Spaceplane Shelved? (Aviation Wk)

[katty]

cont'd: http://www.aviationweek.com/avnow/news/channel_awst_story.jsp?id=news/030606p1.xml

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Two-Stage-to-Orbit 'Blackstar' System Shelved at Groom Lake?
By William B. Scott
03/05/2006 04:07:33 PM

SPACEPLANE SHELVED?

For 16 years, Aviation Week & Space Technology has investigated myriad sightings of a two-stage-to-orbit system that could place a small military spaceplane in orbit. Considerable evidence supports the existence of such a highly classified system, and top Pentagon officials have hinted that it's "out there," but iron-clad confirmation that meets AW&ST standards has remained elusive. Now facing the possibility that this innovative "Blackstar" system may have been shelved, we elected to share what we've learned about it with our readers, rather than let an intriguing technological breakthrough vanish into "black world" history, known to only a few insiders. U.S. intelligence agencies may have quietly mothballed a highly classified two-stage-to-orbit spaceplane system designed in the 1980s for reconnaissance, satellite-insertion and, possibly, weapons delivery. It could be a victim of shrinking federal budgets strained by war costs, or it may not have met performance or operational goals.

This two-vehicle "Blackstar" carrier/orbiter system may have been declared operational during the 1990s.

A large "mothership," closely resembling the U.S. Air Force's historic XB-70 supersonic bomber, carries the orbital component conformally under its fuselage, accelerating to supersonic speeds at high altitude before dropping the spaceplane. The orbiter's engines fire and boost the vehicle into space. If mission requirements dictate, the spaceplane can either reach low Earth orbit or remain suborbital.

The manned orbiter's primary military advantage would be surprise overflight.

[ladjf]

1. The Concord was the last piece of advanced aviation

technology. Since then, the accountants have planned the future of aviation, period.

[gordianot]

2. This may now be obsolete. We will not be told until after the fact.

In the days of the SR-71 many were angry Johnson gave away the program, they were also angry at Carter regarding B-1. Now that whateve this is, be fairly sure there is something more expensive and better.

[muriel_volestrangler]

3. See also an extensive criticism of Aviation Week's piece

via this DU Science thread: http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=228x18374

http://www.spacedaily.com/reports/Blackstar_A_False_Messiah_From_Groom_Lake.html

[Karmakaze]

4. There is one problem with that critique...

SpaceShipOne

Basically, that critique is saying that what Burt Rutan did privately, the US government couldn't do with all the money at its disposal, and in secret.

I dunno if the story is true, but the critique seems a little less likely than the claim.

[muriel_volestrangler]

5. Not really - SpaceShipOne replicated what a B-52 and X-15 did

A jet mothership carries the rocket up, and launches it. The rocket then accelerates (to a bit above Mach 3, say 2,500 mph, in SpaceShipOne's case), and climbs, and (just) gets above 100km. That's not quite as fast as the X-15 achieved in the 1960s (highest speed about 4,500 mph) - and they managed 100km too. See http://www.aerospaceguide.net/spaceplanes/spaceshipone.html and http://history.nasa.gov/x15/cover.html . Not to take away from what Burt Rutan achieved - it was great, and I hope he will continue to develop it.

But Aviation Week claims Blackstar was designed to go into orbit - 17,500 mph. That requires a lot more acceleration, and SpaceDaily is saying no-one has ever come close with a single stage rocket, when launching satellites; and carrying the extra weight of a reentry vehicle makes it impossible.

[gordianot]

6. Some engineers thought flight was impossible.

In the current climate of secrecy does anyone expect disclosure by the Bush administration?

[Karmakaze]

7. You didnt get my point

I didnt mean to say SpaceShipOne was doing the same thing as the claimed system, I was saying he did a very similar thing, like maybe 25% of the alleged BlackStar systems capability, with a small private budget. The government should have been abale to easily overcome the price barriers that prevent Rutan from going further than he has.

"SpaceDaily is saying no-one has ever come close with a single stage rocket,"

That is stupid. The F-15 launched ASAT program was a single stage missile carried under a small fighter that was capable of attaining orbital altitudes, and ICBMs are often single stage, and have been used as "single stage to orbit" delivery vehicles for quite some time.

In any case, neither of these systems (BlackStar and SpaceShipOne) is a truly single stage system, the "first stage" is the mothership that carries the delivery vehicle to an altitude and speed where the fuel needs to accelerate to such altitudes are greatly reduced.

The X-15 is 1950's technology and was capable of this:

* First use of reaction controls for attitude control in space
* First practical use of full-pressure suits for pilot protection
* Development of inertial flight data systems in high- dynamic-pressure and space environment
* Discovery of hot spots generated by surface irregularities
* Discovery that the hypersonic boundary layer is turbulent and not laminar
* First demonstration of pilot's ability to control rocket- boosted aerospace vehicle through atmospheric exit
* Successful transition from aerodynamic controls to reaction controls, and back again
* Demonstration of pilot's ability to function in a weight- less environment
* First piloted, lifting atmospheric reentry
* First application of energy-management techniques for reentry guidance
* First application of hypersonic theory and wind tunnel work to actual flight vehicle
* Development of improved high-temperature seals and lubricants

What Im saying is that if they could do THAT in the 1960's with 1950's technology, you can not tell me that nearly half a century later they cant do far better now. The other thing to remember is that unlike a shuttle, this aircraft would not have to maintain orbit. All it would need to do is achieve a high enough speed at a high enough altitude so that its much smaller and lighter payload would be able to maintain orbit at that speed and altitude.

So while the delivery vehicle's orbit may be unstable and result in a quick decay, the far lighter and smaller payload could be easily left behind, within a stable orbit for its weight and speed.

[muriel_volestrangler]

8. What are these single stage rockets - either ICBM or satellite-launching?

ASAT was 2 stage. I can find no single stage ICBMs or satellite launchers - some Atlases were "one-and-half stage", but that still means they dropped rocket engines.

Remember that the orbiter claimed by Aviation Week is nearly 100 ft long - it's not small - that's 80% the length of the Space Shuttle, and, like the shuttle, the whole thing has to be designed to withstand re-entry and glide to a runway, which puts further limitations on the design, and adds weight compared with a disposable rocket. The speed of even the approximately Mach 3 launcher supposedly involved in Blackstar is still a small part of the orbital velocity needed - 2500 mph of 17,500 mph (add on 1000 mph from earth's rotation, and you're still a fraction of the way there); it's nowhere near orbital speed itself. Technology can't overcome the limits of chemistry and physics, which determine the specific impulse of chemical fuel and the velocity they can add to a vehicle. The initial mass needed for a rocket goes up exponentially with the change in velocity required (see http://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation - and that's without taking into account gravity drag, which means some of a rocket's thrust has to counteract gravity while it's also accelerating the craft, or air resistance). This means it's very difficult to make it all the way to orbit.

No-one has listed a successful SSTO vehicle on Wikipedia either. They go into more detail about the problems there.