© Mark Ollig
The X-37B is an uncrewed spaceplane shrouded in secrecy with a design resembling a miniature NASA Space Shuttle.
NASA initiated the X-37 program in 1999, aiming to develop a reusable space transportation system.
This program encompassed the X-37B, a small, autonomous spacecraft designed for operation in low Earth orbit.
In 2004, the X-37B program was transferred from NASA to the US Air Force.
Today, operational control of the X-37B resides with the US Space Force, which assumed responsibility in 2020.
This American-made X-37B is a reusable orbital spaceplane that is 29 feet in length, 15 feet in wingspan, and 9.5 feet in height.
Its weight remains officially classified, although various sources suggest it is around 11,000 pounds.
The X-37B is designed for vertical takeoffs and is launched encased within a protective fairing shell atop a rocket.
After completing a mission, the spaceplane lands on a runway, similar to NASA’s space shuttle.
The US Air Force’s official website states that the X-37B is a reusable experimental spacecraft for conducting orbital experiments and advancing future US space technologies.
The payloads and experiments conducted using the X-37B are mainly classified.
The X-37B’s designation follows the US military’s experimental aircraft naming convention. The “X” denotes experimental, “37” is a sequential number, and “B” indicates the second iteration.
Note that not all numbers in the one through 36 sequence correspond to actual aircraft due to canceled projects and designation changes.
The Orbital Test Vehicle-1 (OTV-1), also known as USA-212, had its first flight as the Boeing X-37B when it was launched aboard an Atlas V 501 rocket from Cape Canaveral, FL.
The Atlas V 501 rocket, operated by United Launch Alliance, stood at 191.3 feet tall, had a diameter of 12.5 feet, and weighed approximately 1.3 million pounds.
The rocket’s RD-180 liquid-fueled engine produced 860,000 pounds-force of thrust.
The Atlas V 501’s Centaur upper stage was powered by an RL10A-4-2 liquid-fueled engine, producing 22,300 pounds-force of thrust.
The X-37B’s first mission, lasting 224 days, tested technologies such as guidance, navigation, and control systems; thermal protection; satellite sensors; autonomous orbital operation; and re-entry and landing capabilities.
The X-37B reportedly operated in a low earth orbit at an approximate altitude range of 150 to 500 miles above the planet.
The X-37B contributes to Space Domain Awareness (SDA), which entails monitoring space activities and objects, including satellites and debris, that could impact US operations.
SDA helps the Space Force identify potential orbital threats and ensure safe operations for US spacecraft and satellites.
The X-37B operates in low Earth orbit, gathering data on satellites, debris, and other space activities.
Its secrecy is driven by national security, the pursuit of technological advantage, and protection against adversaries.
General information about launches, non-classified orbital details, and landings is typically made public; however, specific mission objectives, payload details, and most experiment specifics remain confidential.
The X-37B tests various new space technologies, including advanced reusable spacecraft systems, autonomous navigation and control systems, and novel propulsion technologies.
Today, the Air Force’s Rapid Capabilities Office is involved in the program’s development, while the US Space Force oversees on-orbit operations.
The launch of the X-37B OTV-6 mission was May 17, 2020, from Cape Canaveral Space Force Station, FL, aboard an Atlas V 501 rocket.
A service module was introduced on the X-37B with the OTV-6 mission, enabling the spacecraft to carry out more experiments, store additional fuel, increase the spacecraft’s orbital range and duration, and support complex maneuvers.
The module also facilitates payload deployment and retrieval, hosting experiments like the Naval Research Laboratory’s Photovoltaic Radiofrequency Antenna Module and the US Air Force Academy’s FalconSat-8.
After spending 908 days in orbit, the X-37B landed at NASA’s Kennedy Space Center Nov. 12, 2022, ending the OTV-6 mission.
The seventh mission of the X-37B, OTV-7 (Orbital Test Vehicle-7) spacecraft launched on a SpaceX Falcon Heavy rocket, designated USSF-52, from Cape Canaveral Space Force Station Dec. 28, 2023.
The choice of the Falcon Heavy rocket for this mission may have been needed due to the X-37B’s increased payload capacity to carry more fuel, conduct more experiments, or achieve higher orbits.
The US Air Force announced that the X-37B began a series of aerobraking maneuvers Oct. 10 of this year.
These maneuvers are used to modify the spacecraft’s orbit by slowing it down with Earth’s atmosphere, which saves fuel and enables extended missions.
The secretive miniature ‘space shuttle,’ the X-37B, is currently in Earth orbit. It will continue its mission before eventually de-orbiting and returning to Earth, as it has done successfully in its previous six missions.
While many details about the X-37B remain classified, it continues to intrigue and generate speculation.
The X-37B remains a classified conundrum wrapped in an enigma.
After eight months in space, a Chinese “reusable experimental spacecraft,” landed in the Gobi Desert region located in northern China Sept. 6.
While not officially confirmed to be a direct response to the X-37B secretive spaceplane program, it does seem to signal a strategic response to advancements in US spaceplane technology.
