I’ve done a few posts – A fun idea for a moon mission and A Space Junk Prize – about space missions I would fund if I had a few billion dollars I didn’t know what else to do with. The point of these missions – printing bricks on the moon and putting up satellites as targets for companies to attempt to deorbit them – wouldn’t be to have some big flashy mission that gets all the news, but would do the boring groundwork to help further humanity into becoming a spacefaring civilization. I was wondering what other missions I could think of, and this is what I came up with.
There is an idea,
that if we can’t get enough greenhouse gases out of our atmosphere soon enough,
we could put a giant mirror in space to reflect enough of the sunlight to cool
the Earth. One version is for one giant
mirror, while another is for thousands of smaller mirrors working
together. My idea is a test for the
I figure there
would be at least three small spacecraft – launched on different rockets so if
there is a launch failure you can still test with two – that would each fly out
to the L1 point and deploy a ten-meter shield.
Possibly, each spacecraft would have different shield materials or
deploying patterns so we can test what works best. The whole point of the test would be how
these solar shields react and if we can control several spacecraft flying in close
formation. These wouldn’t be big enough
to make any effect combating climate change, but if we ever needed to do this
then we’d have some real-world data.
This whole idea of
climate engineering is very contentious, with some saying we need to be doing
something now, to others saying we need to conduct tests so that if we do
decide we need to do something we’ll have some idea of what to do, and still
others saying we shouldn’t even do any tests.
As a complex issue, there isn’t a simple answer. And if it’s any help, the data we’d get –
formation flying, unfolding techniques, whatever – could easily be applied to
other space activities that don’t have anything to do with climate engineering
so it wouldn’t be solely a climate engineering mission. Although that probably wouldn’t matter.
More space junk
I thought of the
solar shield idea, but I didn’t think that was enough for a blog. So I wondered what else I could do, and I
went back to thinking about space junk and wondered if there was another
project that would help us combat that.
What I came up with would be a mission that would give us some
real-world data on the smallest of space junk.
The mission would
be a cubesat put into a very low orbit, one likely to only last six months or
so. This cubesat would have a
telescoping rod twenty, or thirty centimeters long. The end of this rod would be an
electromagnet. Attached to the magnet –
by a small bit of metal – would be a fleck of paint one centimeter square with
some design on it. The rod would telescope
out, then wait twenty or so minutes to make sure any vibration had damped
out. Then the electromagnet would be
turned off and the rod retracted.
On the cubesat
would be a camera with a flash, that would take a photo every five minutes or
so. All this depends on how much memory
the cubesat has and how often it can downlink the data. The onboard computer would use the design on
the fleck to figure out the distance to it and it would have tiny gas thrusters
to try to stay within so many meters of the fleck.
The point of all
this would be to see how flecks of paint actually interact with the near-vacuum
of the upper atmosphere. We probably
don’t have much data on this. Ideally,
the cubesat could stay close enough to see if the fleck just disintegrates when
the air density gets so high, if it burns up like a meteor, or if it slows down
gradually enough that it just falls out of orbit. But in reality, with the different drag
between a fleck of paint and a cubesat, the cubesat might run out of fuel trying
to stay close enough to see what happens.
In that case, and if the cubesat will still be in orbit for a month or
two, then maybe it could be used as a target for the more aggressive methods of
deorbiting satellites: ways that might cause the satellite to break up. In higher orbits that would just make the
space junk problem worse, but hopefully any debris resulting from the test
would deorbit within a few weeks.
At first, I
figured such a mission could be jettisoned by a Cygnus as it was getting ready
to deorbit, because I figured it wouldn’t be worth it to use a rocket to put
such a small satellite into such a low orbit, but then I realized that one of
the main things of science is repeating experiments to see if we get the same
results. So instead of a rocket putting
one cubesat in a low orbit, it could put ten or however many will fit. Some of these could have identical paint
flecks, to see if similar things happen, or maybe thicker flecks, or maybe
instead of a fleck of paint it could be a screw or some other random bit of
junk the cubesat may have a better chance of staying close to.
Some would say
this would just be me burning money, but hopefully we’d get some interesting
data out of it.