Röntgensatellit Yohkoh möglicherweise verloren gegangen :-(

[Peter Kuklok]

Hallo,

schlechte Nachrichten.
Posting von Cary Oler aus dem STD-Forum:

"As many of you are already probably aware, the Yohkoh spacecraft entered a "safe-hold" mode on 14 December at the peak time of the annular eclipse. The spacecraft appears to have been unable to handle the weird set of conditions that it observed on that day.
The end result was an attitude anomaly that is (thus far) preventing controllers from accessing the spacecraft. They do not expect to regain control of Yohkoh anytime soon either. It is similar in some ways to what happened to SOHO a few years back when control was only regained when changes in the orbit of the Earth around the Sun permitted sufficient solar energy to impinge upon its solar panels to permit recommanding of the spacecraft. I'm not inferring that this is what has happened specifically to Yohkoh - they're still working the problem (and probably will be for some time). But thus far, the news isn't good. So as of today, we are unable to determine the locations or brightnesses of individual x-ray sources on the Sun. Whole-disc x-ray intensities will continue to be available through the GOES x-ray plots, of course - but its a fairly serious blow to lose these workhorse products. We wish Yohkoh's operations team the best of luck in regaining control of the spacecraft.

As a result of this (of course), there will be no updates of ANY of the Space Based / Solar / Xray Images in the STD Aurora Monitor software. The flow of data will resume when they regain control of the spacecraft - hopefully sooner rather than later."

Ausgerechnet jetzt wurde auch noch die Testphase von GOES SXI beendet. Der Satellit wurde vorerst abgeschaltet, und es wird wohl Monate (Jahre?) dauern bis er wieder reaktiviert wird.

Grüße
Peter

[Ulrich Rieth]

...der Yohkoh steckt wohl in ernsten Schwierigkeiten, die etwa mit denen von SOHO vor ein paar Jahren zu vergleichen sind.
Und hinzu kommt dann wirklich noch das jahrelange Anschalten des genialen neuen GOES Satelliten samt seiner noch genialeren SXI Kamera.
Hier zu auch ein Beitrag von Cary Oler aus dem STD Forum:

The GOES-SXI instrument on the new GOES spacecraft has completed post-launch testing as of today (20 December). As a result, the
spacecraft has been placed in a storage mode and will not produce any GOES SXI imagery until it is needed. When it becomes
necessary to begin using this spacecraft will depend entirely on how long either of the other two operational GOES spacecraft (GOES-8
or GOES-10) remain functional.

Unfortunately for us, this means that there will be no new GOES SXI imagery made available in real-time by the STD Aurora Monitor
software as it has been over the last many months. Nevertheless, the software will continue to support the imagery whenever the
imagery starts to flow again when the spacecraft is turned back "on."

The last few months have been somewhat of a teaser for what we can expect to receive regularly when the new GOES spacecraft
replaces one of the other aging birds. We look forward to seeing the return of the x-ray imagery in the years ahead.

Gruß

Ulrich

[Ulrich Rieth]

Hallo!
Irgentwie kommt mir mein Text jetzt doch sehr überzogen vor.
Im Vergleich mit den Ereignissen, die im vergangenen Jahr auf der guten alten Erde passiert sind, ist dieses "Problem" nicht einmal der Rede wert.
Ich hoffe auf ein besseres Jahr 2002.
Gruß

Ulrich