нОХЯЮМШ ЛЕРНДШ БШЯНЙНРВМНЦН НОПЕДЕКЕМХЪ НПАХРШ, ЙНЯЛХВЕЯЙНЦН ЮООЮПЮРЮ "яОЕЙРП-п", ЙНРНПШИ АСДЕР ГЮОСЫЕМ МЮ БШЯНЙНЮОНЦЕИМСЧ НПАХРС Б 2009 Ц. мЮ ЮООЮПЮРЕ СЯРЮМНБКЕМ ПЮДХНРЕКЕЯЙНО ДХЮЛЕРПНЛ 10 Л. хЯОНКЭГНБЮМХЕ ЙНЯЛХВЕЯЙНЦН ПЮДХНРЕКЕЯЙНОЮ ЯНБЛЕЯРМН Я МЮГЕЛМШЛХ ЮМРЕММЮЛХ АНКЭЬНЦН ДХЮЛЕРПЮ ОНГБНКХР ОПНБНДХРЭ ПЮДХНХМРЕПТЕПНЛЕРПХВЕЯЙХЕ МЮАКЧДЕМХЪ Я АНКЭЬНИ АЮГНИ, ВРН ОНГБНКХР ОПНБНДХРЭ ХЯЯКЕДНБЮМХЕ РНМЙХУ ЯРПСЙРСП ХГСВЮЕЛШУ ПЮДХНХЯРНВМХЙНБ. дКЪ НОПЕДЕКЕМХЪ НПАХРЮКЭМШУ УЮПЮЙРЕПХЯРХЙ йпр Б УНДЕ ОНКЕРЮ АСДСР ГЮДЕИЯРБНБЮМШ ЯРЮМЖХХ СОПЮБКЕМХЪ Х ЯРЮМЖХХ ЯКЕФЕМХЪ, Ю МЮ АНПРС АСДЕР СЯРЮМНБКЕМ м-ЛЮГЕП. мЮ ЙНПОСЯЕ ЮООЮПЮРЮ АСДСР СЯРЮМНБКЕМШ СЦНКЙНБШЕ НРПЮФЮРЕКХ, ВРН ОНГБНКХР ОПНБНДХРЭ ОПЕЖХГХНММШЕ КЮГЕПМШЕ ХГЛЕПЕМХЪ ЕЦН ОНКНФЕМХЪ.

Space radio-telescope (SRT) will be launched on near Earth orbit, having perigee close to the Earth and near-apogee distance ~ 330,000 km. SRT will have an antenna with diameter 10 meters. The orbital parameters are chosen to maximize evolution of the normal to the orbit plane (?-right ascension and i-declination) using the gravitational fields of the Moon and the Sun. The name of the spacecraft is . SRT together with the stations on the Earth surface will be an interferometer with a very large base. To determine current orbital parameters of the SRT tracking stations (TS) and command stations (CS) will be used. To provide high-stability frequency generation an on-board H-maser will be installed. CS will measure range and range rate, and the TS will measure only range rate of the SRT. The laser retroreflectors which will be used for the SRT ranging will increase precision of laser measurements. This paper deals with the questions of the SRT orbit determination.
From the ballistic point of view the SRT is a difficult object. The pressure of solar radiation has a different effects on the different elements of spacecraft surface. As a result the force-moments around the spacecraft center of mass appear. To keep spacecraft orientation constant reaction-wheel system (RWS) will be used. Long-run effects of the force-moments lead to permanent increase of angular velocity momentum which, in turn, will require unloading the momentum of the spinning reaction wheels by switching on gas engines.
The absence of the orientation moments scheme results in perturbation of the SC center of masses motion. As the performed estimation shows, the velocity change, caused by such perturbations, for a day can achieves value of ≈ 1 cm/sec. Per day shift may be within 1 km, what sometimes exceeds an accuracy of radio range measurements. The span of an interval of measurement used for determination of orbit parameters should be not less that one full orbit. During this period the sessions of RWS unloading will be carried out some times, so the SC motion on this span can not be considered as passive. Thus the motion model should take into account perturbations originating owing to work of the attitude control system engine in sessions RWS unloading. The duration of a session of unloading is insignificant (presumably less than 5 minutes), therefore disturbing effects on the SC center of masses motion can be considered as instantaneous impulses of velocity changes in a middle of the RWS unloading session. The parameters of these impulses should be evaluated with the most accuracy by using all available information. For that purpose the following information is going to be used:

– the tracking radio measurements of range and range rate,
– the laser location measurements,
– magnitudes and directions of impulses obtained as a result of telemetry information processing,
– angular velocity of the wheels which will be monitored during the flight.

The estimations have shown that accuracy of available measurements for the SRT position and velocity gives a possibility to embody the high-precision reconstruction of the SRT orbit.