POLL: Should NASA Retire its Space Shuttle Fleet?

[EarthlingX]

Direct link to the above paper, posted by rockett :
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA451531&Location=U2&doc=GetTRDoc.pdf

COMPARATIVE ANALYSIS OF TWO-STAGE-TO-ORBIT ROCKET AND AIRBREATHING REUSABLE LAUNCH VEHICLES FOR MILITARY APPLICATIONS

THESIS

Joseph M. Hank, Captain, USAF

AFIT/GAE/ENY/06-M12

DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY
AIR FORCE INSTITUTE OF TECHNOLOGY
Wright-Patterson Air Force Base, Ohio
APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED

March 2006

Impressive reading.

Just a teaser, there is much more in it, from page 153 (175/254) :

5.3 Summary

This study provided a comprehensive look at 21 alternative launch systems, extending the work done in several previous studies by exploring different launch, propulsion and fuel options. The HCRkt-HCRBCC configuration, which had not been previously studied, proved to be one of the best performers for both empty mass and wetted area despite relatively conservative mass estimates. This study explored growth rates for varying payload masses, as well as defining two additional missions and determined their impact on alternative system sizes. The HCRkt-HCRBCC vehicle has the smallest growth rates for both figures of merit and also proved to be the best vehicle to make an orbital trajectory change. Finally, the global strike mission explored the use of hybrid vehicles, and the HCRkt-HCRkt hybrid vehicle ranked highest. Benefits were identified for horizontal launch for this mission. Hopefully the conclusions of this study will prove useful in the emerging field of airbreathing propulsion in RLVs.

 

[vulture4]

Interesting reading, but it is a student thesis and makes numerous assumptions about the performance of airbreathing hypersonic engines that would require a lot of development and may or may not be achievable, most notably a broad speed range. Historically airbreathing engines have relatively narrow speed ranges in which they are efficient, whereas space launch requires constant acceleration from zero to 7km/sec. The only space launch concept in which speed remains constant for an extended period is that in which the first stage is a conventional jet aircraft, as with the X-15 or SpaceShip. Rocket performance on the other hand is affected little by speed.

The most direct path to a fully reusable vehicle is to take a basic unmanned two-stage launch vehicle and make both stages reusable. The main advance in technology that makes this possible is not propulsion but autonomous guidance and automated runway landing as will soon be demonstrated by the DOD using the X-37B, following NASA's decision to abandon it and all reusable spacecraft forever and go back to balloons -- sorry, go back to expensive re-enactments of Apollo with giant throwaway rockets.

 

[EarthlingX]

You will have to be more specific about what you think is out of operational range. Even Einstein was a student once, and facts don't care who quotes them.
He is using computational tools, which are described, as are their weak points.

As to validity of this thesis, look no further than X-37b thread, that's where you will find it implemented, with plenty of details, described in thesis. It even gives you an idea what X-37b is intended for.

 

[rockett]

EarthlingX is right, Vulture4. Think of it this way, that student's thesis was just the tip of the iceberg. He hints at a lot more than was disclosed in his paper in 2006. Besides the X-37b, also look at the recent X-51 test, and AF Pathfinder RFP for confirmation. Based on those, I would say the "student" either had some influence, or was echoing thinking already going on i n the Air Force.

As for airbreathing to suborbit look at it as "on board stages" with the last one a rockett. This has the additional advantage of a powered return for either the first stage or the orbiter, depending on which way you go.

We really need to get away from sitting on top of a controlled explosion as the only way to go, if it is ever going to be economical

 

[CoffeeBreak]

Re: POLL: Should NASA Upgrade some Shuttles for long missions ?

Aside from the inefficiencies of going to and from low Earth orbit, couldn't the shuttles be upgraded for missions beyond LEO by building a re-fueling station in orbit. The re-fueling station could be re-stocked with fuel and supplies by cheaper more efficient craft. Astronauts could travel in alternative craft to dock at the re-fueling station and board the shuttles in orbit. (Yes, it's from the 1998 Bruce Willis movie "Armageddon")

How long could the shuttles safely operate on a long mission to a near earth asteroid ?

 

[kelvinzero]

They are not suitable for beyond LEO unfortunately, That is really why they are called 'shuttles'
* They have quite a bit of weight in wings (and I guess wheels) which have no use beyond LEO. This would cut directly into their efficiency.
* vehicles returning from beyond LEO, such as the apollo command module, return with significantly greater velocity than vehicles returning from LEO, such as the shuttle. I don't believe the shuttle could survive reentry from a mission to orbit the moon.

 

[vulture4]

The concept, back in the 70's was that the shuttles would support a substantial base in LEO where reusable vehicles going between earth and moon would also dock and refuel. This approach was nicely dramatized in the movie "2001", although there were never serious plans for the LEO station to be a giant wheel.

>>As for airbreathing to suborbit look at it as "on board stages" with the last one a rockett. This has the additional advantage of a powered return for either the first stage or the orbiter, depending on which way you go.

Hey, I think the drawings are great, and all the concepts are fully reusable! But the design choices are based on assumptions that are created from whole cloth. The winning design calls for a rocket-based combined cycle (RBCC) upper stage capable of efficient air-breathing operation at Mach 12! The RBCC concept is certainly worth investigating at the technology demonstrator level, but until that is done no conclusions usable for design decisions can be drawn. And what really impresses me about this study is that even after a very expensive development effort, for the baseline satellite launch mission the airbreathing systems have only a very marginal vehicle size advantage over conventional liquid-fueled rocket propulsion for both stages. Although the X-37B has limited internal propulsion, what is has is a conventional rocket rather than an airbreathing system.

If anything this study supports the concept that the next step in RLV technology development should use conventional liquid-fueled rocket propulsion for both stages. The DOD appears to be looking in this direction nowadays with talk of an approach which avoids the need for cruise propulsion during a return flight. Instead the rocket-powered booster reverses heading immediately after stage separation and uses a brief period of powered thrust with residual propellant to reverse its horizontal velocity, heading it back toward the launch site, where it makes a gliding approach followed by a runway landing.

 

[ElmiraViking]

No. Don't retire them until there is a valid replacement.

 

[rockett]

MAN! I wish I had gotten THAT kind of SEVERENCE!

Florida Gets $15 Million Grant to Help Shuttle Workers
http://www.space.com/news/florida-shuttle-workers-grant-sn-100602.html

Looks kinda like a pay-off to me...

 

[EarthlingX]

MAN! I wish I had gotten THAT kind of SEVERENCE!

Florida Gets $15 Million Grant to Help Shuttle Workers
http://www.space.com/news/florida-shuttle-workers-grant-sn-100602.html

Looks kinda like a pay-off to me...

They want to make teachers out of Shuttle workers, and this money is supposed to cover costs of getting them ready for the role.
I think this is one of the best possible options - Shuttle engineers teaching the next generation. I wouldn't mind being one of the students
It's probably not for everyone, but i'm rather sure that Shuttle people will not have trouble getting a job in the space industry, academia, or abroad.

 

[vulture4]

It is pretty silly. Where will the teaching jobs come from when our local (Republican) government is cutting the school district budget by $15 milllion to provide more tax cuts for the county's wealthy developers? The loss of Shuttle will create more losses. The crime was committed by Griffin in 2006 in canceling both the Shuttle and Station to make it appear that his juvenile fantasy of reliving Project Apollo would cost taxpayers nothing. It is being exacerbated by the current leadership which doesn't give any clear signal to the Obama administration and by Constellaiton advocates who are still claiming that "we always knew the Shuttle would be retired".

 

[rockett]

It is pretty silly. Where will the teaching jobs come from when our local (Republican) government is cutting the school district budget by $15 milllion to provide more tax cuts for the county's wealthy developers? The loss of Shuttle will create more losses. The crime was committed by Griffin in 2006 in canceling both the Shuttle and Station to make it appear that his juvenile fantasy of reliving Project Apollo would cost taxpayers nothing. It is being exacerbated by the current leadership which doesn't give any clear signal to the Obama administration and by Constellaiton advocates who are still claiming that "we always knew the Shuttle would be retired".

No question about Griffin getting suckered by his advisors.

As for the current leadership, they don't care. Their plan seems to be do nothing, leave it for a succeeding administration, and keep the media and critics off their backs...

 

[EarthlingX]

It is pretty silly. Where will the teaching jobs come from when our local (Republican) government is cutting the school district budget by $15 milllion to provide more tax cuts for the county's wealthy developers? The loss of Shuttle will create more losses. The crime was committed by Griffin in 2006 in canceling both the Shuttle and Station to make it appear that his juvenile fantasy of reliving Project Apollo would cost taxpayers nothing. It is being exacerbated by the current leadership which doesn't give any clear signal to the Obama administration and by Constellaiton advocates who are still claiming that "we always knew the Shuttle would be retired".

No question about Griffin getting suckered by his advisors.

As for the current leadership, they don't care. Their plan seems to be do nothing, leave it for a succeeding administration, and keep the media and critics off their backs...

Current plan is to fill the holes, which were left after the propaganda course was set. It is time for spaceships, not for boots and flags and other hollywoodish gimmicks anymore.

'Exploration' is going on in ISS labs, it's just not that fancy, but rather boring, that's why they wanted to dump it - costs a lot, no propaganda value, and hard to care about something you don't understand :
http://www.spaceref.com : NASA ISS On-Orbit Status 2 June 2010

All ISS systems continue to function nominally, except those noted previously or below.

Working in Node-3 on the WRS-2 (Water Recovery System 2), Caldwell-Dyson set up the sufficiently filled RFTA (Recycle Filter Tank Assembly) for UPA (Urine Processor Assembly) processing by accessing the RFTA, reconfiguring the backfill QD (Quick Disconnect) hose, and closing out the WRS-2 for RFTA activity.

It has also become a bit bigger politically than some would like, i guess.

One fancy shot :

 

[vulture4]

>>No question about Griffin getting suckered by his advisors.

Could you be more specific? You may be entirely right, but Griffin supposedly wrote the "Planetary Society" paper in which he pretty much laid out the Constellation program. I had one chance to talk with him briefly. He wasn't the sort to ask other people what they thought. He bears most of the blame for the current mess.

 

[rockett]

>>No question about Griffin getting suckered by his advisors.

Could you be more specific? You may be entirely right, but Griffin supposedly wrote the "Planetary Society" paper in which he pretty much laid out the Constellation program. I had one chance to talk with him briefly. He wasn't the sort to ask other people what they thought. He bears most of the blame for the current mess.

If you follow the string of events, things with Constellation weren't toooooo bad at first. It was when they abandoned the air-restart version of the SSME in favor resurrecting the J-2 (as the J-2X) for the second stage of the Aries that things really got way off. Somebody recommended it, I doubt that Griffin would have made that decision solo. I'm sure he also found it fitting in a way, as the J-2 was used on the Saturn V...

 

[vulture4]

A good perspective on this topicfrom a very experienced engineer:

http://www.pbs.org/wgbh/nova/columbia/richardson.html

 

[rockett]

A good perspective on this topicfrom a very experienced engineer:

http://www.pbs.org/wgbh/nova/columbia/richardson.html

This article is a VERY nice summary of bits and pieces I have gleaned elsewhere. It's a shame that everyone seems to have forgotten the original shuttle and ISS mission, which was to be a step in the bigger picture of space exploration. New is not always better, and sometimes a huge (and expensive) mistake...

 

[coby21]

We should take a lesson from the Russion's who have been usseing the same manned module for decades. Being up-graded, re-built, etc. In the end a better robust vehicle. The same should be applied to the shuttles. What happend to Venture Star? Did it work too well?

 

[rockett]

We should take a lesson from the Russion's who have been usseing the same manned module for decades. Being up-graded, re-built, etc. In the end a better robust vehicle. The same should be applied to the shuttles. What happend to Venture Star? Did it work too well?

It never got off the ground.

Failures in VentureStar's technology demonstrator, the X-33, in particular with the composite LH2 (liquid hydrogen) tank, led to program cancellation as a federal undertaking on March 1, 2001.

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

 

[EarthlingX]

Just in case, older Venture Star related threads :

New Shuttle, Let's dust off Venture Star!

A Kerosene-Fueled X-33 as a Single Stage to Orbit Vehicle.

from

List of Multiple Threads on the Same Topic

 

[vulture4]

It doesn't cost billions to launch the shuttle. If you divide the total cost of the program by the total number of flights you get about a billion dollars. But most of that is sunk cost or overhead. It costs about $2 billion a year for program overhead and about $165 million for each flight. The total average per flight is typically around $350 million but cold go lower at a high flight rate. So as long as we are going to keep the program going it makes sense to fly as often as possible. And as long as the Shuttle is flying (at this point 2 or at most 3 flights) it makes sense to keep LC-39 as it is.

Terminating the shuttle, now that it's finally flying like it's on rails, was one of the most bizarre decisions of the Bush administration. But we must be clear. Mike Griffin also ordered the Space Station canceled in 2010, as soon as it was finished, which was equally absurd, and without the Station there was nowhere for Shuttle to go, so it was hard to argue the case. What is inexplicable to me is that the thousands of NASA and contractor workers who should have objected to destroying all their work just accepted it like sheep. Now that the party in power has changed, they blame the administration for everything. But with ISS cancelled there was no need for Shuttle. When the ISS was extended, Shuttle should have been extended as well, but instead Orion/Ares was allowed to morph into the role of ISS logistics, for which it was not designed and is singularly unsuitable.

Almost as bizarre, Augustine, when asked by Nelson, specifically offered shuttle extension as an alternative, and even pointed out, correctly, that if Shuttle were extended it would make sense to go ahead with the sidemount HLV concept since it could use the same infrastructure and launch complex. Yet bizarrely, he didn't include this among his formal "laundry list" of choices.

If Shuttle is canceled it does not make sense to continue to use any part of LC-39. The overhead and maintenance are much higher than a modern single-vehicle pad with horizontal integration. We tell all the visitors the crawlers are the eighth wonder of the world, but in reality a system using steel rails, as are used at almost every other launch site in the world, would be much less expensive to maintain.

So it seems like a waste of money to spend billions to "refurbish" LC-39 as is now planned. All the currently planned launch vehicles already have processing facilities, and if a new vehicle is needed it would make more sense to design a new processing facility around it to minimize operating cost.

>>Failures in VentureStar's technology demonstrator, the X-33, in particular with the composite LH2 (liquid hydrogen) tank, led to program cancellation as a federal undertaking on March 1, 2001.

Composite liquid hydrogen tanks are obviously feasible since one was used multiple times in the DC-X. It might be more reasonable to say that the X-33 program was canceled by the NASA program manager because he did not understand the meaning of the letter "X".

http://www.nasaspaceflight.com/2006/01/ ... -happened/
http://forum.nasaspaceflight.com/index.php?topic=1184.0

 

[neutrino78x]

I can't believe people are advocating that we keep the Space Shuttle. It is obsolete technology, and really, there is no need for NASA to maintain a separate LEO launcher. NASA should be the organization that stimulates and regulates the private space industry. Now, if we were talking about a fully reusable rocket plane, that is to say, a device which takes off like an airplane, goes into space, and lands like an airplane, and only needs to be refueled before taking off the next day, that would be different. The shuttle is not only obsolete but also wasteful.

If anything, we should be using the existing fleet of EELVs, make those "human rated" ASAP, as a backup in case SpaceX et al. don't work out. If it takes more than a few months for NASA to adapt those EELVs to launch a capsule with humans, that is pathetic.

--Brian

 

[peteym5]

OBAMATREK - To Boldly Go Nowhere.... That is what many are saying about his space proposals.

NASA needs to maintain a heavy lift ability for any future project. Cutting back on the Constellation Program rather than totally canceling it is more ideal. The ARES V improves upon the Space Shuttle launch components with larger Solid Rocket Boosters and enlarges the External Tank into a larger rocket. It can launch over 180 tons into orbit. The less expensive option is to go with the Jupiter Direct 3.0 approach which converts the existing Space Shuttles External Tank to a rocket with engines on the bottom and a stage mounted on the top. It can either use the current boosters or the larger 5 segment boosters proposed for ARES.

Going with Direct 3 does make it possible to extend the shuttle program because it does use the same boosters and external tank. Michoud will still be make fuel tanks, ATK will still make the boosters, for any of the launch systems. Many do understand that extending the Shuttle Program for several more flights is risky, there are Nitrogen and Helium Tanks inside that are being used beyond their design lifetime. It probably be expensive to replace them. If any of us want to see the Space Shuttle program continue, it probably be better to just build new Shuttles. Build them better with newer technology.

One major concern about the ARES IV and ARES V is NASA needs to upgrade the transport crawlers, vehicle assembly building, roadway, and launch pad. Thus adding more to the expense. Direct 3 can use most of the existing facilities with less modifications. Perhaps it be better if NASA added a few Shuttle Flights along with development for Direct 3 and ARES I development for now. Then Later, upgrade the facilities for ARES IV/V if they need to launch larger rockets.

I am not opposed to private companies like SpaceX sending just people and light payloads up in space. The existing Falcon 9 cannot take up as much as a space shuttle, just use it send people and light cargo up to the space station. ARES I with the ORION can still be used as a back up in the event that any of the private companies cannot get anything off the ground. Maybe ATK Thiokal themselves can put something together to compete with the other companies like SpaceX.

 

[rockett]

OBAMATREK - To Boldly Go Nowhere.... That is what many are saying about his space proposals.

NASA needs to maintain a heavy lift ability for any future project. Cutting back on the Constellation Program rather than totally canceling it is more ideal. The ARES V improves upon the Space Shuttle launch components with larger Solid Rocket Boosters and enlarges the External Tank into a larger rocket. It can launch over 180 tons into orbit. The less expensive option is to go with the Jupiter Direct 3.0 approach which converts the existing Space Shuttles External Tank to a rocket with engines on the bottom and a stage mounted on the top. It can either use the current boosters or the larger 5 segment boosters proposed for ARES.

Going with Direct 3 does make it possible to extend the shuttle program because it does use the same boosters and external tank. Michoud will still be make fuel tanks, ATK will still make the boosters, for any of the launch systems. Many do understand that extending the Shuttle Program for several more flights is risky, there are Nitrogen and Helium Tanks inside that are being used beyond their design lifetime. It probably be expensive to replace them. If any of us want to see the Space Shuttle program continue, it probably be better to just build new Shuttles. Build them better with newer technology.

One major concern about the ARES IV and ARES V is NASA needs to upgrade the transport crawlers, vehicle assembly building, roadway, and launch pad. Thus adding more to the expense. Direct 3 can use most of the existing facilities with less modifications. Perhaps it be better if NASA added a few Shuttle Flights along with development for Direct 3 and ARES I development for now. Then Later, upgrade the facilities for ARES IV/V if they need to launch larger rockets.

I am not opposed to private companies like SpaceX sending just people and light payloads up in space. The existing Falcon 9 cannot take up as much as a space shuttle, just use it send people and light cargo up to the space station. ARES I with the ORION can still be used as a back up in the event that any of the private companies cannot get anything off the ground. Maybe ATK Thiokal themselves can put something together to compete with the other companies like SpaceX.

One of the more sensable posts I've read about the whole thing. I suspect that with the pressure from Congress, and if the Senate has it's way (bi-partisan I might add) we will more than likely see a Direct 3 variant as the immediate replacement. As for Orion, we could just as well launch it on a man-rated Atlas V, Delta IV, or Falcon 9 heavy...