From my post earlier this week:

"Russian MiG-31D Air Superiority Fighter is a dedicated anti-satellite launch platform that was produced and flight-tested in 1986, and carried Vympel ASAT missiles. It has an external payload capacity of 5000 kg, and service ceiling of 20,600 meters."

"The MiG-31S was designed to be a commercial small satellite launch variant, with a Fakel OKB Micron missile capable of delivering 100 kg payload to a 200 km orbit or a 70 kg payload into a 500 km orbit. The MiG-31S could also launch the Aerospace Rally System rocket-powered suborbital glider, for astronaut training, upper atmospheric research or space tourism."

Burt Rutan's Proteus aircraft set three world altitude records on 25 and 27 October 2000 -- peak altitude 19,137 m, sustained altitude in horizontal flight 18,873 m, and peak altitude of 17,032 m with 1000 kg payload. In Jan.2001 Proteus was sold to Northrop Grumman.

Somehow the "records" are a little confused, since the military jets are known to fly higher with greater payload!!! Perhaps "service ceiling" is without any payload? If so what is the max. altitude with max payload? If someone could clarify this I'd appreciate it.