General concept of space debris
Space debris or trash is all non-operational space objects, including upper stages of multi-stage rocket, disabled spacecraft caused by damage or expiration, any parts caused by breakdown and other waste related with space activities in geostationary orbit. Currently a few percent of more than 17000 objects registered in geostationary orbit is active devices, rest of them are the space debris. According to the NASA’s estimation, there is around 28000 space debris defined as 10 cm across or larger. Total debris:
- 42% of satellite components (battery, antenna etc.)
- 22% of non-operational satellites and other space devices
- 19% of household waste of astronauts\
- 17% of parts of rockets
Increasing number of space debris each year and reaching to be serious threat to active space devices are attracting properly international attention.
Figure 1. Space debris
Today, the damage in satellites and space devices influences directly our daily activities because of using satellite service to all sectors. Small waste sized 0.1 cm may damage spacecraft. The first debris was considered US satellite, known as Vanguard 1, which became immediately unavailable after running into orbit in 1958. The first case of collision with space debris for space device was in 1966, a large part of one French satellite and another French satellite were made unavailable in result of collision with one space debris. The recent example is that the space debris, “Cosmos-2251” Russian disabled spacecraft, were collision with US active spacecraft “Iridium-33” in February 10, 2009. It’s considered the probability to damage seriously human is 1 trillion as everyday one space debris falls down on Earth’s surface.
For current contamination issues for space, the leading powers in space are responsible for conducting safely their own space activities, ensuring the safety of orbit and controlling their own air space.
According to it, the following requirements are for scientific organizations:
- Observe, record and index the objects as space debris in accordance with astronomical methods
- Design origin, distribution and further movement of evolution for those objects
- Assess potential hazards to active spacecraft
- Conduct studies for determining and anticipating the probability of potential collision
We have achieved some results in terms of discovering, recording and identifying traffic patterns of space debris though this sector is relatively young science.
Mongolia is not leading power in space, but on the one hand, we use widely satellite service like other countries of the world, on the other hand, it is necessary start to study and observe space debris in order to review safety of national air space. Space debris is investigated through radar and optical observation. Advantages of using optical instruments are relatively low cost and accurate results of studies.
Observations of space debris and satellite comb-out are made by 40 cm telescope, ORI-40.
Figure 2. ORI-40 telescope
The telescope is conducted by the computer in observational point.
Figure 3. Observational point
Semi-automatic telescopes is moving through given coordinates and using CamControl for controlling camera and CHAOS for controlling movement of telescope to take pictures. In order to observe space debris and satellite, the telescope combs out twice visible part with broadband in geostationary and takes pictures from 10 to 15 seconds for 3x3 each area. Figure 4 shows the trajectory of observation.
Figure 4. Trajectory of observation
Observation plans are made for each night based on weather conditions, duration of nigh and position and movement of moon. In order to get results by developing visual pictures, it’s necessary to take from 1700 to 2000 frames per second for winter long night. Thus, data of a lot of pictures is developed by automatic APEX program and then determine the coordinates of objects like space debris or satellite on the frame. In some cases, data is developed manually by TargetPosition program.
Figure 5. Developed by TargetPosition program
Observations of space debris and satellite comb-out in more than 240 night have been made from 2014 to 2016. The results of observations have been published in “Center for collecting, storing, developing and analyzing space objects” of Russian Academy of Science. It is one way to support the permanent activities of dynamic and orbital archive of geostationary objects, evaluate and design traffic evolution and improve accuracy. During observations, we have discovered and registered five lost objects and six new objects in space debris catalog:
- КО ГСО 90264, re-discovered
- КО ГСО 95425, re-discovered
- КО НГСО 90161, re-discovered
- КО НГСО 90473, discovered
- КО ГСО 95641, re-discovered
- КО ГСО 90478, discovered
- КО НГСО 90491, discovered
- КО НГСО 96070, discovered
- КО ГСО 95342, re-discovered
- (КО ГСО– Space objects of geostationary,
- КО НГСО - Space objects of non-geostationary)
And the results of observations have been published in “Classification of Geosynchronous Objects”, issue 16 circular of European Space Agency.
http://www.astrobrock.com/ESA/ESAclassification_Issue16.pdf