Not Russian to co-operate
RUSSIA has once again captured the attention of the world, and this time it is specifically in relation to its space activities, in particular human spaceflight.
Russia will pull out of its involvement with the International Space Station during this decade, but exactly when this will happen is uncertain.
An initial announcement was that its involvement would end after 2024, although a later one mentioned 2028. Whatever the date, it is a bad sign for any hopes of USRussian co-operation in space.
I had hoped that such a situation would not eventuate. However, the comments by the former head of the Russian space agency Roscosmos, Dmitry Rogozin, earlier this year were a warning.
His words were threatening and, in particular, included a comment that without Russian participation, the ISS would fail to remain in orbit and could fall over the US or Europe.
The fact is that without taking the appropriate steps, the ISS could indeed, eventually, fall anywhere.
To see why, it’s important to understand the make-up of the ISS and the effect of Earth’s atmosphere.
The ISS is divided into two generally different areas: the Russian part, and the international part run by the other
four members of the project (the US, Europe, Japan and Canada). As former ISS commander Terry Virts commented last week, the chief function of the Russian part is propulsion, but it’s not propulsion simply to keep the ISS moving. It is so that it can periodically have its orbital path changed, mainly to lift it into a higher orbit when necessary.
The ISS orbits in a nearly circular path at an altitude of just over 400km. That may
seem to be a long way up, but even at that altitude, the ISS still encounters a little “drag’’ from Earth’s atmosphere, even though the air is extremely thin at that altitude. The effect of this on a spacecraft is to lower its orbital energy, which causes it to lose altitude.
Once an object is in orbit, there is nothing required to keep it simply moving forward. However, to solve the problem of atmospheric drag and to boost the ISS into
higher, safer orbits, the Russian segment is equipped with small rocket engines. As Virts commented, the non-Russian segment would need to have “some sort of propulsion system to retain control’’.
Indeed it will, and a solution will be necessary. The most famous example of atmospheric drag affecting an object, at least for us in Australia, was the re-entry of the US space station Skylab in 1979. Parts of it reached the ground in Western Australia,
although no person was injured.
Another well-known reentry was that of the Russian space station Mir over the Pacific Ocean in 2001. From time to time, smaller objects re-enter, including parts of rockets and “dead’’ satellites.
Mention of Mir is a reminder that the first space stations were actually sent up into orbit by the Soviet Union, preceding Skylab. They were called Salyut 1 and Salyut 2, although Salyut 2 quickly failed and its orbit was decaying as Skylab was launched.
So, what will Russia do next? The new head of Roscosmos, Yury Borisov, has stated that Russia will concentrate on building its own space station. It will be their first independent space station since Mir, although in recent years China has established its own station called Tiangong, orbiting about 380km up.
There has been speculation that Russia may seek co-operation with China. China has, relatively quickly, gained considerable expertise in space, including the stunning successes of the first soft landing of a spacecraft on the far side of the moon, and a Mars orbiter and surface rover on its first attempt.
Being able to send people and equipment into space, including spacecraft to the moon and other planets, is a magnificent human achievement. I shall always remember president John F. Kennedy’s words that the US chose “to go to the moon, not because it is easy, but because it is hard’’.
I can also remember my very positive feeling when, in 1975, the Apollo-Soyuz project saw US and Soviet crewed craft docking in space for the first time, with astronauts and cosmonauts shaking hands as they met.
I feel that full co-operation in space is now just a dream. Let’s hope I can, some day soon, be proved wrong.