Cool things that won't last

13 February 2019

Some things are cool but won’t last forever

Iridium flares

The Iridium communication (well, actually navigation) satellites has been flying since the late 1990s. The initial plan was that there were to be 77 of them, however only 66 of the original satellites were launched. These original Iridium satellites are now being superseded by the next generation Iridium NEXT satellites.

The thing that most people will miss about the old satellites is their habit of "flaring". There are flat panels hanging off the sides of each satellite, and these reflect the sun like a mirror, causing a bright flash as they fly overhead. These were quite predictable, meaning that you could stand there and count down before one went off. Very cool. This photo was taken through my study window!

The Hubble Space Telescope  (Image: NASA)

The HST is also getting a bit long in the tooth, and is starting to have reliability problems. The latest one is that its main camera went down in early January for (as yet) "unspecified reasons". It does have other instruments, of course.

What is going to complicate matters is that the HST has six gyros, three of which have croaked already. If another one goes, the HST will not be able to manoeuvre precisely. This will seriously affect its ability to take awesome photos of the sky.

This just shows that it might be cool having a totally remote observatory, but if you can’t get to it regularly to fix things, it’s not going to last forever.

Mars Rover Opportunity (Image: NASA)

Opportunity’s mission on Mars began in 2004, and it wasn’t expected to last more than about three (Earth) months on the planet. Instead it rolled slowly on for all of 14 years, gathering science, and losing only one wheel as it went.

It survived summers and winters, but was finally finished off by a dust storm. This seems to have covered its solar panels so much that Opportunity’s batteries died before enough light returned, and it didn't reawaken from its standby mode.