ion engine was RE: [extropy-chat] Saving the Hubble

[Mike Lorrey]

--- Technotranscendence <neptune at superlink.net> wrote:
> On Tuesday, January 20, 2004 9:11 AM Robert J. Bradbury
> bradbury at aeiveos.com wrote:
> >> That new SMART-1 ion engine seems to
> >> be working well.  How much does one of
> >> them cost.  The first was pricey naturally,
> >> but now the price should go down, right?
> >
> > The mission cost was $110m Euros ($126M).
> 
> Which still does not tell us how much the propulsion system cost.
> Hopefully, it would be much lower than 110M Euros.

This is actually rather funny. I have an ion drive in my living room.
Cost me about $100. Cleans the dust up rather nicely... 

> 
> > I could see 3 problems with an ion engine
> > rescue --
> > a) Possibly surrounding the Hubble in a
> > cloud of ions    (though one presumably
> > has a problem with the exhaust
> >     of chemical trusters as well);
> 
> My understanding of ion thrust is that the ions are neutralized
> during or after exiting as exhaust.  If not, all ion propelled craft
> would be lowering their efficiency, no?

The ions are neutralized.

> 
> > b) the low thrust disrupting telescope
> > operations for a longer period
> > (remember the Hubble is *heavy*);
> 
> That's the killer with current ion engines.  I'd rather use chemical
> for
> this job.  Reliable, well tested, and no need for a lot of fancy
> new-fangled development.

Actually, the thruster unit used on the ISS, the ICM, is the same
thruster module used on the KH-12 Improved Crystal (Keyhole) spysat,
which is the same size and architecture as the Hubble.

> 
> > c) the need for the ion engine to take
> > up its own solar  panels for power (I
> > doubt the designers thought far
> >    enough ahead to include a power
> > outlet on the outside
> >    of the Hubble itself...).
> 
> Well, there are more power sources than just solar, e.g., an RTG
> might do the trick or having an external power source -- beaming
> power to the system.  However, this increases complexity and
> mission risk.

Actually, I'd support the solar thermal OTV that the USAF's Phillips
Lab developed several years ago. 

=====
Mike Lorrey
"Live Free or Die, Death is not the Worst of Evils."
                                       - Gen. John Stark
"Fascists are objectively pro-pacifist..."
                                       - Mike Lorrey
Do not label me, I am an ism of one...
Sado-Mikeyism: http://mikeysoft.zblogger.com

__________________________________
Do you Yahoo!?
Yahoo! Hotjobs: Enter the "Signing Bonus" Sweepstakes
http://hotjobs.sweepstakes.yahoo.com/signingbonus