2002 AA29

>
> Greetings,
> There is another near-earth asteroid, 3753 Cruithne, which
> is closer to
> being a natural satellite of Earth. It orbits the Sun with
> the same average
> period as Earth does, and Earth's mass perturbs its orbit,
> but it does not
> directly orbit Earth. There are many web sites, for example,
> www.astro.queensu.ca/~wiegert/3753/3753.html, where you can
> find more about
> it. Search for Cruithne on Google.com for the others.

Cruithne is temporarily a mathematical satellite of Earth; but that doesn't
mean that transitioning it to become a true satellite - or targetting it
with any kind of return mission - would be easy. It might be (given the
chaotic nature of the orbit); but i wouldn't bet on it. 2002 AA29 - which
has interested me ever since it's discovery was annouced earlier this year -
makes six monthly returns to terrestrial space; never gets very far away
from the Earth even at apogee; & has a very small relative velocity - if it
wasn't so (apprently) large, i think a lot of people would assume that it
was just a bit of space flipping round, taunting us.

> I believe it would be cheaper to use the Moon than to
> change the orbits
> of these objects, though.

Don't need it: you just use a lot of very precisely designed corrections; &
the mass of the Earth itself will do a lot of the work. 2002 AA29 is
apparently transitioning in (or out) of a temporary Earth orbit already; so
the job is already half done. It currently appears to be one of the best
targets for a cost effective manned miision beyond Earth orbit,a s Pete
Worden notes in his piece.

> And the Moon has plenty of mass
> and water (ice,
> at the poles). Just staying on less massive objects would be
> a problem,
> where if one kicked up some dust, owing to the low gravity,
> it would take
> months to "settle out".

Very definitely an unproven, on several levels. Dust wasn't any kind of
issue for the NEAR landing; & given that electromagnetic forces are likely
to have a greater influence on particulate matter in microgravity
environments like this, any models based on gravitational action are likely
to be wrong. Anyway: given that this >is< a microgravity environment, it
will be easy to move above the surface without significantly throwing up
dust. Swimming (ie, floating above the surface, using your hands to pull
yourself along in a swimming-style motion) should be feasible; maximising
directional control & minimise surface disturbance.

Live in peace
Robert.Clements@...
endeavour2 project http://www.geocities.com/robtclements/endeavour2.html>