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Very Low Earth Orbit Capabilities

(draft - cluster in making)

Benefits of VLEO

Very Low Earth Orbits (VLEO), situated at an altitude between 100 and approximately 450 km (typically 250-350 km), offer a number of attractive properties for space applications, in comparison with higher altitudes LEOs. Low power and possibly low latency communication options, high resolution EO systems with small payloads, natural resiliency to debris build-up, are just a few advantages. VLEO may become attractive for a variety of low cost systems or constellations given the lower launch cost and higher versatility in launch options, such as micro-launchers and in-orbit transfer vehicles. Furthermore, the more benign radiation environment widens the opportunities for utilisation of terrestrial grade, general purpose, electronic components.

The interest of VLEO comes from commercial and defence applications as well as scientific interest. As an example, ESA has operated GOCE, a geodynamics and geodetics mission to determine the stationary gravitational field, in a sun-synchronous orbit at an average altitude of 250 km for over 4 years until November 2013. It used a dedicated platform form factor and a highly efficient ion propulsion system to compensated for the drag force experienced by the satellite’s orbit in real-time.

Satellites in VLEO will naturally decay thanks to the presence of residual drag and re-enter the Earth's atmosphere at the end of their operational lifetime, minimising the risk of collisions in space and not contributing to the increase of the number of space debris.

Challenges of VLEO

However, operating at such altitudes comes with challenges, such as shortened lifespans due to residual atmosphere, active orbit maintenance, surface erosion from atomic oxygen, short communication windows.

Related Activities and Resources

This topical cluster lists activities that result from ideas submitted to OSIP, including but not necessarily limited to those of the dedicated VLEO call for ideas from 2023.

In addition to these, ESA has a number of ongoing activities related to VLEO missions and technologies, including:

  • Skimsat, a study for a technology demonstration in-orbit testbed  (link)
  • LoLaSat, an in-orbit low-latency experiment (link)
  • Atmosphere-breathing electric propulsion systems for very low orbit (link)

Selected VLEO related ESA papers and resources

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Selected VLEO related events

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