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Secretive X-37B wins Collier Trophy

August 14, 2020
By Jon Robinson

Boeing became the prime contractor of the Orbital Test Vehicle program in 1999, originally developing the smaller X-40 variant, before the X-37A and X-37B, with the latter aircraft completing a record-breaking 780-day on-orbit mission in 2019. (Photo: United States Air Force)

The National Aeronautic Association named the X-37B autonomous spaceplane, also referred to as the Orbital Test Vehicle, as the 2019 winner of the prestigious Robert J. Collier Trophy. Presented annually since 1911, the Collier Trophy recognizes the greatest achievement in American aeronautics and astronautics.

Collier winners over the past decade alone have included: The JPO team behind the Automatic Ground Collision Avoidance System (Auto GCAS), as applied on the F-35 fighter jet (2018): Cirrus Aircraft Vision Jet (2017); Blue Origin New Shepard (2016); the NASA team behind the Dawn Mission (2015); Gulfstream G650 (2014); the Northrop Grumman team behind the X-47B, as the first unmanned, autonomous air system operating from an aircraft carrier (2013); the NASA team behind Mars Curiosity (2012); Boeing 787 Dreamliner (2011); and the Sikorsky X2 helicopter demonstrator team (2020).

Designed and built by Boeing, the X-37B resembles NASA’s Space Shuttle, but is much smaller at just under nine metres in length and three metres in height, with a wingspan of 4.6 metres. It is now operated in partnership with the U.S. Space Force, and managed by the U.S. Department of the Air Force Rapid Capabilities Office, as an uncrewed testbed to carry experiments into orbit. The aircraft is effective for space-based experiments because it is relatively inexpensive (reusable) with available quick turnarounds.

In May, 2020, the X-37B was launched onboard an Atlas V rocket for its sixth mission from Cape Canaveral Air Force Station in Florida. The spaceplane returned from mission number five in late 2019 after setting a new 780-day on-orbit endurance record. The program has logged more than 2,865 days and travelled more than 1 billion miles on orbit.


As opposed to the multi-nation effort behind the International Space Station (ISS), the X-37B is a U.S.-only endeavour and its payloads – carried in a pick-up-size cargo bay – are typically classified, creating its mysterious mystic. Its mission ending in 2019 was known to carry an oscillating heat pipe experiment, designed to test heat exchange within a space-based vehicle, and its fourth mission tested out a 13 kW Hall-effect (ion) thruster, as well as new materials for testing their exposure to space.

The X-37B can orbit at a distance of up to 805 kilometres (km), but it was largely operated at a distance of around 320 km during its fifth mission, observed as a challenging target by a range of citizen astronomers and scientists. The ISS orbits at around 350 to 400 km, requiring thrusting from the station itself and visiting aircraft to maintain its orbital plane. This is a costly in terms of propellant and fuel, which is primary reason for testing ion drives that could one day maintain satellites in more cost-effective lower orbits.

Based on studying images of its landings, and its various configurations since first flight in 2006, observers believe the U.S. is operating two X-37B spaceplanes. The Orbital Test Vehicle’s first mission was in 2010.

X-37B General Characteristics Provided by Unites States Air Force
Primary Mission: Experimental test vehicle
Prime Contractor: Boeing
Height: 9 feet, 6 inches (2.9 metres)
Length: 29 feet, 3 inches (8.9 metres)
Wingspan: 14 feet, 11 inches (4.5 metres)
Launch Weight: 11,000 pounds (4,990 kilograms)
Power: Gallium Arsenide Solar Cells with lithium-Ion batteries
Launch Vehicles: United Launch Alliance Atlas V (501) and SpaceX Falcon 9