GK: Starlink Constellation (S&T)

SpaceX CEO Elon Musk had spoken of Starlink, a constellation of satellites that would provide a cheap, high speed, global Internet connection.

So, what is the Starlink constellation?

Starlink will likely have 12,000 small satellites in two layers — low earth orbit (LEO) and very low earth orbit (VLEO).

The LEO constellation will have 4,425 satellites at altitude between 1,110 km and 1,325 km, and will operate in the Ku, Ka and V band (in increasing order of frequency). The VLEO constellation will have 7,518 satellites at altitude between 335 km and 346 km, and will operate in V band frequencies.

The LEO constellation will provide high-speed broadband services around the world; the VLEO constellation will enhance capacity.

Being at a higher altitude, LEO constellation satellites will have a larger spot beam, i.e. the area on Earth covered by a satellite’s transmission antenna. LEO satellites will travel at high speeds, and VLEO satellites are expected to compensate for possible losses of satellite-device connection, and signal attenuation.

What can go wrong?

12,000 satellites is more than the total number ever launched, and will be a challenge to build and maintain. Also, as Joseph W Gangestad of the nonprofit Aerospace Corporation has written, “This unprecedented proliferation of satellites, particularly in LEO, will bring with it dramatic jumps in the risk of collision, debris generation and its cascading effects for future collisions, and the number of close-approach warnings for active satellites.