First Flight:
May 23, 1955
Mission: Test bed for high-mach effects on space reentry
vehicles
Major Accomplishments: Provided practically all information regarding
the effects of high speed reentry for manned and unmanned spacecraft.
Information from the X-17 program became the major source of data for the design
of virtually all reentry vehicles.
Power Source (1st Stage): 1 Thiokol XM-20 (Sergeant) rocket,
48,000 lb thrust
(2nd Stage): 3 Thiokol XM-19 (Recruit) rockets, 33,900 lb thrust each
(3rd Stage): 1 Thiokol XM-19E1 (Recruit with modified exhaust) rocket,
35,950 lb thrust
Fin Span: 8' 6"
Length: 40' 4"
Maximum Achieved Speed: Mach 14.4 (9,504 mph)
Maximum Achieved Altitude: 245 miles (typical altitude was approx. 95
miles)
Additional Information: The X-17 was designed to test reentry
characteristics of payloads, including intercontinental warheads, manned
spacecraft and unmanned reentry vehicles.
During a typical mission the X-17 would climb only on the thrust of its first
stage. With the first stage fuel spent, the X-17 would coast, reaching an
altitude of about 500,000 ft, then would begin a "controlled" freefall
back to Earth. At about 120,000 ft (22 miles), with an speed of mach 5, the 2nd
stage would ignite, pushing the craft to nearly mach 10. At approximately 72,000
ft (13 miles), the final stage was ignited, pushing the reentry test bed to
speed of up to mach 14.4, over 9,500 mph.
26 X-17's are known to have been built and flown, though others may have been
constructed from spare parts for the USAF secret "Project Argus". The
last known X-17 flight was August 22, 1957.
