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Hubble Telescope Hit By Mechanical Failure (bbc.com)
The Hubble Space Telescope is operating with only essential functions after it lost one of the gyroscopes needed to point the spacecraft. From a report: The observatory, described as one of the most important scientific instruments ever created, was placed in "safe mode" over the weekend, while scientists try to fix the problem. Hubble had been operating with four of its six gyroscopes when one of them failed on Friday. The telescope was launched in 1990. After the gyro failure at the weekend, controllers tried to switch on a different one, but that was found to be malfunctioning. That leaves Hubble with only two fully functional gyros. At any given time, Hubble needs three of its gyroscopes to work for optimal efficiency.
The Earth is flat. You only need 2 gyros to point oneself in 2D space.
That's true but they need 3 because the telescope can rotate, which messes with the image. There's X, Y, and rotation, that need to be controlled for. They can operate with a single gyro but that means they can't stop rotations, and in fact use the rotation to their advantage to reposition the gyro for controlling X and Y alternately as rotation puts the gyro in the proper plane. Hubble launched with 4 gyros, meaning it had a spare from the start. With the first gyro failure they simply lost the spare. With the second failure they lost the ability to control rotation and/or ability to position with as much speed and accuracy. Going down to one means they can still move but very very slowly.
I am armed because I am free. I am free because I am armed.
How embarrassing.
Lissajous curves are the family of curves described by [...] parametric equations ...
Go away.
The James Webb Space Telescope will not be in orbit around the Earth, like the Hubble Space Telescope is - it will actually orbit the Sun, 1.5 million kilometers (1 million miles) away from the Earth at what is called the second Lagrange point or L2.
It little behooves the best of us to comment on the rest of us.
A service call to Hubble is out of scope
Hubble had Servicing Missions in 1993, 1997, 1999, 2002, and 2009.
The 1999 and 2009 missions replaced the gyroscopes. So this was expected.
The Hubble was being built around the time the Commodore VIC20 and Sinclair ZX80 were released, though the launch was long delayed.
So maybe it is time to retire it. Perhaps a small ceremony and fireworks display over the South Pacific.