Space Forum / Space Policy / July 2009

Am wondering what the minimal requirements are for the google lunar
prize.  Consider a simple H2O2 based monopropellant rocket to slow it
based on a simple highway speed radar.  A few m above the surface, the
payload separates and inflates (base it on an auto-airbag system to
minimize cost).  It bounces across the surface with the camera
rolling.  When it finally stops, antenna of fine wire shoots out and
data transmission at slow speed starts.  Total mass of this lander,
what would you think, maybe 10 Kg?
So, what about guidance to the moon.  We do not care where ti hits the
moon as long as it does.  If it hits far side, well, maybe it is cheap
enough to try again.  So, how hard is it to hit the moon?  I assume
that if you get to a place where the lunar grav force is larger than
earth grav force with low enough speed, you WILL hit the moon instead
of orbiting or simply passing by.  This should not be that difficult
as we always know where the moon will be and can predict the speed of
our spacecraft at any time simply by shutting down engine at right
time.