Mars Camera's Worsening Eye Problems 93
Mr_Foo writes "According to a Nature article, the Mars Reconnaissance Orbiter's HiRISE imager is suffering from a loss of peripheral vision. The problem surfaced less than a month after the orbiter reached Mars. One the camera's four color detectors has completely stopped working, and it is feared that the problems are spreading. Currently seven of the fourteen HiRISE's detectors are sending back corrupted data and although the issue is only creating a 2% loss of signal at this time it is expected to worsen. The lead investigator for the mission is quoted as saying the problem is systemic: 'In the broken detectors, extra peaks and troughs are somehow being introduced, causing... a "ringing" in the signal. "We don't know where the ringing is coming from," [the investigator] says.' Warming the electronics before taking images seems to help the problem. This effect might be one reason why the detectors on the cold periphery of the array were the first to pack up."
A Damn Shame (Score:5, Informative)
Incidentally, this is the camera that could pick out the rovers from orbit [nasa.gov]. Losing definition on this camera would certainly impact one of the missions objectives, which is to look for good landing spots for future missions (robotic and human).
Camera problems common of late? (Score:3, Informative)
More detail on HiRISE (Score:0, Informative)
http://www.hugeurl.com/?ZDNlMDVkMDI1N2Y0YWUxMmU5O
The second best camera around Mars (Score:4, Informative)
I completely agree with you: the problem with space missions is that even a very small problem can be unsolvable if the hardware is more than 100 million km away!
But even if we completely lose the camera, it will be a big problem but not a disaster for science: there are currently 3 operational spacecrafts orbiting Mars (2 American + 1 European) and High Resolution Stereo Camera [esa.int] on ESA Mars Express [esa.int], the second best camera after HiRISE with a resolution of up to 2 metre/pixel, is still working and sending back beautiful images [esa.int].
Re:Next time... (Score:3, Informative)
Re:No pictures (Score:4, Informative)
Because it's a circuitry/transmission problem, they can essentially recover the image from a particular detector or not. For the 'ringing' problem they've mentioned, if it's a small enough effect they can subtract it from the data.
Also in that picture, they show the 'focal plane assembly'; this is essentially a separate CCD for each color filter used (except the red color which goes all the way across). The problem is very bad in one of the IR chips; bad enough that they can't use the data at all.
In other words, it's a problem with the digital transmission. Just like for digital phone, radio, or TV; you either get a usable signal (perhaps with some drops) or no signal at all.
Re:Ringing? Duh! (Score:3, Informative)
"Ringing", in electronics, is small unwanted oscillations in the signal. It is usually caused by stray capacitances and inductances in the circuit. Stray capacitances and inductances are caused not by components in the circuit, but just the innate capacitances etc. of things like tracks on the printed circuit board (two PCB tracks close together naturally form a very small capacitor). A great deal of thought is needed in laying out some printed circuit boards to minimize stray capacitances and inductances.
Re:uh oh (Score:1, Informative)