X-38

The X-38 project was an initiative by NASA to develop a prototype spacecraft, known as the Crew Return Vehicle (CRV), intended for the safe return of crew members from the International Space Station (ISS). The X-38 prototype vehicles were designed to function autonomously and to perform landings both in space and within Earth's atmosphere, as part of efforts to develop a wingless reentry vehicle. The project aimed to test the spacecraft's reentry systems, guidance parachute, and flight control mechanisms under operational conditions.

Project Background

The X-38 project was initiated in 1995 at NASA's Johnson Space Center, shaped by data obtained from earlier lifting body programs and precision delivery system tests conducted by the U.S. Army at Yuma Proving Grounds. The first atmospheric test flights began in 1997 using prototype vehicles manufactured by Scaled Composites. The project aimed to enhance the aerodynamic structure of the X-38, as well as its guidance systems and parachute deployment technologies.

In 1996, a contract was awarded to Scaled Composites for the production of two atmospheric test vehicles. The first vehicle was delivered to Johnson Space Center in 1996, where it was outfitted with avionics, computers, and other essential equipment. The second vehicle followed in 1997. In 1998, the V131 vehicle was modified and redesignated as the V131R.

Key Milestones

• 1995–1996: Initial parachute system tests conducted at Yuma Proving Grounds.
• 1997–2000: First atmospheric drop tests of X-38 vehicles, released from a B-52 carrier aircraft.
• 2001: The X-38 achieved its highest altitude, fastest speed, and longest flight to date.
• 2003–2005: Continued atmospheric test campaigns and preparations for space-based flight tests.

Technological Innovations

Parachute Technology

The X-38 utilized a large, steerable parachute during descent, designed to enable the vehicle to land precisely within designated target areas. This parachute system was notably larger than those employed in previous spacecraft, providing enhanced maneuverability and control during the final phases of reentry and landing operations.

Flight Control Systems

The X-38’s flight control system was developed using electrically powered actuators combined with advanced software architectures. These systems enabled the vehicle’s descent through the atmosphere to be fully automated, ensuring precise control without the need for manual piloting.

Aerodynamic Configuration

Unlike conventional winged spacecraft, the X-38 was designed based on a lifting body concept. This configuration allowed the vehicle to generate aerodynamic lift during atmospheric reentry without relying on traditional wings, enhancing stability and control throughout the descent phase.

Participants and Principal Organizations

The X-38 project was conducted through extensive collaboration among several NASA centers. These included the Johnson Space Center (JSC), the Dryden Flight Research Center (now known as the Armstrong Flight Research Center), and the Langley Research Center. Notably, the X-38 was one of the first projects in which NASA engineers internally designed and constructed prototype vehicles rather than relying entirely on external contractors. This approach provided NASA with greater authority and flexibility throughout the design and testing phases.

Primary Contractors Included:

• Scaled Composites: Responsible for the fabrication of the atmospheric test vehicles.
• GenCorp Aerojet: Developed the de-orbit propulsion system for the X-38.