NASA’s famous space telescope Hubble faced some gyroscope trouble recently, though the space agency appears to have fixed the problem. However, more tests will be needed before Hubble telescope is restored to its regular science operations.
Hubble is the world’s first space-based optical telescope, which was launched in 1990. The problem was detected with the backup gyroscope on October 5. NASA had to turn this on after the first gyroscope failed. When the spacecraft was originally launched, it had six gyroscopes in total and three are needed to work in ideal conditions, though it can manage with one as well. In the 2009 servicing mission, astronauts had replaced all six of the gyroscopes.
It has been reported that NASA simply turned the gyroscope on and off in order to fix things, but when it comes to the Hubble Space telescope things are not so simple. The US space agency had to do a lot more than just turning this on and off to fix the problem.
Here’s what happened with NASA’s Hubble telescope and how the problem was eventually fixed.
NASA Hubble space telescope: What was the problem?
The Hubble space telescope had a problem with one of its three remaining gyroscopes on October 5. When the backup gyroscope was brought into operation, it was noticed that this was sending back extremely high rotation rates to the Hubble computer.
A gyroscope on Hubble helps keep a track of the speeds at which the spacecraft is turning, but high rotation rate could not have been accurate. On the Hubble, the gyroscope has a wheel, which is mounted in a sealed cylinder called the float. The wheel is spinning at constant rate of 19,200 revolutions per minute, according to information shared by the space agency.
The float or the sealed cylinder is then placed inside a thick fluid (motor-oil like thickness) and electricity is sent to the motor by thin wires. These wires are thinner than human hair, and immersed in the fluid. The electronics detect movement of the axis of the wheel, and then send these rotations back to the Hubble central computer, explains NASA.
The accuracy of this data is crucial because NASA needs this to help Hubble “turn and lock on to new targets.” There’s no margin for error considering that the telescope is there for observation and gathering more data about the Universe.
NASA’s website further explains that there are two modes on the gyroscope: low and high. The former is needed for more precision, when spacecraft has locked onto a target and needs to stay still.
Hubble Space telescope: So how did NASA fix the problem?
NASA did try turning the gyro off and then restarting it, but that did not solve the problem. This was first done on October 16. NASA explains they turned the “gyro off for one second, and then restarted it before the wheel spun down.” This was done to clear any faults that may have taken place in the startup process, according to the website.
The backup gyroscope has only been turned on after nearly 7.5 years, since the first gyroscope was doing the job. However, restarting this one did not fix the problem.
Then on October 18, the Hubble telescope did turns in the opposite directions. This was to clear any blockage around the float of the backup gyro. This is the sealed cylinder placed in fluid.
The gyro was also switched from high to low mode to clear any blockage around the float. That appeared to result in some reduction of the high-rate of rotations, according to NASA. But it took some more efforts and “additional maneuvers and gyro mode switches” on October 19, which finally sorted the problem.
However, NASA’s press release does state that while the rotation rates have reduced, they will need to do more tests to make sure that Hubble can return to science operations with this gyro.
NASA Hubble space telescope: Launch date, objectives and findings
Hubble is the first space telescope developed by the US space agency. It is named after Edwin Hubble, an astronomer from Pasadena, California, who built one of the world’s largest telescopes from the Mt Wilson Observatory in the 1920s.
The Hubble spacecraft is made up of a pair of optical mirrors that detect light from various sources. The Hubble telescope has a total length of 13.2m, with a maximum diameter of 4.2m. It weighed over 11 tons at the launch, with a weight of around 12.25 tons after its servicing missions.
Hubble was launched in April 24, 1990 by the Discovery space shuttle. NASA’s Hubble space telescope has made over 1.3 million sightings of celestial objects. The spacecraft is managed and operated by NASA’s Goddard Space Flight Center, which is located Greenbelt, Maryland in the US.