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Smart Bombs: Military, Defense and National Security

X-38: The NASA ‘Space Plane’ Built for a Special Purpose

The X-38, a research vehicle built to help develop technology for an emergency Crew Return Vehicle (CRV) for the International Space Station, descends under its steerable parachute during a July 1999 test flight at the Dryden Flight Research Centre, Edwards AFB, California. It was the fourth free flight of the test vehicles in the X-38 programme, and the second free flight test of Vehicle 132 or Ship 2. The goal of this flight was to release the vehicle from a higher altitude -- 31,500 feet -- and to fly the vehicle longer -- 31 seconds -- than any previous X-38 vehicle had yet flown. The project team also conducted aerodynamic verification maneuvers and checked improvements made to the drogue parachute.

NASA’s X-38 was an experimental re-entry vehicle, designed to serve as an emergency crew return vehicle (CRV) for the International Space Station (ISS). The program was conceived in 1995 and first flew in 1999 but was canceled in 2002, a casualty of NASA budget cuts. 

Space logistics are complicated. And space travel is dangerous. Emergencies happen. Astronauts die. The X-38 was designed to mitigate the logistical challenges of space travel, and hopefully, avoid catastrophe; the X-38 was meant to be an alternative to the more time-intensive “rides” that astronauts typically rely on: (formerly) the Space Shuttle, Russian Soyuz capsules, and lately, SpaceX Dragon capsules. The Space Shuttle, Soyuz, and Dragon all required elaborate launches to reach the ISS.

So, in the event of an emergency, astronauts aboard the ISS would not have an immediate exit; they would have to wait for their ride, which would require that elaborate launch. The X-38, on the other hand, was meant to be semi-permanently docked to the ISS, standing by in case of emergency, a high-tech escape vessel. 

Use in Case of Emergency

The X-38 was designed to dock with the ISS. If the ISS crew ever needed to get out in a hurry, say for illness, injury, or ISS systems failure, the crew would enter the X-38 through a hatched docking mechanism. Once the X-38 was initiated, the CRV would autopilot the crew back to Earth using a deorbital propulsion system (DPS). The DPS, which would include eight thrusters, would adjust the X-38’s attitude and retrofire until the X-38’s speed was sufficiently reduced to allow for Earth’s gravitational pull to grasp the X-38, dragging the vehicle and the crew back down into Earth’s atmosphere. 

Once the X-38 reentered the atmosphere, the DPS would be jettisoned, and the X-38 would have glided, using a steerable parafoil on its final descent and landing. The X-38 was a “lifting body aircraft,” which typically require very high speeds to land. The parafoil would have assisted in slowing the X-38, making landing a bit easier. The parafoil was developed from U.S. Army technology. 

Sequencing the Escape Pod

First, a drag chute would be released, to stabilize and slow the CRV. Then, the parafoil itself, with a massive square area of 687 square meters would deploy in five distinct stages. The five stages only required 45 seconds to complete, but the increments were important to prevent the billowing parafoil from tearing in the high-speed winds experienced during a return to Earth. And like NASA’s first space plane, the X-15, the X-38 relied on landing skids rather than traditional rubber landing gears, which would have burnt up on reentry.

The landing, too, was to be completely automated. If absolutely needed, the crew could override the autopilot and pilot the aircraft manually. If all else failed, the X-38 was packed with seven high-altitude low opening (HALO) parachutes. 

The entire escape process – undocking from the ISS to reentry to glide to landing – was expected to take between two and three hours. The X-38’s battery system, used for power and life support, was capable of lasting three times longer than necessary.

The 30-foot, 12-ton X-38 performed three drop tests from altitudes of up to 45,000 feet. Dropped from beneath the wing of a B-52 mothership, the atmospheric prototype X-38s glided at near transonic speeds before landing safely at just 60 miles per hour. 

Sadly, the X-38 program was canceled in 2002, after an ISS budget analysis recommended making cuts that included the CRV. Frustratingly, the X-38 orbital prototype was 90% completed when the program was canceled. 

Harrison Kass is the Senior Defense Editor at 19FortyFive. An attorney, pilot, guitarist, and minor pro hockey player, he joined the US Air Force as a Pilot Trainee but was medically discharged. Harrison has degrees from Lake Forest College, the University of Oregon, and New York University. He lives in Oregon and listens to Dokken. Follow him on Twitter @harrison_kass.

Written By

Harrison Kass is a Senior Defense Editor at 19FortyFive. An attorney, pilot, guitarist, and minor pro hockey player, he joined the US Air Force as a Pilot Trainee but was medically discharged. Harrison has degrees from Lake Forest College, the University of Oregon School of Law, and New York University’s Graduate School of Arts & Sciences. He lives in Oregon and regularly listens to Dokken.