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#26 2004-09-08 07:49:42

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Space Initive Launch Vehicle

Cargo, droids, components and even supplies for humans in space are easy

Ummmmm unfortunatly, this is not true. Not true in the slightest. Getting anything of signifigant size or mass into space is very difficult and expensive at the moment. The biggest current rocket in the world, the Ariane-V, could hardly launch a single fully loaded semi trailer truck into LEO and that only for a nine-digit sum nor could it do so often.

Comstar, I am beginning to be real skeptical about you now that you've started going on about how you will personally develop a super engine... There have been roughly a century worth of very, very smart people who haven't come up with anything better than Cryogenic rocket engines (which are reaching the limits of their fuel) and prototype Scramjet engines... I find it hard to believe you have a concept for somthing better, particularly one that isn't air-breathing.

The bennefit of using wings on a space ship is that it is easier to make it reuseable than a ballistic rocket.


[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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#27 2004-09-08 08:11:26

comstar03
Member
From: Australia
Registered: 2004-07-19
Posts: 329

Re: Space Initive Launch Vehicle

GCNRevenger,

I didn't say that, what we are doing here is taking existing technologies and also technologies discussed in scientific journals and remodelling them, and then running them through computer modelling to find the best outcomes, to fit the process for our implementation plan.

I didn't say anywhere that its only me, I actually said that my corporation has provide the IT equipment the research team. I don't mind you being a skeptic, because I told you would wouldn't believe it until it happens.

In business you look at your competitors and analysis their actions and examine data publicly, then remodel or innovate newer technologies. That's what my micro-thinktank is doing for our corporation - Design, concepting and modelling new technology ( includes all specifications and load factors ) then we move into the development stage ( mini-prototypes - more testing and fine tuning the technology) and full scale working versions for implementation in the overall strategy.

GCNRevenger,

I understand you have some issues, but in order to meet my goals and objects within the corporation, I need to development rapid development strategies across a vast variety of technologies and it is proceeding well.  I am not the smartest person, I have abilities to look outside the normally processes and suggest to the think tank different concepts then they refine them for future modelling and possible future use in the implementation strategy.

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#28 2004-09-08 08:40:51

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Space Initive Launch Vehicle

I believe I got this right in that a scram jet engine requires a pre push of mach 6 or higher before it will work. Question from start of a rocket launch pad lift off, How long would it take a first stage engine burn to reach that speed. I know that we used a pegasus carried by the plane and a mock vehicle for the engine test bed but lets have some practical size to see if it has any future benifits.

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#29 2004-09-08 11:23:39

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Space Initive Launch Vehicle

Trouble is, by the time a ballistic rocket achieves that speed by flying straight up, you are already at or near the edge of the atmosphere, so an air-breathing engine like a Scramjet won't do you a whole lot of good.


[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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#30 2004-09-08 11:47:08

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Space Initive Launch Vehicle

So basically the scram jet works like an air ram on a car motor or turbo charger or nitrox injection to make the fuel burn more effiecently.

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#31 2004-09-08 13:33:10

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Space Initive Launch Vehicle

No, a Scramjet is a jet engine, it takes in air through an intake, compresses it, and heats it up (chemical combusion generaly) causing it to expand and push against the engine. In a Scramjet, like a subsonic Ramjet, the motion of the engine as it moves through the air and the shape of the intake do the compressing, fuel is injected and ignited, and the hotter gasses at higher pressure are squirted out the back. The difference is, in a Scramjet engine, the air is traveling supersonicly through the engine so it can operate efficently at very high speeds. But, the engine also relies on the air traveling at high supersonic speeds before the compression intake and combustion chaimber will work properly.

The hope is, that the engine will be able to provide serious thrust without having to rely on a onboard supply of oxidizer, reducing the weight of the vehicle an order of magnetude potentialy, and you get "free" reaction mass, permitting you to achieve higher thrusts more easily compared to a regular rocket engine. Eventually, the hope is that the entire vehicle's surface could be regenerativly cooled, which will push the efficency of the Scramjet higher while keeping temperatures more sane, and make it possible to aproach orbital velocities.


[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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#32 2004-09-08 22:17:13

comstar03
Member
From: Australia
Registered: 2004-07-19
Posts: 329

Re: Space Initive Launch Vehicle

GCNRevenger,

Yes scramjet is jet engine, but look into the principles of a scramjet, or rocket engine, or other forms of propulsion then look into increasing the force of the propellant vs velocity produced. ( example cannon or rail gun - both are projectile based weapons but the rail gun can fire hypervelocity projectiles that are more destructive force. )

You want to delivery a hypervelocity engine system that will provide the ability for spacecrafts to launch from ground to Earth Orbit without harming the earth environment.

I use illustrations to describe the concepts and research that we are doing in general terms to you , So you can understand the technology at work or development.

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#33 2004-09-09 05:53:18

ANTIcarrot.
Member
From: Herts, UK
Registered: 2004-04-27
Posts: 170

Re: Space Initive Launch Vehicle

The bennefit of using wings on a space ship is that it is easier to make it reuseable than a ballistic rocket.

That has been the standing assumption for amny years. But that doesn't make it true.

Aircraft type spacecraft will need large airports and large runways. These will not be cheap. They will need to fly through the atmosphere at high speed. Permission for that won't be easy. And they'll always be vaulnerable to a columbia style problem with the leading edge. And they are fundimentally a design compromise. When getting into space is as hard as it is at present, compromising on any aspect of the 'space' bit is shooting yourself in the foot in terms of cost and complexity.

Ballistic spaceships will also need a large areas. But launch pads take up less space than 5000m long runways, (so you can have more backups) and you aren't over-flying land outside your airport. You will not be building a super-concorde so you'll not face that class of political oposition. VTOL designs are by definition, pure rockets with sometimes a deployable aerofoil and landing legs. Yes this adds to the complexity, but nearly so much as wings do.

ANTIcarrot.

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#34 2004-09-09 06:02:00

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Space Initive Launch Vehicle

The problem with a winged space vehicles like the shuttle is that it is the wrong size for crew tranportation, much to large and for cargo why use wings at all, this case may be most true for the ISS.

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#35 2004-09-09 08:09:50

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Space Initive Launch Vehicle

The bennefit of using wings on a space ship is that it is easier to make it reuseable than a ballistic rocket.

That has been the standing assumption for amny years. But that doesn't make it true.

Aircraft type spacecraft will need large airports and large runways. These will not be cheap. They will need to fly through the atmosphere at high speed. Permission for that won't be easy. And they'll always be vaulnerable to a columbia style problem with the leading edge. And they are fundimentally a design compromise. When getting into space is as hard as it is at present, compromising on any aspect of the 'space' bit is shooting yourself in the foot in terms of cost and complexity.

Ballistic spaceships will also need a large areas. But launch pads take up less space than 5000m long runways, (so you can have more backups) and you aren't over-flying land outside your airport. You will not be building a super-concorde so you'll not face that class of political oposition. VTOL designs are by definition, pure rockets with sometimes a deployable aerofoil and landing legs. Yes this adds to the complexity, but nearly so much as wings do.

ANTIcarrot.

I think that you are missing the point, at least in part Anti,

I'm not talking about launching such a vehicle a dozen times a day from a dozen major airports worldwide... i'm thinking on the smaller scale and nearer term, when we need to move beyond the EELV concept for small, medium, and manned payloads. I make no argument that such a vehicle will be simple and cheap, I am sure building a good two-stage runway-takeoff RLV will cost on the order of $10Bn for a small one and $20-30Bn for a large one, and it will be much more complicated than a conventional style rocket... but that doesn't make it inherintly inferior, and a real order-of-magnetude reduction in launch costs is possible with sufficent demand.

As for the giant airport with the long runway, we already have that at the Cape.' Build a new strip in French Guiana maybe. Or Hawaii... its not such a big problem. Since there wouldn't possibly be more than 100-200 flights a year most likly, this would do just fine. As you have to launch east, launching over water like from the Cape will bypass noise concerns.

I also don't think you have given enough credit to the RCC materials, particularly the more modern and stronger ones, as used on Boeing's SMV. They are strong enough, provided they are not abused. One of the few componets on Shuttle that don't need refurbishing between flights... with no external tank foam and a clean runway, it will work just fine.

Yes, there will be some design compromise between an optimal aircraft and an optimal spacecraft, but the bennefit of free oxidizer, free reaction mass, and the lift from wings with or without power can partially overcome the loss of mass fraction versus a pure ballistic rocket, and you get your spaceplane back more easily and safely with its inherintly gentler dynamics.

As long as we are stuck using chemical fuels, any sort of ballistic rocket VTOLs imparticularly will be pretty big, the little DC-I with its puny Delta-II sized payload would be roughly 40m tall and over a dozen meters around, one with a Shuttle sized payload will be Shuttle-sized at least. No easy feat either... and if the engines fail? Well, then landing might get a little "bumpy." With a spaceplane reentering you can glide home. Wings do add complexity to the shape and frame, but not as much as you think to the mechanical complexity.

Okay Comstar, how do you intend to make a vast increase in performance for a Hydrogen powerd Scramjet engine? Or over such an engine?

"The problem with a winged space vehicles like the shuttle is that it is the wrong size for crew tranportation..."

Bingo, that the Shuttle was designed to please everyone... the USAF with Titan-IV sized launch capacity over Polar orbits often, NASA with the manned capacity and emphasis on orbital operations, and the accountants with low development costs, low cost per-flight, and overall space program price reductions thanks to reuseability... In all these things, other than perhaps Shuttle's utility as a space repair/assembly truck, it has failed miserably. Not enough spent to develop it right, and when the "cheap" route turned out to be expensive, it was too late.


[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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#36 2004-09-09 08:33:49

BWhite
Member
From: Chicago, Illinois
Registered: 2004-06-16
Posts: 2,635

Re: Space Initive Launch Vehicle

Fly cargo independent of crew.

For cargo shots modify the mass fraction to increase fuel and reduce dry weight as much as possible. That points towards extreme disposable. As flimsy as will achieve orbit.

"If it doesn't break, it's too heavy"

For crew a smaller RLV so a more robust crew compartment can be re-used a large number of time.

A flimsy crew compartment built on the principle "If it doesn't break, it's too heavy" is plainly unacceptable. Therefore build it rugged and robust and re-use it.

But don't fly bulk cargo (food, water, fuel) in your Rolls Royce spacecraft.


Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

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#37 2004-09-09 09:10:58

Cobra Commander
Member
From: The outskirts of Detroit.
Registered: 2002-04-09
Posts: 3,039

Re: Space Initive Launch Vehicle

Exactly, what Bill said.  big_smile

They're looking at luxury SUV's when we need a little sportscar and a bigass truck.


Build a man a fire and he's warm for a day. Set a man on fire and he's warm for the rest of his life.

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#38 2004-09-09 11:07:07

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Space Initive Launch Vehicle

The extremely-extremely-simple and disposable route has already been tried... unfortunatly, it really just isn't practical to make any rocket cheap enough to sustain a high failure rate as you would inevitibly have. For bulk cargo when you don't want to use an HLLV, then a small or intermediate size RLV can accomplish real cost savings provided the vehicle is useful for other purposes. The extremely low flight costs for a true RLV makes all the difference... It is perfectly reasonable to discuss a vehicle that would cost 1/10th as much of a comperable RLV would and would have high reliability.

Since regenerative scramjets are a ways off, i'm thinking somthing along the lines of a two-stage vehicle, one that is airbreathing with a LOX "precompressor" booster to reach the low hypersonic range and high altitudes beyond the majority of the atmosphere. Then, the upper stage lift body, powerd by Slush Hydrogen rockets, boosts to orbit. Make two upper stages with similar mold lines, one optimised for maximum payload and the other for dead-stick or TPS-failure surviveability, perhaps with an esacpe pod.

Oh, and I would like to mention, Russia doesn't HAVE an upper stage engine available like the RL-12 or RL-60.


[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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#39 2004-09-09 11:14:45

BWhite
Member
From: Chicago, Illinois
Registered: 2004-06-16
Posts: 2,635

Re: Space Initive Launch Vehicle

The extremely-extremely-simple and disposable route has already been tried... unfortunatly, it really just isn't practical to make any rocket cheap enough to sustain a high failure rate as you would inevitibly have.

When was it tried?

The Thiokol RSRM has a 99.5% success rate and costs $30 million with a very small production run. No one has ever tried to lower that cost by buying in bulk.

Oh, and I would like to mention, Russia doesn't HAVE an upper stage engine available like the RL-12 or RL-60.

What about the http://www.pratt-whitney.com/prod_space … sp]RD-0146 Pratt & Whitney offers it for sale. Its made by the Russians.

= = =

An RLV flown a few dozen times a year won't be cheap either.

= = =

Edit to add. The original RL-10 is 40 years old. I am no patent attorney yet I think a number of those patents might have expired.

Therefore, maybe someone else could make knock off RL-10s if P&W declined.


Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

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#40 2004-09-09 11:20:14

ANTIcarrot.
Member
From: Herts, UK
Registered: 2004-04-27
Posts: 170

Re: Space Initive Launch Vehicle

I think that you are missing the point, at least in part Anti,

Oh I see. So what you want is a shuttle, built to fly into space, owned only by America, operated only by NASA, which will be of an all new, innovative design to replace those silly old fashioned ELV rockets.

Hmm. You know, that sounds vaguely familiar... I can't think, where have I heard that before? tongue

it will be much more complicated than a conventional style rocket... but that doesn't make it inherently inferior, and a real order-of-magnitude reduction in launch costs is possible with sufficient demand.

Funny, you never accepted either argument for the DH-1.

I also don't think you have given enough credit to the RCC materials

RCC was what failed on Columbia. Up until then it was seen as a indestructible wonder material. NASA viewed it as the one part of the shuttle that could be hit repeatedly with a hammer and still certified for flight. And true, it *is* amazingly tough. But also true, it was smashed into uselessness by a piece of foam that I could crush in my hand.

It will work fine up until it hits something. Just like Concorde's wheel's worked fine until some stupid fog-leg twit left a piece of jagged metal on the runway that was as long as my arm.

Having such a vital part of the reentry shield face forward during flight is, I believe, fundamentally unsafe and a fundamentally bad idea.

can partially overcome the loss of mass fraction

If it's several times larger than a 747, yes.

you get your spaceplane back more easily and safely with its inherintly gentler dynamics

With an inherently more complex heatshield, with inherently longer reentry times and inherently higher heatshield temperatures.

DC-I with its puny Delta-II sized payload

VTVL SSTO does not equal HTOL TSTO! You cannot use such an argument to say HTOL carries more payload because multiple stages will almost always produce a higher mass ratio.

and if the engines fail?

What if your hydraulics fail?

A large VTOL would probably have 4 or more engines. Probably tending to much more. wink Small VTOLs will probably be fitted with parachutes or aerofoils. Even in a full mechanical/electronics failure, I'd rather be in the VTOL, as I don't need a runway to land safely in that.

Wings do add complexity to the shape and frame, but not as much as you think to the mechanical complexity.

As a studied aerospace engineer I can quite happily say, yes they do. They also add orders of magnitude to development complexity, time, and cost.

Bingo, that the Shuttle was designed to please everyone...

Very true. But the other flaw with the shuttle was that it was all new.
*New engines.
*New heatshield.
*New method of launch.
*New method(s) of recovery.
*New and complex shape.

All new (and especially complex, high performance all new) doesn't always work too well.

ANTIcarrot.

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#41 2004-09-09 11:24:37

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Space Initive Launch Vehicle

All New....
One more reason to develope with off the shelf maybe slightly modified for the next real manned vehicle.

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#42 2004-09-09 11:35:59

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Space Initive Launch Vehicle

Here is a link to a document that list all contracts handed out recently for the exploration initiative.

http://www.exploration.nasa.gov/documen … t_0902.doc

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#43 2004-09-09 12:17:50

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Space Initive Launch Vehicle

"The Thiokol RSRM has a 99.5% success rate and costs $30 million with a very small production run. No one has ever tried to lower that cost by buying in bulk."

Ohhh you mean intermediate-cheap, I was thinking launch costs even lower than the $50M range for a SRB+Centaur setup. The trouble of building/refurbishing an SRB is pretty involved, I don't know how much the costs can be slashed by simply making lots more of them. I thought you were referring to stuff like these crazy ideas...
http://www.astronautix.com/lvfam/lclv.h … m/lclv.htm

"...which will be of an all new, innovative design to replace those silly old fashioned ELV rockets."

Thats correct, I think that it can be done, but not until we need it and are willing to seriously invest in it, not doing it half-way like Shuttle and living with the high launch costs.

"RCC was what failed on Columbia. Up until then it was seen as a indestructible wonder material... But also true, it was smashed into uselessness by a piece of foam that I could crush in my hand... Having such a vital part of the reentry shield face forward during flight is, I believe, fundamentally unsafe and a fundamentally bad idea."

The piece of foam that hit Columbia was quite large, weighing as much as your computer monitor, hard as rock since it was frozen by the fuel, and hitting at nearly Mach-1. Frankly, without the debries issue and if you keep your runway clean, there aren't any launch hazards to the TPS. It is perfectly safe as long as you don't mistreat it.

"With an inherently more complex heatshield, with inherently longer reentry times and inherently higher heatshield temperatures."

Actually again, no. A lift body won't have higher temperatures in part because of its more liesurely reentry. In fact a metal heat shield is practical for the majority of the TPS system... Shuttle doesn't use such an arrangement because of its USAF requirement for huge crossrange demanded the low TPS surface area, which will not be a big deal for a NASA launch vehicle.

I also never said that such a vehicle would have a better mass fraction or a much larger payload, what I stated was that the added efficency and engineering leeway of air launch compensates to some degree for the added vehicle weight compared to a VTOL rocket, particularly since a real VTOL rocket would have to carry landing fuel. Return by parachute or aerofoil does not make it as practical to turn around as a vehicle which soft-lands in flyable shape. You certainly aren't going to land a giant 50m tall "DC-II" with parachutes and expect to turn it around within a week or two.

"What if your hydraulics fail?

A large VTOL would probably have 4 or more engines. Probably tending to much more. wink Small VTOLs will probably be fitted with parachutes or aerofoils. Even in a full mechanical/electronics failure, I'd rather be in the VTOL, as I don't need a runway to land safely in that."

Oh thats easy... it won't have any hydraulics. Electromechanics are good enough for the F-18, they are good enough for a spaceplane. Are you sure it would have four engines? The DC-I only has one, a large cryogenic aerospike engine.

And the question of safety and landing and such, the big question is surviveability and then the reliability of the vehicle. A lift body can be built in such a fasion that it will naturally right itself during reentry even dead-stick, and as you will be able to glide and bleed off energy, so even if you can't land then bailing out is relativly safe. For a ballistic VTOL rocket, and you come in unpowerd (provided you can even reenter dead-stick), and your parachutes fail... well... splat just like Genesis did. Or you can try the ever-popular high-speed bail out with its low probability of survival.

Finally, a little size comparison... The DC-I with its little 9MT-10MT payload, if it could reach the optimistic mass fractions, would have been about as big as the Space Shuttle external tank at about 40m tall. One that could carry medium sized payloads would be even larger, and begin to aproach the size of the Saturn rockets, easily being 50% larger.

The X-30 NASP would have been a little bigger than a 747, and a TSTO vehicle would be slightly smaller size with its denser fuel for the medium launch or much smaller for a light/medium launcher... The old Shuttle-LSA concept supports this notion, with its all-rocket cryogenic propulsion, plain old liquid hydrogen instead of Slush, being about 67m long and 50m long and about half that wide for each stage respectivly.


[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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#44 2004-09-09 13:23:48

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Space Initive Launch Vehicle

Article about why rocket science is hard.

High Technology Vs. Space Travel
http://www.spacedaily.com/news/oped-04y.html

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#45 2004-09-09 13:40:24

BWhite
Member
From: Chicago, Illinois
Registered: 2004-06-16
Posts: 2,635

Re: Space Initive Launch Vehicle

Article about why rocket science is hard.

High Technology Vs. Space Travel
http://www.spacedaily.com/news/oped-04y … d-04y.html

Reading Jeff Bell's latest and http://www.washingtontimes.com/op-ed/20 … r.htm]this and Trent Lott's preference for asphalt, I once again come to the conclusion we need a better reason "why" for crewed spaceflight.


Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

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#46 2004-09-09 13:44:52

ANTIcarrot.
Member
From: Herts, UK
Registered: 2004-04-27
Posts: 170

Re: Space Initive Launch Vehicle

It is perfectly safe as long as you don't mistreat it.

So are nuclear power stations. Accidents still happen. Probably nothing we can do to stop that but I still believe this is a foolish risk.

which will not be a big deal for a NASA launch vehicle.

Hmm. Which hopefully will not...

a real VTOL rocket would have to carry landing fuel.

A properly designed space shuttle would also carry landing fuel. The orrigonally intention was to give it jet engines. The reasons will still be valid for shuttle-II.

Return by parachute or aerofoil does not make it as practical to turn around as a vehicle which soft-lands in flyable shape.

You refused to believe that a space vehicle could land in a flyable state when we were discussing the DH-1. Fitting a new parachutte will probably not be a turn around limiter, as it'll take less time than the other tasks that need to be done; for either design.

A lift body can be built in such a fasion that it will naturally right itself during reentry even dead-stick

And it's kinda hard to design a cone that *doesn't* do that. Most capsules enter dead-stick and all slow down to safe ejection speeds long before hitting the ground.

Finally, a little size comparison...

By all means. By your numbers the DC-I would be smaller than the X-30 NASP, since a 747 is much bigger than 40m.

In any case, I'm the twit who favours the DH-1 remember wink That'd be about as small as the DC-I and comes apart into two pieces for easy handling. tongue

ANTIcarrot.

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#47 2004-09-09 13:45:05

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Space Initive Launch Vehicle

Mmmmm so the Ruskies did build an RL-10ish engine, I suppose it must be somewhat more recent then my memory.

A properly designed VTOL rocket will have to carry quite a bit of rocket fue for landing, and repressurization tankage probobly, and the trouble of spinning up the turbopumps again, etc etc thus doubling the risk of engine failure for every flight... alot more trouble than small jet engines and a little jet fuel. I also am not convinced that you need a powerd flight capacity, getting down within range of the runway isn't the hard part.

The trouble with a parachute landing isn't so much attaching a new chute', as it is that you can't land with accuracy. You can't return to the pad, and so, a very large vehicle will not be able to turn around easily because you have to pick it up and move it, not to mention the added inspection and engineering needed for the slightly harder landing. The parachutes of that size would be tremendously big too, and would have themselves a nontrivial mass.

The DC-I, since that seems to be the most viable VTOL rocket concept, could NOT return unpowerd. It would HAVE to execute a reentry allignment maneuver half way down, then nose down and fire the main engine to land, at the very least... The DH-1 concept, as previously mentioned, is a pitiful toy many times too small.

A real TSTO spaceplane able to carry Shuttle sized payloads would not be a signifigantly larger than a 747 airliner. A DC-I style rocket with a similar payload would also be on the order of >60-70m long, making it cumbersome to handle. a TSTO spaceplane will be a little smaller since it uses more dense fuels for both stages and jet rather than rocket engines for the first stage. One able to carry small DC-I sized payloads would probobly not be much bigger then Shuttle is.

TSTO spaceplane technology checklist:

-Composit fuel tankage - Mature/Prototype by MSFC etc
-LOX-boosted turbine engines - Prototyped, F-15 engine modified and ground tested
-Large reuseable LOX/LH2 engine - Development by P&W (COBRA et al)
-Metal heat shield materials - Prototyped and flight tested on STS
-Lift body design - Prototyped by Russia, X-38 ACRV, various ground tests and confirmed modeling

-NASA experience with spaceplanes of high complexity - 20+ years and counting
-Computer modeling and design now common
-Composits, ceramics, metal alloys, engineering polymers, etc have advanced considerably since the Shuttle days

Etcetera


[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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#48 2004-09-09 14:03:41

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Space Initive Launch Vehicle

Actually there is a contract out for a steerable parachute design under another thread.

http://www.newmars.com/cgi-bin....uidance

Boeing got the contract
Boeing to design Mars parachute technology
http://www.spaceflightnow.com/news/n040 … parachute/

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#49 2004-09-09 14:21:43

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Space Initive Launch Vehicle

Steerable down to the tens of meters, able to adjust attitude for essentially tail-down perpandicular landing, and to do so reliably even with wind? ...On a vehicle thats 40m or even 60m tall that weighs many tons, but is fragile?


[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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#50 2004-09-09 14:24:47

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Space Initive Launch Vehicle

We will see if your wish is in the actual returns from Boeing.

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