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TAAS Company Presents New Orbital Space Plane
RobGoldsmith writes "The TAAS Company have released details on their new Orbital Space Plane. The new design has many attributes to set it apart from its rivals. One highlight is the integrated Safety System; this is where an escape vehicle can eject from the main body of the craft then fly home safely. They claim: 'With the system's performance capability, economical first stage tow and independence from ground launch facilities, it can offer the lowest price. It also offers the safest flight.' Could this spaceship rival Virgin Galactic's SpaceShipTwo?"
Reader wooferhound points out related news from XCOR Aerospace (which we've discussed previously), that they're beginning to take orders for seats on their own suborbital flights, with test runs planned for 2010. Seats will be going for around $95,000 each, less than half the cost of the first tickets for SpaceShipTwo.
I can see the need for commercialized flights to sub-orbital and even to orbit.
But really, what's next after this? I'd like to be able to get to the ISS for a not insane sum, like MAYBE 200 thousand dollars.
But, failing that, OK, you're in orbit. Now what? I think that "space tourism" will only be genuinely successful is if there is a destination in orbit. The whole "space hotel" thing makes a LOT of sense in that it is a destination AND a safe haven if the vehicle can safely reenter.
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"The TAAS Company have released details on their new Orbital Space Plane."
Is the word "orbital" being used in some context I don't understand? This vehicle does not appear to be anywhere close to capable of reaching orbit. "Suborbital space plane," I can get behind.
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Funny - looks a little like the original Learjet.
Nice to see the escape module. Bearing in mind that even NASA - and the Russians, Chinese etc. - have had some spectactular & sad blow-ups, it would seem likely that some of these less well resourced attempts will have the same. Shame there was not one in the shuttle - I seem to remember it was in the original proposal?
Neat idea also to tow the thing up, therefore avoiding the need for a special launch aircraft like Rutan's designs. Still, he did get there first, and this thing's only on paper...
TAAS: Who? No matches to TAAS or Talmage when searching Personal Spaceflight http://www.personalspaceflight.info/ or Encyclopedia Astronautica. The latter is particularly notable, as the NASA history office recommended it to National Geographic when they were looking for some historical data. TAAS apparently recognizes itself though: taascompany.com
Stability: "With the center of gravity now well behind the center of lift, the parent vehicle will be unstable and pitch up." All true, basic aerodynamics. Specifically AEROdynamics. This will be true in the atmosphere. If the vehicle is in the atmosphere, there's no reason to rely on structural aerodynamics, because the vehicle has control surfaces. A much safer ejection sequence would be to kick the capsule forward, lower the flaps for aerobraking, trigger any other brakes that may exist, lower the elevators to "nose" down the main vehicle. Bring it down and away from the capsule under control is far safer than hoping instability won't backfire and somersault the tail over and forward, into the capsule.
Wings and Reentry: "Wings are the most efficient means of air transportation and air-breathing engines are the most efficient form of propulsion. A vehicle that takes advantage of these two components will be the most efficient. The wings also play a role in orbital transfer maneuvres and reducing thermal loads during re-entry."
The fastest atmospheric speed ever achieved was Mach 9.6 by NASA's X-43. The "wings" were integral to the airframe. Nothing that pokes out from the body like those imagined for the TAAS thing would stay attached at anywhere near that speed. And nothing running at lower Mach could possibly make it outside enough of the atmosphere to accelerate to orbital speed unless it were carrying an enormous fuel load to make up for lack of lift since the wings wouldn't be working any more.
As for reentry, the wings would absolutely be a hindrance. The greater surface area (as compared to the body alone) would result in much more aerodynamic compression heating than any amount of radiative cooling that could possibly occur. Now, if they were to use the wings as ablative cooling, by having them absorb heat and then get ripped off by the high Mach forces, it might just bear itself out to be as silly as the rest of the article.
A couple details to put some of this in context: Low Earth orbit speed is around Mach 25.
The temperature of the X-43's leading edges approached 4,000 degrees. The SR-71's reached 3,300 at Mach 3.3. The nonlinearity in the speed/heat comparison was due the the X-43 flying much higher (110,000 ft); less air, less heat generated.
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Gosh. I find myself getting really riled up by this article. I work on the Shuttle External Tank, so I see every day how demanding, how difficult and precise manned space flight has to be.
I have a lot of respect for the suborbital tourism industry, and for SpaceX, since they're both doing very difficult things, too (getting a human to the boundary of space, and getting a payload to orbit without government funding, respectively).
And here, this guy just waltzes in and claims he can do all of that and more for a low, low cost of $4 million and a bad Photoshop of a Lear Jet with "rocket" and "propellant tank" drawn on the fuselage? Cripes!
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The first four flights had modified SR-71 ejection seats, but they'd only be useful in the last stages of descent, and were only there because they were test flights.
Escaping from dying spacecraft is rather harder than it looks. It's only in the first 45 seconds or so after launch when a rocket's going slowly enough to eject from. Challenger broke up about 70 seconds into flight, at which point it was already travelling at over a kilometre per second --- and the breakup wasn't caused by the explosion; it was caused by the explosion wrecking the shuttle's aerodynamics to such an extent that it started tumbling, and then the hypersonic wind tore the vehicle apart. You don't eject into that. Most fighter aircraft ejection seats can only be used at speeds of 300 metres per second or so (although I'm sure someone can quote me something really esoteric that works at faster speeds).
The shuttle does have an escape protocol; you put the vehicle into a stable glide and jump out the door (using a frankly ludicrous system to avoid hitting that huge wing). They put that in after the loss of Challenger. It wouldn't have helped.
The best way of escaping during launch is to fire the entire crew capsule free. Mercury, Apollo, Soyuz and the upcoming Orion, if it doesn't get cancelled, all used/will use escape towers; a set of solid fuel rockets on the crew capsule designed to get the capsule clear of an impending explosion in a hurry. But they're intended to work on the ground, and get ejected about 50 seconds into the flight.
You might be interested to read up about Soyuz 18a; the second stage hadn't separated when the third stage fired! The Soyuz capule was jettisoned, reentered normally, and landed safely. But that accident happened much later, when the whole vehicle was out of the atmosphere in a suborbital trajectory. Not having to worry about atmosphere makes things far easier.
Escaping on reentry is much harder. Columbia broke up while travelling at about *eight* kilometres per second, through atmosphere. I don't know of any way to survive an event like that.
At least one successful ejection has been made from an SR-71 at mach 3, which is roughly the speed that Challenger was doing when it broke up, assuming that your 1km/s figure is correct. The reason why this was survivable is because what kills an ejecting pilot isn't speed, but rather dynamic pressure caused by speed. Dynamic pressure increases with the square of speed ,but it also drops off with altitude. Your 300m/s figure is correct, but that's assuming a sea-level ejection. If you're at a high altitude then the true speed goes up accordingly. (If you're familiar with aviation terms, it's the indicated airspeed that kills you, not the true airspeed.) I don't know how high Challenger was when it broke up, but if it was more than about 12 miles then it's conceivable that ejections from it could have been survivable.
Not to take away from your post overall, as you make many excellent points, I just wanted to elaborate on that one thing.
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F-111 had an ejection capsule which protected occupants at high speeds, up to the top Mach 2.5 speed
http://www.f-111.net/ejection.htm
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Challenger broke up at 48kft (14.6 kilometers or 9 miles).
Ejections seats for Shuttle ascent were rejected on three grounds, none of them related to dynamic pressure:
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