Forty Years ago in the X-15 Flight Test Program, Table of Contents


Forty years ago, the three X-15 rocket planes were the pinnacle of aerospace engineering. They were capable of higher speeds and altitudes than any other piloted vehicle. Except for the Space Shuttle, they are still the fastest and highest flying winged vehicles ever. This series of pages follows the history of the X-15 program, tracking the events as they occurred forty years ago.

1959 - January 1960, a series of three flights were made with the X-15-1 captive on the wing of the NB-52A. The X-15-2 was first displayed to the public at the 1959 Air Force Flight Test Center Open House Display alongside the NB-52A. Scott Crossfield made the first glide flight in the X-15-1. He then made three powered flights testing the pair of XLR-11 rocket engines in the X-15-2. An engine explosion cut the third powered flight short, and the fuselage of the X-15 broke when it landed heavy.

January - April 1960, Scott Crossfield made the first powered flight of the X-15-1, after which it was transferred to NASA. He expanded the flight envelope of the X-15-2 following its return to Edwards Air Force Base. Joe Walker and Bob White made the first NASA flights of the X-15-1.

April - May 1960, reaction control thrusters were installed in the X-15-2. Joe Walker exceeded Mach 3 in the X-15-1. The X-15-1 and X-15-2 were displayed at the 1960 Air Force Flight Test Center Open House Display with the NB-52B.

June - August 1960, a series of attempts were made to launch Joe Walker in the X-15-1 to make an assault on Mel Apt's speed record. The X-15-3 arrived at Edwards Air Force Base with the XLR-99 engine. The engine exploded during a ground test run, nearly destroying the X-15-3. After a two month hiatus, Joe Walker set a new speed record in the X-15-1, and Bob White set a new altitude record.

August - October 1960, The X-15-2 was out of service until the installation of its XLR-99 engine in September. Walker and White collected control and performance data and new pilots Commander Forrest Petersen and NASA pilot Jack McKay were checked out in the X-15-1. A series of technical difficulties postponed Crossfield's first flight with the XLR-99 installed in the X-15-2.

November 1960, Captain Robert Rushworth and Neil Armstrong made their first flights in the X-15-1, and Scott Crossfield piloted the first X-15 flight powered by the XLR-99 engine.

November 1960 - January 1961, Scott Crossfield concluded the North American contractor demonstration of the X-15 equipped with the XLR-99 rocket engine.

February - March 1961, Major Robert White flew the last X-15 mission powered by the XLR-11 twin pack of rocket engines. NASA conducted its first operations with the X-15-2 which had received a new nose. The X-15 made the first mach-4 flight and set a new altitude record.

April - June 1961, Joe Walker and Major Bob White set three new speed records in the X-15-2, including the first flight faster than Mach 5. Frank Sinatra's Essex Productions filmed scenes for the movie X-15 at the Air Force Flight Test Center.

July - August 1961, Commander Forrest Petersen made the first flight of the X-15-1 with the XLR-99 engine.

September - November 1961, Four pilots made six X-15 flights. The maximum Mach number attained by the X-15 was increased on three occasions and the altitude record was increased from 169,600 to 217,000 feet. The X-15 attained Mach 6, the goal originally established for the program. On two occasions, one of the panes of the windshield broke as the X-15-2 was decelerating after setting a new speed record. Major Robert Rushworth made one flight with the lower ventral removed to evaluate the stability of the X-15 in that configuration.

November 1961- March 1962, Following the achievment of the X-15's design maximum mach number on November 9, 1961, the emphasis of the program shifted from envelope expansion to flight research at high mach numbers and altitudes. Repairs to the X-15-3 were completed North American at El Segundo, and it returned to Edwards Air Force Base for its first flight a year and a half after it exploded in the rocket engine test stand.

April 1962, No X-15 missions were launched between January 17 and the beginning of April 1962. The pace of the program picked up significantly in April. Sixteen X-15 missions would be launched in the next four months. The X-15-3 was expanding its altitude envelope. The X-15-2 was slated to evaluate airframe heating, and the X-15-1 was expected to set another new altitude record.

At the beginning of May 1962, Major Robert Rushworth was preparing to fly an airframe heating investigation with the X-15-2, but first it would be carried across the country by the NB-52A to appear at the Eglin Air Force Base airshow. Major Bob White was planning to evaluate the performance of the Alternate Stability Augmentation System (ASAS) of the X-15-1 at high angle of attack.


Link to NASA Dryden X-15 Photo Gallery Contact Sheet.

The best source of information about the X-15 program is X-15 Research Results, which is now available online.


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