IN A PERIOD of a little more than sixty years since the first
flight of the Wright Brothers, man's exploration of three-dimensional space
above the surface of the Earth has extended beyond the atmosphere. Spectacular
and exciting events in this dramatic quest have been well publicized. Behind
these milestones of practical flight have been less publicized achievements in
scientific research, making such progress possible. Although the X-15 has had
its share of newsworthy milestones, its contributions to scientific research
have been a more essential and more meaningful part of the program from its
inception. This semi-technical summary of the X-15 program is directed toward
the less publicized aspects of its achievements.
The year 1964 marks the
tenth anniversary of the inception of the X-15 flight-research program, the
fifth year since the first X-15 flight. When the program was first approved, its
objectives were clearly stated in terms of aerodynamic heating, speed, altitude,
stability-and-control research, and bioastronautics. Although these objectives
have been essentially accomplished, it now appears that the three X-15's may be
flown for perhaps another five years, in a new role as test beds for fresh
experiments utilizing the X-15 performance, which still offers more than twice
the speed and three times the altitude capability of any other aircraft now in
existence.
Even though the program has been most successful in terms of
achieving its planned objectives and is continuing to play an important role in
aerospace research, many notable benefits have been of a different nature - more
intangible and somewhat unforeseen at the time the X-15 program was approved. In
the early years of our nation's space program, which has been based to a large
extent on the unmanned-missile technology that had been developed over the five
years prior to Project Mercury, the X-15 has kept in proper perspective the role
of the pilot in future manned space programs. It has pointed the way to
simplified operational concepts that should provide a high degree of redundancy
and increased chance of success in these future missions. All of the people in
industry and in government who have had to face the problems of design and of
building the hardware and making it work have gained experience of great value
to the more recent programs now reaching flight phase and to future aeronautical
and space endeavors of this country.
The X-15 program and Project
Mercury have represented a parallel, two-pronged approach to solving some of the
problems of manned space flight. While Mercury was demonstrating man's
capability to function effectively in space, the X-15 was demonstrating man's
ability to control a high-performance vehicle in a edge was obtained on the
techniques and problems associated with lifting reentry.
Already the
lessons learned are being applied to our new manned space programs. The pilot is
playing a much greater role in these programs. Certainly the problem of
launching the lunar-excursion module from the surface of the Moon through the
sole efforts of its two-man crew must appear more practical and feasible in the
light of the repeated launchings of the X-15 through the efforts of its pilot
and the launch operator on the carrier B-52 than would be the case if it were
compared only with the elaborate launch procedures and large numbers of people,
buried safely in blockhouses, that typify all other launch operations to date.
Future space programs may well include a lifting reentry and a more conventional
landing on Earth, in the fashion demonstrated by the X-15.
Edwards, California November 1,
1964
PAUL F. BIKLE, Director NASA Flight
Research Center
