How's this thing powered? Are solar or big RTGs enough? I would think power requirements for these scale lasers, detectors, and transmissions would be pretty large. Isn't it an extraordinary amount of data that needs to be constantly sent back to Earth? I thought LIGO was generating a crazy amount of data per day beyond what I'd think would be possible to stream live back to Earth from so far away.
Also, how can the test masses remain in free fall, while each satellite is undergoing course corrections? Or are corrections infrequent enough for satellites in this earth-following orbit that it wouldn't cause any real amount of downtime? Of course Earth is free-falling.
The 2017 proposal is here: https://web.archive.org/web/20171017043638/https://www.elisa... This information-dense PDF got lost in the shuffle and its contents smeared across a hundred slides on the LISA website, because I guess PR people think only cell phone users exist.
Yes, solar. Laser power is only 5 watts. Total spacecraft power is 760 watts. They're downlinking a mere 334 megabytes a day, sampling at 3.3Hz.
how can the test masses remain in free fall, while each satellite is undergoing course corrections?
That's the hard part. The test mass floats in the middle of the spacecraft, which maneuvers around it, occasionally firing ultra low-impulse cold gas thrusters to counteract drag. They put up a spacecraft back in 2015 to test that concept: https://en.wikipedia.org/wiki/LISA_Pathfinder
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How's this thing powered? Are solar or big RTGs enough? I would think power requirements for these scale lasers, detectors, and transmissions would be pretty large. Isn't it an extraordinary amount of data that needs to be constantly sent back to Earth? I thought LIGO was generating a crazy amount of data per day beyond what I'd think would be possible to stream live back to Earth from so far away.
Also, how can the test masses remain in free fall, while each satellite is undergoing course corrections? Or are corrections infrequent enough for satellites in this earth-following orbit that it wouldn't cause any real amount of downtime? Of course Earth is free-falling.
The 2017 proposal is here: https://web.archive.org/web/20171017043638/https://www.elisa... This information-dense PDF got lost in the shuffle and its contents smeared across a hundred slides on the LISA website, because I guess PR people think only cell phone users exist.
Yes, solar. Laser power is only 5 watts. Total spacecraft power is 760 watts. They're downlinking a mere 334 megabytes a day, sampling at 3.3Hz.
That's the hard part. The test mass floats in the middle of the spacecraft, which maneuvers around it, occasionally firing ultra low-impulse cold gas thrusters to counteract drag. They put up a spacecraft back in 2015 to test that concept: https://en.wikipedia.org/wiki/LISA_Pathfinder