May 2000
The
Space
Shuttle does not seem to be having a good time of it. After over a month
of delays it finally got launched, flying a repair mission to the International
Space Station which has been up there unoccupied so long that parts of
it are nearing the end of their life. As well as changing the batteries
and adding soundproofing, the shuttle Atlantis will lift the ISS up over
40 Km over 6 days to make up for the decay of the space station's orbit.
The latest cause for delay was that the Shuttle had to give way for another
rocket launch that was previously scheduled. This rocket is something of
a milestone in itself; it's an American "Atlas" launcher which is fitted
with Russian rocket engines. There is irony in that the Atlas is a design
originally intended to rain thermonuclear death on the Soviet Union.
The New Moon Race
You might remember that I started this column to tell people about the
race for the moon, and Laingholm's part in it. Well, it's is hotting up.
It now seems very fashionable to be a company which wants to land a camera
on the moon, or bring bits of it back and so forth - I've heard of two
companies starting up in the last week. Obviously I'd be very happy if
my own TransOrbital Inc. is the
first one there, but the good news is that there is now so much interest
in going to the moon again after more than a quarter of a century of inactivity.
So much in fact, that NASA is now proposing to run exactly the same kind
of low-budget mission to return a sample of moondust that many of these
little companies have been proposing, and TransOrbital has been proposing
pretty much since it's conception. The 
more
cynical space enthusiasts view this as NASA trying to steal some of the
thunder, or at the very least to make life awkward for the independent
space companies - to basically stifle the competition.
Sailing Ahead
Other futuristic plans are being hatched by NASA, who are at long last
seriously considering the concept of a light
sail. That's the thing on the left that looks like it came from the
movie Tron. Unlike a rocket, solar sails don't need to take any
fuel, but they're not quick and have problems stopping. As long as they're
in sunlight though, they accelerate gently away, pushed by the constant
gentle caress of photons. You wouldn't notice the acceleration yourself,
but day by day the speed grows, and ultimately solar sails could in theory
reach a substantial fraction of the speed of light. If launched on schedule
in 2010, the proposed NASA sail would accelerate to 4 times the already
incredible velocity of Voyager which it would pass in 2018.
The trick with the sails is to make them very, very light so that the
light has enough power to accelerate the sail at a reasonable rate (0-60
eventually sort of thing). The square shape gives the maximum sail area
for the lowest number of struts. The current favourite material for the
sail is a carbon fibre fabric which looks like solid smoke, weighing in
at about the same as a raisin would if you got a really heavy rolling pin
and spread it out over a square metre. Unfurling the sail is something
they might care to take a few tips from the Kiwi Black Boat's team on.
Pretty
Shifty Bang Bang
At last, rocket science the average motorhead can get their cognitive gear
around. NASA's Marshal Flight Centre are experimenting with a new type
of rocket design called a Pulse
Detonation Rocket Engine. Now this is as much fun as it sounds. Current
rockets have to have the fuel squirted into the engine bell at high pressure
using expensive, temperamental things called turbopumps. Without the pump,
the rocket exhaust would blast the fuel back out of the engine and right
back into the fuel tank with much unpleasantness and noise.
The new design shoots in a blast of fuel (it uses hydrogen) and oxygen
into a pipe, closes the valves - much like a car engine charging its piston
- and then fires off a high-tech spark plug. The mix goes boom, and out
comes the flame for a fraction of a second. When the flame is out, the
rocket reloads and fires again many times a second, again just like a car
engine.
Their test item was a mere 10cm long and 1.5cm across, but their plan
is to use it as a supercharged sparkplug to ignite a tube 10cm in diameter
and about a metre long. That way a tiny little spark can fire up a very
powerful rocket. With very little weight to the rocket, and fewer expensive
parts, this opens up another way to cheaper spaceflight.
Just
Mir Tourists
Mir is still making news, with the two cosmonauts still up there and testing
out new space glues. They hope to track down and fill more of the fine
cracks that were made during the Progress Supply Craft vs. Mir fiasco,
fortunately all of which are now in a module that is sealed off. While
on a spacewalk, the cosmonauts discovered some wiring on that module that
had shorted and left scorch marks. It's not too serious and due to the
lack of air isn't about to start any fires. However, MirCorp are taking
no chances and have scheduled a photographic survey of the outside of Mir
so that experts dirtside can study the craft at their leisure.
It was rumoured at one point - and published in a Russian newspaper
- that MirCorp had taken a US$10 million booking for the first tourist,
supposedly an Italian. MirCorp deny the rumours, but say that they have
ongoing negotiations with a number of clients in different countries including
Italy, France and Japan. I can't help wondering if there's someone out
there planning to take their spouse up to Mir and be the first official
member of the "100 Mile-High Club".
This edition is also on the web, just point
your web browser to http://family.gen.nz/launchpad .
vik@family.gen.nz
" There is nothing so far removed from
us to be beyond our reach, or
so far hidden that we cannot discover
it." - Rene Descartes
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