Feb 2007

Happy New Year, and welcome into the 'year of the fire pig' or 2007 according to your preference. Plenty to catch up on after our break: Comet McNaught certainly gave us a great display at the start of the year, but the Hubble Space Telescope's main camera looks like it's out for the count. Good news though for Rosetta as it chases off after another comet, but more on that later.

But 2007 is looking like a good for access to space, with 50 launches scheduled worldwide. The space-race is hotting up with the entry of Iran, who on the 25^th February, sent up their first indigenous sounding rocket to a height in excess of 100km - theoretically entering space. It didn't orbit, it just came straight back down, but they are following the usual tradition of modifying long-range war rockets for satellite launching purposes. In this case it looks like the Shahab-3 medium-range ballistic missile, normally used for chucking explosives 1,300km, will find a new lease of life as a satellite launcher. The unadulterated version is shown on the right, courtesy of Iranian TV channel IRIB.

Among the other nations aiming for space, Japan finally got their H2A rocket up without incident and launched an engineering test satellite from the Tanegashima Space Centre just before Christmas. This year they'll be sending up a couple of spy satellites on it.

I'm looking forward to China's first lunar probe, Chang'e, launching on the 17^th April - that's their mission logo over there on the left. It'll take some cameras, a laser altimeter and various sensors useful for mapping the chemical makeup of the ground from orbit. The mission is headed by Ouyang Ziyuan, who wants to look for helium-3 on the moon. This is potentially useful as an ultra-low emission nuclear fusion fuel, and the Chinese think that by the time they're ready to mine the stuff we'll have figured nuclear fusion out. It's a bit of a gamble but it is one of the few materials that is worth the expense of shipping back from the moon using current technology.

Private companies are going up next year too, with Bigelow Aerospace scheduled to launch their Genesis 2 inflatable demonstration model also in April. Genesis 1 worked fine, and they're gradually scaling up to something that they can put people inside - as opposed to free-floating models of Spongebob Squarepants and Superman, for example. Oh yes they did.

On now to the Hubble Space Telescope, our window through which we can view distant stars and the furthest galaxies. Now fate has thrown a brick through it, and the power supply for the Advanced Camera for Surveys, or ACS, has blown a fuse. This camera was responsible for most of the fantastic images returned of nebulae and galaxies, and accounts for about 2/3 of the use of Hubble.

But every cloud is stuffed with a silver lining, and in this case it means that the other 1/3 of astronomers are going to be able to book much, much more observing time than they originally bargained for and some research that was only scheduled "just in case" will now actually get done. Hubble remains the best way of doing ultraviolet observations because it is above our (admittedly patchy) ozone layer and atmosphere. The ultra-violet stuff still works, and they're doing strange things with it like photographing the aurora on Jupiter. It's a shame about the ACS, but by no means is it "game over".

The slingshot effect is being used a lot recently. No, not the device used to project bait out to considerable distances, or in earlier days to launch fizzling double-happies into the wild blue yonder. This is the process of almost but not quite going into orbit around another planet. Do it just right, and as you pass it the planet's gravity tries to pull you in, increasing your speed. With much planning, you deftly arrange it so that you fall past the planet rather than into it, and you pick up an awful lot of speed as you flick past. The planet slows a little in return, but it's really not going to notice.

We just can't launch rockets with the kind of energy you can pick up from a slingshot orbit, short of going nuclear, so if you want to get somewhere in a hurry you want to do one. It's even often worth heading off in completely the wrong direction just so you can pull a slingshot around somewhere while en route to somewhere else.

NASA's New Horizons spacecraft just did this to Jupiter, en route to Pluto, and made its closest approach to Jupiter on February 28^th. It has made several observations in concert with Hubble, which is good because data is now available from two points of reference.

The European Space Agency's Rosetta just did the same trick past Mars, skimming 240km above the surface at a mind-boggling 36,000km/hr and taking some great silhouettes of Martian sandstorms. It is now headed to do the same thing to Earth - twice. These fly-bys should bring it up to enough speed to catch comet 67P/Churyumov-Gerasimenko in early 2014.

Right, I'm off to line up some tin cans and, er, experiment with orbital dynamics.

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

"Human beings will be happier-not when they cure cancer or get to Mars or eliminate racial prejudice or flush Lake Erie but when they find ways to inhabit primitive communities again. That’s my utopia." - Kurt Vonnegut, Jr.