Space Forum / Space Flight / June 2005

At the NSS meeting in May, Rusty Schweikert made the case that asteroid
2004 MN4 could hit the earth in 2036 or 2048, due to perturbations
caused by its close encounter with the earth in April 2029.  We won't
know until 2029 whether that is more likely to happen and Rusty was
promoting the idea that we should send a mission to asteroid 2004 MN4
sometime in the next couple of years to attempt to gently nudge it away
from its current orbit so that it would never come close to the earth
again.  If we wait until 2029 to find out conclusively, it may be too
late to accomplish anything.
The ideas advanced for trying to modify its orbit with a mission sooner
rather than later included the usual suspects - solar sail, ion drive
engine anchored to the asteroid, or chemical or nuclear rocket of some
sort.  The theory being that smaller thrust over a longer period of
time would give us a better chance of modifying its orbit sooner.
If such a mission was attempted, how difficult would it be to change
the direction of orbit so that it impacts either Mars or the moon?   It
would help us determine lots about the composition of whatever it hit,
and might succeed in heating up the Martian environment and releasing
liquid water in the immediate environment, wouldn't it?
On the other hand, wouldn't the most appropriate place to try to modify
its orbit be at its closest approach in 2029?  And if so, how hard
would it be to change its orbit at that point so that it hits either
the moon or Mars?
Harmon