New Way of Extending Satellite Life Saves Millions 173
coondoggie writes "A new technique to save aging satellites promises to save millions of dollars by extending the life of communications spacecraft. A process developed by researchers from Purdue University and Lockheed Martin has already saved $60 million for unnamed broadcasters by extending the service life of two communications satellites. In a nutshell the technique works by applying an advanced simulation and a method that equalizes the amount of propellant in satellite fuel tanks so that the satellite consumes all of the fuel before being retired from service. Some aging communications satellites are each equipped with four fuel tanks. If one of the tanks empties before the others, the satellite loses control and should be decommissioned, wasting the remaining fuel in the other tanks."
NSS?! (Score:3, Interesting)
Seriously, who didn't learn the lesson of the limiting reagent in high school chemistry?
Re:Wow! What an innovative idea! (Score:5, Interesting)
Re:NSS?! (Score:5, Interesting)
Tricky business (Score:5, Interesting)
You can't let it run out of fuel since you need enough fuel to deorbit it at end of life. But given the cost of a satellite, each extra month of life is worth millions.
The fuel is floating around in microgravity so you can't weigh it. I'm not sure but I think the most promising technique involves looking at the rate of heating when the tank-heaters are on. But accurately correcting out the effects of solar-heating and the various forms of heat loss is still lots of work.
Re:Slashdot swamped with IDG Shills (Score:3, Interesting)
~S
Re:It's amazing that this was not done initially (Score:2, Interesting)
But obvious stuff like writing easy-to-understand, well-documented code... that's just expected, no matter how hard it is to do in practice.
Re:Wow! What an innovative idea! (Score:5, Interesting)
The real problem: Getting NASA off their asses. (Score:5, Interesting)
I had another solution to the same problem, back about 1990. I worked for Contel, my job was to write an expert system to assist in dumping momentum (use propellent to counter build-up caused by attitude gyros spinning too fast) for the TDRSS satellite system. I asked why momentum builds up. Answer: solar wind against antenae. My suggestion was to build models of antenae configurations or solar array that would drive up or down the momentum as needed... in essence to sail back into normal configuration. The potential exists here to NOT USE PROPELLENT, extending the life of satellites dramatically.
I talked to my bosses and to NASA. And basically, I was told to shut up and sit down. They had procedures for dumping momentum. As a sub-contractor we were PAID to dump momentum. And even though they re-orient the antennae array all of the time, they have no procedure to move the antennae to slow dump momentum during times of low utilization.
In other words, NASA didn't want to deal with new ideas, and have to deal with the work associated with it, or overseeing the work in others. Everything is risky when you don't want to bother.
This has since become one of my stories... the moral being that the tech solution is not necessarily the right solution.
Re:Estimating hydrazine mass by its thermal effect (Score:2, Interesting)
Sounds familiar ... (Score:4, Interesting)
Some folks formerly at Schriever Air Force Base did something similar with Defense Satellite Communication Systems satellites, which saves the Air Force $5 million per year per satellite. There's more on that story here [af.mil].