compexp

Dave Graham, in charge of Northrop's wind tunnel, and EC Welch, head of Nortronics Control System Development, ready the Q-Ball for low flow sensitivity tests.

Bob Hayos, Nortronics

Nortronics engineers David Ruch and George Mills in the wind tunnel with the Q-Ball.

Bob Hayos, Nortronics

Left and right surfaces of the upper vertical stabilizer of X-15 no. 1 following an early NASA flight. Note all the access panels removed for servicing and inspection.

author's collection



				Close-up on lower ventral. Note the parachute markings to designate that it has been reflown successfully ten times prior to this flight. author's collection

	X-15 no. 3 right-side vertical tail ablative test sample (pink area) flown on 23 Apr. 1965. Armstrong Flight Research Center

A technician uses a Mobile Internal System Test Equipment Rack for X-15 check-out.

North American Aviation

X-15 operations required hydrogen peroxide, a dangerous substance to handle.

North American Aviation

Technicians attach the transport dolly to the rear of the X-15.

TD Barnes collection

Forward ballistic control system rockets installed in the nose of the X-15.

Armstrong Flight Research Center

Rear view of the lower ventral speed breaks in the open position.

author's collection

Front view of the upper ventral speed breaks open on X-15 no. 3 in the NASA hangar.

author's collection

Access panels removed from the fuselage fairing along the left side of an X-15.

NASA Headquarters

X-15 no. 3, with wiring connectors hanging out of the instrumentation bay.

author's collection

The left rear skid shown deployed after landing.

Armstrong Flight Research Center

The dual-wheel nose gear and oleo assembly.

Armstrong Flight Research Center



				A third skid was installed between the lower ventral speed brakes on X-15 no. 1. This was flown by Michael Adams on Mission 1-71-121 on 28 Apr. 1967. Armstrong Flight Research Center

		Helium pressure vessel installed in the rear fuselage of the X-15A-2 on 5 Mar. 1965. Armstrong Flight Research Center

	— The Nortronics "Q" Ball Attitude Sensor —

	Nortronics, the electronic development division of the Northrop Corporation, developed the Flight Path Control Sensor for use on the X-15. More simply, it was known as the "Q Ball" because it sensed dynamic air pressure, known as Q in aeronautical terms. That measurement of Q by the sensor told the X-15 which direction it was flying, especially important for angle-of-attack during re-entry. The sensor was literally the nose cone of the X-15.

The Nortronics Flight Path Control Sensor design team. On the right is shown a clear-view model of the Q-Ball, while on the left is an actual finished sensor instrument.

Bob Hayos, Nortronics

The Q Ball sensor package installed on the front of the X-15. Wires come out of an access panel for testing.

Bob Hayos, Nortronics

A Nortronics Q Ball publicity illustration.

Bob Hayos, Nortronics

The Flight Path Control Sensor housing under construction on a milling machine.

Bob Hayos, Nortronics

Neil Armstrong flew the first X-15 mission using the Q Ball sensor.

Armstrong Flight Research Center

	— Examples of Experiments Carried Aloft by the X-15 —

The Western Test Range (WTR) experiment extended up out of an access hatch behind the cockpit called the "skylight." It was used to track a missile launched from Vandenberg AFB. Photographed on 2 Aug. 1966. Bill Dana would fly this experiment on Mission 3-53-79 on 4 August to 132,700 feet at Mach 5.34 or 3,693 mph.

TD Barnes collection

WTR experiment installed in X-15 no. 3 on 2 Aug. 1966, with access cover removed.

Armstrong Flight Research Center

The WTR experiment stowed with the skylight hatch opened.

Armstrong Flight Research Center

Left-hand wingtip pod with cap open and experiment mount extended.

Armstrong Flight Research Center

The same pod after a hypersonic flight on the tip of X-15 no. 1's wing.

Armstrong Flight Research Center

The Atmospheric Density Measurement experiment. The sensor is shown deployed in the image at left, while the pod, covered in green thermopaint is shown on the right.

author's collection

The Jet Propulsion Laboratory Solar Spectrum experiment carried in the rear of the wing-tip pod. On the left it is undergoing testing, and at right, is installed in the rear of the pod.

Armstrong Flight Research Center



	The X-15 with tip pods is mounted to the B-52 pylon. Note the small clearance between the left wingtip pod and the B-52s fuselage. Image taken 13 Sep. 1966, prior to Mission 3-55-82 which will be flown by Bill Dana the following day. TD Barnes collection

			A wing tip pod experiment under test. TD Barnes collection

A test was devised to mount a section of insulation, to be used on upcoming Saturn V missions, to the upper left side speed brake of X-15 no. 3.

The insulation would be exposed to hypersonic speeds and heating effects when the speed brake was deployed during flight.

TD Barnes collection



			The camera ports for the KS-25 on the bottom fuselage of X-15 no. 1. Robert Rushworth flew this on Mission 1-45-72 on 27 Mar. 1964. Armstrong Flight Research Center

	The KS-25 reconnaissance camera installed in the X-15 instrumentation bay. author's collection

A Star Tracker system was flown by Pete Knight on Mission 2-47-84 on 3 Aug. 1966. The instrument was constructed by the University of Wisconsin's Washburn Observatory. It photographed stars from 249,000 feet while flying at Mach 5.03 or 3,440 mph. At left is the experiment before installation in the X-15A-2. At right is after installation.

Armstrong Flight Research Center

The Rarified Wake Flow experiment deployed a Mylar balloon for photography. Joe Walker unsuccessfully attempted this on Mission 3-21-32 on 19 Jul. 1963.

author's collection

Like the Wake Flow experiment, this Horizon Definition infrared experiment from NASA Langley was installed in a box at the rear of the X-15 no. 3 upper vertical tail.

author's collection