MOSCOW, October 14 (Itar-Tass) — Russian cosmonaut from the crew of Expedition 29 to the International Space Station (ISS) Sergei Volkov is beginning in orbit a session of a plasma experiment, which will help prepare a manned mission to Mars.
“Within the Ten'-Mayak (Shadow-Beacon) experiment Volkov on Friday evening will switch on a radio station and launch the program,” spokesman for the Mission Control Centre (MCC) outside Moscow Valery Lyndin told Itar-Tass. During several bays before bedtime the cosmonaut will be switching on the equipment, and in the morning will be switching it off.
“The purpose of the Shadow-Beacon experiment is to drill the method of radio sounding of the air-ground communication space to ensure the preparation of the plasma experiment Shadow in which any radio fan on our planet will be able to take part,” the MCC specified.
“Low-thrust electric propulsion engines will be installed on spaceships that will fly to other planets. During a space flight there may be situations in which the plasma cloud from the engine will block the passage of the radio signal to Earth, so it is necessary to study in advance the effect of dispersion of radio-frequency emission in artificial plasma build-ups in space,” the author of the idea cosmonaut Alexander Kaleri told Itar-Tass earlier.
According to him, to create an artificial plasma cloud in orbit, he said, it is necessary to install on the outer surface of the ISS a special injector that in a certain period will emit a plasma jet. The ISS onboard radio beacon that works in the VHF amateur radio frequency bands, should emit probing signals, which are control time tags. These signals can be received by all the radio hams involved in the experiment.
The plasma jet, said Kaleri, partially screens the radio beacon’s antenna, creates an area of radio shadow the boundary of which moves along the Earth’s surface according to the ISS movement. When a ground-based receiver gets into the radio shadow area the signal is jammed, and when it gets out of it - the signal reception resumes. The task of each ground-based participant in the experiment is by the onboard control time tags to register the points of jamming and resumption of reception and, having reported his geographical location, to send the information to the centre where it will be collected and processed.
For the purity of the experiment is necessary to involve as many receivers in different parts of the world as possible. Any enthusiast of space exploration, including schoolchildren and students will be able to make a contribution to science without leaving home. But before conducting the “Shadow” experiment with the plasma jet, it is necessary to work out the methodology, in the first place - the transfer from the ISS beacon of the single for all radio hams time code, allowing immediately to determine at which point and at what time the signal was received. This work is being done by cosmonauts in orbit, the MCC explained.
The purpose of the experiment, according to the RKK Energia Rocket-Space Corporation, is to study of USH-radio signal transmit/receive conditions in the mode of onboard radio beacon in the ISS RS using world-wide ham radio network; determining characteristics of radio Signals retransmitted through onboard transceiver, their quality and spatial distribution; assessment of disturbing actions, such as re-reflection, shading caused by structural elements and value of the ISS elevation angle.
Its objectives include: generation of onboard radio beacon probing pulses as time marks to ground receiving network (including ham radio receivers of USW) and transmission of the measurement results throughout Internet network. Check of the concept of forced radio silence in the mode of short-packet generation by radio communication Protocol AX25. Determining of ISS structural members effect on onboard antenna directional pattern (DP) in flight conditions. Determining zones of DP radio shadowing zones by the station structural members depending upon its spatial orientation. Assessment of ground receiving network non-uniform sensitivity on accuracy in spatial-time measurements. Determining of ground receiving network radio visible configurations depending upon an angle of elevation and light-shadow situation along the flight course.