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Keldysh Institute of Applied Mathematics
Orbit determination in "Radioastron" mission
G.K. Borovin, M.V. Zakhvatkin,
Yu.N. Ponomarev, V.A. Stepanyants
Pushino 2012
1
The main tasks of Radioastron navigation
2
Perturbations from the jet engines during the
flywheels unload
• Two engines D1 and D2 are not a pair. They provide SC turn
round the Z exes and create the center of masses acceleration
• Two pairs of engines rotate SC round X axes, not disturbing
the center of masses motion
3
Antennas of the service radio-system
RT-64, Bear Lakes
RT-70, Ussuriysk
4
Antenna RT-22, Pushino
5
Telescopes of Scientific system of optical instruments for
astrometric and photometric observation of space object
(NSOI APO)
6
International Laser Ranging Service (ILRS)
Observatoire de la Cote d'Azur
7
North Caucasus
Special Laser Optical Locator
8
The problems identified during the mission
• Measurement of service systems in Ussuriysk and
Bear Lakes contain systematic errors
• Many of laser range station still have not been
able to perform the measurements, despite the
efforts
• Actual disturbance from jet engines of the
stabilisation systen differ significantly from those
of telemetry data
9
Laser range successful sessions
10
The SC motion model the SC
• Noncentral gravitational field of the Earth model EGM-96
(degree 75x75)
• Gravity of the Moon, Sun and planets (coordinates are
taken from the DE 403)
• Solid Earth tides (Model of Rezos and Stolz, 1985)
• Solar radiation pressure, taking into account the Midel area
changes due to SC orientation
• Earth atmosphere up to a height of 1500 km (dynamic
model)
11
Prospects for improving the accuracy of the
orbital parameters
• We are going to continue to calibrate the measurement
system performance and achieve accuracy range of 20 m
and the radial velocity of 1 mm / c
• Currently under revision of the software and hardware at
the laser range station in the North Caucasus.
• There are plans to attract the laser ranging station in
Simeiz (Ukraine). Currently there work carried out for
equipments modification.
• Efforts to begin the work at the Australia laser ranging
station
12
The time intervals
where laser range measurements may be
perform by European stations
13
Improvement of the dynamic model
14