Yinghuo-1 (YH-1)

1. Historical Background and Detailed Objectives

Yinghuo-1 represented the People's Republic of China's first foray into the exploration of the Martian system using a dedicated probe. Conceived as a microsatellite orbiter, the project sought to comprehensively study the space environment of the red planet. Primary objectives focused on analyzing the magnetosphere, ionosphere, plasma distribution, ion escape mechanisms, dust storms, and Mars' equatorial gravitational field, in addition to complementing the mission with optical imaging for surface topography studies.

2. Vehicle Architecture and Main Subsystems

The microsatellite featured compact dimensions of 750 mm × 750 mm × 650 mm in its stowed configuration, deploying a solar panel wingspan of 6.85 meters that guaranteed an average electrical power of 90 W. Communications operated via a 950 mm diameter high-gain antenna. Lacking its own propulsion for orbital insertion, its mobility depended entirely on the Russian Phobos-Grunt mothership, to whose side chassis it was docked as a secondary or piggyback payload for the interplanetary journey.

3. Payload and Scientific Instrumentation

• YPP (Yinghuo Plasma Package): Instrumental package developed jointly with Sweden, composed of ion and electron analyzers for studying the space environment and the ionosphere.
• YPP-i (YPP-ion mass spectrometers / YPP-i1 and YPP-i2): Ion mass spectrometers intended to quantify the composition and distribution of plasma, as well as ions originating from the Martian atmosphere.
• Flux-gate Magnetometer: Instrument responsible for recording the planetary magnetic field and direct interaction with the solar wind.
• Sat-sat occultation receiver: Device configured to perform radio and atmospheric measurements.
• Optical imager: System intended for capturing surface images and topographic analysis.

4. Launch Vehicle and Flight Profile

The launch took place on November 8, 2011, at 20:16:03 UTC via a Zenit-2M (Zenit-2SB) launcher from pad 45/1 of the Baikonur Cosmodrome. The flight plan required the Russian upper stage to propel the combined assembly toward the interplanetary trajectory to Mars.

5. Chronology and Mission Phases

Following the nominal liftoff on November 8, 2011, the mission suffered a critical failure when the planned Russian burns to leave Earth orbit failed to execute. On November 17, 2011, the CNSA formally declared the loss of the Yinghuo-1 probe as the assembly remained stranded in low Earth orbit. The trajectory progressively decayed until culminating on January 15, 2012, with the destructive atmospheric reentry over the Pacific Ocean.

6. Results and Technical Conclusion

The mission obtained no scientific data from the Martian environment as the interplanetary transfer was thwarted. The failure in the propulsion stage of the Phobos-Grunt mothership resulted in the total operational loss of the Chinese platform before initiating its cruise phase.