|Here's the X-15-2 (rebuilt following the McKay accident) with jettisonable fuel tanks attached to its side fairings. Those tanks carry an extra 13 500 lb. of propellants and will boost the plane's top speed to Mach 8 or provide longer flights. The plane's surface must be covered with an ablative coating to protect its structure from the 4000-deg. air temperatures of Mach 8 flight.|
X-15 with pods fastened to its wingtips for the collection of micrometeorite
particles at high altitude is seen here attached to a B-52 drop plane just prior
to takeoff on one of its most recent research missions.
|An infrared horizon-scanner, with cover plate removad, is seen here in its compartment behind the upper speed brakes of an X-15 before a research flight to high altitude. The instrument helped measure background noise for the design of satellite instruments. Those bundles of stainless-steel pressure tubes on the aft end of the upper vertical tail lead to pressure rakes on the sides of the tail.|
are outline drawings of two structural modifications of the X-15
for further research. Both involve a 29-inch extension of the fuselage.
The topmost profile reveals the plane with underwing tanks and
additional propellants for probing speeds to Mach 8. The lower profile
above shows the X-15 modified for in-flight study of small ramjet engines,
carried in the area usually occupied by the ventral fin. The drawing below
shows how a modified X-15 will make leading-edge (1) and panel (2)
experiments, and environmental tests with detachable wingtips (3).