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The Phobos-Grunt/Yinghuo-1 spacecraft did not perform its scheduled burn to begin its trajectory to Mars and could not leave Earth orbit. It re-entered Earth's atmosphere on 15 January 2012.

The Yinghuo-1 ("Firefly") mission is a Chinese Mars orbiter scheduled to launch in tandem with the Russian Phobos-Grunt mission in November 2011. The primary scientific objectives of the mission are to study martian space environmental structure, plasma distribution and other characteristics; the solar wind-atmosphere coupling and energy deposition processes, martian ion escape processes and mechanisms, the regional gravity field of Mars, and to perform martian and Phobos surface imaging. The mission will also test deep space navigation and communication techniques.

Spacecraft and Subsystems

The Yinghuo-1 satellite has a mass of 115 kg. The main body is box-shaped, 0.75 x 0.75 x 0.65 meters with two solar panel wings, extending to 6.85 meters from tip to tip, and a 95 cm diameter high gain antenna. The solar panels will provide an average power of 90 W. The communications and tracking of Yinghuo-1 will be achieved using an X-band receiver and 12 W transmitter system at 8.4 and 7.17 GHz and open-loop tracking using Very Long Baseline Interferometry (VLBI), DOR/DOD, and one-way Doppler measurements. Data transmission will be up to 16 Kb/sec. Yinghuo-1 and Phobos-Grunt will carry similar space physics payloads to allow coordinated observations of the martian space environment. They will also combine to study the martian ionosphere using UHF radio occultation links. The payload includes a camera, plasma detector, and magnetometer.

Mission Profile

Yinghuo-1 was stacked on a common booster below Phobos-Grunt. Yinghuo-1 launched on 8 November 2011 at 2016 UT on a Zenit 2SB41.1 rocket from the Baikonur Cosmodrome in Kazakhstan into an elliptical Earth orbit. The plan was to use a Fregat upper stage to carry Phobos-Grunt and Yinghuo-1 on an eleven month cruise to Mars. However, the later firings never occured and the spacecraft remained in Earth orbit. The spacecraft is expected to re-enter the atmosphere between December 2011 and February 2012.

The plan for the mission if it had made it to Mars is as follows: after a 10-11 month cruise to Mars, the connected spacecraft will be injected into an 800 x 80,000 km near-equatorial (1 - 5 degree inclination) orbit with a period of about 72 hours. The spacecraft will stay connected for approximately 3 of these orbits, after which the Phobos-Grunt will detach and head towards Phobos. Yinghuo-1 will remain in this orbit.

Alternate Names

  • Firefly

Facts in Brief

Launch Date: 2011-11-08
Launch Vehicle: Zenit
Launch Site: Tyuratam (Baikonur Cosmodrome), Kazakhstan
Mass: 115 kg
Nominal Power: 90 W

Funding Agency

  • China National Space Administration (Peoples Republic of China)


  • Planetary Science

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



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