The Department of the Air Force Rapid Capabilities Office, in collaboration with the United States Space Force, is slated to launch the seventh mission of the X-37B Orbital Test Vehicle (OTV) via SpaceX’s Falcon Heavy rocket no earlier than Sunday, December 10, 2023. This mission will mark a significant milestone for the reusable spaceplane as this will be the first time the X-37B is launched on a heavy-lift launch vehicle, after five previous launches aboard Atlas V and one on Falcon 9.
The mission, designated USSF-52, aims to conduct a series of groundbreaking tests and experiments in cooperation with NASA alongside other government agencies to leverage the uncrewed X-37B’s capabilities. Among the objectives are operating X-37B in new orbital regimes, experimenting with future space domain awareness technologies, and investigating the radiation effects on materials provided by NASA.
General B. Chance Saltzman, Chief of Space Operations, emphasized the significance of these upcoming experiments, stating in a press release, “The X-37B continues to equip the United States with the knowledge to enhance current and future space operations. X-37B Mission 7 demonstrates the [Space Force]’s commitment to innovation and defining the art-of-the-possible in the space domain.”
One key focus of the USSF-52 mission is to expand the Space Force’s knowledge of the space environment through experiments with future space domain awareness technologies. The Space Force intends to use findings from these experiments to improve the safety and stability of future space operations.
The NASA experiment that will be flying aboard X-37B, dubbed “Seeds-2,” will involve exposing plant seeds to the harsh radiation of the space environment during a long-duration spaceflight. Seeds-2 will be building upon the knowledge gained during similar experiments named RAD-SEED 1 and RAD-SEED 2 which flew upon the previous X-37B mission in 2020.
X-37B Mission 6, the predecessor to the upcoming USSF-52, investigated the effects of extended exposure to microgravity and radiation on the viability and quality of seeds as well as being evaluated for germination rates, developmental abnormalities, and molecular changes compared to a control group of seeds on the ground.
Although there have been crops grown on the International Space Station, these experiments are specifically looking to see the effects a variety of space radiation will have on seeds over an extended spaceflight. Dr. Ye Zhang, an advisor to the team of scientists who had studied the seeds upon their return to Earth reminded of the long-term goal of these experiments stating, “Remember, when we have a round trip to Mars, we’ll be traveling for two or maybe three years, so we want to determine how long these seeds can be stored and still be viable.”
The X-37B set to be launched in just a few days traces its roots back to 1999, as NASA began developing the X-37 as part of its Approach and Landing Test Vehicle (ALTV) project. X-37 was first designed by Boeing under NASA’s purview, but the project was soon handed over to the Department of Defense to be managed by the Air Force Space Command in 2004, raising speculation about military applications for the vehicle.
Without a propulsion system, the X-37A was used as an atmospheric drop test glider, dropped from the Scaled Composites White Knight high-altitude research aircraft. The X-37A completed three successful free flights from April to September 2006.
Shortly after the X-37A’s third flight, the Air Force announced its intention to build the glider’s successor, designing it to be an Orbital Test Vehicle. Boeing was selected for the development of the X-37B, an autonomous and reusable spaceplane designed for long-term experiments and space vehicle testing. X-37B’s maiden flight occurred just four years later in 2010 and was managed by the Air Force Space command until 2019 when the United States Space Force took control of the program.
Throughout its six missions to date, the X-37B has played a crucial role in advancing spaceplane technology, allowing for long-term space experimentation and testing to be done that otherwise could not be done by a creed vehicle. Originally designed to stay in orbit for 270 days at a time, the X-37B continued to push the limits of spaceplane technology over its proceeding missions by increasing its time in orbit mission over mission with its longest time in orbit being nearly 909 days on its sixth mission.
Since its inception, the X-37B has been cloaked in a shroud of secrecy, with many of its missions and payloads being classified. Because of its secrecy and oversight from the Department of Defense, the spaceplane has been the source of much speculation regarding the vehicle’s purpose and missions, with accusations of it being used for testing and delivering space-based weapons as well as reconnaissance missions on China’s Tiangong-1 space station.
Although the X-37B is still partially shrouded in secrecy, the Space Force has been taking steps towards shining a light on the space plane’s abilities and activities. With X-37B’s Mission 7, the spaceplane will be continuing to build its legacy of planting the seeds of long term human spaceflight on the journey to permanent human presence on the moon and beyond.