On November 15 last year, Russia destroyed one of its own malfunctioning satellites to test its “anti-satellite” “upward” system. The Cosmos 1408 satellite, launched in 1982, was supposed to orbit the Earth at an altitude of about 650 km, but has since “disintegrated” to about 490 km. The destroyed satellite shattered into more than 1,500 large fragments and added an estimated 166 million pieces of space debris – each traveling about ten times faster than a bullet.
About 10,000 satellites have been launched in the last 60 years. Launches have been increasing from year to year and it can be said that about 1,000 were sent in 2020 alone. This number is expected to increase to 12,000 by 2029, bringing the number of satellites in orbit to 100,000. Until then, space debris would accumulate at an estimated 100 billion.
Satellites are now experiencing the gravitational pull of all celestial objects, no matter how far they may be. To keep the satellites in their designated orbits, the navigation systems “push” them back into orbit whenever they deviate, starting one of the onboard engines. (Satellites don’t need any fuel to orbit the Earth because gravity takes care of it. Fuel is only needed to correct the course.)
This is an inefficient system – but it is the only one we have – because once the fuel runs out, you will lose the satellite and its valuable, well-functioning equipment. To delay this eventuality, more fuel is packed into the onboard engines, which increases the satellite’s weight and launch costs.
Another, bigger pain is that a satellite that is out of control becomes a danger to other satellites. Imagine that after ten years, tens of thousands of non-functional and released satellites will threaten the functional ones! Collisions do occur and can lead to thousands of fragments or potential fast-moving “missiles”.
Space scientists are furiously working to find a solution to this problem. Electric propulsion is one possible solution, but it is not good enough because it requires batteries charged by solar panels, and these usually have limited charging and discharging cycles.
The world therefore needs a whole new agreement. One such idea that is played with is refueling in space. Investors also seem to be interested. The US start-up, called Orbit Fab, which announced last month that it has raised $ 12 million, is offering US military satellites a system called RAFTI – a “quick-connect fluid transfer interface.” The goal is to have a fuel tank in space that can be directed to connect to the satellite and refuel into it through the port. The Indian start-up Manastu Space works on similar routes.
Docking in space is not easy, but also not impossible. The shuttles regularly moor at the International Space Station; you just have to find a way for the satellites.
Once you’ve mastered the dock, you can use it beyond just refueling. For example, you can connect a vehicle to a malfunctioning satellite and steer it off a dangerous path to go into space or fall into the Earth’s atmosphere and burn safely.
This – known as deorbiting – and refueling are among the space services that will be in demand in the space industry of the future.
Published April 24, 2022