Like the other satellites do as well yeah?
they have to rotate the whole satellite to point it at something
schmidtster@lemmy.world 6 months ago
Oszilloraptor@feddit.de 6 months ago
They have to rotate it fast enough, and hubble is not built to rotate that fast
schmidtster@lemmy.world 6 months ago
Is it an actual limitation of the hardware or a software safety limit? The designs are similar it more has to do with limitations put on it.
They mention they can’t because the gyro vibrates, so it does sound like it’s capable of spinning faster it’s limited for specific reasons.
Oszilloraptor@feddit.de 6 months ago
The sattelite bus for the KH-11 Spy sattelites uses thrusters for orientation (and has a huge propellant tank) while the Hubble sattelite bus uses several gyroscopes for orientation. They are not as similar as you might think.
mkwt@lemmy.world 6 months ago
And the angular momentum is conserved.
Your choices are basically RCS thrusters or reaction wheels. Thrusters burn limited fuel. Reaction wheels are flywheels inside the satellite that you spin in the operator opposite direction to where you want to rotate. They are limited by the mass and size of flywheel, and the maximum speed you can spin it up to.
yetiftw@lemmy.world 6 months ago
electromagnets also work as the earth has a magnetic field. a pair of reaction wheels can be rotated (which yes, adds complexity) opposite directions along an axis perpendicular to the axles once they have reached saturation, effectively resetting the reaction wheels