Blogs / Bad Astronomy

I have just learned that the launch of the NASA/DOE Gamma Ray Large Area Space Telescope has been moved back a bit, to January 31, 2008. Prior to this, the launch was scheduled for December 14. Delays like this are fairly typical given how hard it is to get spacecraft hardware put together. Mission planners know there will be issues, but since they don’t know what the issues will be exactly, they can’t make an accurate schedule too far in advance. So as launch approaches, delays are inevitable.

I’ll be glad to see this one go up. I worked on the education and public outreach for GLAST for six years, and I know it’ll do amazing science.

Keeping up with the problems on ISS is difficult; the situation is complex.

Apparently, when the new solar panels brought up by Atlantis were installed, a power supply box failed. This provided power to the six computers on board used to maintain the station’s orientation, which in turn is critical to keeping the solar panels aligned with the Sun. The leading hypothesis is that electrical noise generated in the solar panel wiring is affecting the electronics. Several attempts to correct the problem have not worked, though of course the spokesfolks for NASA are saying this is not a serious problem yet. That may very well be correct, but this situation is very much cause for concern. The Russians may move up a launch to get a new power supply sent up in July.

An interesting line from an MSNBC news article caught my eye:

The [electronic intereference] spike apparently knocked out an electronics box that provides power to all six of the German-built control computers.

Which makes me ask: why would there be a critical single point of failure aboard the space station? This to me is the bigger story here. Once this problem is fixed — and it probably will be — I wonder if the media will follow up with this?

As usual, James Oberg has more info on the situation.

Last week, the Mercury probe MESSENGER passed by Venus, changing its orbit and preparing it for its series of rendezvouses (yeah, yeah, I know, three years of French I took) with the solar system’s smallest planet. The probe took some interesting images of Venus this time, too. I particularly liked this one:

These were taken as MESSENGER left Venus. I like them because first, they look like the views of Venus I get through my own Earthbound ’scope (though right now Venus is only half full, and not a crescent). But also, I like them because of the sense of leaving, of moving on. It’s not an animation or anything, but it does convey the sense that MESSENGER is still on the go and has things to do.

Incidentally, the "480nm" in the image title means 480 nanometers. That’s the wavelength of light passed by the filter in the camera, and it’s roughly the blue-green part of the spectrum. It corresponds to one wavelength of light emitted by hydrogen (the "H-beta" line), though I’m not sure that matters here. It’s also is the wavelength of light where the Sun emits the strongest — some people assume it’s yellow, but it’s actually blue-green. The Sun doesn’t look that color because it emits yellow, orange, and red light too, and we see them blended together.

Anyway, next stop for MESSENGER: Mercury. Well, that’s misleading: it’ll pass by Mercury several times before getting into its parking orbit. The images from there will be very cool indeed.

Tip o’ the sunshield to Emily, of course.