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Hack in Space
MelloDawg writes: "From the press release: NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) spacecraft, which some had given up for dead in December after critical guidance components failed, was returned to full operations when the team developed an innovative new guidance system. The system uses a complex new set of procedures that lets controllers use electromagnets in the satellite to push and pull on the Earth's magnetic field. Details of the mission are online."
Don't be ridiculous. I can tell you that in IT, this line of thinking will get you fired quickly.
Most often, if a system breaks in a production environment, it's imperative to get a it working again as fast as possible. Treating the symptom is paramount in a high availability situation, and while finding and resolving the cause is of course important, it takes an immediate back seat to getting the system back into production. If you can do both at once then that's grand. If not, then you restart the daemons or reboot the server once you've deemed it safe to do so.
Then, armed with log files and information gathered while the system was on error, you can go back through and trace the cause. Even better, you can duplicate the issue on a staging server. What you do NOT do is leave the system down for any reason one second longer than you have to, no matter how much the urge to tinker grabs you.
On the other side of the coin, diagnosing a problem on trivial or near-trivial system is a waste of your valuable time. Why the hell, except for fun, would you diagnose a BSOD issue on a secretary's computer when you could just back up her home directory, restore an image, then restore her personal files?
Obviously, every situation is different, but there are times when inexperienced techs will spend a day searching for the cause of a trivial problem instead of getting back to work.
Taking the time to root out a deep problem instead of just hitting the reset button is most often a luxury.
Even Jesus hates listening to Creed.
You can couple to a planetary magnetic field, like these guys are doing. Again, only good for one axis
Not really. Full 3-axis stabilization can be implemented using the Earth's magnetic field. Unlike a passive pole the magnetotorquers are active elements and the magnetic field doesn't always point down so at different parts of an orbit it can be used to control all 3 axes.
Design and Experimental Test of Magnetic-Torquer-Based 3-Axis Satellite Attitude Controllers
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
What the article omits is that the fine pointing accuracy is achieved using the magneto-torquers in combination with the two still operational reaction wheels. From the original NASA press release (dated 14 Dec 01) where the anomalies with the two reaction wheels were reported the strategy was laid out to rescue the science mission:
One of the new control mode concepts being investigated is to use the two operational reaction wheels in conjunction with the satellite's magnetic torquer bars to provide control in all three axes. The magnetic torquer bars are presently used to manage the momentum of the reaction wheels by applying a torque on the satellite against the Earth's magnetic field. The torques necessary to make up for the failed wheel would be in addition to that required for momentum management. This is well within the capability of the magnetic torquer bars.
What they probably managed to do is to use the two remaining wheels to do the fine pointing but the satellite will tend to slowly spin 'of course' lacking the two other wheels to compensate. By bringing the torquers into the loop they cancel the spin and attain the fine pointing.
It is nowhere mentioned but I wonder if they can maintain the pointing accuracy long enough to get maximum exposure time. Since they've said that the spacecraft has been restored to full operations I guess it is not a problem.
I'm not trying to take anything away of what they achieved, only to clarify what is omitted from the article (possibly not to make it too technical I guess). It still is an impressive feat and indeed a super hack!
something wicked this way comes...
"The mission to Mars sounds even less appealing once you consider how much cancer / AIDS / environmental / fusion / fuel cell / quantum computing / immortality / (name your favorite project) research it would replace."
Actually its more appealing because of just how much it could benefit these areas of research. Don't forget that the first American space program that eventually sent man to the moon was the basis for many technologies we take for granted today.
There is reason to believe that the obstacles overcome to support man living on the moon or venturing to Mars would also produce such technological findings that many seemingly unrealated areas would benefit.
I thing power production, the environment, and manfucturing would be the 3 key areas of benefit, and from them others areas would benefit as well.
* Winners compare their achievements to their goals, losers compare theirs to that of others.