The first successful “soft Landing” of an unmanned vehicle using self-contained automatic control and a technical feat equaling the first launch of a ballistic missile was achieved Nov. 22 with the Surveyor T-2N-1 test spacecraft at Alamogordo, N. M.
The entire terminal descent test at the Air Force Missile Development Center was termed by Senior Project Engineer Bob McNamara as “perfect in every detail.”
This means that the entire flight control system, including the vernier propulsion system, designed to slow or speed the descent of the Surveyor spacecraft to the desired landing speed during the final few miles of flight after the 18,000-mile-per-hour trip fro earth to the moon, and the unique Ryan radar system worked “A-OK.”
“The technical problems involved in slowing a speeding unmanned vehicle so that it lands without damage are no less complex than those in launching the first ballistic missile,” said R. R. Roderick. Surveyor Program Manager. “In effect, we’ve reversed the launching procedure to get a soft landing.”
He pointed out that newspaper accounts of Soviet attempts to soft-land a vehicle on the moon said that the vehicles crashed into the moon apparently because of failures in their radar systems.
“A great deal of credit goes to the men who have struggled with and conquered these flight control problems,” Dr. Roderick added.
The T-2N descent test program is under the direction of Warren Nichols at Culver City. Larry Steffan is the test director at AFMDC, supported by Flight Test Division’s Holloman Operations under Manager Lloyd McClellan. Mr. McNamara headed systems engineering.
Others cited by Dr. Roderick are subsystems engineers Truett Black, Davey Alders, Ray Barber, Rob Smith, Bernie Malitsky, Saul Briskin, Walt Shippy, Chuck Anthens, and Jack Preston who directed the reliability effort.
Also credited were Larry Albright, Merle Borman, Gordon Brooks, Bill Cook, Bill Edenfield, Rod Edwards, Ep Epstein, Roy Goodgion, Freer Gottried, Sam Kerr, Sam Parker, Russell Ridgeway, Harry Schiller, Frank Zolner, and Darlene Pickerd.
The T-2N-1 was returned to Culver City via airplane late Nov. 24 for additional tests before returning to AFMDC for a new series of descent tests. A second test spacecraft, T-2N-2 left Culver City last Monday to begin its role in perfecting the soft-landing technique.
The following is excerpted from JPL Space Programs Summary No. 37-37, January 31, 1966.
T-2N Descent Test Program
a. T-2N-1 first descent test vehicle. On November 22, 1965, a successful descent test was performed. The vehicle trajectory control during free flight followed the predicted profile. During the descent, the vehicle maintained a velocity of 5 ft/sec for 4 sec. At approximately 600 ft from the ground, after a free flight from approximately 1430 ft, recovery was initiated as programmed and all recovery functions were successful. Good test data were received on all telemetry channels and optical tracked was complete. Detailed analysis of the data is being performed, after which a complete report will be issued. At the conclusion of the test, the T-2N-1 vehicle was returned to Culver city for minor upgrade, inspection, and repeat of the system functional tests.