This week, Bigelow was notified by the US Air Force that there is a 5.6% chance that now defunct Bigelow Aerospace Genesis II will collide with dead Russian satellite Cosmos 1300 on September 18th. Although the probability is still relatively low, it prompted Bigelow Aerospace to share a tweet about the growing problem of Space Debris – a serious concern. Bigelow Aerospace shared that it “brings to light that low Earth orbit is becoming increasingly more littered.” They went on to highlight that future habitable space stations will face this reality and danger and that it could, if not properly controlled, become a dangerous problem for humans in low Earth Orbit. In the case of Bigelow Aerospace and their II spacecraft, it had a planned End of Life (EOL) decommissioning plan to burn up through natural orbit decay.
The Russian satellite, Cosmos 1300 / Kosmos 1300 (AKA Tselina-D #30 COSPAR ID 1981-082A / SATCAT no. 12785) was an electronic signals intelligence satellite launched by the former Soviet Union on 8 August 1981. It’s launch from Plesetsk Cosmodrome Site 32/1 on a Tsyklon-3 rocket is lacking in details, but it is believed to be a 2,000 kilograms (4,400 lb). By definition, this satellite has been space debris since it stopped functioning, along with the now dormant Genesis II satellite. The danger in this situation is that these are two relatively large satellites that could make even more space debris should a collision occur.
Space debris isn’t a new thing. The oldest known debris is satellite Vanguard 1 (1958-1964). During the first American spacewalk astronaut Edward White lost his spare thermal glove out of Gemini 4. It stayed in the orbit of the earth traveling around Earth with velocity about 28 000 km/h. As per the Inter-Agency Space Debris Coordination Committee (IADC) recommendations (2002), two specific regions of outer space are of interest for space missions and must be protected:
- The Low Earth Orbit (or LEO) Region, a spherical region that extends from the Earth’s surface up to an altitude of 2 000 km.
- The Geosynchronous (GEO) Region, a segment of the spherical shell defined by the altitude of 200 km above and below GEO with latitude plus-minus 15 degrees. (geostationary altitude = 35 786 km.)
Just as satellites in Low Earth Orbit (LEO), space debris is moving with speeds up to 30000km/h. The orbits of debris differ in direction, orbital plane and velocity, however given enough time collisions are inevitable. With this speed even the smallest pieces of space junk present a real threat for functional satellites, space stations, and astronauts on spacewalks.
Space debris objects can be large or small. This doesn’t represent the physical size of the object, but current ability to detect and track them.
The space debris conundrum has long been exercising the minds of scientists and engineers. In 2016, Roscosmos experts concluded that if the problem is not dealt with then space exploration could entirely grind to a halt as all near-earth orbit would be clogged up with junk equipment. According to the European Space Agency’s Space Debris Office, there is currently more than 8,400 tons of space trash orbiting the Earth. While some of this is accounted-for by functioning spacecrafts, the vast majority is waste from thousands of launches and deployments as well as from explosions and collisions.
Concern space junk goes back to the beginning of the satellite era, but the number of objects in orbit is rising so rapidly that researchers are investigating new ways of solving the problem. Such as at End of Life (EOL) parking satellite to graveyard orbit and deactivating it later. There are two ways of doing this” re-orbitation” (above GEO) and “de-orbitation” (below GEO). For the LEO Region, spacecraft should be either deorbited (direct re-entry) or maneuvered into an orbit where lifetime is limited to 25 years under the main effect of the atmospheric drag. Large satellite hunter, laser broom techniques can be useful in the near future also earth’s gravitational pull is ensuring that orbital debris fall back on Earth or burn up in the atmosphere. NASA estimates that one object hits the Earth on a daily basis, which can be helpful for researchers for tracking and finding out the solution.
Recent news from Russia’s Roscosmos space agency says that they have invented a satellite with the ability to destroy itself at the end of its life, offering a solution to the significant problem of space debris. The materials used in the satellite means it would “evaporate” when it is no longer useful, preventing it from adding to the increasing volume of defunct man-made objects that are floating around in space. A patent filed with the Federal Service for Intellectual Property (Rospatent) shows that this would involve constructing the satellite out of materials that sublimate, meaning they transition directly from solid to gas without becoming liquid. This clever construction would allow the satellites to self-decompose when they get a signal from Earth.
According to latest statement of ESA’s Space Debris monitoring team a satellite was forced to perform an evasive maneuver to avoid hitting a SpaceX spacecraft. The ESA’s Aeolus Earth observation satellite fired its thrusters as part of a collision avoidance maneuver. In its original path lay a satellite owned by Elon Musk’s SpaceX that is part of the company’s Starlink system, which aims to set up a constellation of thousands of satellites capable of beaming internet to every corner of the Earth.
Aeolus is the first satellite with equipment capable of performing global wind-component-profile observation and will provide much-needed information to improve.
ESA contacted Starlink, which said it did not plan to move its satellite, according to the statement, so the ESA team decided to increase the altitude of its Aeolus satellite to avoid a collision. After maneuver, ESA tweeted – The maneuver took place about 1/2 an orbit before the potential collision. Not long after the collision was expected, #Aeolus called home as usual to send back its science data – proving the maneuver was successful and a collision was indeed avoided.
Although this is the first incident of this kind and no one was at fault here, this example does show the urgent need for proper space traffic management, with clear communication protocols and more automation. Some Space agencies are also working on an artificial intelligence (AI) system to automate the process of avoiding. Starlink, Amazon, Oneweb are in pipeline of sending huge constellation of satellite; but now space operators need to get together to define automated maneuver coordination.
About The Author
Harshal More
Space and Astronautical Engineer, Contributing Author for WestEastSpace.com
Harshal More is interested and has studied Artificial Intelligence, System engineering, Control Theory and Space Flight Mechanics, propulsion along with foundation base of using the concepts of Compressible Fluids and the tools of Numerical Analysis, MATLAB which entails a host of applications ranging from research to commercialism in areas of Rocket Propulsion, Aerospace Structures, Robotics and Space Missions. Harshal is a contributing Author for WestEastSpace.com
Amazing, Would like to know more!