Re: Orbital Mechanics

[email protected] wrote:
> For instance, to put the Hubble (v â?^ 7.575 km/s) in the ISS orbital plane
> (inclination change of 23.17 deg), where it would presumably be okay to service
> it by shuttle, you'd need about 3.04 km/s--about enough to send it to Mars!
> It's not an impossible number, howeverâ??basically, you'd need to send up about
> 1.72 times the HST's weight of 3.04 km/s-exhaust-velocity fuel and a small
> rocket engine which you fire at every node for a few months or so (the HST won't
> take much acceleration).  When it comes down to it, this brute force approach
> might be a lot simpler than the robotic repair mission and even cheaper now that
> they're talking billions for the robot!

So what's the required delta-V for a "minimal mothball orbit-raising mission" - 
i.e., boost it to an orbital altitude such that the orbit won't decay any time 
soon, and it can safely be powered down and allowed to "go passive" pending a 
later full-repair mission? 

This would be much easier than a plane change for an acceleration-sensitive object 
like the Hubble, since it could done with a gentle continuous thrust. (I wonder if 
the numbers work out for some sort of electric propulsion.)

-dave w