The conflict in Ukraine has shed new light on the power of satellite imagery, revolutionising military tactics and shaping public perception. In a notable instance, as Russia poised for potential aggression, the United States government dramatically increased its procurement of commercial satellite data. This move provided unparalleled transparency regarding Russia’s intentions and marked a significant shift in how satellite reconnaissance is utilised in geopolitical crises.
Amidst this evolving landscape, the strategic significance of Very Low Earth Orbit (VLEO) has come to the forefront. Satellites operating at altitudes half that of traditional Low Earth Orbit (LEO) counterparts, typically ranging between 250 to 350 kilometres, offer an unprecedented perspective, bringing them twice as close to ground activities. This enhanced proximity has unlocked new possibilities for military and intelligence operations, albeit with notable engineering challenges to overcome.
Reflecting on history, the United States’ early ventures into space-based reconnaissance during the Cold War era provide valuable insights. The Corona satellite program, launched in response to the downing of an Air Force U-2 spy plane over the Soviet Union in 1960, was instrumental in pioneering the concept of space-based imagery. These early satellites, essentially modified Agena rocket upper stages equipped with cameras, operated at VLEO altitudes, providing critical intelligence during a period of intense global tension.
In recent years, nations including the United States, European Union, Japan, and China have embarked on modern VLEO demonstrations, leveraging advancements in electric propulsion, navigation, and imaging technology. Notable missions such as the European Space Agency’s Gravity Field and Steady-State Ocean Circulation Explorer and Japan’s Super Low Altitude Test Satellite highlight the growing interest and investment in this domain.
Advancements in electric propulsion, navigation, onboard computing, and low-cost digital imagery have laid the groundwork for contemporary VLEO missions. Examples include the European Space Agency’s Gravity Field and Steady-State Ocean Circulation Explorer, operational from March 2009 to November 2013, and Japan’s Super Low Altitude Test Satellite, which completed its mission in 2019. More recently, the European Space Agency’s Skimsat program aims to reduce the cost of Earth observations by operating in VLEO.
In addition to its military applications, VLEO offers unique advantages in addressing the growing threat of space debris. Unlike cluttered LEO orbits, VLEO’s self-cleaning nature ensures rapid degradation of debris, mitigating collision risks and safeguarding operational integrity.
Recognizing the potential of VLEO, countries like China have announced plans to deploy constellations of VLEO satellites, signalling a broader trend toward leveraging this domain for enhanced remote sensing capabilities.
Thanks to these advancements and demonstrations, national security missions are on the brink of harnessing VLEO’s potential to unlock higher-resolution imagery while simultaneously reducing costs. This reduction in expenses can be achieved through various means, including the utilization of smaller launchers, the adoption of commercially available cameras that do not necessitate radiation-hardened electronics required for higher orbits and the avoidance of large optics typically needed to compensate for the higher altitudes of LEO. However, the benefits of operating in VLEO extend beyond mere cost savings and enhanced imaging capabilities; it also presents a unique solution to the growing threat of space debris in LEO.
The proliferation of debris and discarded stages resulting from the rapid increase in commercial launches poses a significant challenge to orbital safety. One striking example of this peril was Russia’s anti-satellite missile test on November 15, 2021. In a reckless manoeuvre, Russia deliberately targeted and destroyed one of its satellites, resulting in a cloud of debris that endangered the lives of astronauts aboard the International Space Station. As industry insiders and casual space enthusiasts alike learned from the movie “Gravity,” collisions between objects in LEO can trigger cascading chain reactions, further exacerbating the debris issue. Such debris clouds in LEO orbits may persist for a decade or more, posing ongoing hazards to operational satellites.
In stark contrast, VLEO presents a self-cleaning solution to this predicament. Debris and unpropelled satellites in VLEO naturally reenter Earth’s upper atmosphere and safely disintegrate, typically within a matter of days. This inherent characteristic significantly mitigates the risk to other operational VLEO satellites, making it an attractive option for national security missions.
Furthermore, near-peer competitors have recognized the strategic advantages offered by VLEO and have initiated programs to capitalize on this domain. The China Aerospace Science and Industry Corporation, a prominent player in China’s defence sector, has announced plans to deploy a constellation of VLEO satellites. Orbiting at altitudes between 150 and 300 kilometres, these satellites represent a significant advancement in China’s quest to enhance its remote sensing capabilities, promising higher-resolution imaging and faster data transmission.
General James Dickinson, former Commander of the United States Space Command, articulated the strategic importance of space in his 2021 vision titled “Never a Day Without Space.” Dickinson underscored the relentless efforts of competitors to undermine U.S. access to space and hinder its freedom of operation. Indeed, the value that VLEO offers to the U.S. and its allies cannot be overstated. The fusion of high-resolution imaging, pioneering propulsion technologies, and the sustainability of VLEO operations underscores its pivotal role in shaping the future landscape of defence and intelligence operations. As these developments continue to unfold, VLEO is poised to play a pivotal role in shaping the dynamics of space-based defence strategy, ensuring continued U.S. and allied supremacy in an increasingly contested arena.
