Video of the Juno probe headed out to Jupiter

a reply to: Phage

And, it should be pointed out; it was done using Newtonian physics to negotiate the route.

Ya' think?

'Star Trackers' Help Juno Find Its Way
www.npr.org...

And a Sun sensor of course.

a reply to: GaryN
Well then, it must be Newton because of course, neither the Sun nor stars can be seen in space. Right?
I thought you were leaving?

Post-Orbit Insertion briefing starts now in case anyone's awake

originally posted by: Phage
a reply to: GaryN
Well then, it must be Newton because of course, neither the Sun nor stars can be seen in space. Right?

Bye eye, correct. I have the greatest respect though for the designers of the instruments that can see what's out there.

I thought you were leaving?

You wish...

originally posted by: GaryN
a reply to: Phage
'Star Trackers' Help Juno Find Its Way
www.npr.org...

And a Sun sensor of course.

I suggest you actually read that article yourself. Juno's sun sensor and star tracker help it with orienting itself, in order for it to point its antenna at Earth and its camera at Jupiter.

A star tracker can tell scientists the spacecraft's orientation in space. Orientation is analogous to pitch, yaw and roll on an airplane: Pitch is whether the plane's nose is up or down; yaw is whether the nose is left or right; and roll tells you whether the plane banking left or right. If you know your orientation, you know whether your destination is straight ahead, or off to the left.

So in the case of NASA's Juno mission to Jupiter, once the probe knows its orientation, it knows how to find Jupiter and the Earth. That means Juno knows where to point its antenna to send a signal back to Earth, and which way to point its camera to take a picture of its destination.

Juno's actual trajectory through the Solar System is indeed Newtonian. Which is why it's been looping the loops around Earth and Mars for 3 years, in order to build up the momentum and speed towards the renzedvous point with Jupiter.


www.youtube.com...

originally posted by: GaryN

originally posted by: Phage
a reply to: GaryN
Well then, it must be Newton because of course, neither the Sun nor stars can be seen in space. Right?

Bye eye, correct. I have the greatest respect though for the designers of the instruments that can see what's out there.

STEREO uses a standard E2V CCD42-40 for its heliospheric imagers.
www.e2v.com...
Nothing magical about it, yet it can clearly see the stars in space, far from earth. Indeed, if you have the funds, you can buy your own E2V CCD42-40 in a camera to use with ground-based telescopes.
www.buytelescopes.com...
It's not a hoax either. I know, because I personally discovered a comet using the STEREO spacecraft's heliospheric imager.

a reply to: ngchunter

STEREO uses a standard E2V CCD42-40 for its heliospheric imagers

Correct, but if you think your eyes could see anything that the HI-1 or 2 imagers see, then you don't understand the devices. Here are a couple of references:

The Heliospheric Imagers On-board the STEREO Mission
www.stereo.rl.ac.uk...

Design of the Heliospheric Imager for the STEREO mission
orbi.ulg.ac.be...

And one about spectroscopy:
SPECTROSCOPY AND THE STARS
www.smallscalechemistry.colostate.edu...

If you think your off-the-shelf camera, or your eyes, would see anything at all, you are dreaming.

a reply to: GaryN
I've taken a quick look at the first link, before I'm off to work, and the only relevant bits I saw say that "these instruments are wide-angle visible light imagers" and that "the detectors are CCDs (charge-coupled detectors)." Both telescopes are designed to image visible light. HI-1 sees in 630 – 730 nm, which is basically red light. HI-2 sees in 400 – 1000 nm, which is everything from violet and into near-infrared (which is in order to maximise the weak coronal signal at large solar elongations). The cameras take images at short exposures and then stack the images to amount to an exposure of 40s and 50s respectively.

I don't see anything that makes these sensors special in such a way as to make "invisible light" visible (apart from that sensitivity into near IR for the second camera).

So excellent!
Juno is able to keep an eye on her gassy husband at last!

Wonderful achievement, fingers crossed the instruments work ok now for as long as we can get.

originally posted by: GaryN
a reply to: ngchunter

STEREO uses a standard E2V CCD42-40 for its heliospheric imagers

Correct, but if you think your eyes could see anything that the HI-1 or 2 imagers see, then you don't understand the devices. Here are a couple of references:

I've already read them. In case you don't understand them, there's no magic involved. Nor is it a spectrometer nor a spectrograph. It's just a standard CCD, with well-designed baffles to keep out as much stray light as possible, and it uses a spacecraft radiator to cool itself instead of a standard convective-based cooling system like you would find on a ground based astronomical camera.

And one about spectroscopy:

Which has absolutely nothing to do with the E2V CCD42-40 on HI-1.

If you think your off-the-shelf camera, or your eyes, would see anything at all, you are dreaming.

You are demonstrably wrong. The E2V CCD42-40 is an off-the-shelf CCD and you can get it off the shelf in a similar astronomical camera. If HI-1 sees my comet, and it did (it's how I discovered it), then the same off-the-shelf camera I showed you would see it if adapted to use the cooling and electrical systems of STEREO and plugged into the same hardware.