Hi Alex,

I'd love to get some firm confirmation (or otherwise) that the Aurora ever actually existed, but if it ever did this will be a long time coming !

It always strikes me as odd that the superb SR-71 was "retired" so quickly and with so little fuss. Either the official line is true, and the servicing difficulties and "peace dividend" resulted in the retirement, or it was retired because its successor was waiting in the wings.

Maybe, one day, we'll find out !

Alastair

Alastair,

I agree with you about the SR-71 retirement story. It was so sudden and nonsensical. I am highly skeptical of the idea that we abandoned an important category of intelligence gathering capability simply because the aircraft were getting old. So at a maximum we have Aurora, not announced. At a minimum we have a fleet of newly-built SR-71s that has not been announced.

I think we had another example of "methinks the lady doth protest too much" when Edward Teller announced that the spaceborne X-ray laser program had been shut down because the device did not and never would be able to work.

Yeah, right. All that quasi-public discussion about underground nuclear tests bathing test articles with early fireball radiation. (The tests with the massive doors that slam shut in milliseconds just before the blast wave reaches them.) All those tests -- and nothing important was learned or developed.

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Now there's a problem here. Conspiracy theories can never be disproven, so we have to take everything with a grain of salt as Alex has done. Otherwise we will all become like the people who buy T-shirts in Roswell, NM.

Those things said ...

Alex,

What arguments do you see for retaining an airborne reconaissance facility like SR-71 and therefore like Aurora?

I see one and it is the (backup?) ability to put a bird over any spot on the earth at 80,000 feet with six hours notice.

Satellites can't come closer than perhaps 250,000 feet, and if they are to be useful for long periods of stare time they will have to be in high polar orbit, meaning that they will be looking at the earth from quite a distance, probably through adaptive optics, which is a clever idea but which probably can't cure cancer.

But an Aurora type craft can fly low enough over/alongside the target area to eliminate the need for adaptive optics, and it seems to me that this COULD cure cancer.

You could arrange to have a satellite in low polar orbit, and to de-orbit it temporarily so as to bring it down to 250,000 feet, but then you'd have to wait for the earth to rotate beneath that satellite so as to bring the point of interest roughly beneath down-looking optics.

Now you could improve things by having a constellation of such satellites, say one over each time zone ... But what if they're knocked out by some enemy capability that nobody's talking about -- like a spaceborne (or seaborne) Chinese X-ray laser.

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So it seems to me that if an aircraft like Aurora CAN be built then most likely it HAS been built -- as a backup to the recon satellites. They might never be needed in practice, but why take a chance?

So I think we're now down to the question not of whether but how. Can such an aircraft be built? I think that both Alastair and I will be very interested to hear anything you might have to say on that subject.

ok; I just finished looking up some information on the Aurora at http://www.fas.org/irp/mystery/aurora.htm, and I learned a bit about why aircraft are better than satellites, how the engine/cooling systems work, and how the project was funded.

According to the Department of Defense, the SR-71 was retired due to financial reasons. Operation and Maintenance of the SR-71 was around $710,000,000 in 1990 and 1991, plus they claimed that the new reconnaissance satellites

could perform worldwide surveillance more efficiently and less expensively than manned reconnaissance aircraft.

Aeronautical engineers claimed that these satellites were not as good as aircraft, agreeing with what Mike had to say. Aircraft, for example, are inherently flexible and unpredictable. Though not as fast as satellites, they can fly lower and the interval between over the horizon arrival and time-over-target is just as short. Aircraft have a wide choice of routes, so tracking ships are unlikely to see it on the way in. Application of low observable technology could further reduce warning time. Thus, it appears plausible that aircraft may still have a role in global reconnaissance.

The first suggestion that these studies might be translated into operational hardware appeared in the Fiscal Year 1986 procurement program document, colloquially known as the P-1, dated 4 February 1985. A line item in this document, labeled "Aurora," was slated to receive $80 million in 1986, and over $2.2 billion in 1987. Since this line item appeared next to the line funding the TR-1 reconnaissance aircraft, it stirred up a hornet's nest of conjecture that a secret aircraft was being developed to replace the aging SR-71.

The Air Force quickly denied the existence of a secret program, and said the "Aurora" budget line was simply one site for B-2 bomber funds when that program was highly classified. One Air Force official commented, "I wish I could say it is (an SR-71 follow-on), because we'd love to have it. But it's just accounting, I'm afraid."

Keeping an aircraft sufficiently cool during extreme speeds is a primary challenge of hypersonic flight. According to studies done by General Dynamics and Boeing, an aircraft travelling at between Mach 5.5 and Mach 6 would have an average skin temperature of approximately 1100-1300 degrees Fahrenheit. One potential solution incorporated in the Air Force studies, also being explored by researchers at NASA's Langley Research Center and Wright-Patterson Air Force base, is the use of Methylcyclohexane (MCH) as both the fuel and the thermal management medium of the vehicle.

MCH has several advantages over other possible hydrocarbon or cryogenic fuels. Unlike standard hydrocarbon fuels, MCH has a very high capacity to absorb heat prior to combustion, up to 1800 Btu per pound of fuel, which is ten times the capacity of most hydrocarbon fuels. Cryogenic Methane and Hydrogen have high heat absorbtion capacities as well, but their use as an aviation fuel is limited by the logistical difficulties of handling, storage and fuel boil off.

The principle behind MCH thermal management is based on a catalytic reaction transforming MCH into Toluene and Hydrogen, which are then used to fuel the aircraft.

A fuel pump pressurizes the fuel to avoid boiling. The preheater heats the fuel to the proper reaction temperature while removing heat from a secondary coolant. After preheating, the fuel passes through the catalytic heat exchanger/ reactor.

The secondary coolant, Syltherm, circulates to the hot spots to maintain skin temperatures to within specified tolerances.

One aerospace journal says that an aircraft travelling at Mach 6 would be inside the combustion envelope of a subsonic-combustion ramjet. It suggests that the aircraft would thus need an accelerator to get it moving. One type of accelerator would be a ducted-rocket cycle into the engine. A fuel-rich, liquid rocket exhaust would be injected into a ramjet duct, pumping air through it even at rest. A second combustion then takes place, using atmospheric oxygen.

For more information, read the site at the top of this comment (yes, I know I copied and pasted from they're site. But they explained this stuff way better than I could ever hope to do).