Author Topic: Future LEO Taxi Concepts (Orion-lite, etc)  (Read 36802 times)

Offline gladiator1332

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #40 on: 06/03/2010 08:24 PM »
I believe: The companies would provide their own pilots. NASA's astronauts would be passengers.

But where are these pilots coming from? The most qualified pilots would be NASA astronauts.

Some have described commercial crew on here as "NASA buying a service", but in effect, are they not also buying the vehicle? So if they are "buying the vehicle" doesn't NASA have a say in who flies on it, and who does the training? It doesn't really have to be a big shakeup in how NASA does things.

Why does commercial crew have to any different then how things were done in the early days of NASA...buying capsules from McDonnell and launching them on existing vehicles?
« Last Edit: 06/03/2010 08:25 PM by gladiator1332 »

Online Robotbeat

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #41 on: 06/03/2010 08:29 PM »
I believe: The companies would provide their own pilots. NASA's astronauts would be passengers.

But where are these pilots coming from? The most qualified pilots would be NASA astronauts.
You're right. Which is why a lot of the commercial pilots will be old NASA astronauts.

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Some have described commercial crew on here as "NASA buying a service", but in effect, are they not also buying the vehicle?
No, they aren't buying the vehicle. The vehicle belongs to SpaceX.
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Offline mmeijeri

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #42 on: 06/03/2010 08:31 PM »
Look, we have Orion well along in development. Do we want to go exploring, or not?

I thought you agreed the lander was the sticking point.

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NASA needs to focus on building BEO spacecraft. Orion is one of those.

Yes, but it has a lot of synergy with commercial crew taxis and a lot of potential to get in their way. The same is not true for a lander - not yet.

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While I support commercial crew, at some point, it makes sense to use what you've got. We just about have our BEO capsule: Orion.

Under my proposal there is no reason why the eventual beyond LEO capsule couldn't be based on the currently gestating Orion if LM decides to enter the commercial crew taxi competition. It would just take a bit longer, since any work on a beyond LEO capsule would be put on hold until after completion of a commercial LEO capsule and until after completion of an Altair precursor - with the Altair based on Orion. The flip side of that is that Altair would be completed sooner - and completed at all.

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I don't think it makes sense to make a lander based off of Orion. Orion is too massive a design. It might make some sense if you are doing direct-ascent (instead of LOR or EOR), but that architecture is dead and buried and decomposed entirely. As it should be.

I disagree. I think Orion is perfect. There would have been a lot of commonality between Orion and the Altair ascent stage. What I'm thinking of is transforming it into a dual thrust axis reusable lander with a disposable crasher stage as we've discussed (and agreed I think) before. It wouldn't need a heat shield, and again that could be spun off if it's far enough along to be useful.

The Orion team could be kept together, JSC could stay in the spacecraft business, NASA could own beyond LEO spacecraft, LM could keep a modified Orion contract, LM would be free to enter the commercial crew taxi competition, the eventual beyond LEO capsule would be just as capable as the currently planned Orion and could even be based on it but would have more synergy, all useful work to date would be preserved, commercial synergy would be maximised and we'd be doing exploration sooner. What's not to like?
« Last Edit: 06/03/2010 08:34 PM by mmeijeri »
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Online Robotbeat

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #43 on: 06/03/2010 08:36 PM »
I actually think a lander like the JPL MobiLander would be a better fit for early missions.

Ideally, later you would have a smaller lander for crew rotation and base resupply, just the size of the tiny ascent module for the Mobilander, but with additional propellant for terminal descent, small legs, and a(n) (un)crasher descent stage, of course.
« Last Edit: 06/03/2010 08:37 PM by Robotbeat »
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Offline pathfinder_01

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #44 on: 06/03/2010 08:49 PM »
The over-riding advantage of designing a vehicle to fit the "LEO Taxi" role comes from having high confidence that there will be many LEO taxi missions into the foreseeable future, and that the requirements for those missions will be essentially the same.

Longer term, adding BEO capabilities to an existing LEO taxi design might be the most efficient way to get a BEO spacecraft, but even the best designers sometimes have difficulty avoiding the traps inherent in "feature creep" situations.

Given the state of the aerospace engineering art, I personally hope development of the LM Orion BEO exploration vehicle is continued with as little distraction as possible.  I also hope the same for development of the Dragon LEO taxi.  Separate mission types; separate requirements; separate, focused efforts.

Actually without the crew rescue version Orion is much harder to justify. There are no immediate plans for BEO exploration, so why build it now? It would have no where to go. The crew rescue  version has immediate use today while allowing for a growth that is compatable with BEO exploration. Longer shelf life is useful to both the ISS and long term deep space missions(like Mars, NEO, even keeping a return craft in orbit of the moon for use of a moon base). Basically the choice isnít between CRV and BEO Orion. The choice is between CRV Orion or no Orion.

Offline pathfinder_01

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #45 on: 06/03/2010 09:00 PM »
I believe: The companies would provide their own pilots. NASA's astronauts would be passengers.

But where are these pilots coming from? The most qualified pilots would be NASA astronauts.

Some have described commercial crew on here as "NASA buying a service", but in effect, are they not also buying the vehicle? So if they are "buying the vehicle" doesn't NASA have a say in who flies on it, and who does the training? It doesn't really have to be a big shakeup in how NASA does things.

Why does commercial crew have to any different then how things were done in the early days of NASA...buying capsules from McDonnell and launching them on existing vehicles?



No they are just buying a service. The taxis remain property of their owners and the only reason to use current NASA astronauts as pilots would be political.  In its purest form NASA would train it's astronauts for ISS missions and commercial crew its pilots and passengers.

Offline space_dreamer

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #46 on: 06/03/2010 09:18 PM »
A re-usable two stage space plane system would get my vote. Some thing like this-

http://www.bristolspaceplanes.com/projects/spacecab.shtml


Offline gladiator1332

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #47 on: 06/03/2010 10:02 PM »
I believe: The companies would provide their own pilots. NASA's astronauts would be passengers.

But where are these pilots coming from? The most qualified pilots would be NASA astronauts.

Some have described commercial crew on here as "NASA buying a service", but in effect, are they not also buying the vehicle? So if they are "buying the vehicle" doesn't NASA have a say in who flies on it, and who does the training? It doesn't really have to be a big shakeup in how NASA does things.

Why does commercial crew have to any different then how things were done in the early days of NASA...buying capsules from McDonnell and launching them on existing vehicles?



No they are just buying a service. The taxis remain property of their owners and the only reason to use current NASA astronauts as pilots would be political.  In its purest form NASA would train it's astronauts for ISS missions and commercial crew its pilots and passengers.

Is this similar to what we already do with the Russians? NASA trains them for the ISS mission, then they go to Russia to train for the Soyuz.

Offline sdsds

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #48 on: 06/03/2010 11:40 PM »
I personally hope development of the LM Orion BEO exploration vehicle is continued with as little distraction as possible.

Actually without the crew rescue version Orion is much harder to justify. There are no immediate plans for BEO exploration

Nor could Orion be available in time if there were "immediate plans" for BEO exploration.

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so why build it now?

So that it can be used, with good confidence, for the kinds of BEO missions with which NASA expects to be tasked, e.g. visiting a near-Earth object.  It will take time to develop a spacecraft appropriate for that task.  We're already late in the development of one!

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The crew rescue  version has immediate use today

Not really "today", because there are no commercial crew taxis today, and Soyuz provides its own rescue capability.  But we are nonetheless more or less agreed:  the CRV path works so long as the goal (a BEO spacecraft) doesn't get lost.

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The choice is between CRV Orion or no Orion.

Well, actually, "No."  Congress has a wide range of options as regards the future of Orion.  Limiting the choice to the President's Feb 1 proposal and his Apr 15 proposal would be artificially constraining.
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Offline Lobo

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #49 on: 06/06/2010 06:07 AM »
I don't see why a spacecraft like Dragon couldn't work for BEO if it needed to. Sure, it'd need modifications.

But it's besides the point. If FY2011 now includes CRV Orion with the stated intent of using it in another revision for BEO.

And an HLV is not required for BEO exploration with Earth-orbit rendezvous. In-orbit refueling makes an HLV even more optional.

There ain't no HLV big enough to launch a conventional round heatshield big enough for more than 20 tons to the surface of Mars, so an HLV doesn't fix Martian EDL, either.

And IMHO, the fixed costs of the VAB and LC-39 are an anchor around NASA's neck when it comes to BEO HSF.

A Mars landing would likely use some type of Aeroshell that would fit just fine on a Jupiter rather than that a round heatshield.

Dragon -could- possibly be used for BLEO, but I've seen not plans to do so.

Your other points are valid, but debatable.

Offline Lobo

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #50 on: 06/06/2010 06:13 AM »
Okay, I actually really like the current plan the way it is now (i.e. lifeboat Orion and commercial crew to ISS), because it could allow ISS-rendezvous-based BEO exploration. That's just cool. I don't know if it's the best way to do it, but it's just cool to me. Since at the minimum there will be two ways to get to ISS (i.e. commercial crew and Soyuz), a stand-down of a man-rated launch vehicle won't necessarily stop any exploration effort.

Also, it allows easy shake-down missions that can test BEO exploration hardware while docked to the ISS.

Plus, there are lots of prop tankers already flown to the ISS, 5 in 2009. We already know how the Russians do it.

We can assemble the spacecraft at ISS, test all the systems, fix any issues, inspect with the Canadarm2, refuel, stock up for the trip, even go for a short cruise to some other orbit before coming back and refueling and doing another check-out of everything. Then, load the crew and depart without worrying about weather delays.

So cool. Doesn't require any Orion LAS systems or crew launch pad  or manned launch vehicle (other than commercial crew).

Probably wouldn't be able to deploy large solar sails or a nuclear reactor while attached to ISS, though.

As I understand, a lifeboat Orion would be stripped to the bone and have no BLEO capability.  Besides, you can't go joyriding in yor lifeboat, right?   So a lifeboat Orion will stay at the ISS unless needed as a lifeboat.

And since it'd stay there until needed, that means probably only on Orion would ever get built, maybe with a spare on the ground. That's it.

No, I don't like the current plan myself.  Not at all..

Offline Lobo

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #51 on: 06/06/2010 06:17 AM »
Look, we have Orion well along in development. Do we want to go exploring, or not?

NASA needs to focus on building BEO spacecraft. Orion is one of those.

While I support commercial crew, at some point, it makes sense to use what you've got. We just about have our BEO capsule: Orion.

I don't think it makes sense to make a lander based off of Orion. Orion is too massive a design. It might make some sense if you are doing direct-ascent (instead of LOR or EOR), but that architecture is dead and buried and decomposed entirely. As it should be.

Agreed.
I'd be good if a new lunar lander would also be designed to be upgraded for a Mars landing.  There's a lot of differences, but make what you can the same, with similar controls and hardware that you test on long duration on the moon before any Mars attempt is made.

Offline Lobo

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #52 on: 06/06/2010 06:26 AM »
The over-riding advantage of designing a vehicle to fit the "LEO Taxi" role comes from having high confidence that there will be many LEO taxi missions into the foreseeable future, and that the requirements for those missions will be essentially the same.

Longer term, adding BEO capabilities to an existing LEO taxi design might be the most efficient way to get a BEO spacecraft, but even the best designers sometimes have difficulty avoiding the traps inherent in "feature creep" situations.

Given the state of the aerospace engineering art, I personally hope development of the LM Orion BEO exploration vehicle is continued with as little distraction as possible.  I also hope the same for development of the Dragon LEO taxi.  Separate mission types; separate requirements; separate, focused efforts.

Actually without the crew rescue version Orion is much harder to justify. There are no immediate plans for BEO exploration, so why build it now? It would have no where to go. The crew rescue  version has immediate use today while allowing for a growth that is compatable with BEO exploration. Longer shelf life is useful to both the ISS and long term deep space missions(like Mars, NEO, even keeping a return craft in orbit of the moon for use of a moon base). Basically the choice isnít between CRV and BEO Orion. The choice is between CRV Orion or no Orion.

Not really, Orion is the successor to the shuttle, and it has long duration and BLEO capacibity.  You build in now and build Jupiter to launch it.  Jupiter would be ready before Orion anyway.

Lifeboat ORion could languish as just that, a lifeboat, forever.  Can it be upgraded to a full survice ORion?  I've heard others that say it'd be too hard.  A stripped down "Orion-Lite" would like not be able to ever become full-Orion. I'd assume it's the same for "Lifeboat-Orion".

NASA needs to get back into the exploration business, and they need a full version ORion to do it, and they already have a HLV, they just need to modify it some to make it inline and launch Orion.

Besides, you don't need a Lifeboat Orion.  Makes no sense.  The LEO taxis can just be rotated like Soyuz.  And if it holds at least 6 people like Dragon wold, you only need one to be there.

Offline Lobo

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #53 on: 06/06/2010 06:29 AM »
A re-usable two stage space plane system would get my vote. Some thing like this-

http://www.bristolspaceplanes.com/projects/spacecab.shtml



Refer to my post about capsule vs. spaceplane on the first page of this thread.

Offline butters

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #54 on: 06/06/2010 10:30 AM »
Elon Musk mentioned in the post-F9 press teleconference that the long-term plan for Dragon Crew is to retain the integrated abort system through reentry and use it for propulsive terminal landing on dry ground. 

It's unclear from his statement if such a landing would be similar to Soyuz or hopefully a little bit softer.  But a capsule that lands on dry ground and can be reused breaks the case for mid-air recovery and almost renders runway landing a frivolous luxury.

They deliver the spacecraft from Hawthorne to the Cape for launch and it lands at Edwards for reprocessing at Hawthorne.  That's an LEO taxi concept that makes sense to me.  If SpaceX can make that work, why do anything more complicated?

Offline Cog_in_the_machine

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #55 on: 06/06/2010 11:09 AM »
A small reusable spaceplane has advantages and disadvantages.
Pros:
Controlled landing to a precise targe LZ
Les expensive recover
REusability

Cons:
Less mass efficient
Heavier TPS
More complex geometry for the TPS
Launch issues (do you enclose it in a PLF?  Or have open?)
LAS problems.

Capsule
Pros:
More mass efficient.
More simple geometry
Potentially reusable if a soft & dry landing system is implemented.
Easy to have a LAS
Easier to launch
Protected TPS in space

Cons:
Less sexy
More difficult to have a controlled descent after reentry
Poor pilot visibility for any type of controlled descent.

I scratched out two of the cons of capsules.
Controlled descent is unnecessary. Let's look at the shuttle: the only time humans have control is on orbit and the final stage of landing. Autopilots are superior to humans and they handle the hard stuff that's impossible for people, like ascent and reentry. I don't see why they can't handle every phase of the flight.

Not being "sexy" isn't a serious issue. And if it's really so important, I think that it makes sense to say rockets are sexier, since they're shaped like a certain body part *cough* :P

To paraphrase a certain someone: "gradually developing planes into spaceships, makes as much sense as gradually developing steam locomotives into airplanes"
^^ Warning! Contains opinions. ^^ 

Offline douglas100

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #56 on: 06/06/2010 01:02 PM »
From butters:

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Elon Musk mentioned in the post-F9 press teleconference that the long-term plan for Dragon Crew is to retain the integrated abort system through reentry and use it for propulsive terminal landing on dry ground.

Nice idea--in principle. I wonder how expensive it would be to develop to the level of safety needed for a manned vehicle?
Douglas Clark

Offline butters

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #57 on: 06/06/2010 08:54 PM »
From butters:

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Elon Musk mentioned in the post-F9 press teleconference that the long-term plan for Dragon Crew is to retain the integrated abort system through reentry and use it for propulsive terminal landing on dry ground.

Nice idea--in principle. I wonder how expensive it would be to develop to the level of safety needed for a manned vehicle?

Well, the abort system obviously has to be developed to a high level of safety in its capacity as an abort system in order to be certified under NASA human rating standards.

My understanding is that the abort system consists of pressure-fed hypergolic engines (like the Draco thrusters but considerably bigger).  The operation of this type of engine basically involves isolation valves and throttle valves.  The reliability of the engine may be approximated by the reliability of the valves.

Landing requires a different control strategy than abort separation.  Jon Goff would be the best person to answer questions about the difficulty of controlling a propulsive soft landing from parachute velocity.  I'd imagine the accuracy of the range/altitude sensors is one of the limiting factors.

The literature quotes Dragon splashdown velocity at <6.1m/s.  The latest Soyuz TMA lands "soft" at 1.4m/s on "three-mode" (step throttling?) solid rockets.  So one could assume that a reusable capsule should land a bit slower than that.  I'd imagine that 1m/s should be soft enough, and the throttle capability of the hypergolics should be significantly smoother than those solids.

Offline pathfinder_01

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #58 on: 06/06/2010 10:53 PM »


Not really, Orion is the successor to the shuttle, and it has long duration and BLEO capacibity.  You build in now and build Jupiter to launch it.  Jupiter would be ready before Orion anyway.

Ah depends on how one defines long duration and what one wants to do in that time. I would hate to spend 30+ days coped up in a capsule. You could build a habit module dock it with an propulsion unit. The habitat could have closed life support and the propulsion be refuelable. You could leave it parked it at a lagarine point or if aerocapture or solar electric tugs work up move it back to the ISS unmanned.

You then don't need a capsule with long term lifesupport. You now only need a capsule that can taxi you to and from it. The habit unit could have things orion does not have you know like robot arm, air locks. It could be reusable and it could simplify Orion(now it only needs 8 days of lifesupport and ability to be stored). This simplfied Orion could be cheaper than ORION BEO.

In addition Nasa needs heavy lift, esp shuttle derived heavy lift like an hole in the head. Too expensive to run. I think a little R/D and an heavy lift system that uses EELV facilties will be a better investment.

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Lifeboat ORion could languish as just that, a lifeboat, forever.  Can it be upgraded to a full survice ORion?  I've heard others that say it'd be too hard.  A stripped down "Orion-Lite" would like not be able to ever become full-Orion. I'd assume it's the same for "Lifeboat-Orion".

Orion lite is based on beoing's failed bid for the Orion system and would be built for LEO only. Orion CRV is based on LM winning bid. It would be gutted ofcourse, but it would be in a better position than anyone else depending on how much is taken out. I would expectthem to leave the heat sheild alone.

Lifeboat Orion has one thing in common with a BEO capsule the need for long term storage. Without this you are limited by how long your capsule systems are good for.

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NASA needs to get back into the exploration business, and they need a full version ORion to do it, and they already have a HLV, they just need to modify it some to make it inline and launch Orion.

Note quite. Direct would require new engine development, heavy modifcations of the shuttle fuel tanks and not reduce the cost substainly enough to allow BEO exploration.

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Besides, you don't need a Lifeboat Orion.  Makes no sense.  The LEO taxis can just be rotated like Soyuz.  And if it holds at least 6 people like Dragon wold, you only need one to be there.

Life boat Orion is the only Orion you are likely to see from LM. Having a capsule with long term storage helps make BEO(esp. mars) more possible. I am not opposed to CRV dragon, but if dragon is the CRV you don't need Orion at all. And BEO exploration is currently off the table. To me Lifeboat Orion is an investment because without it you are going to have to develop it from scrath(again) or heavly modify a LEO TAXI when we are ready do BEO exploration.

Offline neilh

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Re: Future LEO Taxi Concepts (Orion-lite, etc)
« Reply #59 on: 06/07/2010 01:23 AM »
The literature quotes Dragon splashdown velocity at <6.1m/s.  The latest Soyuz TMA lands "soft" at 1.4m/s on "three-mode" (step throttling?) solid rockets.  So one could assume that a reusable capsule should land a bit slower than that.  I'd imagine that 1m/s should be soft enough, and the throttle capability of the hypergolics should be significantly smoother than those solids.

Wouldn't there then be the problem of contaminating the landing site with toxic hydrazine?
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