Are the Voyager spacecraft completely still (fixated) when travelling through space or are they a little unstable because they are travelling at high velocities?
$\begingroup$
$\endgroup$
8
-
1$\begingroup$ See www2.jpl.nasa.gov/basics/bsf11-2.php $\endgroup$– innisfreeApr 11, 2015 at 16:18
-
2$\begingroup$ It says that Voyager 1 and 2 used "3-axis stabilization" to keep themselves pointing in particular directions. The alternative is to keep the whole thing spinning, like a big gyroscope. I don't know much about it, to be honest, but it sounds interesting. If I read enough to understand it properly, I'll try to write an answer. $\endgroup$– innisfreeApr 11, 2015 at 16:20
-
8$\begingroup$ Why would a high speed make it unstable? $\endgroup$– HDE 226868Apr 11, 2015 at 16:22
-
3$\begingroup$ and @HDE226868, in addition considering Einsteinian or even classical relativity, how it is it that Voyager is even at high speed? from Voyager's point-of-view it's perfectly still. $\endgroup$– robert bristow-johnsonApr 11, 2015 at 18:54
-
1$\begingroup$ @robertbristow-Johnson Exactly. $\endgroup$– HDE 226868Apr 11, 2015 at 19:01
|
Show 3 more comments
1 Answer
$\begingroup$
$\endgroup$
1
Although the craft can be turned if necessary, the Voyager probes are not intentionally rotating. They use small thrusters that try to zero out any rotations.
These thrusters aren't infinitely precise, nor are the instruments that drive them. So there is some error in the firing that means the probe has a (small) residual rotation. Instead of having a perfectly fixed direction, it will slowly drift away from the intended attitude over time. When the residual rotation moves the platform too far from the antenna pointing at earth, the thrusters fire to to return the alignment.
This error in the rotation rate has nothing to do with the speed of the probe.
-
$\begingroup$ aha, look what the cat dragged in! Could the Voyager spacecraft be spin-stabilized to keep their high gain antennas pointing towards the Sun and Earth? $\endgroup$– uhohMay 8, 2019 at 6:13