Space Situational Awareness: Keeping the Space Blips from Bumping

Government Agencies and Private Companies Each Have Roles to Play

ESA image. Note: Artist's impression; size of debris exaggerated as compared to Earth

As Earth orbit becomes more crowded with constellations of thousands of satellites, CubeSats, SmallSats, defunct satellites and space debris, Space Situational Awareness (SSA) becomes a critical factor in making sure all those expensive satellites can accomplish their missions.

In aviation parlance, Air Traffic Control is sometimes referred to as the art of “keeping the blips from bumping”. In space, the number of “blips” is exponentially larger, and while space is also much larger than the airspace above the Earth, the blips are also moving as much as 17,000+ miles per hour. So, keeping the blips from bumping becomes an impossible task for a human operator alone.

SSA relies on a variety of advanced technologies. Radar systems, both ground-based and space-based, are used to track objects in low Earth orbit (LEO) by bouncing radio waves off them and measuring the return signal. Optical telescopes, also ground-based and space-based, observe objects in higher orbits by capturing their reflected sunlight. Laser ranging systems use lasers to measure the distance to an object by timing the reflection of laser pulses, providing highly accurate tracking.