The above post is almost completely correct. However, even the cheapo equatorial drives should be ok for wide-field astrophotography with a 18-55mm lens. Their poor guiding will only start to show if you attempt to do zoomed shots on specific targets. So as long as you don't care about taking pictures through your telescope then this should be ok.
I'm on the 10th floor of my building and we had some pretty decent swaying going on.
I would love to install this on my RHEL5 office system, but our IT guy has SE Linux enabled on all the systems. The new firefox throws AVC denials so I guess I'm stuck with older versions.
and we don't have root access.
An actual Spitzer image of L1448 is here: http://www.astro.lsa.umich.edu/~jjtobin/images/L1448.jpg and the preprint of the Astrophysical Journal paper is located here: http://arxiv.org/abs/1004.2443
BEfore we wet our pants in excitement, let's remember:
* The Hubble passed a slew of design reviews too.
* Even so, it went up with many, many flaws, including:
* Electronics not shielded well enough to handle the South Atlantic Anomaly.
* Gyroscopes not qualified for the temperature cycles and SAA.
* Solar panels that oilcan buckle when going from sunlight to shade.
* Solar panel mount that does not go through the center of mass of the scope, so oilcan buckling causes the whole thing to oscillate.
* Unbalanced and uncushioned light cap that likewise shakes the whole thing when it's operated.
Although the new scope will have been checked against that list of problems, without major overhaul of the management structure, it's likely the same thing will happen this time.
Granted Hubble had many problems when it launched mainly because it was one of the first and most advanced general purpose observatories launched.
We have had tons of experience building space telescopes over the past 30 years since Hubble was designed and Hubble is the only one that is serviceable by the shuttle.
Just to list all the successful observatories since Hubble:
Infrared Space Observatory (Europe)
Chandra X-Ray observatory
Spitzer Space Telescope
WMAP
FUSE
Herschel Space Observatory (Mostly Europe)
Planck (Europe)
Suzaku X-Ray observatory (Japan)
and probably a few others I forgot about.
Bottom line, we know a lot about building space telescopes now, the doom and gloom you forecast is probably a bit over the top. Every project has problems, that's why we have brilliant engineers to find solutions.
It is a pity more isn't put into projects like this - I personally feel that we've have learnt so much from Hubbble that it is, at least for the time being, the best option for space exploration. But what wil happen to Hubble? Surely it will retain some functionality into the future?
They'll keep Hubble going as long as they can since its capabilities aren't going to be duplicated by any mission within the next decade. The weak link of the telescope seems to be the gyroscopes, which are used to point the telescope. They'll probably fail before the instruments have completely failed.
OK so their instrument had an upset. That sort of thing happens in space. Why did it take them 5 months to switch over to the redundant string?
It took them 5 months to switch over to the redundant system because they wanted to be sure that they fully understood what happened with the first failure. The problem was that there wasn't software protection for the critical systems.
They then had to put preventative measures in place to ensure that it didn't happen to the redundant system; otherwise they would be screwed. The HIFI instrument has some of the most discovery potential and its capabilities cannot be duplicated from earth or and only partly with the SOFIA airborne mission.
He explained that each vehicle contains "layers of computer code that may be added from one model year to next" that control nearly every system, from acceleration to braking to stability. Rizzoni said this software is rigorously tested, but he added: "It is well-known in our community that there is no scientific, firm way of actually completely verifying and validating software."
Here's an example everyone is familiar with: You're working at your computer in Windows software and an error message pops up. It asks whether you want to report the error to Microsoft. Microsoft has exhaustively tested this version of Windows before its release, but it cannot completely predict how it will operate out in the world, subject to user demands. That's why it gathers error reports and uses them to fix the software on a rolling basis.
If you put a lot of parts together to form a complex electromechanical machine and make it talk to itself via software, it can behave, sometimes, in ways you cannot anticipate. It can fail for reasons you cannot anticipate.
Ahrens ends the piece with a quote from a 2009 LA Times interview with a psychologist:
"Richard Schmidt, a former UCLA psychology professor and now an auto industry consultant specializing in human motor skills, said the problem almost always lies with drivers who step on the wrong pedal.
'When the driver says they have their foot on the brake, they are just plain wrong,' Schmidt said. 'The human motor system is not perfect, and it doesn't always do what it is told.' "
This file will self-destruct in five minutes.
