Broke From United States of America, joined Apr 2002, 1322 posts, RR: 3 Reply 4, posted (11 years 6 months 2 weeks 1 day 5 hours ago) and read 2092 times:
The X-15 went in excess of Mach 6.5 (4500 mph) and 370,000 feet (not on the same flight). there were 3 built, one was lost during the program, one is at the Smithsonian Air and Space Museum in Washington, DC and the other is at the Air Force Museum in Dayton, Ohio. You can get pictures of the X-15 from the Air Force Museum web site at http://www.wpafb.af.mil/museum/
There is a book by Jay Miller called The X-Planes which has excellent articles on all the X Planes. A new release came out last year and should be available at most aviation book stores.
The X-15 was launched from a B-52 at about 35,000 feet.
SJC-Alien From United States of America, joined Jul 1999, 919 posts, RR: 1 Reply 5, posted (11 years 6 months 2 weeks 3 hours ago) and read 2046 times:
I always thought that the SR-71 was a twin-engined X-15 variant anyways...slightly modified,,,,,if you look at it and expand on it....could be, ya know,,,,but had to be an air-breather...I imagine the fuel supply on the X-15 was rather short in duration...