Author Topic: NASA considers alternatives to its Orion spacecraft  (Read 26881 times)

Online Navier–Stokes

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Eric Berger (Ars Technica) just published an article detailing an RFI that may signal trouble for the Orion program.

As Trump takes over, NASA considers alternatives to its Orion spacecraft
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NASA has initiated a process that raises questions about the future of its Orion spacecraft. So far, this procedural effort has flown largely under the radar, because it came in the form of a subtle Request for Information (RFI) that nominally seeks to extend NASA’s contract to acquire future Orion vehicles after Exploration Mission-2, which likely will fly sometime between 2021 and 2023.

Nevertheless, three sources familiar with the RFI, who agreed to speak on the condition of anonymity, told Ars there is more to the request than a simple extension for Orion’s primary contractor, Lockheed Martin. Perhaps most radically, the RFI may even open the way for a competitor, such as Boeing or SpaceX, to substitute its own upgraded capsule for Orion in the mid-2020s.

Offline pikawaka

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #1 on: 11/10/2016 06:00 PM »
The 2 big problems I can see with switching off Orion are SLS compatibility and the service module, specifically the available Delta-V. Orion has around 1.3 KM/S in the SM, and I'd think both Dragon and CST-100 would have significantly less, being designed for LEO ferry operations. So any proposal would need to account for the cost of adding extra propulsion to either craft.

Offline Robotbeat

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #2 on: 11/10/2016 06:14 PM »
Star liner in particular should have no big problem with adding more propellant except it makes abort more sluggish.
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Offline Proponent

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #3 on: 11/10/2016 06:22 PM »
On the other hand, that delta-V was built into Orion with a Constellation-style lunar sortie mission in mind.  That mission is long gone.  ARRM has now been designed around that delta-V, but ARRM seems unlikely to survive the upcoming change of administrations.  So there may not actually be any requirement for it, and it probably isn't sized right for most other purposes.

Maintaining an additional large-delta-V version of CST-100 would probably be cheaper than keeping Orion on line.
« Last Edit: 11/11/2016 02:09 AM by Proponent »

Offline pikawaka

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #4 on: 11/10/2016 06:28 PM »
Star liner in particular should have no big problem with adding more propellant except it makes abort more sluggish.

So the Starliner SM can be used for orbital maneuvers? What engine(s) does it use, and what kind of performance can you get relative to the AJ10 on Orion?

Online brickmack

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #5 on: 11/10/2016 07:42 PM »
The 2 big problems I can see with switching off Orion are SLS compatibility and the service module, specifically the available Delta-V. Orion has around 1.3 KM/S in the SM, and I'd think both Dragon and CST-100 would have significantly less, being designed for LEO ferry operations. So any proposal would need to account for the cost of adding extra propulsion to either craft.

Starliner at least could probably use an ACES as a tug for BEO missions. ULA has studied this option before. SpaceX doesn't have anything available off the shelf, but they could fit a decent propellant load plus a couple (Super?)Dracos in the trunk, and this would almost certainly be much cheaper than continued Orion development.

As for SLS compatibility, I see little reason for that to be a requirement. Vulcan and FH can perform the job just fine, though distributed launch may be needed to deliver any additional payloads and fuel (still cheaper than an SLS launch, and doesn't require SLS to be manrated if that program continues)

Online Navier–Stokes

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #6 on: 11/10/2016 07:46 PM »
Do Starliner and Dragon have enough ECLSS endurance to be useful in cislunar space? I did some searching but I haven't been able to find CCtCAP ECLSS requirements. 

Also, is the Starliner heat shield robust enough for cislunar return trajectories?

Online Coastal Ron

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #7 on: 11/10/2016 08:11 PM »
Starliner at least could probably use an ACES as a tug for BEO missions. ULA has studied this option before. SpaceX doesn't have anything available off the shelf, but they could fit a decent propellant load plus a couple (Super?)Dracos in the trunk, and this would almost certainly be much cheaper than continued Orion development.

If launched on a Falcon Heavy, the 2nd stage would be able to stay attached and provide propulsion beyond LEO.  You could probably create a module for the trunk area (which would not abort with the spacecraft during an ascent emergency) that would house the additional life support equipment and supplies.

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As for SLS compatibility, I see little reason for that to be a requirement. Vulcan and FH can perform the job just fine, though distributed launch may be needed to deliver any additional payloads and fuel (still cheaper than an SLS launch, and doesn't require SLS to be manrated if that program continues)

Agreed.
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Online rayleighscatter

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #8 on: 11/10/2016 08:31 PM »
This would, in theory, also allow LM to propose a non-ATV based SM for Orion.
« Last Edit: 11/10/2016 08:31 PM by rayleighscatter »

Offline hkultala

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #9 on: 11/10/2016 08:36 PM »
The 2 big problems I can see with switching off Orion are SLS compatibility and the service module, specifically the available Delta-V. Orion has around 1.3 KM/S in the SM, and I'd think both Dragon and CST-100 would have significantly less, being designed for LEO ferry operations. So any proposal would need to account for the cost of adding extra propulsion to either craft.

Where is that 1.3km/s delta-v needed? Getting back from LLO to earth?

But who wants to go to moon anyway? The aim is now to Mars?

And that 1.3 km/s is not enough to get back from LMO, especially with a habitat attached to the orion capsule.

Orion just looks like to be "Apollo CSM 2.0" when something else is needed.
« Last Edit: 11/10/2016 08:37 PM by hkultala »

Offline redliox

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #10 on: 11/10/2016 08:40 PM »
Never hurts to have a plan B...or perhaps we should say "plan T" in light of the election.

I would prefer to keep the SLS but kill Orion.  If it does end up replaced, it'd make sense to replace it with something current or well underway, which would include Dragon, Starliner, or even Dream Chaser.  The poor Orion was a mess simply because they couldn't mesh the launcher and SM requirements together since the Ares 1 days.
« Last Edit: 11/10/2016 08:40 PM by redliox »
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Offline TrevorMonty

Re: NASA considers alternatives to its Orion spacecraft
« Reply #11 on: 11/10/2016 09:06 PM »
Specification for vehicle depends on mission requirements. As taxi to and from DSH it only needs support crew for few days. The right US (eg ACES) could deliver vehicle direct to DSH leaving a DV requirement of 7-800m/s for return trip.

Both Starliner and Dragon would need separate service modules that can be left behind during an launch abort.
Enlarging Starliner service module fuel tanks would make it too heavy for LAS, better to have extra one that is left behind in an abort. Dragon has to abort with trunk attached, extra fuel and engines in trunk wouldn't be option. A Dragon service module would require more powerful engines than Dracos. SuperDracos are too inefficient  (<250ISP) for large orbital changes.

Blue could be dark horse in this race. The NG with BE3 3rd stage could be capable of delivering crew vehicle direct to DSH while reusing booster. With moon as long term destination, it is good bet Blue orbital crew vehicle will be designed for BLEO missions.
« Last Edit: 11/10/2016 09:07 PM by TrevorMonty »

Online brickmack

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #12 on: 11/10/2016 10:15 PM »
or even Dream Chaser.

Would be quite interesting to have a BEO spaceplane, theres been a few proposals over the years. It would be an attractive option in terms of crew volume, if not mass efficiency. And SNC seems quite willing to build multiple configurations for different uses

Do Starliner and Dragon have enough ECLSS endurance to be useful in cislunar space? I did some searching but I haven't been able to find CCtCAP ECLSS requirements.

CCT-REQ-1130 is the closest I've found (requirements document for commercial crew in general), but it doesn't say a huge amount on ECLSS. Looks like they're expecting launch to docking to take about 24 hours, plus a 24 hour contingency for rendezvous/docking failures, and undocking to landing would be about 8 hours at most. So 56 hours total, for a maximum 7 man crew. Thats about 4 days endurance with a 4 man crew, not good enough. However, I'd expect that all the companies have gone at least a little bit beyond the minimum requirements, and those 3-4 extra seats can be filled with consumables, so its not completely out of the realm of possibility.

Offline docmordrid

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #13 on: 11/10/2016 11:34 PM »
Elephant in the room; ITS

They say a mid-20's replacement which coincides with SpaceX's timeline, by definition it'll have a long duration ECLSS, large internal propellant stores, and its cargo capability would eliminate the need for developing a large cargo lander for Mars. Crew size: no problem.

Just saying...
« Last Edit: 11/10/2016 11:39 PM by docmordrid »
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Offline okan170

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #14 on: 11/11/2016 12:48 AM »
Elephant in the room; ITS

They say a mid-20's replacement which coincides with SpaceX's timeline, by definition it'll have a long duration ECLSS, large internal propellant stores, and its cargo capability would eliminate the need for developing a large cargo lander for Mars. Crew size: no problem.

Just saying...

If SpaceX can build, test and fund the entire thing on their own by that time, while building a revolutionary ECLSS system of unprecedented scale, I'll honestly be very impressed.  But I'm not going to count on it, especially with SpaceX's dates.

Offline docmordrid

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #15 on: 11/11/2016 12:56 AM »
Have NASA's CEV, Constellation, SLS/Orion dates been better?  Even if Spaceship testing slips 5-6 years it beats SLS/Orion to Mars.
« Last Edit: 11/11/2016 12:58 AM by docmordrid »
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Offline Rocket Science

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #16 on: 11/11/2016 01:22 AM »
Have NASA's CEV, Constellation, SLS/Orion dates been better?  Even if Spaceship testing slips 5-6 years it beats SLS/Orion to Mars.
I said a few years back that I liked having the CST-100 in the works for a potential vehicle for a BEO upgrade but I never thought it would be considered so soon... ???
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Online brickmack

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #17 on: 11/11/2016 01:38 AM »
Elephant in the room; ITS

They say a mid-20's replacement which coincides with SpaceX's timeline, by definition it'll have a long duration ECLSS, large internal propellant stores, and its cargo capability would eliminate the need for developing a large cargo lander for Mars. Crew size: no problem.

Just saying...

ITS is quite something, but it has the problem of being unmatched. NASA probably won't want to go with a commercial provider with no backup. Unless BO's capsule for NG is something really huge (like 40+ people), or someone else pops up with a colonization-class spacecraft, theres no backup for ITS yet. I expect NASA will eventually fund a "mega-CCDev" to make more vehicles like that, but by the time it actually happens ITS will probably have a very large lead

Offline okan170

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #18 on: 11/11/2016 02:27 AM »
Have NASA's CEV, Constellation, SLS/Orion dates been better?  Even if Spaceship testing slips 5-6 years it beats SLS/Orion to Mars.

Yes, assuming miracle development and funding and no hitches it could.  And nothing SpaceX has decided "isn't a problem."  Basically yes, SLS/Orion dates are significantly more believable, and to most non-space people as well.

Offline ChrisWilson68

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Re: NASA considers alternatives to its Orion spacecraft
« Reply #19 on: 11/11/2016 02:40 AM »
Elephant in the room; ITS

They say a mid-20's replacement which coincides with SpaceX's timeline, by definition it'll have a long duration ECLSS, large internal propellant stores, and its cargo capability would eliminate the need for developing a large cargo lander for Mars. Crew size: no problem.

Just saying...

If SpaceX can build, test and fund the entire thing on their own by that time, while building a revolutionary ECLSS system of unprecedented scale, I'll honestly be very impressed.  But I'm not going to count on it, especially with SpaceX's dates.

What SpaceX can do entirely with internal funding is irrelevant.  What is relevant is what they could do with the Orion plus SLS budget.  And the answer is: ITS.

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