One of two compact, blunt-nosed experimental NASA spacecraft proposed as a small space-taxi vehicle. The horizontal lander is a ‘lifting-body’ space vehicle, and was designed to use an expendable launch vehicle and to return and land on a runway like a space shuttle. HL-10 was built by Northrup and first test-flown from a modified B-52 bomber in 1966. By 1970 it had attained an altitude of 27 500 m and a speed of 1 965 kph. HL-20, which resembled HL-10, was built at Langley Research Center in 1990 as a non-flying full-scale mock-up that was 8.8 m long. It had been planned that HL-20 would be used to take crews and supplies to the International Space Station and to rescue stranded astronauts. However, it has not been developed further.
Subjects: Astronomy and Astrophysics.