ATV Credit - Gary Hudson

George Detko of NASA's Marshall Space Flight Center produced designs for SSTO vehicles as early as 1960. The expendable vehicle had a gross listoff mass of only 22 tonnes, and could deliver a two-person crew to orbit.

Alternatively it could be used to deliver as a rapid response transport to deliver critical goods anywhere on earth within 30 minutes. Detko continued to refine the design, proposing a reusable version in 1972. NASA managers remained indifferent to Detko's proposals, as was their attitude to all SSTO concepts. Detko's design was refined by Gary Hudson and Tom A Brosz and renamed the 'Aerospike Test Vehicle'. This was the precursor of Hudson's smaller Phoenix designs, notably the Phoenix L (light) and Phoenix L-Prime.

Manufacturer: NASA Marshall. LEO Payload: 1,000 kg (2,200 lb). Associated Spacecraft: ATV. Total Mass: 22,000 kg (48,000 lb).

• Hudson, Gary C, History of the Phoenix VTOL SSTO and Recent Developments in Single-Stage Launch Systems, AAS 91-643, included in Proceedings of 5th ISCOPS, AAS Vol. 77, pp 329-351, November 1991.