This week you get three pictures (all from the Air Force Space and Missile History Center at the Cape Canaveral Air Force Station in Florida) of an interesting little footnote in the history of winged spacecraft — the ASSET re-entry vehicle program.
The ASSET (Aerothermal Elastic Structural Systems Environmental Tests) program was set up in 1960, originally in support of the X-20 “Dynasoar” program. The idea was to use these little flyers, launched on Scout sounding rockets, to test out materials and methods that could be used to help the Dynasoar craft survive re-entry. The vehicle’s shape was intended to represent the forward section of an X-20, which would experience the most severe heating during re-entry.
When the X-20 was cancelled in 1963, the ASSET program somehow managed to survive on its own, and was used to further development of technology for future manned spaceplanes.
Model of an ASSET on a Thor rocket
Meanwhile, the United Kingdom began to return Thor missiles to the U.S. after they were obsoleted — so the ASSET program switched to use this now-abundant resource for its launch vehicles. Thor rockets were used for two 4,000 m/sec re-entry flights, while Thor-Delta rockets were used to launch four 6,000 m/sec flights. Complicating matters for students of history, two types of ASSET vehicles flew — AEVs (Aerothermoelastic Vehicles), and ASVs (Aerothermodynamic Structural Vehicles). The two differed primarily in the content of their onboard experiments.
Model of an ASSET on a Thor-Delta rocket
All ASSET launches were conducted from Pad 17B at Cape Canaveral, with re-entry occurring south and east of Florida (the farthest ending up about 2,300 miles away from its launch site). Of six launches conducted between 1963 and 1965, five were successful (the second ASSET launch, carrying ASV-2 on a Thor-Delta, suffered a launch vehicle failure); only one vehicle of the six was recovered out of four attempts. This survivor was ASV-3, which now rests on display at the National Museum of the United States Air Force in Dayton, Ohio.
| # | Date | LV | Vehicle | Results |
| 1 | 18 Sept., 1963 | Thor | ASV-1 | Successful, but vehicle not recovered due to separation from flotation device after splashdown |
| 2 | 24 March, 1964 | Thor-Delta | ASV-2 | Delta (2nd) stage ignition failure |
| 3 | 22 July, 1964 | Thor-Delta | ASV-3 | Successful, recovered and on display at National Museum of the USAF |
| 4 | 27 Oct., 1964 | Thor | AEV-1 | Successful, vehicle not equipped with recovery system |
| 5 | 8 Dec., 1964 | Thor | AEV-2 | Mostly successful (some mission goals not met), vehicle not equipped with recovery system |
| 6 | 23 Feb., 1965 | Thor-Delta | ASV-4 | Successful, vehicle not recovered due to parachute failure |
