Daily news

23 June 2005

Failure of solar sail mission virtually certain’

Two days after the launch of the Cosmos 1 solar sail, there is still no agreement between ground controllers on opposite sides of the globe as to what happened to the spacecraft.

It may have crashed back to Earth very soon after launch, or have ended up an unexpected orbit. But either way, the chances of anything being salvaged from the mission now look remote. The Planetary Society, which sponsored Cosmos 1, said late on Wednesday that failure was now “virtually certain”.

Cosmos 1, which would have been the first solar sail spacecraft to ride the Sun’s light in space, launched on a Russian Volna rocket from a submarine in the Barents Sea on Tuesday. Just 83 seconds after lift-off, the rocket’s first stage engine shut down prematurely, according to a statement from the Russian space agency. The spacecraft was supposed to cruise up towards space for 6 minutes and 17 seconds.

However, this account conflicts with information collected by the Planetary Society, which sponsored the solar sail. One tracking station reported seeing data consistent with the fourth-stage engine firing.


Further data provided evidence that Cosmos 1 was circling the Earth. “We have tracking data from three different stations which seems consistent with a spacecraft in some type of orbit,” says Bruce Betts, director of projects for the Planetary Society. But the US Air Force, which tracks objects in space, did not see the spacecraft in its expected orbit.

Mysterious moves

Potential scenarios include the rocket crashing shortly after launch, in which case the object showing up in the tracking data cannot have been Cosmos 1.

Another option is that something did go wrong with the firing of the first stage of the rocket firing, but that the later stages did fire and placed the spacecraft into an unexpected orbit. If so, that orbit could have been brief and soon decayed to a crash. Or Cosmos 1 could still be circling the globe in an unknown orbit.

The spacecraft is programmed to transmit to the ground at predetermined times. If it is not in the correct orbit, controllers could use broader search patterns in the sky to try to pinpoint the craft.

The mission would only be salvageable if the spacecraft has made it into a high enough orbit, with the altitude boost given from the solar sails counteracting the atmospheric drag pulling the craft towards Earth.

In Moscow, hopes for a surviving spacecraft were only about 1%, project director Lou Friedman told reporters. And Betts told New Scientist: “No conclusions are drawn, but the probability’s getting worse.”

Insurance loss

The Planetary Society attempted to launch a pair of solar sails on a suborbital flight aboard a Volna rocket in 2001. On that occasion, the rocket’s third stage did not separate from the spacecraft, so the solar sails could not be deployed.

In 2001, the Planetary Society had launch insurance to cover the loss, but this time around cost constraints meant there was no insurance.

A solar sail is designed to harness the impact of photons from the Sun on a very thin sail to push a craft along. The force imparted is small, but given time, it can accelerate a spacecraft to very high speeds. Because of this, it is hoped that solar sails may one day allow probes to travel huge distances with a minimal fuel burden.