NASA designed the HL-10. The Northrop Corporation manufactured it. The name represents its horizontal landing and being the 10th design studied by NASA engineers. The concept tested safe manoeuvring and re-entry from space landing. In 1966, the HL-10 flew. The HL-10 glided the first 11 drops, not using its XLR-11 rocket engine. The aircraft soared when the rocket engines activated. In 37 flights, the HL-10 reached 1,228 mph and eclipsed an altitude 90,030 feet above ground. NASA ultimately rejected the HL-10 despite its flight success. Designers leaned towards delta wing aircraft, wings shaped like triangles, over the fixed winged HL-10. The HL-10 displays at NASA’s Flight Research Center.