Guess what everybody, the Hubble Space Telescope is back in business and we're
gonna find out how they managed to fix a telescope in space from the ground.
Welcome back to Launch Pad, I'm Christian Ready your friendly neighborhood
astronomer. the Hubble Space Telescope is back to full science operations with
three working gyros. It won't have to make any adjustments for dropping back
to a single gyro, it won't be constrained as to what parts of the sky can look at,
none of these other constraints that we were so worried about before. So how did
the engineers on the ground manage to fix a telescope up in space? Well, we
talked about the nature of the gyro problem a little bit before in our
previous videos, so if you haven't caught them yet you may want to just go ahead
and check them out. I'll put a link up here and in the description below. But
in order to understand how they fixed the gyro, we need to understand the gyros'
inner workings in a little bit more detail. The gyro is a wheel that spins at
19,200 rpm. It's mounted in an assembly that is suspended
in a fluid that's a little bit like motor oil. The operations team attempted
to recover a backup gyro when the third gyro failed on October 5th. This backup
gyro wasn't totally dead, but it wasn't totally operational either. It was
reporting ultra-fast spin rates that were actually higher than the gyro can
physically produce. Since this gyro had been off for the last seven-and-a-half
years, the team were hoping that maybe it was just some bad data in the readouts
and it could be cleared by doing a running restart. So they turned the gyro
off for one second and then started to back up again before the wheel had time
to slow down. Unfortunately, that didn't work.
The gyro was continuing to report abnormally high spin rates and so the
team had to do some more analysis. They thought perhaps the float assembly
inside the gyro had been knocked off center, perhaps by some debris from
corroding wires. So on October 18th the team commanded Hubble to execute a
series of maneuvers in different directions in an attempt to dislodge
whatever debris might have been blocking the gyro. In other words, they
ship telescope back and forth to see if they could shake the gyro loose. During
these maneuvers, the gyro was switched between high and low rates and the RPM
data started to return to normal. So the team conducted another set of maneuvers
the following day, and the gyro data returned back to normal.
Last week the team conducted additional maneuvers to verify that everything was
normal with the gyro and they even conducted some simulated science
observations just to verify that the gyro could lock up and maintain that
lock on target. On Friday, the science instruments were brought back up and
Hubble returned to full normal science observations early Saturday morning. I
mean, how cool is that? They fixed the Hubble Space Telescope in a space from
the ground - well done operations team! And even
before Hubble got back in business, the Chandra x-ray Observatory returned
to normal science operations as well. Chandra went into safe mode on October
10th due to a glitch in one of its gyros - figures - and this caused a three second
period of bad data. That in turn caused the computer onboard Chandra to
miscalculate its momentum and put the whole thing in a safe mode. So the team
switched to a backup gyro and put the glitchy gyro in reserve. So there you go,
Hubble and Chandra are back in full science operation with three gyros each.
Now nobody has a crystal ball and can predict exactly when either of these two
spacecraft will lose one of its gyros, but this does mean that Hubble and
Chandra should be able to continue operating for maybe up to another decade
or so. Maybe more if we're really lucky. And that'll be super cool because the
James Webb Space Telescope will be in space starting - hopefully - around 2021 and
that means that Hubble Chandra and James Webb could all potentially be doing
science on the same target simultaneously in the next decade! One
can hope. Anyway, that's the news from the "people's telescope",
I hope you've appreciated some of these updates. I know they got a lot more
detailed and technical and in the weeds that I normally would go, but I do find
this stuff so fascinating and if you're watching this right now you
probably do as well. So thank you for watching, and if you'd like to stay
informed on the latest goings on in our amazing universe, well please make sure
to subscribe and ring that notification bell so that you don't miss out on any
new videos. Until next time I'm Christian Ready, and keep....you know, all I can say is
thank you for watching. I've got 1,000 subscribers and thanks, I don't
know what to say. A big shout out and a big THANK YOU to
you! Thank you so much my friends and keep watching the skies.