Physicists at the Tomsk State University have created a mathematical model for computing the trajectories of space debris, such as defunct space satellites and fragments of spacecraft, for 100 years ahead and more. The Russian Foundation for Basic Research has established a special grant for determining the trajectories of such objects in near-Earth space, the university’s press-service has said.

Back in 1978 NASA scientist Donald Kessler warned that the accumulation of space debris in near-Earth space and their growing density might result in a situation where the collision of two such objects would trigger a chain reaction resulting in the destruction of all satellites operating at the altitude of the International Space Station and higher. Already now space mission control specialists have to bear this problem in mind and adjust the orbits of the ISS and satellites to avoid collisions with debris.

"There is such a problem: uncontrolled objects may damage operational satellites. There can be two solutions: either the derelict satellites are to be deorbited or reliable information obtained they would not damage others. For this, the long-term evolution of their orbits will have to be established. Say, a certain uncontrolled object may stay in space for ten years without damaging other objects. But over a timespan of 100 years or more its orbit may change considerably. For this reason, we made a decision to conduct research into this problem," the university’s press-service quotes the work’s author, research fellow of the astronomical data computer modelling and analysis laboratory of the Tomsk State University, Yevgeniya Blinkova, as saying.

Uncontrolled objects

The term uncontrolled objects applies in the first place to old defunct satellites and large fragments of spacecraft. They are most frequent in low and medium Earth orbits (LEO and MEO) - from the atmosphere to the orbits of navigation systems GLONASS and GPS. Objects in this area of outer space are prone to the effects of the Earth’s gravitational field, the attraction of the Moon and the Sun, the pressure of light and difference resonances resulting from the speed of the Earth’s rotation and the precessions of the orbits of the Earth and the Moon. Tomsk State University Scientists have been studied and converted into a mathematical model.

"The obtained knowledge will now be applied to real objects. Yevgeniya Blinkova will find out how they will move and be redistributed in space and study the dynamics of the whole entity of uncontrolled objects in near-Earth space. The RFBR grant is extended for two years. It is essential to know the location of such objects in orbiting any new spacecraft," the press-service said.

Scientists explain that space objects can be either timely deorbited or parked in a new orbit, where they will not constitute a hindrance.

"In the launch orbits there are more than 13,400 objects, of which a tiny 6% are operational ones. All the others are debris. Keeping track of them and analyzing the evolution of their orbits is essential to current and future experiments," the press-service quotes Professor Tatyana Bordovitsyna, of the astronomy and space geodesy branch of the Tomsk State University’s Physics Department as saying.

Quelle: TASS