ORION— USA, 2014/2026?

Orion isn’t a commercial craft — it was developed for NASA as their new Multipurpose Crew Vehicle. It resembles an Apollo capsule, being a cone with a sharp 32.5 degree taper, but is quite a bit bigger, having a base 5 meters wide, and 19 cubic meters of pressurized space... though only 9 of these are accessible crew compartment — the rest holds stuff such as a water recycler, which is necessary for long missions such as visiting a near-Earth asteroid, or eventually Mars. I sure wouldn’t want to live in one for the time it would take to travel that far, but it may not be as bad as it sounds: for Mars at least, the plan is to attach it to some larger habitation module — a bubble, or something more substantial. It seats four, but in theory you could fit six for short missions. The point of this craft is to support longer spaceflights than any other vehicle. Even with no additions or upgrades it can maintain four people for at least three weeks, and they say that’s a very conservative rating — it could probably last months, recycling air and water indefinitely until some other factor becomes a problem.

To support that long range capability, it needs a heavy service module, weighing over 15 tons fueled, and the capsule brings the total to a hefty 26 tons. It is reusable, though the number of missions that would use it may be small, and for now, all currently planned missions are each getting a new craft. Development of the Orion has consumed an astonishing sixteen billion dollars, making it possibly even more expensive than the SLS rocket which it rides on. And that’s just the cost they admit to — an Inspector General’s report says another $18 billion is hidden elsewhere in the budget, including future costs through 2030, though many of those may be avoided if the Orion program gets cut, as the White House proposed in 2025.

The builder is Lockheed. The service module on the back is made in Europe, and is a bit of an awkward misfit as they are reusing a design made for a different craft. Like any other service module, this is used once and then ditched to uncover the heat shield for reentry. It supplies Orion’s propulsion — it has a single large nozzle, plus maneuvering thrusters and solar panels. Without it, the capsule has its own minimal steering thrusters, just like Starliner or Apollo. It sounds like they might be figuring on making an even bigger service module for the long trips, but nothing specific has been described yet for that. They had hoped to develop a way for it to land on dirt with airbags, but this was abandoned — they’ll stick with ocean splashdown.

As mentioned, the launch vehicle for these ambitious missions is NASA’s SLS. Given the Orion’s heft, it would be tough for any smaller rocket to send it to the moon or beyond — a New Glenn would be the bare minimum, probably. Such a large rocket under a compact capsule means that aiming at nearby targets like the Space Station would be ridiculous, so they aren’t going to bother with anything like that. They sent an uncrewed Orion around the moon on the SLS’s very first test flight. That was scheduled for 2019 but slipped to 2022. (There was briefly some public talk in 2020 about adding a crew to this mission, but that was just Trump administration ignorance talking.) So far that is the only flight by a complete Orion, but an early test version actually flew way back in 2014 to try out high speed reentry.

Speaking of reusing engines from the shuttle, as the SLS is doing, the motor on the back of the Orion’s service module comes from the Orbital Maneuvering System — the two smaller nozzles you see on the back of the shuttle above the three main engines. They aren’t just copying the designs: on the Artemis service modules they are reusing engines that actually flew in shuttles. It burns hypergolics, and despite its large bell only produces a tenth of a gee for Orion if the tanks are full. The service module also has eight smaller nozzles on the back (besides the 24 tiny thrusters for rotation), and I would have thought those made the large engine redundant, but the craft sometimes has to perform fairly large burns at low altitudes over the moon, and in those cases you don’t want to spread the burn over half an hour — making it quick saves fuel. The total delta-V that the service module can provide is around 1.5 km/s depending on load, which is a lot more than most other spacecraft, though well short of what the Apollo service module did.

For launch escape it has an Apollo-style external tower... which adds another seven tons, including the fairing which covers the windows during ascent. (The craft has four rectangular windows of high optical quality in the walls, plus little ones on the door and the docking hatch.) This escape tower is very powerful because of the Orion’s heft, and the danger level of the SLS’s solid boosters. Once the boosters are gone, the big tower is also discarded, and there is no escape capability for the rest of the ascent unless the core stage engines are shut off first.

There was also a parallel project in the early part of Orion’s development which was called “Orion Lite”. This eventually, after changing hands a couple of times, became the Boeing Starliner, after they threw out the Orion heritage and started clean.

Though the SLS development was troubled, it seemed like the Orion was fine... until it actually went out to the moon on Artemis 1. When it came back, the heat shield was way more burnt and cracked than it was supposed to be, apparently because gases were getting produced inside the material and only escaping by creating cracks. This ended up delaying Artemis 2 (when they put people in it). But they were in no hurry because it was obviously going to be quite a while before they could prepare Artemis 3, because that has to wait for the Lunar Starship, which had quite a ways to go. And when announcing the delay into 2026, they said they’d also have to give the Orion a more conservative reentry trajectory to save the heat shield. Revising the heat shield would have made the delay longer, so they’ll baby it for this one flight and fix it for the next.

NASA is exploring options for leaving the service module active after the capsule reenters. If its fuel isn’t too low, it could perform an extended supplementary mission of its own, maybe even an interplanetary one, such as knocking away a scary asteroid — a mission where having something pretty big and heavy is a plus.

The Orion may be cancelled soon as part of Artemis cuts, but the day will come soon enough when we want it back again, and unlike the SLS it has no fundamental shortcomings to make it obsolete. I think it could be an important asset for a long while yet, even if there are some who resist acknowledging its value.