April 2006

Launch fever broke out this month, with rockets and payloads going skywards from Russia, Israel, China, America and even Pakistan as if it were Guy Fawks night. OK, so the Pakistani one was the Hatf VI, their longest-range ballistic missile with a theoretical range of 2,500km. The US launched a Minuteman 3 from Vandenberg in California to somewhere off Guam, so Pakistan didn't feel like it was sabre-rattling all on its own. While Israel is quite capable of launching large rockets – it does so at the Palestinians frequently – it chose to put its satellite, Eros B, on a Russian launcher; the launch worked and the Israelis are still running the diagnostics as I write. The satellite is intended primarily to spy on the Iranian nuclear energy program, any possible moves they may have to make nuclear weapons, and any interesting long-range missiles that could make life awkward in Tel Aviv should anything prompt Iran to fire them off. As Sir George Porter pointed out, “If sunbeams were weapons of war, we would have had solar energy centuries ago.”

The Russians also launched another Progress resupply rocket, ferrying over 2½ tonnes of supplies and additional oxygen to the International Space Station. It too contained a satellite called a SPHERES (Synchronized Position Hold Engage and Reorient Experimental Satellites); one designed to operate inside the ISS. There are 3 slightly different kinds, but the one in the NASA picture on the right gets the general idea across. It appears to float in the picture because the developers are shown testing it inside NASA's KSC-135 freefall test aircraft, otherwise known as the “Vomit Comet” (a description that really winds up the managers, apparently).

The idea is to send up a couple more and try to dock them using specially designed docking adaptors – pads of Velcro to you and me. Why do all this inside a space station rather than in the big, wide, empty parking lot outside of it? Well, you can be sure it won't wander off too far for one thing. Plus the craft are powered by little carbon dioxide cylinders and 16 AA batteries each. Very convenient, but even more so if you actually have someone hanging around to change the batteries when they go flat. Astronauts and cosmonauts can also shepherd any overly-enthusiastic satellites away from any possible interception course with something that might be bad for the structural integrity of the satellite.

Once the skills and software have been developed in such a relatively friendly environment, NASA plans to use the same concepts to create arrays of telescopes in space. The ageing Hubble Space Telescope needs a replacement as bits of it are dying off, and the beauty of having a telescope made of lots of little mirrors flying in formation is that if one or two drop dead you can still use the rest. It's also possible to spread things out over a larger area, which gets you more detail provided you can still get enough light. This kind of telescope is the one you hear talked about when astronomers speak of looking at the surfaces of planets in other solar systems.

And speaking of the good old Hubble, unkindly referred to as “a great squint for mankind”, it's just had its 16^th birthday and most Hubble-related websites are hosting stacks of anniversary pictures. They don't come out too well in the dead-tree edition of Launchpad, so have a quick Google around if you're on the internet.

And finally, an update on the miraculous RepRap machine that Vik is helping to create. One day it might be used on space stations to print spare parts, or even to make medicines for the crew.

With the help of Simon McAuliffe from Wellington, I've now got all the circuitry going and pretty much behaving itself. OK, the end-stop circuits are not yet in place, so I have to be careful not to tell it to run off the end of the bench, but all the individual motors, heaters, slides and carriages are all moving as they should. I've got them moving in harmony too. I test it by sticking paper on the top of the stage, suspending a pen over the paper, and getting the computer to move the stage around underneath the pen. That way I can draw shapes on the paper.

The serious reason behind turning it into a computerised Etch-a-Sketch(TM) is that I can tell it to do the same thing a few dozen times and see if it strays off course. So far it doesn't. This is good news, as I have been writing a technical paper for submission to SEARCC, and it might be necessary to fly over to Colombo in Sri Lanka to show it off. They're having “interesting times” over there at the moment and I hope it all quietens down by September – for everybody's sake.

This edition is also on the web, just point your web
browser to http://olliver.family.gen.nz.   vik@olliver.family.gen.nz

"Never doubt that a small group of thoughtful, committed people can change
the world. Indeed, it is the only thing that ever has.”- Margaret Mead