Wednesday, April 18, 2012

Launching an X-15 from an XB-70



"The proposed X-15A-3 was a stretched, delta-winged version intended for extended duration flight at Mach 6+. As with the X-15 and X-15A-2 versions, the plan was to launch the X-15A-3 from a B-52 underwing pylong. However, North American Aviation proposed launching it from atop a B-70 bomber. The theory was that the B-70 could get the X-15 up to around Mach 3 prior to separation, thus greatly improving the rocketplanes performance."

Um... sick idea! Launching insane things from other insane things is a theme we need to continue. For example, why not get this XB-70 to launch off a giant blimp? More seriously, this kind of strategy comes back around every now and then. It would have been better for the Shuttle orbiter to fly from a reusable aircraft as initially designed.

From APR

2 comments:

Dick said...

Launching the Shuttle off a plane would be a trick as it didn't hold the fuel for its own engines. That aside, it seems Mmach 3 and a high launch altitude would be a good start for a launch system. We have a lack of big Mach 3 planes, however. I wonder why there wasn't a more direct follow on to the Blackbird?

High Power Rocketry said...

Well the initial shuttle designs would not be like the cludge we wound up with.

Initially it was to be two large rocket-gliders, each with a significant load of propellant within it. The first "stage" would fly to a certain altitude and speed, and glide home. The 2nd stage would be the orbiter, and it would carry a good amount of propellant also. This could have saved money because there would be no disposable parts. Also, the airframes were to be protected with metal - inconel et al. as well as ablative coatings. Safer and cheaper, with better turnaround time in theory. The only problem? A higher initial development cost. To save a few billion bucks back in the 70s, the shuttle program picked the design we now have, and it wound up being worthless and dangerous for crew. That is to say, without going 100%, we wound up with something that was just a drain on the space program.