SOHO Is Back

c4tp's friend writes "Space.com reports that SOHO (Solar and Heliospheric Observatory) is back and almost fully operational. The satellite should be able to transmit 98% of the data it was able to transport before an electric motor stuck disabling its high gain attenae in June (covered by Slashdot). The fix includes a 180 degree rotation of SOHO and use of another satellite dish transmitting the information via the Deep Space Network. SOHO will be out of order for about nine to sixteen days every three months."

Comments

Deja vu?

[pen]

It looks like SOHO was already "nearly back in business in 1998...

Regardless of administrative crap, here are some nice shots of our by far biggest source of life energy!

Long distance repairs

[FTL]

It continually amazes me what ground control can do with damaged hardware. Galileo had an LED (part of the tape drive) which had burned out; but they managed to repair it. Voyager 2 had its entire OS replaced from half way across the solar system. A space telescope with a dead tracking system was revived using software to watch stars using the main camera. Sats with dead gyroscopes have been reactivated using jury-rigged torquer bars which interact with Earth's magnetic field. One communications sat used the Moon as an unscheduled slingshot to get it into the correct orbit after its main booster failed.

So don't laugh when one of these upgrades goes wrong. Like one of the Vikings which was accidentally sent the command "switch off your reciever" while on the surface of Mars (it is still there, patiently waiting for the next order).

Re:Deep Space Network

[confused one]

Actually it's kind of misleading. They're using the low gain antenna now which, using the original uplink, was only capable of low bandwidth. Basically, it was for sending control commands, etc; not for transmitting back the images and other data. By using the big antennas in the deep space network, they increase the sensitivity on this end; and, they've worked out an algorithm (uploaded to the SOHO) which allows them to transmit the data collected back to Earth, using the low gain antenna for higher bandwidth.

I bet the electrical engineers and software people missed a few nights sleep working this out...

Space is the least of NASA's worries

[AtariAmarok]

"I never cease to be amazed by all that NASA is capable. Time and time again they have had (understandable) glitches occur, because space is the most hostile environment."

When you get right down to it, space is not the problem. It is getting there, or getting back that is the problem (especially atmospheres). Once you get out into the void, things seem to work pretty well (at least until you leave space and try to enter another atmosphere, such as Mars)

Voyager II was still transmitting data recently, and it's out of the solar system! How many other systems built three decades ago are still functioning? And do they have to contend with the harshest environment known to man?"

Again, this is not near as harsh on NASA's equipment as our own atmosphere is. Once the stuff gets into space safe and clear, it seems to run pretty well precisely because space is pretty safe when it comes to danger to the craft.

Making Trouble

[Betelgeuse]

The thing about this is that the SOHO engineers really made more trouble for themselves. When they first discovered the possible problem with the motor on the high gain antenna, it was in a relatively good position (i.e. they would have had to roll the telescope every three months, but never would have lost any data). Then, just to "test out" to see if they could get the motors to work, they moved the high gain antenna to its two extremes. Of course, the antenna got stuck near one of its extreme positions. Don't you just hate it when people can't leave well enough alone? :-)

Also, I find it entertaining that a standard way to try to fix something on a space-based instrument is to shake the entire instrument. Seems rather low-tech, but they did it both with SOHO along with other satelites at one point or another.

SOHO: Operational or scientific?

[marcel-jan.nl]

The problem with SOHO is, that everyone has grown rather dependent on, what originally was a scientific, not an operational mission. It has now become a single point of failure in the gathering of important space weather forecasting data.

Space.com recently had an article about this. Without the constant stream of SOHO data, "it isn't too far off the mark that our forecasting methodology would revert back to the way it was many years ago," Joseph Kunches Chief, Space Weather Operations at the Space Environment Center told SPACE.com. "So without it for a little while...well, you keep your fingers crossed. You hope the Sun doesn't know," he said.

Re:NASA Amazes Me

[ChuckDivine]

You haven't been paying attention the past several years, have you?

Consider:

• Two space shuttles lost. A poor design, dishonestly sold, a marked failure. Routine, cheap access to space it isn't. Successor vehicles aren't doing too well, either.
• Hubble trouble -- not because "space is hard" but because people didn't bother to correctly test the observatory on the ground.
• Probes crashing into Mars because one part of the team working in metric, another in English units.

These are just some high profile failures.

Yes, some (probably most) people at NASA do good work. But quite a few knowledgeable people don't trust the organization. There is a lack of "honesty and openness" (to quote Donna Shirley, who led the team that gave us the successful Mars rover) that adversely affects NASA.