RADIOSCIENCE EXPERIMENTS WITH "MOON-GLOB" ORBITER RECEIVER AND BEACONS ON MOON'S LANDERS A.S. Kosov 1, O.N. Andreev 1, V.M. Aniskovich 1, I.A. Babushkin 1, S.V. Fedorov 1, L.I. Gurvits 3, R.S. Kalandadze 1, V.V. Korogod 1, S.M. Maleev 1, V.G. Nechaev 1, S.V. Pogrebenko 3, V.S. Rozhkov 1, D.P. Skulachev 1, I.A Strukov 1, Y. Sun 5, V.K. Sysoev 2, S.G. Turyshev 4, V.A. Zotov 1. 1 Space Research Institute RAS, 84/32 Profsouznaya, , Russia; 2 Lavochkin Science Production Association, Chimky, Moscow Region, 24, Leningradskaya St., , Russia; 3 Joint Institute for VLBI in Europe, Dwingeloo, The Netherlands; 4 JPL, 4800 Oak Grove Drive, Pasadena California Dwingeloo, USA; 5 Center for Space Science and Applied Research, Chinese Academy of Sciences, No.1 Nanertiao Zhongguancun, P.O.BOX:8701 Beijing , China. Contact:

Hardware of Landers - beacon

SPECIFICATION OF X-BAND CHANNEL Central frequency: 8400/8420 MHz Irradiated power:0,3 W, no less Main beam direction:to the Earth Beam width :120 degrees Polarization type:CR Modulation type: QPSK, different Fm Frequency instability (Allan variance), no more: Integration time 3-30 sec:8· sec:1· , sec:1· hours5· year2·10 -9

SPECIFICATION OF KA-BAND CHANNEL Central frequency: 32 GHz Irradiated power:0,3 W, no less Main beam direction:to zenith Beam width :120 degrees Polarization type:CR Modulation type: no Frequency instability (Allan variance), no more: Integration time 3-30 sec:8· sec:1· , sec:1· hours5· year2·10 -9

Reference oscillator, OCXO BVA9607

Comparison of frequency stability of different space clocks

Modes of operation 1.32 GHz signal, only carrier GHz signal, only carrier GHz signal, carrier and ±3 MHz subcarriers GHz signal, carrier and ±20 MHz subcarriers GHz signal, carrier and ±50 MHz subcarriers 6.Internal cyclogram, when beacon will be powered from nuclear source

Spectrum of X-band signal, carrier and ±20 MHz subcarriers

Beacon’s position on lander’s panel

Navigation task solution Navigation task - determination of lander’s position with accuracy 10 cm or less. Method – VLBI. Planning cyclogram – each lunar day, lunar days.

Radio interferometric network "Quasar“, 1.S. Petersburg, 32 m 2.Siberia, 32 m 3.Caucasus, 32 m

Celestial mechanics experiments

Hardware of the orbiter, Ka band receiver

Structure of the Ka-Band (32 GHz) Receiver

Chart of the 32 GHz Receiver

SPECIFICATION OF KA-BAND RECEIVER Central frequency: 32 GHz Noise temperature:150 K, or less Antenna main beam direction:to nadir Beam width :120 degrees Polarization type:CR Bandwidth:0.5 MHz Frequency instability of local oscillator (Allan variance), no more: Integration time 3-30 sec:8· sec:1· , sec:1· hours5· year2·10 -9

Navigation task and experiment INGL (Investigation of non-uniformaty of Lunar Gravitation)

Bouguer gravity anomaly map from SGM90d. N Namiki et al. Science 2009;323: Published by AAAS

Experiment GRAIL, NASA, 2012 GRAIL is the lunar analog of the very successful Gravity Recovery and Climate Experiment (GRACE) twin- spacecraft terrestrial gravity recovery mission that was launched in 2002 and continues to operate. GRAIL will be implemented with a science payload simplified from GRACE and a spacecraft derived from the Lockheed Martin Experimental Small Satellite-11 (XSS-11) launched in GRAIL will place two spacecraft (represented as GRAIL-A and GRAIL-B to the left) in a low-altitude (50 km), near- circular, polar lunar orbit to perform high-precision range-rate measurements between them using a Ka- band payload. Subsequent data analysis of the spacecraft-to-spacecraft range-rate data provides a direct measure of the lunar gravity. The payload, flight system and mission design ensure that all error sources that perturb the gravity measurements are contained at levels well below those necessary to meet science requirements. The figure below illustrates performance margin between the science requirements (red and green), the allocated performance (black), and Current Best Estimate (CBE) performance (gold). These margins enable GRAIL's low- risk implementation

Features of the 32 GHz receiver in INGL experiment ParameterValueNote Noise figure, dB≤ 1.6 Stability of LO frequency3-30 sec, 8· ; sec, 1· ; 0, sec, 1· ; 24 h, 5· ; year, 2·10 -9 ; -30 О …+60 О С, 1· Reference oscillator 8607 Accuracy of acceleration measurement, mGal 3Averaging time 3-30 sec, 1 Gal = 1 cm/sec 2 S/N40 dBP TX = 0.5 W, 0.1 Hz, 500 km

Experiment INGL features, comparison with GRAIL ParameterINGLGRAIL Accuracy, mGal Resolution, km Area of investigation +/ km from beacons Front side of the Moon Ground networkNOYES Scheduler

Mutual operation with another instruments Optical instrument and Ka-band receiver on orbiter could measure 3D displacement of the with respect to lander’s position. Laser corner reflectors and light emitting beacons on landers will support navigation task. It is possible to use precise clock of beacons and receiver to synchronize the navigation complex instruments.

Thanks for attention Questions?