Hi,
Whoa, Darren! True, the asteroid will be closer than a geosynchronous
satellite, but
since it's not gravitationally bound to the Earth's g-field, the local
speed limits will not
apply! You're going to have to really hop up your police interceptor
rocket if you're going
to get close enough to even slap it on the ass on its way by!
I don't know what its geocentric velocity will be when it gets here,
but the figure of
42 degrees per hour apparent movement through the sky field contrasted
with the 15 degrees
per hour of a geosynchronous satellite orbit, suggests it'll really be
bookin'!
The delta-V required to match up with it would probably be, you'll
pardon the
expression, astronomical. And, then, after you've had the space walk, the
flag planting,
the call from the President, etc., you still have to get back before you,
too, disappear
into the Wild Black Yonder. Another big hunk of delta-V.
There's another problem unique to high speed close approach missions:
not only do you
have to execute a high delta-V maneuver, you have to do it in a big hurry.
That thing is
movin'! That means you will have to accelerate at very high gee's. Either
that, or you have
to go out to meet the thing well in advance and accelerate at a slower
rate, matching
velocities after a long "bow chase," as the sailors say.
In fact, the only feasible mission plan would be a long voyage to the
asteroid long
before the Earth encounter, ride it by the Earth and back out to the best
point for the
Earth Return leg. Much less delta-V but a lot more time to play solitaire
in the capsule.
As for nudging, hey! You'd better practice on some asteroids that
aren't going to pass
near the Earth first, before you try nudging anything that is. In fact, I
wouldn't mind if
you skipped that nudging part altogether. :-]
Sterling K. Webb
----------------------------------------------------------------------
Darren Garrison wrote:
> On Fri, 4 Feb 2005 16:32:42 -0800 (PST), Ron Baalke <[EMAIL PROTECTED]> wrote:
>
> >Paul Chodas, Steve Chesley, Jon Giorgini and Don Yeomans of NASA's Near
> >Earth Object Program calculate that the asteroid will pass 4.7 Earth
> >radii (30,000 kilometers, or 18,600 miles) from Earth's surface. This is
>
> Wow. Plenty of time to plan a (relatively) easy visit and sample recovery
> mission. That's lower
> than geosynchronous orbit!
>
> Of course, if you wanted to be a bit more ambitious, given 24 years we could
> probably even throw
> together a project to nudge it into Earth orbit, but I think that would get
> some pretty bad press.
>
> Maybe we could nudge it into the moon and watch it hit!
______________________________________________
Meteorite-list mailing list
[email protected]
http://six.pairlist.net/mailman/listinfo/meteorite-list
