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NASA releases Hubble image taken in new pointing mode

science.nasa.gov

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Re: NASA releases Hubble image taken in new pointing mode

#41

Post by cubefox »

bordakt wrote: post #39
cubefox wrote: post #32

Naive question: Today, smartphones use microscopic gyroscopes based on MEMS (micro-electromechanical systems) technology. Would these also work on Hubble? I suspect they'd work fine in space, perhaps while also being more durable (the failing Hubble gyroscopes were only installed in 2009). Though I guess their precision is not good enough for a telescope.

You are thinking of the sensor in smartphones, in this case it is a spinning disc that uses gyroscopic torque to rotate the spacecraft.

So there are two different technologies that are both called "gyroscope"? One a sensor detecting rotation, the other an actuator inducing rotation?

Re: NASA releases Hubble image taken in new pointing mode

#42

Post by bloomingeek »

sgc wrote: post #36
Tostino wrote: post #30

Earlier quoted context omitted.

The majority of inefficiency seems to leek into NASA via our Congress.

I agree, NASA would be much further along without that bunch of turnips.

Perhaps if they used Raspberry pi, they wouldn't be in such a pickle? (Sorry)

Re: NASA releases Hubble image taken in new pointing mode

#43

Post by bongodongobob »

EncomLab wrote: post #5

Pretty incredible what they are able to do with a i486!

Is it though? All you'd need to control some gyros is a microcontroller. I can't imagine it'd be more than a couple hundred lines of code implementing a PID controller or something. In fact, you could probably do it with standalone controllers, some sensors and relays.

Re: NASA releases Hubble image taken in new pointing mode

#45

Post by moffkalast »

BurningFrog wrote: post #38

I just think it's sad that they're doing fixes on a 34 year old telescope instead of sending up a new improved model every 10 years.

Well the JWST is in fact a thing. Why not keep getting science from the old ones while they're still working?

NASA really needs to just fill their telescopes with gyros upon gyros, like just plaster the things with gyros and reaction wheels for 50x redundancy since that's always the mission critical thing that fails first. Or maybe a xenon powered ion reaction control system or something that would last longer then hydrazine.

Re: NASA releases Hubble image taken in new pointing mode

#46

Post by dr_orpheus »

bordakt wrote: post #39
cubefox wrote: post #32

Naive question: Today, smartphones use microscopic gyroscopes based on MEMS (micro-electromechanical systems) technology. Would these also work on Hubble? I suspect they'd work fine in space, perhaps while also being more durable (the failing Hubble gyroscopes were only installed in 2009). Though I guess their precision is not good enough for a telescope.

You are thinking of the sensor in smartphones, in this case it is a spinning disc that uses gyroscopic torque to rotate the spacecraft.

No, these are actually referring to the gyroscopic sensors on the spacecraft. This article [0] makes it a little bit more clear. While there are actuators that use gyroscopic torque, referred to as Control Moment Gyros (CMG) Hubble uses reaction wheels for pointing the spacecraft.

[0] https://science.nasa.gov/mission/hubble/observatory/design/h...

Re: NASA releases Hubble image taken in new pointing mode

#47

Post by olleromam91 »

cubefox wrote: post #41
bordakt wrote: post #39

Earlier quoted context omitted.

You are thinking of the sensor in smartphones, in this case it is a spinning disc that uses gyroscopic torque to rotate the spacecraft.

So there are two different technologies that are both called "gyroscope"? One a sensor detecting rotation, the other an actuator inducing rotation?

The sensor you’re describing is usually called an accelerometer.

Re: NASA releases Hubble image taken in new pointing mode

#49

Post by SaberTail »

cubefox wrote: post #41
bordakt wrote: post #39

Earlier quoted context omitted.

You are thinking of the sensor in smartphones, in this case it is a spinning disc that uses gyroscopic torque to rotate the spacecraft.

So there are two different technologies that are both called "gyroscope"? One a sensor detecting rotation, the other an actuator inducing rotation?

No, the comment you're replying to is confused. These gyroscopes are entirely used for determining Hubble's orientation. Reaction wheels effect the actual rotation, and Hubble's are fine.

I think the confusion is a result of imprecise language talking about how they are used to slew the telescope. They are "used" but as feedback, in conjunction with other systems. Also, there have some prominent reaction wheels failures on other missions, and that contributes to the confusion.

Re: NASA releases Hubble image taken in new pointing mode

#50

Post by dr_orpheus »

cubefox wrote: post #32

Naive question: Today, smartphones use microscopic gyroscopes based on MEMS (micro-electromechanical systems) technology. Would these also work on Hubble? I suspect they'd work fine in space, perhaps while also being more durable (the failing Hubble gyroscopes were only installed in 2009). Though I guess their precision is not good enough for a telescope.

The accuracy of MEMS gyros is orders of magnitude worse than the gyros on Hubble. I suspect based on this article [0] that Hubble uses hemispherical resonator gyros (HRG [1]). The really high accuracy rate sensors that you find in spacecraft are usually HRGs or Fiber Optic Gyroscopes (FOG).

[0] https://science.nasa.gov/mission/hubble/observatory/design/h...

[1] https://en.wikipedia.org/wiki/Gyroscope#HRG

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