May 2007
May 2007
In
late February, the space shuttle Atlantis
took a pounding from a freak hail-storm. This did a lot of damage to
the fragile insulation on the outside of the big, orange fuel tank –
no great surprise considering NASA measured the wind at 115km/hr and
hailstones 38 millimetres across were found littering the pad. But
NASA now say they have patched up the 4,200 dings with PDL; the NASA
equivalent of bog. Tests done with ball bearings flung at the tank
show the repairs to be sound, and the shuttle will be fit to fly on
the 8th of June (happy birthday Mum!). There were weather
protection panels in place – NASA aren't daft, just unlucky - but
these just seemed to trap the hail. Most of the damage was on the top
end of the tank where the liquid oxygen was stored, not on the side
where the foam slab fell off and caused the loss of Columbia.
The body of Atlantis itself was undamaged, though Launchpad
would like to suggest a modification to the shuttle's mission patch,
as per the example on the right.
Earthbound issues may delay the launch, however, as 570 United Space Alliance union workers have rejected NASA's latest pay offer at the Kennedy Space Centre. Both sides agreed to a 5 day "cooling off" period, which will take them to the 9th of June – the day after the shuttle's launch. If the shuttle misses its initial launch date for any reason this could spell more trouble for the mission.
NASA
need better luck with the Phoenix
mission to Mars, which made the trip from it's fabrication site in
Denver, Colorado to Cape Kennedy in Florida on the 7th
May, safely ensconced in its hail-proof shipping container. Aside
from having the coolest mission patch yet created by NASA, Phoenix
is carrying some of the most sophisticated equipment ever sent to
Mars. There is a robotic arm strong enough to dig through ice, and an
amazingly compact laboratory to analyse both the ice and the soil.
It is important to know what happens where the two meet, because experiments on Earth have shown that even in the Earth's Arctic this is a habitable zone. With bacterial spores capable of surviving for millions of years, and the possibility of water existing for brief periods of time on Mars, life could still be surviving in there. A thorough analysis by Phoenix should tell us if this is possible, or if the powerful oxidants on the surface of Mars will disinfect the soil.
Phoenix
will land just as the spring comes, and the sun just starts to
hit the ground after the long Martian winter (see
NASA/JPL artist's conception by Corby Waste on the right).
That way we get to see what the conditions are like through the
Martian summer and autumn. Sadly, Phoenix's mission ends
there. As the sun sinks below the horizon, its solar panels will
become less efficient. Frost will cover them, preventing the lander
from functioning and finally the polar ice will return, burying the
lander in an icy tomb from which it is not expected to emerge intact.
NASA's
Mars Exploration Rover Spirit has made two important
discoveries in the last month or so of it's 4 year stay on Mars.
First it found some balsatic rocks that had clearly gone through some
layers in an exposed rock face. This clearly shows that a volcano had
been erupting at some point as basalt is volcanic in origin, but
closer examination of the rock showed that it had chlorine in it.
This, it is thought, came from brine – salty water.
More
proof of water on Mars came later in May, thanks largely to Spirit's
dud wheel. This does not rotate, and so it scuffs up the surface as
the rover limps along; so far it has gone over 7 kilometres.
Recently, it happened to scuff up some white soil hidden under the
sand, and this was shown by an onboard spectrometer to contain quite
a lot of silica. As far as we know, this is usually deposited by
water in environments such as hot springs – like New Zealand's Pink
and White Terraces that were destroyed by Mt Tarawera (painting
by Charles Blomfield on the left, currently at the Alexander Turnbull
Library). It looks more and more like Mars was a wet world once.
And
finally, news that Launchpad won't have much to write about in 3
trillion year's time. Physicists from Vanderbilt University have
calculated that trillions of years into the future, the information
that currently allows us to understand how the universe expands will
have disappeared over the visible horizon. We'll just have our own
local galaxy – or what's left of it. Before then, in a mere 5-10
billion years, our galaxy the Milky Way will have collided with the
Andromeda galaxy (NASA photo on left), creating some new scenery for
us. I'll note it down in my diary.
This edition is also on the web, just point your web browser to http://olliver.family.gen.nz. vik@olliver.family.gen.nz
"Nothing exists except atoms and empty space; everything else is opinion" - Democritus (Greek philosopher, 460-370bc)