1. Brief introduction of YINGHUO-1 Micro-satellite for Mars environment exploration J. Wu, G. Zhu, H. Zhao, C. Wang, L. Lei, Y. Sun, W. Guo and S. Huang Center for Space Science and Applied Research, CAS Shanghai Astronomical Observatory, CAS

2. Yinghuo (YH) -- Name of the mission China has long history of astronomical observation of Mars, the very first observation record was made during 475-221BC. The mission is named after the ancient Chinese name for Mars “YingHuo” Ying --- Red Huo --- unpredictable Yinghuo-1 (YH-1) mission

3. Fly opportunity with Phobos-Grunt China and Russia signed the agreement in March 2007. The cooperation includes: 1)Piggy back launch of a Chinese Mars exploration satellite YH-1 (~115kg) 2)Russia will provide ground TTC support to YH-1 3)Phobos-Grunt and YH-1 will carry out joint measurements of Martian space environment

4. Fly opportunity with Phobos-Grunt

5. Overview of the spacecraft YH-1 –3 axis stabilized platform, with deployable solar panel –Mass: 110kg –Power: 90W (average) 180W (peak) –payload mass: 11 kg –payload power: 20 W –nominal life time: 1 year

6. Overview of the spacecraft YH-1 orbit parameters ： apogee ~80,000 km perigee 800 km inclination  36  800km 80000km Orbit of Phobos

7. Scientific objectives of YH-1 This orbit will well cover the areas of solar wind, bow shock, magnetosheath, magnetic pileup region, and tail and plasma sheet. Nagy et al.,2004

8. Scientific Objectives 1To study details of Martian space magnetosphere, ionosphere and the plasma distribution and their variations; 2To study Martian ion escape mechanism, its implication for water loss. 3To have moderate surveys of Martian surface topography, sandstorm and its influence on ionosphere; 4To explore the Martian gravity field near equator by analyzing orbital data of YH-1.

9. InstrumentsGoals Flux gate magnetometerSpace magnetic field measurement P lasma package Electron analyzerMeasuring plasma distribution : energy, mass, velocity two ion analyzers Two frequency occultation receiver Ionosphere occultation Photo-imagerSandstorm and Mars surface imaging Scientific payloads of YH-1

10. Magnetometer Flux-gate magnetometer, measures 3 components of magnetic field. 2 sensors –double redundant –gradiometer to eliminate S/C remnance Sensor A Sensor B Solar panel YH-1 spacecraft

11. Magnetometer

12. Plasma package two identical ion analyzers one electron analyzer electronics Plasma Package

13. Plasma package Ion analyzer –Electrostatic analyzer + TOF scheme, to resolve ion mass/direction/energy Specifications –Field of view: 360  160 , 8 angular sectors in polar direction –Energy range: 20eV-15keV –Energy resolution: 7%, 96 bins –Mass resolution: 1, 2, 4, 8, 16, >32 amu 2 identical ion sensors simultaneous measurements –Better angular coverage and resolving ability

14. Plasma Package Electron analyzer –Electrostatic analyzer –Electron direction/energy spectrum Specifications –Field of view: 9  120  8 azimuth angular sectors –Energy range: 20eV-15keV –Energy resolution: 15%, 32 bins

15. Occultation Receiver –Sensitivity: ≤-145 dBW; –Measuring accuracy of carrier phases: 1/100 cycle(0.02m); –Sampling rate: 10Hz; –Antenna polarization: linear polarization; –Operating frequencies: 833MHz, 416.5MHz

16. Receive signals at two frequencies from Phobos mission, Ionosphere Occultation between YH-1 and Phobos Focused on sub-solar and midnight ionosphere, never tapped by previous occultation due to limit of Sun-Earth-Mars geometry. Occultation Receiver

17. Optical Imager CMOS Imaging Sensor Specifications Wide FOV camera Narrow FOV camera Pixels≥ 4 million SNR≥30dB Power ＜ 3W Weight1.3±0.1kg Resolution global images@ 10,000km ≤0.5Km at Perigee ≤ 0.3Km at Perigee SDRAM10 full resolution image 5 full resolution image

18. Besides independent observation of the Martian environment, joint operations with Phobos mission are also planned: 1.Two-point measurements of the Mars space environment 2.S/C to S/S radio occultation measurements 3.Data archiving and exchange Joint Operations

19. 1.Two-point measurements of the Martian space environment Joint Operations

20. 2.S/C to S/C radio occultation measurements Before/after FGSC landed on Phobos

21. Start time (UTCG) Off time （ UTCG ） duration backup 1 2010 10.10 17:53 :55.812010 10.10 18:04:21.2311min 2 2010 10.13 17:24:41.592010 10.13 17:40:36.2916min 3 2010 10.16 16:56:04.512010 10.16 17:16:16.6820min 4 2010 10.19 16:27:46.322010 10.19 16:51:40.9124min 5 2010 10.22 15:59:39.012010 10.22 16:26:56.7027min 6 2010 10.25 15:31:39.532010 10.25 15:35:37.824min 7 2010 10.25 15:58:09.982010 10.25 16:02:6.844min 8 2010 10.28 15:03:45.992010 10.28 15:07:23.064min 9 2010 10.28 15:33:36.762010 10.28 15:37:12.914min 10 2010 10.31 15:12:58.212010 10.31 15:15:27.383min 11 2010 11.21 12:15:22.002010 11.21 12:17:54.692.5minEclipse

22. YH-1 and Phobos-Grunt are going to make a series scientific break through in the area of Mars space environment exploration. We should get fully prepared for these exciting events with good plans of joint operation. Summary

23. Thank You! IEEE Spectrum