NACA met with USAF and Navy BuAer representatives to propose the X-15 as an extension of the cooperative rocket research aircraft program. The NACA proposal was accepted as a joint effort and a memorandum of understanding was signed on December 23 naming NACA as technical director of the project, with advice from a joint Research Airplane Committee.

Details of X-15 rocket research airplane were publicly revealed for the first time.

First of a series of three X-15 experimental rocket-powered manned research aircraft was rolled out at the Los Angeles plant of North American Aviation, Inc., in the joint USAF-USN-NASA program.

First flight for X-15 # 1. Planned glide flight. Maximum Speed - 840 kph. Maximum Altitude - 11445 m.

First flight for X-15 # 2. First powered flight. Maximum Speed - 2241 kph. Maximum Altitude - 15954 m. Turbopump case failure resulted in fire in engine compartment.

Maximum Speed - 2283 kph. Maximum Altitude - 18831 m. Nose gear door failed on landing.

Engine fire; fuselage structural failure on landing. Aircraft returned to North American for rebuild. Maximum Speed - 1062 kph. Maximum Altitude - 13857 m.

Maximum Speed - 2685 kph. Maximum Altitude - 20374 m.

Maximum Speed - 2359 kph. Maximum Altitude - 26858 m.

Maximum Speed - 1667 kph. Maximum Altitude - 16045 m. Automatic shutdown of one chamber in upper XLR-11.

Maximum Speed - 2283 kph. Maximum Altitude - 16045 m. 6G maneuver test.

Maximum Speed - 2124 kph. Maximum Altitude - 14822 m. Roll damper malfunctioned.

Maximum Speed - 2080 kph. Maximum Altitude - 15235 m.

Maximum Speed - 2156 kph. Maximum Altitude - 15653 m. 3.5 to 5G pullouts to simulate reentry.

Maximum Speed - 2018 kph. Maximum Altitude - 14630 m.

Maximum Speed - 2718 kph. Maximum Altitude - 18134 m.

Maximum Speed - 2336 kph. Maximum Altitude - 18574 m.

Maximum Speed - 3397 kph. Maximum Altitude - 23738 m.

Maximum Speed - 2558 kph. Maximum Altitude - 33222 m.

Maximum Speed - 2336 kph. Maximum Altitude - 15631 m. First test of reaction control system.

Maximum Speed - 3533 kph. Maximum Altitude - 23809 m. Unofficial world speed record. This topped Captain Apt's speed of 2,094 mph attained in the X-2 on September 27, 1956.

Maximum Speed - 2851 kph. Maximum Altitude - 41605 m. Established a new altitude record for a manned vehicle of 136,500 feet. This topped Captain Kincheloe's record altitude of 126,200 feet attained on September 7, 1956, in the X-2 rocket research aircraft.

Maximum Speed - 3195 kph. Maximum Altitude - 23159 m.

Maximum Speed - 3510 kph. Maximum Altitude - 24343 m.

Maximum Speed - 1783 kph. Maximum Altitude - 16168 m. Premature shutdown of both XLR-11's.

Maximum Speed - 2059 kph. Maximum Altitude - 16398 m.

Maximum Speed - 2145 kph. Maximum Altitude - 15453 m.

Maximum Speed - 2071 kph. Maximum Altitude - 14905 m.

First flight with XLR-99 engine. Maximum Speed - 3154 kph. Maximum Altitude - 24750 m.

Maximum Speed - 2018 kph. Maximum Altitude - 16688 m. Lower XLR-11 shutdown but restarted.

First restart with XLR-99 engine. Maximum Speed - 2665 kph. Maximum Altitude - 18867 m.

Maximum Speed - 1858 kph. Maximum Altitude - 14886 m. Only 7 of 8 XLR-11 chambers ignited.

Maximum Speed - 3027 kph. Maximum Altitude - 16268 m.

First hot nose flight. Maximum Speed - 1911 kph. Maximum Altitude - 15269 m.

Maximum Speed - 1949 kph. Maximum Altitude - 15170 m.

Maximum Speed - 3660 kph. Maximum Altitude - 23820 m. Last XLR-11 flight.

Maximum Speed - 4674 kph. Maximum Altitude - 23610 m.

Maximum Speed - 4441 kph. Maximum Altitude - 51700 m.

Maximum Speed - 4946 kph. Maximum Altitude - 32000 m.

Maximum Speed - 5321 kph. Maximum Altitude - 32850 m.

Harmon International Aviator's Trophy for 1961 announced as going to three winners for the first time-X-15 rocket research airplane pilots: A. Scott Crossfield, of North American; Joseph A. Walker, of NASA, and Maj. Robert A. White, U.S. Air Force.

Maximum Speed - 5797 kph. Maximum Altitude - 32830 m. Lost cabin pressure.

Maximum Speed - 4401 kph. Maximum Altitude - 23830 m. Lost cabin pressure.

Maximum Speed - 5821 kph. Maximum Altitude - 34840 m. Smoke in cockpit due to scorching paint.

Maximum Speed - 5792 kph. Maximum Altitude - 31030 m. Test reentry heat limit. Smoke in cockpit due to scorching paint.

Flight made with lower ventral off. Maximum Speed - 4553 kph. Maximum Altitude - 23770 m.

Outer panel of left windshield cracked. Maximum Speed - 5868 kph. Maximum Altitude - 66150 m.

Maximum Speed - 6275 kph. Maximum Altitude - 33100 m.

Design speed achieved. Outer right windshield shattered. Maximum Speed - 6586 kph. Maximum Altitude - 30950 m.

First flight for X-15 # 3. Maximum Speed - 4026 kph. Maximum Altitude - 24700 m.

Emergency landing on Mud Lake after engine failed to light. Maximum Speed - 1038 kph. Maximum Altitude - 13,640 m.

Maximum Speed - 6058 kph. Maximum Altitude - 40690 m.

Maximum Speed - 4586 kph. Maximum Altitude - 54860 m. The X-15 was flown in a test of a new automatic control system to be used in the Dyna-Soar and Apollo spacecraft. The previous electronic control system had been automatic only while the X-15 was in the atmosphere; the new system was automatic in space as well.

Maximum Speed - 6220 kph. Maximum Altitude - 46940 m.

Maximum Speed - 6097 kph. Maximum Altitude - 63250 m.

Maximum Speed - 5879 kph. Maximum Altitude - 32160 m.

Design altitude flight. Maximum Speed - 5614 kph. Maximum Altitude - 75190 m.

Maximum Speed - 5670 kph. Maximum Altitude - 21460 m.

Maximum Speed - 5551 kph. Maximum Altitude - 30600 m. Roller coaster flight with 3 peaks for local airflow investigation.

Maximum Speed - 5913 kph. Maximum Altitude - 40420 m. Steepest reentry descent with highest angle of attack (27 degrees) to date.

Maximum Speed - 5908 kph. Maximum Altitude - 31580 m.

Maximum Speed - 5659 kph. Maximum Altitude - 56270 m.

Maximum Speed - 5858 kph. Maximum Altitude - 75190 m.

Unofficial world speed record. Maximum Speed - 6603 kph. Maximum Altitude - 37700 m.

Maximum Speed - 5911 kph. Maximum Altitude - 32670 m.

FAI world altitude record. Maximum Speed - 6166 kph. Maximum Altitude - 95940 m. First astronaut wings flight (USAF definition).

Maximum Speed - 5590 kph. Maximum Altitude - 25680 m.

Maximum Speed - 6418 kph. Maximum Altitude - 30150 m. Roller coaster descent to simulate emergency reentry.

Maximum Speed - 5532 kph. Maximum Altitude - 44040 m.

Maximum Speed - 4735 kph. Maximum Altitude - 27700 m.

Maximum Speed - 6029 kph. Maximum Altitude - 59010 m. New reentry technique using pitch angle instrument instead of AOA.

Maximum Speed - 5686 kph. Maximum Altitude - 27000 m.

Maximum Speed - 5546 kph. Maximum Altitude - 29630 m.

This and most following flights without lower ventral. Maximum Speed - 4450 kph. Maximum Altitude - 20790 m.

Maximum Speed - 5620 kph. Maximum Altitude - 34200 m.

Maximum Speed - 5979 kph. Maximum Altitude - 39700 m.

Maximum Speed - 6056 kph. Maximum Altitude - 41000 m.

Engine only produced 35% power. Emergency landing at Mud Lake. Aircraft seriously damaged when gear failed. McKay injured. Maximum Speed - 1640 kph. Maximum Altitude - 16450 m.

Maximum Speed - 6021 kph. Maximum Altitude - 43100 m.

Maximum Speed - 6103 kph. Maximum Altitude - 48900 m.

First civilian flight above 80 km. Maximum Speed - 5917 kph. Maximum Altitude - 82810 m. Second astronaut wings flight (USAF definition).

Maximum Speed - 4608 kph. Maximum Altitude - 22680 m. First flight in scientific and advanced research series - carried aerial mapping camera.

Nose landing gear failed. Maximum Speed - 6066 kph. Maximum Altitude - 28190 m.

Maximum Speed - 5612 kph. Maximum Altitude - 63820 m. Carried earth background radiation instrument in support of Midas reconnsat development.

Maximum Speed - 5792 kph. Maximum Altitude - 29140 m.

Maximum Speed - 6204 kph. Maximum Altitude - 37860 m. Lost both nose landing gear tires and forward fuselage buckled after APU gear box pressure loss.

Inner panel of left windshield cracked. Maximum Speed - 6208 kph. Maximum Altitude - 28040 m.

Maximum Speed - 5694 kph. Maximum Altitude - 68180 m.

Maximum Speed - 6293 kph. Maximum Altitude - 34080 m.

Maximum Speed - 5511 kph. Maximum Altitude - 86870 m. Third astronaut wings flight (USAF definition).

Maximum Speed - 5842 kph. Maximum Altitude - 69010 m.

Maximum Speed - 6315 kph. Maximum Altitude - 31940 m.

Maximum Speed - 5969 kph. Maximum Altitude - 106010 m. Astronaut wings flight. 80 cm diameter balloon dragged on 30 m line to measure air density. First X-15 astronaut flight (FAI definition); fourth astronaut wings flight (USAF definition).

Unofficial world altitude record. Maximum Speed - 6105 kph. Maximum Altitude - 107960 m. Second X-15 astronaut flight (FAI definition); fifth astronaut wings flight (USAF definition).

Maximum Speed - 4560 kph. Maximum Altitude - 23710 m.

Maximum Speed - 4364 kph. Maximum Altitude - 22600 m.

Maximum Speed - 4706 kph. Maximum Altitude - 25080 m. First flight with sharp-edged vertical stabilizer.

Maximum Speed - 5287 kph. Maximum Altitude - 27680 m.

Maximum Speed - 5326 kph. Maximum Altitude - 27371 m.

Maximum Speed - 6465 kph. Maximum Altitude - 30785 m. Camera test in combination with U-2 flight.

Maximum Speed - 5818 kph. Maximum Altitude - 42642 m.

Maximum Speed - 5216 kph. Maximum Altitude - 21641 m.

Maximum Speed - 5821 kph. Maximum Altitude - 32736 m. First test of hypersonic speed brakes.

Maximum Speed - 5662 kph. Maximum Altitude - 23957 m.

Maximum Speed - 5458 kph. Maximum Altitude - 23165 m.

Maximum Speed - 6158 kph. Maximum Altitude - 30937 m. Secret reconn camera test.

Maximum Speed - 5580 kph. Maximum Altitude - 53340 m.

Maximum Speed - 6285 kph. Maximum Altitude - 30968 m.

Maximum Speed - 4962 kph. Maximum Altitude - 22189 m.

Maximum Speed - 5262 kph. Maximum Altitude - 59680 m.

Premature engine shutdown at 41 sec. Maximum Speed - 3001 kph. Maximum Altitude - 19568 m.

Maximum Speed - 4994 kph. Maximum Altitude - 25390 m. First flight of X-15 No. 2 in X-15A-2 configuration, but without drop tanks.

Maximum Speed - 5364 kph. Maximum Altitude - 30358 m.

Maximum Speed - 5664 kph. Maximum Altitude - 51938 m. First test of IR horizon scanner.

Maximum Speed - 5250 kph. Maximum Altitude - 23774 m. First test of various heat-resistant panels attached to fuselage.

Maximum Speed - 5688 kph. Maximum Altitude - 24750 m.

Maximum Speed - 5776 kph. Maximum Altitude - 31486 m. Nose landing gear extended at Mach 4.5. Both tires blew on landing.

Maximum Speed - 6216 kph. Maximum Altitude - 27737 m.

Maximum Speed - 5817 kph. Maximum Altitude - 23957 m.

Maximum Speed - 6256 kph. Maximum Altitude - 29566 m.

Maximum Speed - 5699 kph. Maximum Altitude - 29809 m.

Maximum Speed - 4904 kph. Maximum Altitude - 25878 m. First flight with X-20 INS and wing tip pods.

Maximum Speed - 5009 kph. Maximum Altitude - 25786 m.

Maximum Speed - 4970 kph. Maximum Altitude - 26579 m.

Maximum Speed - 5990 kph. Maximum Altitude - 28164 m.

Maximum Speed - 5913 kph. Maximum Altitude - 34503 m.

Maximum Speed - 5781 kph. Maximum Altitude - 24750 m.

Maximum Speed - 5973 kph. Maximum Altitude - 30297 m. Immediately after burnout aircraft gyrated around all 3 axes for 7 seconds.

Maximum Speed - 6253 kph. Maximum Altitude - 29931 m.

Maximum Speed - 5649 kph. Maximum Altitude - 28986 m. Right main landing gear extended at Mach 4.1; normal landing.

Maximum Speed - 6034 kph. Maximum Altitude - 46817 m.

Maximum Speed - 5760 kph. Maximum Altitude - 31059 m.

Maximum Speed - 5760 kph. Maximum Altitude - 24293 m.

Maximum Speed - 5266 kph. Maximum Altitude - 28224 m. First star tracker checkout.

Maximum Speed - 5697 kph. Maximum Altitude - 31120 m.

Maximum Speed - 5100 kph. Maximum Altitude - 54803 m.

Maximum Speed - 6040 kph. Maximum Altitude - 63886 m.

Maximum Speed - 5477 kph. Maximum Altitude - 74585 m.

Maximum Speed - 5697 kph. Maximum Altitude - 33071 m.

Maximum Speed - 6336 kph. Maximum Altitude - 47518 m.

Maximum Speed - 5522 kph. Maximum Altitude - 85527 m. Astronaut wings flight (USAF definition).

Maximum Speed - 5887 kph. Maximum Altitude - 64800 m. Star tracker mission to photograph Gamma Cassiopeia.

Maximum Speed - 6050 kph. Maximum Altitude - 32126 m.

Maximum Speed - 5796 kph. Maximum Altitude - 63612 m.

Maximum Speed - 5686 kph. Maximum Altitude - 31455 m.

Maximum Speed - 5712 kph. Maximum Altitude - 82601 m. Astronaut wings flight (USAF definition).

Maximum Speed - 5799 kph. Maximum Altitude - 65258 m.

Maximum Speed - 5426 kph. Maximum Altitude - 73030 m.

Maximum Speed - 5744 kph. Maximum Altitude - 73091 m.

Maximum Speed - 5686 kph. Maximum Altitude - 29627 m.

Maximum Speed - 5662 kph. Maximum Altitude - 72847 m.

Maximum Speed - 5712 kph. Maximum Altitude - 30571 m.

Maximum Speed - 6005 kph. Maximum Altitude - 90099 m. Astronaut wings flight (USAF definition).

Maximum Speed - 4373 kph. Maximum Altitude - 23350 m.

Maximum Speed - 5001 kph. Maximum Altitude - 28770 m.

Maximum Speed - 5718 kph. Maximum Altitude - 81230 m. Astronaut wings flight (USAF definition).

Maximum Speed - 5662 kph. Maximum Altitude - 72210 m.

First flight with empty external tanks. Ammonia tank recovered; Lox tank destroyed. Maximum Speed - 2414 kph. Maximum Altitude - 21520 m.

Maximum Speed - 4450 kph. Maximum Altitude - 24440 m.

Premature engine shutdown at 32 sec. Maximum Speed - 2307 kph. Maximum Altitude - 20850 m.

Maximum Speed - 5936 kph. Maximum Altitude - 30170 m.

First flight with fueled external tanks. Engine shutdown at 34.6 seconds due to fuel flow anomalies. Maximum Speed - 1646 kph. Maximum Altitude - 13720 m.

Maximum Speed - 5876 kph. Maximum Altitude - 39620 m.

Maximum Speed - 5176 kph. Maximum Altitude - 29290 m. First flight with X-20 energy management system.

Maximum Speed - 5741 kph. Maximum Altitude - 58610 m.

Maximum Speed - 5957 kph. Maximum Altitude - 73700 m.

Maximum Speed - 5535 kph. Maximum Altitude - 75890 m. UV photos of stars in Auriga.

Maximum Speed - 6376 kph. Maximum Altitude - 40450 m.

Maximum Speed - 5776 kph. Maximum Altitude - 76500 m.

Maximum Speed - 5586 kph. Maximum Altitude - 70440 m.

Maximum Speed - 5804 kph. Maximum Altitude - 54250 m.

Maximum Speed - 5701 kph. Maximum Altitude - 78490 m. Collected micrometeorites and extraterrestrial dust.

Maximum Speed - 5701 kph. Maximum Altitude - 30540 m.

Premature engine shutdown at 38 sec. Maximum Speed - 2578 kph. Maximum Altitude - 22310 m.

Maximum Speed - 5770 kph. Maximum Altitude - 22980 m. JPL spectrometer measured solar flux; radiometer characterized exhaust plume in UV for reconnsat sensors; collected micrometeorites.

Maximum Speed - 4666 kph. Maximum Altitude - 22980 m. Engine shut down at 90 seconds.

Maximum Speed - 6034 kph. Maximum Altitude - 93540 m. Astronaut wings flight (USAF definition).

Unofficial world's speed record. Maximum Speed - 6838 kph. Maximum Altitude - 30140 m.

Maximum Speed - 5020 kph. Maximum Altitude - 28040 m.

Maximum Speed - 6150 kph. Maximum Altitude - 40570 m. Inertial system failed after peak altitude; cabin pressurization lost during descent.

Maximum Speed - 1871 kph. Maximum Altitude - 16280 m.

Maximum Speed - 5985 kph. Maximum Altitude - 50900 m.

Maximum Speed - 5138 kph. Maximum Altitude - 29750 m. Check out of stability and control with ramjet pod.

Maximum Speed - 5112 kph. Maximum Altitude - 21670 m.

Maximum Speed - 5802 kph. Maximum Altitude - 69890 m.

Maximum Speed - 5810 kph. Maximum Altitude - 25050 m.

Electrical failure while climbing through 32610 m; lost engine at 69 seconds; landed at Mud Lake with no flaps; Knight injured while exiting aircraft. Maximum Speed - 4618 kph. Maximum Altitude - 52730 m.

Maximum Speed - 5942 kph. Maximum Altitude - 25720 m.

First test with full ablative coating, ramjet pod. Maximum Speed - 5419 kph. Maximum Altitude - 27740 m.

Maximum Speed - 5012 kph. Maximum Altitude - 25720 m.

Unofficial world speed record (full ablative coating, dummy ramjet, mechanical eyelid). Maximum Speed - 7273 kph. Maximum Altitude - 31120 m.

Maximum Speed - 7270 kph. Maximum Altitude - 76530 m.

Maximum Speed - 6204 kph. Maximum Altitude - 85500 m. Astronaut wings flight (USAF definition).

Fatal accident, aircraft destroyed. After reaching peak altitude, entered spin at Mach 5. Entered dive at 30,000 m, began high frequency pitch oscillations, disintegrated when these reached 15 Gs.Maximum Speed - 5744 kph. Maximum Altitude - 81080 m.

Maximum Speed - 4631 kph. Maximum Altitude - 31850 m. Tested Saturn V insulation.

Maximum Speed - 5808 kph. Maximum Altitude - 57150 m.

Maximum Speed - 5704 kph. Maximum Altitude - 63090 m.

Maximum Speed - 5733 kph. Maximum Altitude - 67090 m.

Maximum Speed - 5442 kph. Maximum Altitude - 67510 m.

Maximum Speed - 5540 kph. Maximum Altitude - 81530 m. Astronaut wings flight (USAF definition).

Maximum Speed - 5990 kph. Maximum Altitude - 77450 m.

Last flight. Maximum Speed - 5979 kph. Maximum Altitude - 77720 m.