gigneil
Posts: 14133
Joined: Fri Nov 08, 2002 10:25 am

House Forces Nasa To Launch AMS/Accelerate Orion

Tue Jun 17, 2008 9:08 pm

Thank whatever deity you want, but this year's NASA appropriation passed the House swimmingly last week.

$20.2 billion, $1b of which is intended to accelerate Orion development. Also, the bill requires NASA to fly the AMS to the station on a new Shuttle flight, and funds same.

http://www.hcnonline.com/site/news.c...=1574&PAG=461&dept_id=635585&rfi=6

NS
 
Sinlock
Posts: 1631
Joined: Fri Dec 22, 2000 12:55 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Tue Jun 17, 2008 10:07 pm

Thats great news! Very glad to hear that AMS will fly even with all the drama that surrounds it, it's still a nice and useful piece of equipment.
 
TheSonntag
Posts: 4296
Joined: Wed Jun 15, 2005 7:23 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Tue Jun 17, 2008 10:19 pm

Moon came a little bit closer again  Wink

To me, it seems they want to get Orion so much underway that Obama cannot cancel it...
 
gigneil
Posts: 14133
Joined: Fri Nov 08, 2002 10:25 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Tue Jun 17, 2008 10:32 pm



Quoting Sinlock (Reply 1):
Very glad to hear that AMS will fly even with all the drama that surrounds it, it's still a nice and useful piece of equipment.

Its also the single most expensive scientific experiment ever built, and we'd be stupid to not launch it.

Also in the bill: NASA is required to be prepared to support the station until 2020, rather than 2016.

NS
 
TheSonntag
Posts: 4296
Joined: Wed Jun 15, 2005 7:23 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Tue Jun 17, 2008 10:48 pm



Quoting Gigneil (Reply 3):
Also in the bill: NASA is required to be prepared to support the station until 2020, rather than 2016.

Which is no real surprise, because once it is up, it would be stupid to use it for only 6 years at full capacity... I just wonder how long the oldest, 1998 launched modules can be used without bigger issues.
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 1:02 am



Quoting Sinlock (Reply 1):
Thats great news! Very glad to hear that AMS will fly even with all the drama that surrounds it, it's still a nice and useful piece of equipment.

Don't celebrate yet. The Senate has to sign on as well. And they probably won't, at least not in the same form as the House bill. And then there is the little matter that the Columbia Accident Investigation Board found that the Shuttle needs to be "recertified at system and subsystem level" if NASA is to fly the Shuttle beyond 2010, a finding both NASA and the White House accepted in 2003.

Quoting TheSonntag (Reply 2):
Moon came a little bit closer again

Not really. The new money in the NASA budget in the House bill would just replace Shuttle funding that Constellation was planning on using in Fiscal Year 2011 after Shuttle retirement. Constellation needs the Shuttle's funding to really get going, any delay in retiring Shuttle results in a year-for-year delay in getting Constellation going. $2.5 billion, which is what the House bill added to the budget, won't accellerate Constellation, it will just prevent the year-for-year slip (and not even all of that, as the Shuttle's budget is closer to $3 billion.)

Right now, they have a fighting chance of getting STS-134 off before the end of Fiscal Year 2010, but only if no more delays hit the Shuttle program, but the Shuttle program has been hit with delay after delay these last few years.

Quoting Gigneil (Reply 3):
Its also the single most expensive scientific experiment ever built, and we'd be stupid to not launch it.

I guess you're not counting Voyager, Viking, Galileo, Cassini, Hubble, Chandra, etc. as "single" experiments? They all exceed AMS's $1.5 billion, some by huge margins (Hubble is well over $3 billion in today's dollars.)
 
TheSonntag
Posts: 4296
Joined: Wed Jun 15, 2005 7:23 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 11:48 am



Quoting Thorny (Reply 5):
Not really. The new money in the NASA budget in the House bill would just replace Shuttle funding that Constellation was planning on using in Fiscal Year 2011 after Shuttle retirement. Constellation needs the Shuttle's funding to really get going, any delay in retiring Shuttle results in a year-for-year delay in getting Constellation going. $2.5 billion, which is what the House bill added to the budget, won't accellerate Constellation, it will just prevent the year-for-year slip (and not even all of that, as the Shuttle's budget is closer to $3 billion.)

Ok I see your point, but the way the last Shuttle missions went, isn't it pretty likely that Shuttle will end as planned in 2010?
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 6:07 pm



Quoting TheSonntag (Reply 6):
isn't it pretty likely that Shuttle will end as planned in 2010?

The missions themselves are going well, thankfully. It is the "getting them ready for launch" that has been the bottleneck, primarily due to External Tank delays (first the ECO sensor fiasco and now botched manufacturing planning.) We might be through the worst of them, but right now, I'd say it is 50/50 that STS-133 gets off before September 30, 2010, nevermind squeezing in an STS-134.

The last schedule has 133 in April, 2010. I think that probably is delayed a month or two now, because STS-119 has slipped from December 2008 to February 2009 thanks to External Tank delays, and that delay isn't reflected in the rest of the launch dates. If 133 is now aiming toward June 2010, they still have three months contingency time.
 
Venus6971
Posts: 1415
Joined: Tue Dec 14, 2004 1:55 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 7:21 pm

Bring back the Saturn V to do the heavy lifting.
I would help you but it is not in the contract
 
User avatar
N328KF
Posts: 5807
Joined: Tue May 25, 2004 3:50 am

RE: House Forces Nasa To Launch AMS/Accelerate Ori

Wed Jun 18, 2008 7:33 pm

Quoting Venus6971 (Reply 8):
Bring back the Saturn V to do the heavy lifting.

You do know that Ares V (guess what the "V" is in reference to?) has a similar lift capability right?

http://en.wikipedia.org/wiki/Comparison_of_heavy_lift_launch_systems

It's too bad that we didn't have this sort of lift all along...the Saturn V or Ares V could have lofted ISS in a fraction of the number of launches.

[Edited 2008-06-18 12:40:38]
When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt
 
nomadd22
Posts: 1566
Joined: Fri Feb 22, 2008 7:42 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 7:36 pm

Couldn't one of the logistics or contingency missions be used to haul the AMS? I know there are some things that only the shuttle can handle, but racks and supplies could go via ATM.
What besides S6, Kibo's porch, Node 3 and maybe the Express logistics carriers couldn't go by anything but the shuttle?
Anon
 
dl021
Posts: 10836
Joined: Fri May 21, 2004 12:04 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 8:01 pm

At some point the unified space effort will have to start taking real precedence over national programs (outside of defence requirements) as we're going to have to start going off planet for resources and space eventually. The sooner we get started on that the less of an emergency it'll be when it becomes necessary rather than fantasy.
Is my Pan Am ticket to the moon still good?
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 8:13 pm



Quoting Venus6971 (Reply 8):
Bring back the Saturn V to do the heavy lifting.

That would cost more and take as much time as Ares V.

Quoting N328KF (Reply 9):
You do know that Ares V (guess what the "V" is in reference to?)

Nothing. It was tribute to Saturn I and Saturn V. Some say it meant number of engines in the first stage, but that seems like reaching to me.

Quoting Nomadd22 (Reply 10):
Couldn't one of the logistics or contingency missions be used to haul the AMS?

Not without sacrificing other things the ISS needs more critically, like spare parts.

Quoting Nomadd22 (Reply 10):
but racks and supplies could go via ATM

(I presume you mean ATV.) Supplies, yes. Racks, no.

Quoting Nomadd22 (Reply 10):
What besides S6, Kibo's porch, Node 3 and maybe the Express logistics carriers couldn't go by anything but the shuttle?

All the racks in the three MPLMs flying before Shuttle retirement. ATV can't deliver racks, as it docks at the smaller Russian port, too small and the wrong shape to fit a rack through. (HTV can, but is a lot smaller and won't fly until sometime in 2009 at the earliest.) Also, the US is obligated to deliver the racks for Columbus and Kibo. It isn't obligated to deliver AMS, which was the sad truth that caused NASA to cancel it.
 
User avatar
N328KF
Posts: 5807
Joined: Tue May 25, 2004 3:50 am

RE: House Forces Nasa To Launch AMS/Accelerate Ori

Wed Jun 18, 2008 8:24 pm

Quoting Thorny (Reply 12):
Nothing. It was tribute to Saturn I and Saturn V. Some say it meant number of engines in the first stage, but that seems like reaching to me.

That was my point -- that it was a tribute.

[Edited 2008-06-18 13:25:28]
When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt
 
TheSonntag
Posts: 4296
Joined: Wed Jun 15, 2005 7:23 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 8:32 pm

I always thought the last 2 contingency flights were never supposed to fly? Couldnt you use one of them for the AMS?
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 9:27 pm



Quoting TheSonntag (Reply 14):
I always thought the last 2 contingency flights were never supposed to fly? Couldnt you use one of them for the AMS?

They are contingency flights to refly cargo in the event one of the earlier missions is not successful (failure to rendezvous, dock, what-have-you) and are otherwise intended to launch spare parts that can't fly on Progress, ATV or HTV (large, unpressurized elements like CMGs.)
The two flights, STS-131 and STS-133, are carrying four Express pallets with unpressurized cargo. There isn't room for them and AMS.
 
Venus6971
Posts: 1415
Joined: Tue Dec 14, 2004 1:55 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Wed Jun 18, 2008 10:34 pm



Quoting N328KF (Reply 9):
You do know that Ares V (guess what the "V" is in reference to?) has a similar lift capability right?

Yes the new Constellation program is more or less Apollo on steroids, the main engines are more or less updated versions of the engines the Saturn V used but it takes a goverment program to mess up "if its not broken don't fix it", with todays computers a digital watch with a caculator has more ram than the Apollo Command module and Luner Lander.
I would help you but it is not in the contract
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Thu Jun 19, 2008 12:42 am



Quoting Venus6971 (Reply 16):
it takes a goverment program to mess up "if its not broken don't fix it", with todays computers a digital watch with a caculator has more ram than the Apollo Command module and Luner Lander.

Which is exactly why it would cost as much to simply rebuild Apollo and Saturn today. Nothing is built that way or with those components anymore, it would all have to be redesigned anyway.

We do have experience telling us this is true, see the Delta II and Atlas II programs... large rockets put back into production after many years absense. They both got the suffix "II" because they had to be redesigned to use contemporary subsystems and manufacturing techniques, because Convair and McDonnell-Douglas found that too many suppliers of the original equipment were out of the business and couldn't produce them anymore. See also the C-5B program, which is very different under the hood from the C-5A's. Atlas II, Delta II, and C-5B all went into production about ten years after the last of their predecessors left the factory.

It has been 39 years since Saturns were built.

Also, remember that Saturn was not an optimized launch vehicle, it was done under the program motto "waste anything but time" and there were a lot of shortcuts taken that drove up costs. The third stage, in particular, was a kludge... an imrpoved, re-engined S-IV stage from the Saturn 1 program, because there wasn't time to develop a TLI-optimized stage (alongside S-1C and S-II) before 1970.
 
User avatar
Revelation
Posts: 13761
Joined: Wed Feb 09, 2005 9:37 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Thu Jun 19, 2008 4:18 pm



Quoting TheSonntag (Reply 2):
To me, it seems they want to get Orion so much underway that Obama cannot cancel it...

I suppose, but Obama knows Florida is a swing state, and Florida sees NASA as its birthright, so Obama will be quiet about it at least for this year.

Quoting Thorny (Reply 5):
And then there is the little matter that the Columbia Accident Investigation Board found that the Shuttle needs to be "recertified at system and subsystem level" if NASA is to fly the Shuttle beyond 2010, a finding both NASA and the White House accepted in 2003.

That sucker will be pencil-whipped, if need be.

Quoting DL021 (Reply 11):
At some point the unified space effort will have to start taking real precedence over national programs (outside of defence requirements) as we're going to have to start going off planet for resources and space eventually.

Oh, come on now!

Quoting DL021 (Reply 11):
The sooner we get started on that the less of an emergency it'll be when it becomes necessary rather than fantasy.

It is fantasy. No one will vote to support such a thing till they are guaranteed a seat. And if you think it's easier to build an ecosystem that will support life on the moon or Mars, etc than to save the one we have now, I think you are very misguided.

I think the whole idea of migrating off the Earth gives people a free ticket to not worry about the Earth and its environment which is absurd to me. We know an awful lot of things we can do that would have impact in a small number of years, but we refuse to do them due to inertia. That is what has to change.

Yes, a metor strike could wipe out life as we know it any day, but that's just the chances we take.

Quoting Thorny (Reply 17):
We do have experience telling us this is true, see the Delta II and Atlas II programs... large rockets put back into production after many years absense. They both got the suffix "II" because they had to be redesigned to use contemporary subsystems and manufacturing techniques, because Convair and McDonnell-Douglas found that too many suppliers of the original equipment were out of the business and couldn't produce them anymore. See also the C-5B program, which is very different under the hood from the C-5A's. Atlas II, Delta II, and C-5B all went into production about ten years after the last of their predecessors left the factory.

What about the restart of U2 production during the Regan administration? Did Lockheed mothball enough of the technology so it could be produced without a lot of re-engineering?
Inspiration, move me brightly!
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Thu Jun 19, 2008 6:15 pm



Quoting Revelation (Reply 18):
What about the restart of U2 production during the Regan administration? Did Lockheed mothball enough of the technology so it could be produced without a lot of re-engineering?

Airframe and major structures, yes. The problem with restarts after so many years is getting all the subsystems back into production. We're seeing this argument now in favor of continuing F-22 and C-17 production.

I forgot about U-2R, that's another good one to look up.
 
PC12Fan
Posts: 1972
Joined: Sat Jan 27, 2007 11:50 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Thu Jun 19, 2008 10:53 pm



Quoting Thorny (Reply 12):
Quoting Venus6971 (Reply 8):
Bring back the Saturn V to do the heavy lifting.

That would cost more and take as much time as Ares V.

That and I believe the Saturn V design couldn't be expanded. The Ares V has some concepts that would be big enough (by volume) to carry payloads s big as the shuttle.

Check out the last page
Just when I think you've said the stupidest thing ever, you keep talkin'!
 
rwessel
Posts: 2448
Joined: Tue Jan 16, 2007 3:47 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 12:34 am



Quoting PC12Fan (Reply 20):
That and I believe the Saturn V design couldn't be expanded. The Ares V has some concepts that would be big enough (by volume) to carry payloads s big as the shuttle.

I don't know any reason you couldn't put an oversized payload shroud on an Saturn V. Certainly it would be trivial to put a 10.1m diameter stack on top of the S-II (loosing the third stage), although that would somewhat limit your mass to LTO (as it did with Skylab/S-V-INT21), so you might want to build a "wide" S-IVB. Or you could just pop the extra wide shroud on top of the S-IVB - although going from 6.7m to 12m would be a bit more than typical (for example, the Delta III's upper section was 4m, stacked on a 2.7m lower section, which was only 50% wider, not 80%).

And there were certainly growth variants of the S-V considered. Take a look at:

http://www.astronautix.com/lvfam/saturnv.htm

For example, the Saturn V-25(S)B concept, four big strap on solids, a stretched S-IC, a strengthened (but otherwise unchanged) S-II, and a stretched and strengthened S-IVB, for a total punt to LEO of 223,500kg(!!). Note it also has a 10.1m payload fairing.

http://www.astronautix.com/lvs/satv25sb.htm

Even the basic design was due for an upgrade with the next (expected) production run with improved performance F-1A engines (20% more thrust, 2% higher ISP).
 
Venus6971
Posts: 1415
Joined: Tue Dec 14, 2004 1:55 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 1:51 am



Quoting Rwessel (Reply 21):
Even the basic design was due for an upgrade with the next (expected) production run with improved performance F-1A engines (20% more thrust, 2% higher ISP).

great links, if they kept up the S-V25sb that monster could of had the ISS complete years ahead of a shuttle supplied system, it only took congress to really mess it up. This would have made a space telescope that is bigger than the hubble possible sooner.
I would help you but it is not in the contract
 
User avatar
N328KF
Posts: 5807
Joined: Tue May 25, 2004 3:50 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 2:03 am

Would it be possible to take Ares V and add more than two SRBs? I'm envisioning a monster similar to Vulkan-Energia here.
When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 2:30 am



Quoting Venus6971 (Reply 22):
great links, if they kept up the S-V25sb that monster could of had the ISS complete years ahead of a shuttle supplied system, it only took congress to really mess it up. This would have made a space telescope that is bigger than the hubble possible sooner.

The original Space Station would have been launched by a Saturn V variant and serviced by a much smaller Shuttle. Station modules were to be 33 feet in diameter, same as S-1C and S-II! Imagine that! We today look at films of SkyLab and think, "Wow, that's huge inside!" Kibo looks big empty, at 15 ft. in diameter.

When Apollo died, there were no other customers for Saturn V, and the Space Station program couldn't afford Saturn V on its own. The same is basically true today. The only customer for Ares V will be Constellation. No one else can afford that monster. There is vague talk of using Ares V to launch a reborn JIMO, but Ares is so expensive that there won't be any money leftover to build JIMO.

Quoting N328KF (Reply 23):
Would it be possible to take Ares V and add more than two SRBs?

No, the Crawler and Crawlerway can't handle that much weight.
 
User avatar
N328KF
Posts: 5807
Joined: Tue May 25, 2004 3:50 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 5:37 am



Quoting Thorny (Reply 24):
No, the Crawler and Crawlerway can't handle that much weight

I wasn't asking about those two systems...I was asking about the Ares stack.
When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt
 
rwessel
Posts: 2448
Joined: Tue Jan 16, 2007 3:47 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 6:06 am



Quoting N328KF (Reply 25):
I wasn't asking about those two systems...I was asking about the Ares stack.

It would require considerable reinforcing and changes to the first stage tank structure to provide the additional attach points, and you might need to reinforce some of the upper bits for the additional acceleration, and you'd need to modify the pad, but other than that, I don't see why not.

Nor is that sort of expansion unprecedented - consider the Titan III, which (optionally) added a pair of (very large) solids to the Titan II core. On the Titan IV, those grew to be even bigger than shuttle the SRBs, and became non-optional.

So sure, if you have the money to spend. And just on that basis, I'm going to give long odds that we ever see such a thing. For that matter, I'm not very confident we'll ever see the baseline Ares V.
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 2:52 pm



Quoting N328KF (Reply 25):
I wasn't asking about those two systems...I was asking about the Ares stack.

Okay. Well, it probably could be done, but it would be enormously expensive. You'd need all new launch infrastructure to assemble, move, and launch it. It is too heavy for Complex 39. The structure would have to be redesigned, with a "four way" SRB support beam through the intertank structure (currently a large, heavy beam connects the two SRBs through the Shuttle ET's intertank structure, and that's what carries all the weight of the Shuttle/ET stack.) By the time you did all this, you would probably be better off with a clean-sheet design that doesn't use solids. In other words, it would be time for a big liquid strap-on.

Quoting Rwessel (Reply 26):
Nor is that sort of expansion unprecedented - consider the Titan III, which (optionally) added a pair of (very large) solids to the Titan II core. On the Titan IV, those grew to be even bigger than shuttle the SRBs, and became non-optional.

No, only about 2/3 the size of the Shuttle SRB.

Shuttle SRB: 149 ft x 12.7 ft, 2.8 million pounds thrust at sea level.
Titan IV-B SRMU: 112 ft x 10 ft, 1.7 million pounds thrust at sea level.

And the Titan II core was heavily beefed up to support the SRMs. That's why it was called a Titan III instead of a Titan II. They're not the same under the hood.

Quoting Rwessel (Reply 26):
I don't see why not.

Because the infrastructure at KSC can't support it. Not the pads (overpressure from four SRBs firing at once), not the Crawler and Crawlerway you'd need to get this beast to the pad. The new 5 1/2 segment proposal for Ares V is already at the razor's edge of what the Crawler and river-rock Crawlerway can support.

Quoting Rwessel (Reply 26):
For that matter, I'm not very confident we'll ever see the baseline Ares V.

Same here. It will be dead and gone by this time next year. The new President won't be able to kill it fast enough, IMHO.
 
DfwRevolution
Posts: 8549
Joined: Sat Jan 09, 2010 7:31 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 4:40 pm



Quoting Rwessel (Reply 26):
It would require considerable reinforcing and changes to the first stage tank structure to provide the additional attach points, and you might need to reinforce some of the upper bits for the additional acceleration, and you'd need to modify the pad, but other than that, I don't see why not.

There is still the issue of exhaust interaction between the SRB and core stage. With an extra pair of SRB, the exhaust from the six RS-68s is unable to expand fully which effectively reduces the thrust of the core stage. Since the SRB are already low-ISP monsters, the payload you gain from a four SRB Ares V is shockingly low for the effort needed to fly that configuration.

It is a totally impractical means to boost the Ares V payload.
 
User avatar
N328KF
Posts: 5807
Joined: Tue May 25, 2004 3:50 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 4:47 pm



Quoting DfwRevolution (Reply 28):
It is a totally impractical means to boost the Ares V payload.

I can see that now. I was just hoping that it would be a cheap and affordable way to bring super heavy-lift to the US program.

Too bad about Vulkan-Energia then. Would have been handy.
When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt
 
norcal
Posts: 1507
Joined: Sun Mar 20, 2005 1:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 4:48 pm

I don't know much about the shuttle, but would it be that far fetched to fly it to the moon and orbit it a few times and then return home? Is it capable of carrying enough fuel to do that?

Might be a little bit of a publicity stunt, but it might get people excited about space exploration again if they showed streaming video (maybe HD?) on the network news stations for weeks on end.
 
User avatar
N328KF
Posts: 5807
Joined: Tue May 25, 2004 3:50 am

RE: House Forces Nasa To Launch AMS/Accelerate Ori

Fri Jun 20, 2008 5:06 pm



Quoting NorCal (Reply 30):
I don't know much about the shuttle, but would it be that far fetched to fly it to the moon and orbit it a few times and then return home? Is it capable of carrying enough fuel to do that?

Escaping a gravity well requires a tremendous amount of energy. In this case, you're escaping the surface, then escaping Earth orbit, slowing down to enter Lunar orbit, escaping Lunar orbit, then slowing down to re-enter Earth orbit. Quite an amount of energy. I do not know the amount of fuel that would be required though.
When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt
 
Thorny
Posts: 1508
Joined: Thu Jul 07, 2005 8:44 am

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 8:36 pm



Quoting NorCal (Reply 30):
I don't know much about the shuttle, but would it be that far fetched to fly it to the moon and orbit it a few times and then return home? Is it capable of carrying enough fuel to do that?

Going to to the moon is all about mass (weight.) The Shuttle weighs about twice what the Apollo Command/Service Module and Lunar Module stack weighed. Apollo needed a 200,000 lb. upper stage (the S-IVB) still nearly full to push out of Earth orbit toward the moon. The Shuttle would need somewhere around 400,000 lbs. of propellant to push out of Earth orbit. The Shuttle's maximum payload capacity is around 60,000 lbs.

Also, communications, thermal control, and re-entry heating on a lunar mission would be very different in the lunar environment. If you magically got enough fuel into orbit and came up with a re-startable Main Engine (which NASA has now abandoned for Ares) the Shuttle still wouldn't survive the trip. It just wasn't designed for that.
 
rwessel
Posts: 2448
Joined: Tue Jan 16, 2007 3:47 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Fri Jun 20, 2008 10:48 pm



Quoting Thorny (Reply 27):
No, only about 2/3 the size of the Shuttle SRB.

Shuttle SRB: 149 ft x 12.7 ft, 2.8 million pounds thrust at sea level.
Titan IV-B SRMU: 112 ft x 10 ft, 1.7 million pounds thrust at sea level.

My mistake - I was looking at a source that listed the total thrust for both boosters. Which oddly listed the Shuttle SRBs on an "each" basis.

Quoting Thorny (Reply 27):
And the Titan II core was heavily beefed up to support the SRMs. That's why it was called a Titan III instead of a Titan II. They're not the same under the hood.

Yes, I was citing the Titan as an example of where that sort of upgrade had happened.

Quoting DfwRevolution (Reply 28):
There is still the issue of exhaust interaction between the SRB and core stage. With an extra pair of SRB, the exhaust from the six RS-68s is unable to expand fully which effectively reduces the thrust of the core stage. Since the SRB are already low-ISP monsters, the payload you gain from a four SRB Ares V is shockingly low for the effort needed to fly that configuration.

Not so fast. There are a *lot* of interactions at that end of the rocket. Expansion is a bad thing - it means your exhaust bell is too small, and you're wasting energy. Not to say that there aren't technical reasons why you might put an undersized bell on a rocket (weight, size, varying atmospheric pressure during the flight, etc.) that may make it practical to accept a bit of inefficiency.

An if the exhaust from the four SRBs prevented the core exhaust for expanding for a while, you'd *increase* the efficiency of the core by providing a larger, albeit virtual, bell.

Nor would you necessarily run the core at full throttle in that configuration. Four SRBs by themselves would give a takeoff thrust of something like 11.2m pounds, or 14.5m total with the core (assuming the 5xRS-68 configuration). Heck, you could lift a heavier Ares V stack on just the (four) SRBs and not fire the core until the four solids burned about a couple minutes into the flight. In fact that's exactly what the Titan IV does. Or (more likely - since the liftoff would be a bit anemic with just the solids) you could throttle back the core until the boosters burn out - the Atlas V heavy configuration does just that - at lift off everything is running 100%, after 10 seconds, the core throttles back to 40% until the (liquid) boosters burn out.

And what does the ISP of the SRBs have to do with it? So long as they're lifting themselves with the desired acceleration, any left over thrust adds to the base vehicles effective launch thrust. The only way a higher ISP really helps is in reducing the size of the SRB needed to get a certain net effect (within reason - at some point the ISP is so low that you can't even lift the SRB off the pad). That's why the Delta-IV and Atlas V heavy configurations switch to liquid fueled boosters (repurposed cores in both cases) - the required solids would be just too big to be practical to develop and use.


Not so fast. There are a *lot* of interactions at that end of the rocket. Expansion is a bad thing - it means your exhaust bell is too small, and you're wasting energy. Not to say that there aren't technical reasons why you might put an undersized bell on a rocket (weight, size, varying atmospheric pressure during the flight, etc.) that may make it practical to accept a bit of inefficiency.

An if the exhaust from the four SRBs prevented the core exhaust for expanding for a while, you'd *increase* the efficiency of the core by providing a larger, albeit virtual, bell.

Nor would you necessarily run the core at full throttle in that configuration. Four SRBs by themselves would give a takeoff thrust of something like 11.2m pounds, or 14.5m total with the core (assuming the 5xRS-68 configuration). Heck, you could lift a heavier Ares V stack on just the (four) SRBs and not fire the core until the four solids burned about a couple minutes into the flight. In fact that's exactly what the Titan IV does. Or (more likely - since the liftoff would be a bit anemic with just the solids) you could throttle back the core until the boosters burn out - the Atlas V heavy configuration does just that - at lift off everything is running 100%, after 10 seconds, the core throttles back to 40% until the (liquid) boosters burn out.

And what does the ISP of the SRBs have to do with it? So long as they're lifting themselves with the desired acceleration, any left over thrust adds to the base vehicles effective launch thrust. The only way a higher ISP really helps is in reducing the size of the SRB needed to get a certain net effect (within reason - at some point the ISP is so low that you can't even lift the SRB off the pad). That's why the Delta-IV and Atlas V heavy configurations switch to liquid fueled boosters (repurposed cores in both cases) - the required solids would be just too big to be practical to develop and use.

But again, the costs make this pretty unlikely.
 
PC12Fan
Posts: 1972
Joined: Sat Jan 27, 2007 11:50 pm

RE: House Forces Nasa To Launch AMS/Accelerate Orion

Sat Jun 21, 2008 12:55 am



Quoting Rwessel (Reply 21):

I'll be damned, I never knew such studies were done. Thanks for that.  thumbsup 

Quoting Thorny (Reply 24):
Would it be possible to take Ares V and add more than two SRBs?

No, the Crawler and Crawlerway can't handle that much weight.

I've seen concepts of an Ares V with four strap on SRB's but it's just that - a concept.
Just when I think you've said the stupidest thing ever, you keep talkin'!

Who is online

Users browsing this forum: Channex757, GloomyDe, zaphod42 and 14 guests