Technicians prepare the Phobos-Grunt spacecraft last week for its upcoming launch. (credit: Roscosmos)

Will Russia end its curse at Mars?

by Douglas Messier
Monday, November 7, 2011

The Russian space agency Roscosmos marked Halloween by publishing a photo essay of preparation work on Phobos-Grunt, the Mars probe set to launch from Baikonur on Wednesday. Although the timing was likely coincidental, the symbolism was rich. Mars has been a house of horrors for the Russian and Soviet space programs for the past 50 years.

Not one of 18 Soviet and Russian missions sent to the Red Planet has been fully successful. Probes have been lost in launch accidents, blown up in Earth orbit, failed en route, and mysteriously fallen silent just as they were about to fulfill their missions. By contrast, NASA has flown 13 wholly successful missions to Mars in 18 attempts, going five for six on landing.

Phobos-Grunt (“Soil”), the first Russian mission to Mars in 15 years, is designed to end the curse. It is one of the largest and most ambitious planetary missions ever launched, with the primary goal of returning nearly a half pound of soil and rock from Phobos. When the Zenit-2 booster lifts on Wednesday, it will carry hopes for not only answering fundamental questions about Mars but for the revival of a long-dormant space exploration program.

A look back

The table below shows all the Soviet and Russian missions launched to Mars since 1960. Seventeen of the 18 missions were launched by the Soviet Union. The lone Russian mission was Mars 96, which never made it out of Earth orbit.

Eight of the 18 missions failed due to problems with their launchers, an unusually high number given Soviet expertise with that technology. But, even when spacecraft made it out of Earth orbit, they were prone to numerous failures that resulted in only a handful of partially successful missions.

The peak of the Soviet Mars effort came with seven launches during the 1971 and 1973 launch windows. Of the four orbiters that made it to Mars, three returned useful data. None of the four landing attempts were successful. Mars 3 came the closest to success, falling silent a mere 20 seconds after touching down on the surface.

After 1973, the Soviets put Mars exploration on hold and turned their attention to other targets. The nation completed an ongoing robotic exploration of the Moon, which ended with a sample return by Luna 24 in 1976. The Soviets also continued a highly successful series of missions to Venus and sent two probes to Halley’s Comet.

In 1988, the Soviets were ready to try their luck at Mars again, launching the twin Phobos 1 and 2 missions to the Red Planet. The main goal was the close study of the planet’s enigmatic moon, where the spacecraft would deploy stationary landers and hoppers on the surface.

Hopes were high–and were quickly dashed. Phobos 1 was lost during the cruise phase when a single character error in uploaded computer code commanded the spacecraft to shut down its attitude control thrusters. The spacecraft lost its lock on the Sun, and thus its ability to orient its solar panels properly. Phobos 1’s batteries depleted and the spacecraft died before controllers realized the error.

The failure showed a lack of sophistication in the spacecraft’s control system. Phobos 1 lacked the fail-safes that are built into a comparable American spacecraft, which would have sent a query back to ground control asking, “Do you want to shut down the attitude control system?” The controller would have immediately realized the error and initiated corrective measures to prevent it.

Like several other missions before it, Phobos 2 came tantalizingly close to success. It arrived safely in Martian orbit and eased ever closer to Phobos. However, just before the critical phase of the mission, during which it would have approached within 50 meters of moon and dropped the landers, the spacecraft suddenly went silent. The precise reason was unclear, but engineers later concluded that a computer failure was likely to blame.

Less than three years after Phobos 2 failed in March 1989, the Soviet Union collapsed. The Russians corrected the flaws in the Phobos spacecraft design for a new mission called Mars 96. The mission never had a chance; the failure of its Proton rocket’s fourth stage on November 16, 1996, doomed the spacecraft to a fiery re-entry over Bolivia.

Russia’s Mars aspirations were then put on hold again as the Russian space program struggled for survival amid the economic chaos of the 1990s.

If at first (and second) you don’t succeed…

After another 15-year gap, the Russians are trying again. One might think, given their long record of failure at Mars and a dearth of recent planetary exploration missions to build upon, that they would launch a relatively small satellite with a fairly simple mission. And if that worked, then launch more sophisticated and risky probes later.

Wrong. Phobos-Grunt is a 13.2-metric-ton behemoth stuffed with a Phobos lander, a sample return vehicle, Chinese subsatellite, and instruments and experiments from France, Finland, Bulgaria, and The Planetary Society. And its primarily mission—to return soil samples from Phobos to Earth—is arguably the most ambitious ever launched to Mars.

After arrival at the Martian moon, Phobos-Grunt will send a lander to the surface. The vehicle will collect soil samples using a piston-driven robotic arm similar to the systems used on Luna 20 and Luna 24 on the moon in the 1970’s. Up to 200 grams (7 ounces) of materials will be placed in a cylindrical container on a rocket mounted on top of the landing vehicle.

The return vehicle will be vaulted away by springs before its engine ignites, an approach intended to avoid damaging any of instruments on the lander. If all goes well, the vehicle will return to Earth in August 2014. The lander will continue surface analysis for a year, including heating up soil samples to measure their properties.

It’s an ambitious plan with enormous rewards—and risks. “Any one of these critical stages goes wrong, and the whole mission is compromised,” says Francis Rocard, who runs solar system exploration programs at the French space agency CNES, which is supplying three Phobos surface instruments.

Despite the challenges, there is reason for optimism. The Russian space program is much more advanced than the Soviet one that explored Mars decades earlier. Roscosmos is also partnering closely with other space agencies on the mission. It can draw upon the experience of successfully returning samples from the moon. Phobos-Grunt also was postponed two years from its earlier 2009 launch window to allow engineers extra time to prepare the vehicle.

Still, the mission seems overly ambitious. It’s as if the Russians are trying to make up for years of inactivity with one big throw of the dice that will allow the nation to quickly leapfrog into the leading ranks of Mars exploration. If it works, great. If it doesn’t, then what?

The opaque nature of the Russian space program makes it difficult to know where precisely Phobos-Grunt fits in the nation’s long-term Mars exploration strategy. Will Roscosmos continue with a series of bold, high-risk missions? Or will it seek to emulate NASA, whose well-funded Mars exploration strategy features a series of small and large missions that carefully balances out risks and avoids putting too many eggs in one basket? That strategy has produced an admirable record of success at Mars, and it has enabled the Americans to bounce back quickly from their periodic failures.

Much is riding on the Zenit-2 rocket that will lift off from Baikonur on Wednesday. A successful sample return would certainly be an electrifying success and remove a dark cloud that has hovered over Russia for 50 years. Failure would be a very bitter pill to swallow for a proud people who have known far too much heartbreak at Mars.

Douglas Messier is publisher of Parabolicarc.com, a website that covers space tourism and much more.

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