Why aren't Boeing and SpaceX spacesuits compatible?

Why aren’t Boeing spacesuits compatible with a SpaceX Crew Dragon? What’s the scenario where Butch and Suni might have to come home on a spacecraft WITHOUT suits? What is going on here?

To be clear: There is still no final decision. NASA will likely tell us what spacecraft Butch and Suni are coming home on late this week or early next week, but while we’re waiting, let’s dive into all the nitty gritty spacesuit questions I’ve been getting in the wake of last week’s press conference and update from NASA.

The talk about launch and entry suits

• Two types of spacesuits to think about

• Why these suits are needed during re-entry

• Leaving the ISS in an emergency

• Why the suits aren’t compatible

Two types of spacesuits to think about

Let’s start with the basics: There are two types of spacesuits. The first is an EVA suit, which is basically a space walking suit. These are the suits that NASA astronauts wear to perform repairs during spacewalks on the ISS.

The second is a suit used within a spacecraft, they’re called different things, often a launch and entry suit. These are much more lightweight, less rigid and softer, mainly designed to protect the crew in case of a loss of oxygen, fire, that sort of thing, within the capsule.

This second type is what we’re talking about here because it has shocked a lot of people that SpaceX suits and Boeing suits are not compatible, and Suni and Butch would need SpaceX suits sent up to them in order to return on a Crew Dragon. (If you’re wondering, the Soyuz suits are also not compatible with other spacecraft. The suit is specific to the spacecraft.)

These suits plug into the spacecraft, and the plugs aren’t compatible. Because in Commercial Crew, the private companies own the vehicles, I can’t give you specifications on how exactly they’re incompatible because that information isn’t publicly available. I can tell you that there is no adapter available to plug one suit into another spacecraft.

The question is, WHY? Has NASA learned nothing from Apollo 13 (if you remember there’s a great scene in real life, but also in the movie — which I HIGHLY recommend if you’ve never seen it, by the way — where they have to make a square peg fit into a round hole because the CO2 filters between the command module and LM weren’t compatible because they were made by different contractors).

Why these suits are needed during re-entry

When a spacecraft undocks from the ISS and starts the procedures for re-entry — the de-orbit burn and such — the capsule is pressurized. The astronauts can breathe, they are comfortable, the interior of the spacecraft remains a comfortable temperature during the heat of re-entry because that’s what these spacecraft are designed to do.

Wearing a launch and entry suit during re-entry is just a safety precaution. If something goes wrong during re-entry, and there is a depressurization of the spacecraft, wearing the suits will offer some measure of protection. Astronauts don’t actually have to wear the suits to come back safely — it’s just one of the ways NASA mitigates risk and cuts down on the odds of loss of crew. In an emergency, crew can and will absolutely come home unsuited if necessary.

And this is why NASA was talking about a possible unsuited re-entry for Butch and Suni during the media conference last week (which is something a lot of people freaked out about). It’s not a huge deal, in terms of it’s only for a emergency situation and only for a short period of time, as I’ll explain.

Leaving the ISS in an emergency

I mentioned this in my previous Starliner video and newsletter, but whenever astronauts are on the ISS, they have to have a way to leave in an emergency. It’s absolutely a requirement.

There are currently two docking parts at the Harmony module of the ISS that Commercial Crew vehicles can dock with. Both are currently taken — the forward port by Boeing Starliner, the space-facing port by the Crew-8 SpaceX Crew Dragon. One of these spacecraft has to undock in order for Crew-9 to launch with those two extra suits for Butch and Suni, if NASA decides to bring them back on a SpaceX Crew Dragon.

Boeing Starliner is cleared to bring Butch and Suni home in an emergency, so it’s not an issue before an autonomous undock. The idea is that undocking in Starliner is less risky than staying on the ISS if there’s some sort of catastrophic failure. (Every decision NASA makes is a just a measure of risk, because everything in spaceflight is inherently risky. I’ll have a newsletter about how NASA weighs risks later this week.)

So why can’t Crew-8 leave, and Butch and Suni have Starliner for an emergency until Crew-9 gets there? Well, NASA likes to do crew handovers, allowing an overlap between Space Station crews. That means that preferably, Boeing Starliner would undock first autonomously, but then — how would Butch and Suni get off the station in an emergency after Starliner undocked but before Crew-9 launched?

This is where the unsuited return comes in — it’s a contingency scenario that would only come into place if there was some sort of emergency on the ISS and the astronauts couldn’t stay there any longer and had to leave. Keep in mind that while astronauts have had to shelter in place in their spacecraft because of debris and other hazards, the space station has been continuously occupied since the year 2000. It has never been abandoned. But space is inherently risky, and the ISS is aging, so NASA has to have these contingency plans.

What would happen is before Starliner undocked, the astronauts would install some sort of makeshift seats on Crew-8 so it could accommodate two more passengers in an emergency. If NASA proceeds with an autonomous undocking, it will be in early September. Crew-9, with, two extra suits (if that’s the route NASA chooses), is scheduled for launch on September 24.

That would be a span of about two or three weeks where, if there was an emergency on the ISS, Butch and Suni would have to jump in the Crew-8 Crew Dragon and come back unsuited. That’s what we’re talking about here, it’s a narrow window of time, and only an issue in an emergency, but it’s space and there’s always unexpected things happening.

Why the suits aren’t compatible

Again, wouldn’t all of this just be easier if Suni and Butch could use their Boeing Starliner suits on the SpaceX Crew Dragon?

Yes, it would be a lot easier if the suits were compatible.

But here’s why they’re not:

This basically has to do with the nature of Commercial Crew and NASA’s evaluation of risk and redundancy.

For every era of spaceflight before this current one, NASA used a different model of procuring spaceships. They laid out their exact needs, identified the contractor, and managed every stage of the spacecraft, from design to development to construction to the flights to the refits. They were deeply involved in every single thing.

They decided to try a different approach with Commercial Crew. Because it was going somewhere we were relatively comfortable with at that point — the ISS — NASA decided to basically partially fund the development of these spacecraft, but allow private companies to design and innovate, as long as the companies met NASA’s broad requirements and safety standards, as well as reach specific milestones (one of which is a successful crewed flight test.)

This also meant that NASA isn’t bearing the brunt of the cost — they paid a set fee for the development, test flight, and subsequent operational flights, and if the contractor went over budget, that was their problem not NASA’s. (Compare this to the ballooning costs of SLS, which is the Artemis rocket which will end up costing NASA an estimated $4.1 billion per launch).

NASA has been in less than ideal budget circumstances for awhile now — anything they can do to get costs down without increasing risk or compromising on safety is a huge win.

For context, the Space Shuttle in the end was about $1.5 billion per flight, whereas NASA paid SpaceX $65 million per flight the latest round of Commercial Crew flights. (Keep in mind that the Space Shuttle could carry up to 7 astronauts, Crew Dragon CAN carry up to 7 but NASA only has it contracted for four astronauts per flight for Commercial Crew, more on this a little later). But even with all the caveats about the difference between Shuttle and Crew Dragon, it’s a huge amount of money. It’s part of why Commercial Crew is so important to the organization — keeping costs down in one area means they can do more as an agency.

But the appeal of Commercial Crew wasn’t just about cost. It was also about innovation. NASA wanted these companies to bring their fresh ideas, their business practices (in this case, given what we know about Boeing now, maybe not the best idea), their innovation to the table to basically push what NASA can do. Remember the Space Shuttle was heritage technology — even into the 2000s, the flight software was from the 1970s. They wanted to bring something new to the table with Commercial Crew.

Basically, that meant that NASA would provide a list of technical requirements that were divided into system safety, control of the spacecraft, and crew survival and abort requirements. These included abort systems, manual override of automated systems, and launch and entry pressure suits. It did not specify that these suits needed to be cross compatible.

That may seem like a huge oversight, but it’s also a way NASA controls risk. If the suits used the same plug, and some sort of flaw was found within that plug or some other standardized connector, it would ground both spacecraft. After their experience with the Space Shuttle, NASA wanted Crew Dragon and Starliner to be as dissimilar as possible. That’s why they didn’t mandate standardization here; it’s how they define redundancy.

Part of it is also just they didn’t want to stifle innovation by mandating too much.

And keep in mind the suits are also specifically designed to work with a particular spacecraft. It would have been a ton of work, and a ton of money, to make them cross compatible. It’s not just about physical protection, they plug into the spacecraft and have a lot of electronics, temperature control, pressure regulation, that sort of things. Even if the Starliner suits could plug into the SpaceX craft with an adapter or a universal plug, the software very well may not be able to talk to a Crew Dragon.

AND there’s the question of where they’d plug in. As I mentioned, while the Crew Dragon is capable of carrying seven astronauts, the Commercial Crew contract only has it configured for four. That means that even if Butch and Suni’s Starliner suits were compatible with the SpaceX Crew Dragon, there would be nowhere for them to plug the suits in.

To be clear, I’m not defending NASA here, I’m just explaining the thought process — I also think it would make a lot of sense if the suits were cross compatible. But like everything in spaceflight, it’s more complicated than it first appears.