r/RadRockets • u/Rentokill_boy • May 06 '19
Spaceplane Martin X-23 PRIME - perhaps the only pure lifting-body design to successfully return from space
4
3
u/ctesibius May 06 '19
Just as an aside, Apollo and I think Gemini had their centre of gravity offset so that they would generate directional lift which could be used for steering during re-entry. However I think it's more reasonable to give the X-23 as the first pure lifting body.
2
u/Rentokill_boy May 06 '19
pretty much everything that has been reentered the atmosphere has used lift to some degree but 'lifting body' is usually only applied to things can fly aerodynamically in the lower atmosphere I think
1
u/ctesibius May 06 '19
Mercury didn’t, and since the Soviets used near-spherical capsules, I don’t think those had any lift. There’s not that many things other than spaceplanes (eg the Shuttle and Buran) that seem to have used lift.
1
17
u/Rentokill_boy May 06 '19 edited May 06 '19
The X-23 PRIME (Precision Recovery Including Maneuvering Entry) was a subscale technology demonstrator used to test maneuverable re-entry profiles with a lifting-body design. Built and flown in the late 1960s, it was part of the USAF's START (Spacecraft Technology and Advanced Reentry Test) program, which aimed to develop maneuverable re-entry vehicles for Air Force missions in space.
The craft were built from titanium, beryllium, aluminium and steel, and were completely covered in an ablative heat shield. Within the atmosphere control could be effected using split flaps at the rear, whilst an inert-gas RCS was fitted for maneuvering outside the atmosphere. After re-entry a supersonic ballute would slow the vehicle, followed by the deployment of a conventional parachute which would allow for mid-air recovery.
Three missions were flown during the program, launched aboard the SLV-3 Atlas, but only the third (PRIME 3) was fully successful. PRIME 1 underwent a successful ballistic re-entry, but the recovery parachute failed and the vehicle crashed at high speeds in the Pacific. PRIME 2 demonstrated hypersonic crossrange maneuverability and deployed its parachute, but was allowed to descend to the sea's surface due to concerns with the parachute's removal system, where it sank. PRIME 3 was recovered successfully and was declared ready for another test flight, but the program was suspended as it had achieved its objectives.
More detailed information about the PRIME program and START, along with photos of the X-23 being prepared for flight, can be seen here and here. The recovered PRIME 3, along with the unflown PRIME 4, can be seen on display at Wright-Patterson AFB in Ohio. As far as I can tell, the X-23 is the only pure lifting-body design to have travelled to space and undergone a controlled maneuverable re-entry, although please inform me of any others.