Context: Orbitt Space, a space technology startup in India, is building next-generation satellite propulsion systems and platforms for ultra low Earth Orbit (ULEO) missions.
Relevance of the Topic: Prelims: Key facts about Ultra Low Earth Orbit (ULEO).
Ultra Low Earth Orbit (ULEO)
- Ultra Low Earth Orbit refers to satellite orbits at very low altitudes, typically below 450 kms, or even below 200 kms.
- The commercial importance of ULEO is increasing in both private and government satellite operations globally.
- Applications include: Earth observation, low-latency telecommunications, climate monitoring, surveillance, rural internet and scientific missions.
Benefits of ULEO:
- Higher resolution imagery due to their proximity to Earth.
- Reduced communication latency due to their proximity to Earth.
- Self-regulating solution to space debris as satellites in ULEO are naturally de-orbited (burn up in the earth’s atmosphere post mission).
- Radiation protection enables the use of cost-effective commercial electronics.
- Alternative to Low Earth Orbit (LEO) with lesser risk of satellite collisions. (LEO has accumulated over 20,000 space objects and high debris)
- Can complement constellations of satellites launched in LEO.
Challenges associated with ULEO:
- High atmospheric drag due to proximity to Earth. To maintain a stable orbit, satellites require constant thrust compensation, typically through onboard propulsion systems. In the near-vacuum LEO there is negligible atmospheric drag, making propulsion less critical for orbit maintenance.
- High cost of operating and Fuel constraints due to the necessity to provide constant thrust compensation.
- Exposure of satellites to very high levels of elemental oxygen (atomic oxygen), a highly reactive form of oxygen that corrodes most substances quickly. This requires the use of special coatings to protect objects and equipment in this orbit.
Orbitt Space is building a new propulsion technology (electric propulsion system) that can compensate for the drag in ULEO, giving the satellite a lifetime of 5 to 7 years. The electric propulsion system uses residual atmospheric gases as propellant, eliminating the need for onboard fuel.