U.S. Space Force Considering VLEO Use
The U.S. Space Force is evaluating the potential applications of Very Low Earth Orbit (VLEO). While Low Earth Orbit (LEO) satellites typically orbit about 500 miles above Earth, VLEO satellites are intended to operate at approximately half that altitude or lower.
Gillian Bussey, deputy chief science officer of the Space Force, discussed VLEO during a panel on service innovation at the National Defense Industrial Association’s Emerging Technologies conference in Washington, D.C., on August 27th. She noted that additional space domains are becoming relevant, including VLEO. Bussey stated that the specific use cases and potential threats in VLEO are still being determined; however, she cited reduced “r squared”, which decreases power requirements and signal losses for communications, data collection, and imaging, as one advantage. Tracking objects in VLEO is more challenging due to their smaller ground track, necessitating a greater number of assets for effective monitoring.
Bussey explained that “r” refers to distance, and with free space loss (FSPL) proportional to the square of the distance, the shorter separation in VLEO results in less signal loss between antennas.
She also identified technical challenges associated with VLEO, such as overcoming atmospheric drag and addressing the harsh chemical environment caused by disassociated oxygen. The Space Force is examining the benefits and requirements for operating in this regime, including maintaining space domain awareness. Bussey also observed that some countries view space and air as a continuum rather than distinct regions, influencing technology development strategies. She suggested that consideration may be needed regarding operations and threats that span or blend these domains.
The Space Force has contracted Rocket Lab USA for a VLEO mission, and the Defense Advanced Research Projects Agency has partnered with Redwire for similar research. In March, Denver’s Albedo Space announced the launch of Clarity-1, described as the first commercial VLEO imaging satellite.