SOHO Spacecraft Back Online

The bright speck to the left of the Sun in this SOHO image is Jupiter (Credits: NASA/ESA).

SOHO, the Solar Heliospheric Observatory co-sponsored by NASA and ESA, is back online. The spacecraft was out of commission for just over a week.

A technical problem of unknown origin derailed the observatory, prompting operators to put it in safe mode. “You safe a spacecraft if you don’t know what its status is,” Joe Gurman, a SOHO scientist from NASA Goddard Spaceflight Center told SPACE.com. “This makes sure that you’re pointing at the sun, it makes sure the solar arrays are power positive.” He continued: “Not quite everything is up and running, but the spacecraft is back.”

The first image returned by the restored SOHO showed Jupiter passing in a near transit of the Sun. SOHO is designed to monitor the Sun, from core to corona, as well as the solar wind. It along with the Solar Dynamics Observatory (SDO) is a key tool in monitoring and studying space weather events stemming from solar flares and coronal mass ejections. Solar observation is critical to forecasting and mitigating damaging radiation events that endanger satellites, aircraft, and electrical grids. Such events are increasing in frequency as the 2013 solar maximum nears.

Originally launched in 1995, the spacecraft was intended for a two year mission that has since been extended five times, covering a full 11 year solar cycle. The spacecraft had experienced a prior mission recovery in 1998 following a loss of contact event. All three of the spacecraft’s gyroscopes failed, but a software upgrade has allowed it to continue to operate. It is the first three axis stabilized spacecraft to maintain navigational control without a gyroscope.

The video below from January 2012 is typical of the data collected by SOHO. This recording shows a coronal mass ejection headed directly towards Earth – and SOHO itself.