China Launches Complex Mission to Mars

China Launches Complex Mission to Mars

China launched its first solo mission to Mars, Tianwen-1, just after midnight July 23 EDT. The spacecraft is a combination orbiter, lander and rover. If successful, China will become only the second country, after the United States, to operate a rover on the Red Planet and the first to attempt such a complex mission all at once.

Tianwen-1 is one of three missions to Mars this year. The United Arab Emirates’ Hope probe was launched on Sunday (Eastern Daylight Time), and NASA’s fifth Mars rover, Perseverance, is scheduled for liftoff on July 30.  All will arrive at Mars in February 2021. The timing is dictated by celestial mechanics – the Earth and Mars are correctly aligned in their orbits only every 26 months to permit such flights.

China’s official news channels apparently did not provide any live coverage of the launch at 12:41 am EDT (12:41 pm in China), but an amateur livestream from an apartment nearby offered a view of liftoff and the first minute or so of flight.

China’s Tianwen-1 Mars probe moments after liftoff from Hainan Island on a Long March 5 rocket. Screengrab.

China Global Television News (CGTN) issued a tweet immediately after launch confirming it took place and another after spacecraft separation and injection into the correct trajectory to Mars.

An official video of the launch was posted by Xinhua after the fact.

China’s first Mars probe, Yinghuo-1, was part of Russia’s Phobos-Grunt mission in 2011, which failed to leave Earth orbit because of a launch vehicle failure. Yinghuo-1 was only an orbiter, but since then China has gained considerable experience with lander/rover combinations on the Moon — Chang’e-3/Yutu and Chang’e-4/Yutu 2. That apparently gave China confidence to attempt this complex three-spacecraft mission to Mars on its first try.

While there have been many successes over the decades, missions to Mars are not easy and the road is paved with complete or partial failures from the United States, Russia and Europe.  Some joke about a “galactic ghoul” near Mars waiting to spoil a mission.

The name Tianwen is from a poem by Qu Yuan (340-278 B.C.) and means Questions to Heaven.  It will be used generically for all future Chinese planetary probes.  Tianwen-1 apparently refers to this entire mission, but specific names for the lander and rover could be announced later as happened with the lunar rovers. In that case, Chang’e is the name of China’s mythical goddess of the Moon. Yutu is her pet jade rabbit.

The entire spacecraft has a mass of about 5 metric tons, including fuel, according to four Chinese scientists writing in Nature last week.  In total, there are 13 scientific payloads, seven on the orbiter and six on the rover.  The orbiter has two cameras, a Mars-Orbiting Subsurface Exploration Radar, a Mars Mineralogy Spectrometer, a Mars Magnetometer, a Mars Ion and Neutral Particle Analyzer, and a Mars Energetic Particle Analyzer. The rover has a Multispectral Camera, a Terrain Camera, a Mars-Rover Subsurface Exploration Radar, a Mars Surface Composition Detector, a Mars Magnetic Field Detector, and a Mars Meteorology Monitor.

Once Tianwen-1 reaches Mars orbit in February, it will wait two-three months before the lander/rover separates and descends to a landing at Utopia Planitia.

CGTN posted an animation of the landing and the rover disembarking.

The 240 kilogram (530 pound), six-wheeled, solar-powered rover has a design lifetime of 90 days on the surface. The orbiter is designed to operate for one Martian year.  In addition to its scientific instruments, it also serves as a communications relay for the rover.

If successful, the mission not only will be a feather in China’s cap, but add to the list of rovers that have or will study the planet’s surface.

The first Mars rover was NASA’s Mars Pathfinder’s Sojourner in 1997, followed by Spirit and Opportunity in 2004, and Curiosity in 2012, which is still operating. NASA’s Mars Perseverance, scheduled for launch next week, will be the fifth.  It is not just a rover, but also carries a helicopter, Ingenuity, that will be the first aerial vehicle on another world.

NASA has a long history of sending probes to fly by, orbit and/or land on Mars. Mariner 9 in 1971 was the first probe to orbit Mars and send back detailed photos of the surface, transforming scientific thinking about the planet. Viking 1 and 2 in 1976 were orbiter/lander pairs and the first two spacecraft to successfully land on Mars. (A Soviet lander, Mars 3, made it to the surface in 1971, but stopped transmitting 20 seconds later.)  NASA also sent two stationary landers: Phoenix in 2008, and InSight in 2018, which is still operating.  Another, Mars Polar Lander, failed.

Mars 3 was the only one of four Soviet Mars landers in the 1970s to send back any signals after landing, albeit only for 20 seconds.  Mars 2 and Mars 6 apparently crashed; Mars 7 missed the planet.

Two European landers – Beagle 2 and Schiaparelli – also failed.

As for orbiters, the success rate has improved with passing years. Right now, NASA, ESA and the Indian Space Research Organisation (ISRO) all have operational orbiters:  NASA’s Mars Odyssey, Mars Reconnaissance Orbiter, and MAVEN; ESA’s Mars Express and ExoMars Trace Gas Orbiter; and ISRO’s MOM.  With luck, in a few months they will be joined by the UAE’s Hope and Tianwen-1.

NASA Administrator Jim Bridenstine and Associate Administrator for the Science Mission Directorate Thomas Zurbuchen both tweeted their congratulations.



This article was updated after the launch, after trans-Mars injection, and with the congratulations from NASA.

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