ATK push for US space flight independence via Liberty

[Chris Bergin]

Chris, in that case what is the appropriate way to discuss worries about the design and potential ways to address those concerns? Either from the perspective of an armchair (or actual) engineer, or a taxpayer who would be funding this hypothetical project.

Sure. Make it an educated and interesting post. You can see MANY of them on this thread.

Problem is there's also a few "Elon didn't invent it, so it sucks" or "It looks like Ares 1, uh oh!" posts too. That's my problem and also problem that whenever I try to keep the noise down, someone's always going to come out with the "oh, so you don't want negative posts then", which fraks me off.

[RyanC]

I always love these Liberty/Ares I threads. They're so fun.

The issue it always seemed to me with Ares I/Liberty was the inherent mass issues involved with solids.

Everything was fixable, from Max Q abort gee force issues, oscillation issues, to the "cloud of burning solids" from a worst case motor explosion.

The problem was the fixes impacted a system that wasn't well suited to handling inevitable weight growth, due to the use of the SRM, which could not be 'goosed' up the way a liquid system could.

The only thing in the stack that could be reduced in weight was Orion...hence the heavy pace of re-designs to Orion to lighten it or change this or that, so that the Ares I stack could still meet it's orbital parameter requirements.

[Downix]

I always love these Liberty/Ares I threads. They're so fun.

The issue it always seemed to me with Ares I/Liberty was the inherent mass issues involved with solids.

Everything was fixable, from Max Q abort gee force issues, oscillation issues, to the "cloud of burning solids" from a worst case motor explosion.

The problem was the fixes impacted a system that wasn't well suited to handling inevitable weight growth, due to the use of the SRM, which could not be 'goosed' up the way a liquid system could.

The only thing in the stack that could be reduced in weight was Orion...hence the heavy pace of re-designs to Orion to lighten it or change this or that, so that the Ares I stack could still meet it's orbital parameter requirements.

*applaudes* You win the cupie doll!

You are quite correct. That Orion is not married to Liberty is the main reason I am not as concerned. A LEO capsule based on the composite pressure vessel can work on such a vehicle.

[neilh]

Chris, in that case what is the appropriate way to discuss worries about the design and potential ways to address those concerns? Either from the perspective of an armchair (or actual) engineer, or a taxpayer who would be funding this hypothetical project.

Sure. Make it an educated and interesting post. You can see MANY of them on this thread.

Problem is there's also a few "Elon didn't invent it, so it sucks" or "It looks like Ares 1, uh oh!" posts too. That's my problem and also problem that whenever I try to keep the noise down, someone's always going to come out with the "oh, so you don't want negative posts then", which fraks me off.

That's sensible, thanks.

[joek]

That Orion is not married to Liberty is the main reason I am not as concerned. A LEO capsule based on the composite pressure vessel can work on such a vehicle.

The link between whatever ATK is proposing for the Liberty spacecraft, and CCM and its benefits(?) still seems murky to me.  Just because it's composite doesn't appear to make it better, only different. (Which may be enough of a reasn?)  From Composite Crew Module: Primary Structure, NASA/TM-2011-217185, Nov 2011:

Near the end of the manufacturing development phase, the team worked with experts from the Orion project to identify implementation issues associated with switching the Orion primary structure from their aluminum-lithium (Al-Li) baseline to the composite system. There were no mass or cost benefits identified to warrant the switch, and cost and schedule risk were increased for the Orion project, thus it was decided that Orion would remain with the Al-Li baseline.

Granted a lot of stuff inside and out of the crew module that Orion carries could presumably be reduced for LEO-only.  But that would also presumably apply regardless of whether they use a composite crew module?  So what does CCM bring to the table?


edit: crew module, not pressure vessel

[Jim]

Everything was fixable, from Max Q abort gee force issues, oscillation issues, to the "cloud of burning solids" from a worst case motor explosion.

Not fixable and maintain projected performance, which is the same as not launching.

[RyanC]

There is performance growth, substantial growth, in the segmented solids, which could be realized by moving to composite booster casings.

At that point, it's a totally new system, and not "shuttle heritage", which is the real tripping point theologically.

[Go4TLI]

There is performance growth, substantial growth, in the segmented solids, which could be realized by moving to composite booster casings.

At that point, it's a totally new system, and not "shuttle heritage", which is the real tripping point theologically.

There is shuttle heritage in some of the systems.  Besides, the whole "shuttle heritage" is a moment in time now past due to strategic mistakes and poor leadership.

That does not mean some systems, components, etc cannot still taken advantage of. 

[spectre9]

If you want to arm wave my posts please provide reasons.

Why doesn't being competent in composites help ATK build CCM?

Why is a long skinny rocket so bad?

Why will there be little to no commonality with Orion?

I'm still not understanding.

You think the answers will come but no just stubborn posters and their +1s 

[Prober]

That Orion is not married to Liberty is the main reason I am not as concerned. A LEO capsule based on the composite pressure vessel can work on such a vehicle.

The link between whatever ATK is proposing for the Liberty spacecraft, and CCM and its benefits(?) still seems murky to me.  Just because it's composite doesn't appear to make it better, only different. (Which may be enough of a reasn?)  From Composite Crew Module: Primary Structure, NASA/TM-2011-217185, Nov 2011:

Near the end of the manufacturing development phase, the team worked with experts from the Orion project to identify implementation issues associated with switching the Orion primary structure from their aluminum-lithium (Al-Li) baseline to the composite system. There were no mass or cost benefits identified to warrant the switch, and cost and schedule risk were increased for the Orion project, thus it was decided that Orion would remain with the Al-Li baseline.

Granted a lot of stuff inside and out of the crew module that Orion carries could presumably be reduced for LEO-only.  But that would also presumably apply regardless of whether they use a composite crew module?  So what does CCM bring to the table?


edit: crew module, not pressure vessel

the CCM a research tool for new technology.   Future real world weight savings etc come out of composites.

[Jim]

Why is a long skinny rocket so bad?

control issues, a less skinny rocket is better

[joek]

the CCM a research tool for new technology.   Future real world weight savings etc come out of composites.

I got that it's research and may pay dividends in the future.  So what is the relevance of that "future real world weight savings" to the  Liberty-CCM-whatever CCiCap entry,  for which much of the rationale appears based on "heritage" and which, by all appearances, is based more on the here-and-now?

If as stated there is "no mass or cost benefits", then why bother?  Why not go with something more mundane and proven closer to a box-stock Orion?  Or are you asserting that ATK has found significant mass or cost benefits where the CCM project did not?  And that they can leverage those benefits without significant risk vs. the other CCiCap contenders?  If so, on what is the assertion based?

[spectre9]

Why is a long skinny rocket so bad?

control issues, a less skinny rocket is better

Thanks Jim will look into this.

[QuantumG]

Problem is there's also a few "Elon didn't invent it, so it sucks" or "It looks like Ares 1, uh oh!" posts too. That's my problem and also problem that whenever I try to keep the noise down, someone's always going to come out with the "oh, so you don't want negative posts then", which fraks me off.

My memory doesn't go back that far, so can your remind me: did you make comments like this back in the DIRECT days when every second comment was about how much Ares-1 is a window maker and anyone who advocates for it is Dr Death?

Cause it seems a lot of opinions were formed back then that will never be shaken. (not even with the full acoustic load of an SRB).

[Downix]

That Orion is not married to Liberty is the main reason I am not as concerned. A LEO capsule based on the composite pressure vessel can work on such a vehicle.

The link between whatever ATK is proposing for the Liberty spacecraft, and CCM and its benefits(?) still seems murky to me.  Just because it's composite doesn't appear to make it better, only different. (Which may be enough of a reasn?)  From Composite Crew Module: Primary Structure, NASA/TM-2011-217185, Nov 2011:

Near the end of the manufacturing development phase, the team worked with experts from the Orion project to identify implementation issues associated with switching the Orion primary structure from their aluminum-lithium (Al-Li) baseline to the composite system. There were no mass or cost benefits identified to warrant the switch, and cost and schedule risk were increased for the Orion project, thus it was decided that Orion would remain with the Al-Li baseline.

Granted a lot of stuff inside and out of the crew module that Orion carries could presumably be reduced for LEO-only.  But that would also presumably apply regardless of whether they use a composite crew module?  So what does CCM bring to the table?


edit: crew module, not pressure vessel

Orion's weight is mostly the propellant needed for a lunar mission. Liberty is LEO only, no need for such a powerful, and heavy solution.

[Mark Max Q]

Problem is there's also a few "Elon didn't invent it, so it sucks" or "It looks like Ares 1, uh oh!" posts too. That's my problem and also problem that whenever I try to keep the noise down, someone's always going to come out with the "oh, so you don't want negative posts then", which fraks me off.

My memory doesn't go back that far, so can your remind me: did you make comments like this back in the DIRECT days when every second comment was about how much Ares-1 is a window maker and anyone who advocates for it is Dr Death?

Cause it seems a lot of opinions were formed back then that will never be shaken. (not even with the full acoustic load of an SRB).

Chris himself said his opinion was negative of Ares 1, but reported it fairly. Remember, this site was one of the first, I think in tag team with the Orlando Sentinel on the NASA documentation showing that was heading into bad times, but this site also reported the attempts to correct the problems. I'm sure if Liberty has development issues, he'll be all over it.

I remember he actually stayed off the DIRECT threads. Said it was OK for Ross and the DIRECT people to use the threads as a discussion tool, but seemed wary to "support" a rebel group to NASA. I think he only ever wrote two articles on DIRECT.

So he's pretty consistent!

[Jason Davies]

It's a fair point from QG about people having Ares 1 overshadow things, but it isn't exactly the same vehicle and it's right people should give it a chance. And as Mark says, if there's problems, Chris will be on it. He didn't shy away from Shuttle problems and he loves those orbiters!

I can see what he's trying to do on this thread, keep the debate clean. That's always been the drive on here.

[joek]

Orion's weight is mostly the propellant needed for a lunar mission. Liberty is LEO only, no need for such a powerful, and heavy solution.

No it's not; the CM+SM weight is primarily a function of the SM loading (with some additional CM).  There was a "light" LEO/ISS-Orion configuration once-upon-a-time.  So how does Liberty's spacecraft configuration differ substantively from previous Orion LEO-ISS configurations?  Again, why use a CCM if there is "no mass or cost savings"?  Again, what substantively differentiates the Liberty CM from the Orion CM?

[Go4TLI]

Orion's weight is mostly the propellant needed for a lunar mission. Liberty is LEO only, no need for such a powerful, and heavy solution.

No it's not; the CM+SM weight is primarily a function of the SM loading (with some additional CM).  There was a "light" LEO/ISS-Orion configuration once-upon-a-time.  So how does Liberty's spacecraft configuration differ substantively from previous Orion LEO-ISS configurations?  Again, why use a CCM if there is "no mass or cost savings"?  Again, what substantively differentiates the Liberty CM from the Orion CM?

What do you want? 

Here are some points:

1.  A substantial amount of Orion's weight is prop
2.  A composite crew module will offer a mass savings over a traditional aluminum module
3. Why ATK chose that is up to them and likely proprietary but it could have to do with so they could also offer the MPLM-like capability
4. The exact differences are again internal to ATK and LM and people here are not owed knowing those details

On a completely speculative front from my perspective, anyone from ATK, LM, etc would likely be turned off from coming here and saying anything more due to the rather hostile environment from people who think they know better about everything

[Jim]

2.  A composite crew module will offer a mass savings over a traditional aluminum module

Not true, it was found to have no substantial weight savings