posted 05-17-2021 09:30 AM               

Space Cover #608: X-15 rocketplane records

Here are three of my most interesting X-15 covers:

On September 17, 1959, Scott Corssfield made the first planned flight in an X-15. He flew it to 52,341 feet. When I asked him to sign the cover, he looked at the date on this cover from about 8 inches away, just to make sure that it was dated for one of his flights.

In all, there were eight different pilots who earned Astronaut Wings for flying the X-15 above 50 miles or 264,000 feet. Of the 12 that exceeded this altitude, the October 17, 1967 flight by Pete Knight was only 280,500 feet.

Although the cover calls this a "Record Flight," a quick scan through Dennis Dillman's well researched, "Edwards Rocketplane Cover Handbook" shows that there were seven of the 13 flights in excess of this altitude.. The record altitude flight was set by Joe Walker on August 22, 1963 and attained 354,200 feet or 67 miles. Knight didn't break the speed record on this flight either. He set that record on his flight of October 3, 1967 at 4,520 mph (6.7 mach).

An X-15 cover for one of Neil Armstrong's seven X-15 flights is one of my treasures. He flew up to 133,500 ft. on this date but his maximum altitude came two flights later at 207,500 feet.