Orion-Atlas With Cygnus-Derived Orbital Module

[Kibble]

So CCTCap is cool and all, and I would love to see (the unfortunately named) Dragon V2 and (the boringly named) CST-100 fly with crew. But in the spirit of the Apollo Applications Project, and Russian incremental improvements on reliable hardware to sustain a near constant human presence in space, this post is meant to propose a few incremental improvements to make on Orion-System hardware for a constant American presence in space for decades to come!

My first thought was to make a little more room, with an orbital module so if you're flying with 6 crew on LEO they don't get crowded up. The best (and most obvious) choice is basing it off Cygnus hardware, only with the propulsion bit chopped off, and replaced with whatever docking thing Orion uses. Surprisingly, standard Cygnus is only 1.5mt dry, but it almost triples the habitable volume of Orion! For 1.8mt enhanced Cygnus, you could almost quadruple the volume, but that is probably overkill.

The other improvement you can make to optimize for LEO activities is to empty those tanks! Orion has ~1.3km/s delta-vee full, and if we dump most of the fuel, you can cut the service module mass to around 5.337mt. Plus the capsule's 8.913mt, and the orbital module's 1.5mt is 15.75mt. That's under 20 metric tons! About twice the mass of Soyuz, for twice the crew capacity.

But System is too overpowered just to launch Orion onto LEO. My original thought was that you could make Slick System by removing the big Shuttle boosters and the Delta upper stage, and adding some Atlas SRMs (or Delta GEMs if they could easily be man-rated). But that still ends up being extremely overpowered. (admirably so, Slick System with 8 Atlas solids can launch 60 whole metric tons to LEO if you offload 29mt of the propellant!)

Then I realized 15.75mt was within the payload capacity of the (apparently man-rated) Atlas V rocket family. A likely option is Atlas V 541, which has plenty of margin in payload capacity (17.443mt) to carry the LAS some of the way. Plus, with the 5m diameter fairing, it just wants to launch Orion! There would be an adapter to fit Orion on the top of the fairing, and then they would do Apollo-style transposition, docking, and extraction with the Cygnus OM, which would be sitting attached to Centaur.

Here's a bad Photoshop I made of Orion plus Cygnus OM on orbit:

And here's a bad Photoshop I made of Orion on Atlas V 541:

Edited December 18, 2014 by Kibble
typo in essential mass figure

[xenomorph555]

Wait what's the point of putting Orion into LEO?

[Kibble]

Wait what's the point of putting Orion into LEO?

Oh just flying astronauts and stuff, anything where you just need to get people onto orbit. Like to Station or an assembled interplanetary spacecraft - an alternative to CCTCap for American access to human spaceflight.

[xenomorph555]

Oh just flying astronauts and stuff, anything where you just need to get people onto orbit. Like to Station or an assembled interplanetary spacecraft - an alternative to CCTCap for American access to human spaceflight.

Oh I see, I don't think a orbital module would be necessary since astronauts should be able to deal with worse (gemini 7) and it would only be for a day at most in Orion before it arrives at the station or interplanetary stack. Maybe lunar though!

[Kibble]

Oh I see, I don't think a orbital module would be necessary since astronauts should be able to deal with worse (gemini 7) and it would only be for a day at most in Orion before it arrives at the station or interplanetary stack. Maybe lunar though!

Well there's little reason not to add one, with that lovely Cygnus hardware sitting underutilized and the extra capacity of Atlas V 541 (531 probably doesn't have enough margin to launch Orion, even without Cygnus OM), plus Gemini VII should not be the precedent we base our astronaut's comfort on! I also imagine it would have the toilet and extra supplies and room for six astronauts (IIRC for BEO it carries a nominal 0-4 astronauts) for a few days. Wait does Orion have a toilet?

Anyway we should totes build on Cygnus hardware, the OM might even lead to development of a nice Cygnus-derived Lunar Module ascent stage

[magnemoe]

Oh I see, I don't think a orbital module would be necessary since astronauts should be able to deal with worse (gemini 7) and it would only be for a day at most in Orion before it arrives at the station or interplanetary stack. Maybe lunar though!

Might be an idea for the future asteroid mission, however how will this affect an launch abort?

[Kibble]

Might be an idea for the future asteroid mission, however how will this affect an launch abort?

The OM would be attached to the Centaur, below Orion, like Apollo LM attached to S-IVB below CSM - it would be completely out of the way in case of a launch abort.

[Nibb31]

Oh just flying astronauts and stuff, anything where you just need to get people onto orbit. Like to Station or an assembled interplanetary spacecraft - an alternative to CCTCap for American access to human spaceflight.

Orion is too expensive to waste on launching it to LEO, and sticking an Orbital module on the front is a no go because of the LAS.

For LEO, I'd rather see a Dragon with a hab module in the trunk. It could be something inflatable, like BEAM, but with an IDS docking port instead of a CBM.

However, if you really want to use Cygnus, there's nothing stopping you from docking with one on orbit or carrying up a Cygnus-based hab module in the cargo area of the SLS, although I would go with something closer to an MPLM than Cygnus.

Something like this would extend Orion's 21-day limit for a circumlunar or EML flight, but there really isn't much point. Orion can handle 21 days, which is ample time to do whatever needs doing in lunar orbit without landing, and this isn't suitable for a really lond duration flight like a Mars or Venus flyby.

Edited December 17, 2014 by Nibb31

[xenomorph555]

Might be an idea for the future asteroid mission, however how will this affect an launch abort?

Actually a Cygnus based mini station at the asteroid is a proposal by Boeing.

[Kibble]

Orion is too expensive to waste on launching it to LEO, and sticking an Orbital module on the front is a no go because of the LAS.

Orion can't be too much more expensive than any other spacecraft though, right? I guess we'll see once it starts flying. Also I mentioned the orbital module would be stowed on Centaur below Orion, and there would be a transposition/docking/extraction maneuver.

For LEO, I'd rather see a Dragon with a hab module in the trunk. It could be something inflatable, like BEAM, but with an IDS docking port instead of a CBM.

That's a good idea! Stow a OM in the trunk, and T/D/E on orbit. I'm not that fond of Dragon though, sticking everything but the solar panels in the capsule means you gotta heat-shield it all which makes it a lot heavier than it has to be. I'm also not that fond of inflatables, I think they are overhyped. In almost all other cases you are better off with a standard tin can, because while an inflatable gives you a bunch of empty space, you can't launch it with any supplies or anything at all. And launching a tin can Skylab-style can probably get you at least 2/3 the habitable volume, without having all the supplies and racks on a separate launch.

In fact I never thought of it before, but Dragon's trunk functions a lot like the Apollo adapter fairing on Saturn V and Saturn IB! Maybe a stretched trunk could stow a Lunar lander...<3

Something like this would extend Orion's 21-day limit for a circumlunar or EML flight, but there really isn't much point. Orion can handle 21 days, which is ample time to do whatever needs doing in lunar orbit without landing, and this isn't suitable for a really lond duration flight like a Mars or Venus flyby.

Really, 21 days? For how many astronauts?

[Nibb31]

Orion can't be too much more expensive than any other spacecraft though, right? I guess we'll see once it starts flying. Also I mentioned the orbital module would be stowed on Centaur below Orion, and there would be a transposition/docking/extraction maneuver.

Orion is MUCH more expensive than the Commercial Crew vehicles. It is not reusable, and each vehicle costs approximately $500 million. It can only be launched on SLS, which also costs $500 million, because no other rocket is man-rated. That is why NASA can only afford to launch 0.5 mission per year.

CST-100 and Dragon are going to cost NASA around $150 to $200 million for each launch.

Centaur isn't man-rated. Delta IV Heavy was big enough to launch Orion EFT-1 unmanned, but it also isn't man-rated, so it can't be used for manned flights either. Atlas V will be man rated for CST-100, but it's not big enough to launch an Orion with any sort of mission module. Falcon Heavy could do the job.

That's a good idea! Stow a OM in the trunk, and T/D/E on orbit. I'm not that fond of Dragon though, sticking everything but the solar panels in the capsule means you gotta heat-shield it all which makes it a lot heavier than it has to be.

If you use Orion for LEO, it's also a lot heavier than it needs to be. It's much heavier and larger than Dragon.

In fact I never thought of it before, but Dragon's trunk functions a lot like the Apollo adapter fairing on Saturn V and Saturn IB! Maybe a stretched trunk could stow a Lunar lander...<3

The trunk is unpressurized volume, but it is limited by mass. It would need to be a very small lander.

But really, what is the mission profile you are looking to fulfill here? It seems like you are starting with the hardware and then trying to find something to do with it. What you need is a mission, and then figure out a way to use what you have, or design what you need, to do that mission.

Really, 21 days? For how many astronauts?

Orion is designed to support an active crew of 4 for 21 days. It can be powered down and stay quiescent for 6 months attached to another vehicle. By itself, it's enough to do a circumlunar or EML flight or a trip to a NEO.

Edited December 17, 2014 by Nibb31

[xenomorph555]

In fact I never thought of it before, but Dragon's trunk functions a lot like the Apollo adapter fairing on Saturn V and Saturn IB! Maybe a stretched trunk could stow a Lunar lander...<3

Really, 21 days? For how many astronauts?

4, Soyuz can also do 21 days for 3.

Actually strangely a Dragon trunk could store an LK lander.

[Kibble]

Orion is MUCH more expensive than the Commercial Crew vehicles. It is not reusable, and each vehicle costs approximately $500 million. It can only be launched on SLS, which also costs $500 million, because no other rocket is man-rated. That is why NASA can only afford to launch 0.5 mission per year.

CST-100 and Dragon are going to cost NASA around $150 to $200 million for each launch.

You mean like one Orion vehicle costs 500 million, but an entire flight of CST-100 or Dragon V2 only costs 200 million? That seems hard to believe.

Centaur isn't man-rated. Delta IV Heavy was big enough to launch Orion EFT-1 unmanned, but it also isn't man-rated, so it can't be used for manned flights either. Atlas V will be man rated for CST-100, but it's not big enough to launch an Orion with any sort of mission module. Falcon Heavy could do the job.

Oh I was under the impression that Atlas V was already man-rated and that's why CST-100 (and formerly Dream Chaser) were going to launch on it. Either way once it is man-rated, the 541 (5m payload faring, 4 SRMs, Single-engine Centaur) could do the job.

If you use Orion for LEO, it's also a lot heavier than it needs to be. It's much heavier and larger than Dragon.

I haven't been able to find any figure's for Dragon V2's mass.

But really, what is the mission profile you are looking to fulfill here? It seems like you are starting with the hardware and then trying to find something to do with it. What you need is a mission, and then figure out a way to use what you have, or design what you need, to do that mission.

The point is to have a flexible set of in-production hardware that you could use for a variety of missions. Like a Cygnus OM could evolve into a LM ascent stage, which could evolve into a FlexCraft-like thing or something. Because you can have a great spacecraft on a Powerpoint, but the spacecraft that will fly, is the one already flying. With Orion flying, it should be a priority to find stuff to do with it, and incremental ways to improve it.

Actually strangely a Dragon trunk could store an LK lander.

That's super awesome! :3

If only that configuration could fly someday...

Edited December 17, 2014 by Kibble
incorrect quoting

[xenomorph555]

You mean like one Orion vehicle costs 500 million, but an entire flight of CST-100 or Dragon V2 only costs 200 million? That seems hard to believe.

That's super awesome! :3

If only that configuration could fly someday...

1. He's telling the truth, Orion is a super sophisticated vehicle that is built one at at time with one completed every 2-3 years. Dragon (I leave out the V2 since it really ruins the name) and CST-100 are much less sophisticated crafts that are mass produced by a less precise production line. Adding to that the rockets are very cheap (50 million for F9).

2. Unfortunately the Dragon could never engage with an LK because Dragon cannot do EVA's. One of the reasons it's less sophisticated.

[Kibble]

2. Unfortunately the Dragon could never engage with an LK because Dragon cannot do EVA's. One of the reasons it's less sophisticated.

Right. But Orion can't do EVA either can it? I mean, unless it carried space suits for all the astronauts. (Another benefit for having OM!)

EDIT : Oh right, you don't need full EVA spacesuits for all the astronauts, they can just wear their partial pressure suits that they'd have anyway, depressurize, open the hatch for EVA, quickly close up the hatch and repressurize. Still harder than just using an OM for spacewalks though.

Edited December 17, 2014 by Kibble
i was being dumb

[Nibb31]

Right. But Orion can't do EVA either can it? I mean, unless it carried space suits for all the astronauts. (Another benefit for having OM!)

Orion can be depressurized for EVAs like Apollo. The commercial crew vehicles don't have that capability.