This photo of the X-15 near touchdown,
accompanied by an F-104
chase plane, is cropped from NASA photo
EC88-0180-9,
which is available on the NASA Dryden web server.
The X-15 Flight Manual called for airspeed at touchdown to be about 200
knots (230 m.p.h.) The slowest landing was about 145 knots; the fastest
were well over 200 knots, mainly in emergency landings with conditions
such as excess residual fuel on board and flap failures. Smoke in the
foreground served as a landing aid, to visually show instantaneous wind
direction and speed.