Well, duh.
Thank you, Captain Obvious.
The US Air Force Space Command's 14-month effort to save a $2bn military communications satellite overcame failed thrusters, threatened explosion, space debris, and destructive radiation, thanks in great measure to tiny thrusters with a mere 0.05 pounds of oomph. It wasn't easy, as airforce-magazine.com reports in a blow-by- …
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This is an amazing and impressive thing to do, but quite frankly I'm missing the last bit of information as to what caused the somewhat assumed fuel clog which resulted in so much problems ?
After all; if the team were able to conclude with some certainty that a fuel block had to be causing these issues surely they have had information from which they could determine that this was the case? So what was causing the fuel block? Flawed design perhaps or other stuff going wrong ?
I know the quote says a full mission life cycle but it would be interesting to know if the satellite lifetime has been impacted by this - particularly the hydrazine burns.
Good to hear of ion thrusters being used in a big way. Where do the xenon atoms come from in the first place and how depleted is this source now?
Xenon lies above iron in the Periodic Table, so production comes from stars going boom or from the radioactive decay of heavier elements also produced in said explosions. We collect it by fractional distillation of our atmosphere.
Costs on par with beer, by volume (as a gas). And is an intoxicant!
From TFA:
"Madden said, as a result of the careful efforts to husband SV-1’s hydrazine and xenon fuel during the orbit-raising phases, there will be no reduction in its planned 14-year life."
As I understand it, they were able to use the Hydrazine intended for the main engine, to power the smaller thrusters.
... of low-thrust, high-specific-impulse ion thrusters.
If whimpy xenon thrusters can help move a satellite from low-/mid-earth orbit to geosync, running continuously for as long as they did, then there should be no problem with using ion engines like VASIMR to cross the Earth-Mars expanse.
Presuming, of course, we can crack the electric power nut. VASIMR takes quite a bit of power, which means any manned spacecraft we send to Mars with a VASIMR engine would almost certainly need a nuclear-fuel based power plant, such as a battery of radioisotope thermoelectric generators (which is likely to be unpalatable to various envirofactions).
Solar panels could -- in theory -- be used to provide the needed electricity, but are vulnerable to damage from interplanetary particulate matter and servo-mechanical failure.*
* "Servo-mechanical failure" refers to the failure of the mechanical equipment used to deploy/retract the solar panels and maintain their orientation.
You can use a bigger/expensive launch vehicle to put it higher, or put a bigger booster on the spacecraft, or you can spend a lot of time doing orbital mechanics games to get it to it's destination.
Depends on how much money/time you have - for some missions spending 5years letting it drift slowly to it's final point might be worth it. For others it would be obsolete when it got there, or would have been clobbered but junk, or some other part would have decayed/warmed up/worn out
I thank our Air Force satellite saviors. Now that the communications satellite is in place, the aliens can use it to coordinate their city-destroying rampage.
Next on the alien's pre-invasion checklist--a working firewall and antivirus software!!!!
Geostationary orbit is fine for high-latency emergency communications between meatware systems. It's also OK for transferring gigabytes of data using large buffers.
But it takes light about a quarter of a second to get up to geostationary orbit and back again (i.e. a network packet round-trip time of half a second). Skynet will need low-altitude satellites, or more probably will just hijack our fibre-optic cables here on the ground.
As for aliens, they must have FTL technology or they wouldn't be here!