Space

What Happened To Orion?

11 Comments

There’s an interesting discussion in comments over at Hyperbola. I do think that people are making a lot of unjustified assumptions about what the architecture will look like. Orion was part of Apollo on Geritol, and the requirements for any beyond-LEO crew system need to be rethought in light of potential new technologies.

11 thoughts on “What Happened To Orion?”

  3. And of course the basic issue that NASA has no expectations of sending anyone beyond LEO for a decade or 2 AT LEAST! So the basic question of what they will use can be left up to the next generation. …Assuming there is a NASA at all by then.

  4. I don’t know Rand, a capsule seems pretty important, even if it is only used as an escape pod. It’s a good thing Obama canceled Orion, because it’s a sign we won’t be going beyond LEO soon which increases the chances of the HLV studies not going anywhere either. But in the long run, wouldn’t you want to upgrade a commercial capsule to be capable of lunar or even GEO returns? Someone posted a link to document showing even something like HL-20 could be fitted with an ablative heatshield, but somehow a capsule sounds like a better first step.

  5. Orion isn’t “a capsule.” It’s a specific design of a capsule, designed to a set of requirements that are no longer valid. And Boeing and Bigelow are reportedly working on a different one.

  6. Why does any potential beyond LEO craft have to have Earth landing capability? Something for aerobraking or capture maybe. Isn’t the first 100 miles the hardest so in that case we can leave it to the private companies to do the driving!

  7. Why does any potential beyond LEO craft have to have Earth landing capability?

    Because it’s a lot more convenient to just go straight to reentry since they’ll aerobrake anyway.

  8. This could also be an opportunity to review the basic configuration of the spacecraft. A single capsule isn’t a very efficient design. For decades, the Soyuz spacecraft have featured a service module, an orbital module and a small reentry module. This configuration saves a great deal of weight because only the small reentry module needs to carry a thermal protection system. The rest burns up in the atmosphere. Soyuz was originally designed with lunar missions in mind. This article states that General Electric proposed such a design for Apollo back in the 1960s.

  10. Why does any potential beyond LEO craft have to have Earth landing capability? Something for aerobraking or capture maybe.

    1) Aerobraking/aerocapture requires a heat shield anyway.

    2) Multipass aerobraking can allow a lighter heatshield but at Earth it involves multiple, lengthy passes through the Van Allen belts, so you will more than pay for it with radiation shielding.

    3) Single-pass aerocapture requires a heatshield almost as heavy as required for direct entry.

    4) In contingency scenarios during aerocapture, sometimes the safest way out is abort-to-Earth, and it really doesn’t take much more heatshield mass to make that work.

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