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[top] General Description

The HL-20, successor to the HL-10, is a Personal Launch System (PLS) developed by NASA Langley Research Center in 1990 as a concept for manned orbital missions. It was envisioned as a lifting body re-entry vehicle based on the Soviet BOR-4. Goals of the project were to achieve low operational costs, improved flight safety, and a possibility of landing on conventional runways. The Dream Chaser spacecraft is based on the HL-20 lifting body design.

Two NASA designs that were considered for PLS differed in their aerodynamic characteristics and mission capabilities. Johnson Space Center's model used a blunt cone shape (similar to the various Moon-mission return vehicles), incorporating a parachute system for coming to rest. Langley Research Center proposed a lifting body that could make a conventional runway landing on return from orbit.

A full-size, non-flying model was constructed in 1990 by the students and faculty of North Carolina State University and North Carolina A & T University for studying crew seating arrangements, habitability, equipment layout and crew ingress and egress. This 29 feet (9 m) long engineering research model was used at NASA Langley to define the full-scale external and internal definition for utilization studies.

Important testing with the HL-20 were in the areas of human factors engineering, ingress and egress procedures, maintenance accessibility, and pilot visibility.



This mockup was used for engineering studies of maintainability of the vehicle, as testing crew positions, pilot visibility and other human factors considerations. The HL-20 was a direct derivative of the HL-10 vehicle tested in the 1960s and bears a very close resemblance to engineering drawings produced at that time. Although evaluated as a possible "space taxi," the HL-20, sometimes called the "Personnel Launch System," was never built.


The HL-20 in early morning fog at NASA Langley Research Center.
The HL-20 is seen here in a computer simulation. Launched using an expendable vehicle, the HL-20 returns to earth in a shuttle-like manner. Using computational fluid dynamics (CFD) tools in concert with the day's most powerful supercomputers, researchers at NASA Langely Research Center were able to predict the flow around the HL-20 at flight conditions, providing designers with valuable surface heating and pressure information. Illustrated are the heating levels on the boddy and the flow velocity encountered when the HL-20 is enterint the earth's atmosphere at Mach 16. Low heating and speed values are represented by dark blue, mid values by green and yellow, and high values by red and white.


The NASA Langley Research Center lifting body, called the HL-20, is shown here in front of the hangar. The HL-20 was one of two concepts considered by NASA as a type of Personnel Launch System (PLS). In essence, it would serve as a space taxi to and from the space station. The full scale engineering model is 29.5 feet long, and 23.5 feet across the wingspan.

[top] NASA HL-20 Characteristics

Serial Number HL-20
Total Time n/a Hrs
Brief Description 10-place lifting body candidate for manned orbital missions boosted to 100 nm (185 km) orbit by expendable launch vehicle
Engine none
Max Weight 22,000 lb (10,000 kg)
Max payload 3000 lb (1,364 kg)
Wing Span 23.5 ft (7.2 m)
Max Cross-range 1100 nm (2040 km)
Mission duration 72 hours
Previous Research Program none
Current research Use Human factors engineering, Ingress and egress procedures, Maintenance accessibility, Pilot visibility
Contact(s) William M. Piland, Chief Space Systems Div

Delma C. Freeman, Head, Vehicle Analysis Br

Howard W. Stone, Project Engineer

[top] Photos

Model Tests

At North Carolina State University in 1990

Arrival at NASA Langley in 1991


Human Factors

Abort Simulations in NASA 511

[top] Documents

1992 HL-20 Model for Personnel Launch System Research

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