navigation system. Apollo did not have the capability to return autonomously, but Orion does that have that capability. It can take that system takes, essentially it's a digital camera. Takes images of the Moon and the Earth, and it uses that to compute where it is between the two, and it can update the navigation state in order to return you safely, even if you completely lost communication with the earth. So again, we've built in a lot of capabilities for crew safety into Orion. And then the final, you know, big new thing with Artemis II would be the displays and controls, and the fact that we've got now the crew interacting with the with the vehicle automation. You know, we tested out the automation extensively on Artemis I, and you know, 1000s and 1000s of hours of testing in Denver at their facility. So, but you know, this will be the first time with the crew again, taking the vehicle automation through all its paces and how they interact using the displays and controls. So that'll be another big, you know, learning opportunity for us on Artemis II.
What message do you want to share to your teams ahead of the mission?
Well, first and foremost, I'm a manager, so my message, as the you know, the past many months, has been, let's get the work done, because the vehicle hardware is going to be ready to fly early next year, and we've got to have all of our analysis and verifications complete so that we can prove it's safe to fly, and so that work has to get done first and foremost. So the team is really working hard. You know, I should mention that, you know, being part of Orion is really amazing. I came from the operations world where, of course, I had great respect for the astronauts and the flight controllers that go fly these missions. But when I came to Orion, I just, I was so impressed with the what the the quality and the dedication of the engineers that, again, are designing the individual components, the depth of their knowledge and dedication to make sure that, you know, every little aspect of how the systems work is understood and and they're excited and ready to go, you know, support the mission. You know, many of them in the in the MER as part of that team. So, um, yeah, so usually, for the team, I'm just emphasized, let's get the work done. But also, I know they're like me that, you know, at night when they look up at the moon, just like when I was a kid, it's, it's exciting to look up at the moon and think, Wow. You know, we're going to be heading back, and this time, I'm a part of that.
What do you want people to know about Orion? So what would you like our listeners to take away from this episode?
Well, I want you know, as an engineer, of course, I'm most interested in how is this, how the system is going to work? You know, how, how's the crew? What kind of feedback are we going to get from the crew? What things do we learn that we need to correct for next time. So you know that that's, that's the part that the the engineer and the Orion Program team member that I'm most interested in, but really, the part that, you know, I hope everyone takes away from it is just the excitement of, you know, we're finally going to be returning humans to the vicinity of the moon for the first time in 50 years. So I think it's just, I. It's just great to be a part of human exploration and taking those next steps. And this is nothing new, you know, NASA has is not in a new business. Humans have been exploring since, you know, since, frankly, we stepped out of trees, you know, on the on the plains of Africa, and eventually leaving Africa and waves of immigration to all four corners of the earth, right? Yeah, from the in the ice age up to Europe, the people that settled America coming across the Bering ice bridge, and those that settled, you know, even going out into Polynesia, across the ocean. So humans just explore in America. You know, we were founded by explorers, and so NASA is continuing that great tradition. So I'm proud to be part of the Orion Program, and all of us are excited to be getting ready to return humans back to the moon.
Thanks for sticking around. I hope you learned something new today.
You can check out the latest from around the agency nasa.gov and keep up with the Orion spacecraft and its Artemis II journey at nasa.gov/orion.
Our full collection of episodes and all the other wonderful NASA Podcasts can be found at nasa.gov/podcasts. On social media we're on the NASA Johnson Space Center pages of Facebook, X, and Instagram. If you have questions for us or suggestions for future episodes, email us at [email protected].
This episode was recorded on August 6, 2025.
Our producer is Dane Turner. Audio engineers are Daniel Tohill and Will Flato. Our social media is managed by Kelsey Howren and Reagan Scharfetter. Houston, we have a podcast was created and is supervised by Gary Jordan. Special, thanks to Rad Sinyak and Erica Peters for helping us plan and set up this interview. And of course, thanks again to Chris Edelen for taking the time to join us on the show.
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