You are such a poor shot that you couldn't throw an AA battery from orbit and have a hope of even hitting the earth.

And so am I.

I noticed recently that a batch of 91 AA sized batteries was delivered
to the ISS.

http://www.usatoday.com/tech/news/20...s-at-iss_x.htm

I thought that it might be fun to throw the used ones at Earth during
a sojourn outside, but despite the size of the target, I reckon you'd
have to be a pretty good throw to hit it, unless you could get some
serious atmospheric braking happening.

But it's a while since I've done the kind of thinking required to
prove it. Given that you are in geostationary orbit (for example) what
direction should you throw the battery to get the closest approach to
earth? A hunch tells me that it'd be back along your orbital path, in
the opposite direction of the earths spin.

Anyone care to enlighten me (us)?

Thanks

Denys Williams

Denys Williams wrote:

And so am I.

I noticed recently that a batch of 91 AA sized batteries was delivered
to the ISS.

http://www.usatoday.com/tech/news/20...s-at-iss_x.htm

I thought that it might be fun to throw the used ones at Earth during
a sojourn outside, but despite the size of the target, I reckon you'd
have to be a pretty good throw to hit it, unless you could get some
serious atmospheric braking happening.

But it's a while since I've done the kind of thinking required to
prove it. Given that you are in geostationary orbit (for example) what
direction should you throw the battery to get the closest approach to
earth? A hunch tells me that it'd be back along your orbital path, in
the opposite direction of the earths spin.

Anyone care to enlighten me (us)?

Your intuition is correct. Whichever direction you throw it, the change
in velocity due to your puny human arm's effort will be quite small
compared to the initial velocity. Therefore the battery will assume an
orbit only slightly different from the one you are in. It will come
closest to earth if you throw it rearwards, as you suggest, since that
will reduce its kinetic energy the most.

Mitchell Timin

--
"Many are stubborn in pursuit of the path they have chosen, few in
pursuit of the goal." - Friedrich Nietzsche

http://annevolve.sourceforge.net is what I'm into nowadays.
Humans may write to me at this address: zenguy at shaw dot ca

Your hunch is right. your pitching it retrograde will give you the
lowest perigee for its new orbit. Its apogee would be the orbit you
started from. Pitching it toward the earth, or away, would have the
battery crossing your path twice an orbit, however its perigee would not
be as low as the retrograde pitch.

Mike



In article ,
(Denys Williams) wrote:

And so am I.

I noticed recently that a batch of 91 AA sized batteries was delivered
to the ISS.

http://www.usatoday.com/tech/news/20...s-at-iss_x.htm

I thought that it might be fun to throw the used ones at Earth during
a sojourn outside, but despite the size of the target, I reckon you'd
have to be a pretty good throw to hit it, unless you could get some
serious atmospheric braking happening.

But it's a while since I've done the kind of thinking required to
prove it. Given that you are in geostationary orbit (for example) what
direction should you throw the battery to get the closest approach to
earth? A hunch tells me that it'd be back along your orbital path, in
the opposite direction of the earths spin.

Anyone care to enlighten me (us)?

Thanks

Denys Williams