Sun Sets on Power-Challenged Russian Solar Observatory

Daniel is a deputy news editor for Science.

The future doesn’t look sunny for Russia’s Koronas-Foton spacecraft, a solar observatory that has been having power system problems since last summer, culminating in a loss of contact in early December. Communications with it were reestablished late last month and controllers in Russia have been trying to recover systems on the craft, but it was reported yesterday that their efforts have so far failed.

Researchers agree that the loss of Koronas-Foton will leave a hole in solar research. “There is nothing yet planned by NASA or ESA [the European Space Agency] that will reproduce all of the Koronas measurements, at least not within the next decade or so,” says Lyndsay Fletcher of the University of Glasgow in the United Kingdom.

The probe was launched on 30 January 2009 for what was meant to be a 3-year mission. But in July, as the craft’s orbit went into a phase that took it increasingly into the shadow of the earth, power supply problems began to emerge. Two onboard batteries were not providing enough power to keep systems working while in the earth’s shadow, so the onboard computer was automatically shutting down systems. On 1 December 2009, the computer abandoned one of the batteries completely and the following day communication ceased. Later in the month, however, the amount of time Koronas-Foton spent in the sun increased; on 29 December the craft made contact again. Despite efforts to revive the craft’s systems, it remained dormant and on 18 January, when its sunlight time peaked at 72.5 minutes in every 95 minute orbit, Russian media reported that it was almost certainly dead.

Koronas-Foton, the third in a series of Russian solar missions, was designed to investigate several enduring mysteries of the sun, such as how its corona is heated, the mechanics of solar bursts, and the nature of solar cycles. It was also part of a worldwide effort to study the sun, known as the International Living with a Star (ILWS) program, and researchers will regret its passing. “It returned some very promising early results and it looks like there are some unique instruments on it, particularly in the hard x-ray and gamma-ray regimes,” says Fletcher.

ILWS Chair Madhulika Guhathakurta of NASA’s science mission directorate in Washington, D.C., agrees: “Several high energy instruments will play a critical role in the observations of the onset of energetic events like flares and Coronal Mass Ejections. Together the NASA/NOAA and international observatories and the Koronas-Foton observatory can observe the complete electromagentic spectrum from radio to gamma-rays.” That is, if the spacecraft was functioning as planned.

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