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#1 2004-03-20 00:28:37

Ad Astra
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Registered: 2003-02-02
Posts: 584

Re: RLVs--Doomed by Moon-Mars Initiative?

As the Orbital Space Plane slowly evolved into the expendable Crew Exploration Vehicle, the supporters of Reusable Launch Vehicles were probably dealt a great blow.  With the imminent shuttle retirement, we will be left without any RLV, and there will be very little reason to build a new one.

The great hope here is that somebody will build a suborbital X-Prize rocket that can evolve into an orbital design.  As a wild guess, I think we will be waiting at least fifteen more years for that to happen.  This is very disappointing.  Plenty of RLV research remains to be done by government and industry, particularly in the areas of propulsion, structures, thermal protection, and autopilot control and guidance.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#2 2004-03-20 02:05:03

Michael Bloxham
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From: Auckland, New Zealand
Registered: 2002-03-31
Posts: 426

Re: RLVs--Doomed by Moon-Mars Initiative?

NASA has no hope left for RLV's. Pity, as the failure of Lockheeds design was a result of being overly ambitious and underfunded, rather than a fundamental oversight of RLV performance. My hope is that NASA will cease operation of the shuttle much sooner than 2010, perhaps selling the ISS to the Russians (or even perhaps the Chinese?) for a reduced price (thereby avoiding the potential for international ridicule, as an alternative to leaving the station out to dry). NASA should then focus solely on its primary objective: Exploration. Forget the CEV or any other set plans and goals, just ask this question:

'Whats the most effective way to explore, and how cheap can we make it?'.

Put another way: Whats the biggest bang for the buck? We shouldn't try to emulate Apollo, and we're not moving forward under the present NASA administration. It frustrates me to hear NASA's many critics babbling about this thing and that... And yes, I am one of them. But I cannot continue citing their specific faults, as my mind insists their must be something fundamentally upside-down in their logic somewhere.

I don't care how, NASA, just go damn forth! 

:bars:


- Mike,  Member of the [b][url=http://cleanslate.editboard.com]Clean Slate Society[/url][/b]

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#3 2004-03-20 08:54:36

GCNRevenger
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Posts: 6,056

Re: RLVs--Doomed by Moon-Mars Initiative?

Shuttle never really was much of an RLV, having to wait to go back up on the Michoud people to build a new tank, waiting on Aerojet to refurbish the SRBs, and the many months that thousands of people spend making the Orbiter (un)safe and assembled for flight... thats no RLV by my definition.

The grim schematic of it is that we don't need an RLV to go anywhere really, launching large completed componets of spacecraft on a super-heavy lifter is easier than launching little bits on a RLV, and these would be half the size of Shuttle's already narrow cargo bay. There isn't much of a market for commertial launches either, heck if the DC-X were built and able to fly weekly, nobody could build satelites fast enough to fly on it.

CEV is a nessesarry componet for exploration if for no other reason that Nasa needs a way to come back down and make short hops to orbiting spaceships or Lunar bases. With Shuttle gone, only Souyz will remain, and its awfully small and underpowerd... oh yeah and RUSSIAN. The Big Q is can CEV be built light enough to ride on a Delta-IV Medium, and can it be built for less than the GDP of small European countries.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#4 2004-03-20 13:39:04

Ad Astra
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Re: RLVs--Doomed by Moon-Mars Initiative?

The way to justify an RLV is with high flight rates, and NASA had to claim that the shuttle would fly 50 times a year or so just to get Congress to approve it.  Today, these flight rates do not exist, although they will hae to emerge if we become a spacefaring society.

The hope in the mid 1990's was that small satellites like Iridium would finally create that large demand for spaceflight; in turn, the existence of a cheap RLV would motivate even higher numbers of satellites to be launched.  Today, the Iridium bubble has burst, but micro-sats have become the new hope of the RLV dreamers.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#5 2004-03-20 15:22:45

GCNRevenger
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Re: RLVs--Doomed by Moon-Mars Initiative?

But unless you have somthing to launch, then the RLV is worthless... microsats can practicly be launched on sounding rockets, much less an RLV.

As far as exploration is concerned, a true SSTO RLV would be mighty nice as a fuel tanker or light cargo (foodstuffs, spacesuits, etc).


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#6 2004-03-20 15:42:26

Bill White
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Registered: 2001-09-09
Posts: 2,114

Re: RLVs--Doomed by Moon-Mars Initiative?

What the launcher industry needs is increased demand. Its a catch-22.

Low cost Earth to LEO is said to be necessary for humanity to become spacefaring yet until humanity becomes spacefaring there is not enough demand for launch services to justify the investment needed to develop low cost Earth to LEO access.

What is needed, perhaps, is a group of people determined to become spacefaring notwithstanding the cost. In other words, to have a desire for spacefaring that is price inelastic, to use the economists term.

Then, the genuis of the free market will lower the cost for the rest of us.

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#7 2004-03-20 15:56:14

GCNRevenger
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Re: RLVs--Doomed by Moon-Mars Initiative?

I think it will require improvements in basic technology first, which was what Nasa was trying to do half-heartedly before Columbia and BushPlan... Composits made the DC-X perhaps possible, and advanced ceramics and CFD will make a Scramjet airplane cheap enough for private corperations to invest in, and selective membranes will make life support equipment lighter... that sort of thing. The cost to get from the ground to up there is a function of technology, at the moment this factor is poor so only governments can afford to go for keeps.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#8 2004-03-20 18:38:49

Ad Astra
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Re: RLVs--Doomed by Moon-Mars Initiative?

But unless you have somthing to launch, then the RLV is worthless... microsats can practicly be launched on sounding rockets, much less an RLV.

As far as exploration is concerned, a true SSTO RLV would be mighty nice as a fuel tanker or light cargo (foodstuffs, spacesuits, etc).

Therein lies problem with SSTO.  SSTO lends itself to big vehicles that loft fairly big payloads.  The current breed of microsat launchers on the drawing boards are essentially Mach 3 to Mach 6 rocketplanes that use solid or hybrid rockets to take the payload the rest of the way to orbit.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#9 2004-03-20 20:44:06

Ad Astra
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Re: RLVs--Doomed by Moon-Mars Initiative?

The reusable RS-84 rocket engine is also on the [http://www.aviationnow.com/avnow/news/c … g03194.xml]chopping block.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#10 2004-03-20 21:26:40

GCNRevenger
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Re: RLVs--Doomed by Moon-Mars Initiative?

The only really good thing that the RS-84 would be for is for a Shuttle-II vehicle like those wierd looking critters to come out of Lockheed art departments, and wouldn't be any good for an SSTO vehicle. Intended to make a good flyback booster engine, which would be nice if you mate them to a Delta-IV CBC or somthing, but would only be a marginal improvement in cost and flight rate. Spend the money on Shuttle-C/Z instead.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#11 2004-03-20 22:15:50

Ad Astra
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Registered: 2003-02-02
Posts: 584

Re: RLVs--Doomed by Moon-Mars Initiative?

Cancellation of the RS-84 will prove to be penny-wise and pound-foolish.  Perhaps the biggest folly of the Apollo years is that little money was invested in the future of the space program (in projects such as the X-20.)  When the time comes to build a new RLV, the designers will have to return to the drawing boards and spend more time and money redesigning an engine they could have had by that time.

True, the RS-84 would have been employed in booster applications, while the RS-83 (whose fate is unknown to me) would be better suited to the core or supper stages of the vehicle.  Both engines were part of a balanced strategy to create sorely-needed engines for an RLV.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#12 2004-03-20 22:35:19

GCNRevenger
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Re: RLVs--Doomed by Moon-Mars Initiative?

Yes they were, a multi-stage one that would only be partially or psuedo reuseable... in short, only some of an improvement over Shuttle. This marginal improvement leads to the question, where are you going to fly this thing? It will not make spaceflight cheap enough to do anything you can't do today with conventional rockets... No, what is needed is an SSTO vehicle for that, and it will almost certainly be powerd by hydrogen, so the RS-84 would be useless.

Edit: You don't need the RS-84 to build Shuttle-C/Z


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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