Ueli, Jim,

That's OK then! Was just looking for a suitable backup system.

By the way, I am uncovering more and more electrothermal-powered
missions, the latest being NASA's Lunar Reconnaissance Orbiter.

http://www.nasa.gov/mission_pages/LRO/main/index.html

http://lro.gsfc.nasa.gov/

http://lcross.arc.nasa.gov/resources/LaunchPreview.ppt

http://www.nasa.gov/pdf/360020main_LRO_LCROSS_presskit2.pdf



From the press-kit, I garner these stats for the Orbiter itself
(excluding primary launch vehicle's fuel and mass etc):

Solar Array Area: 13.68 sq/m

Solar Array Output: 685 watts

Watts/Square Meter = 50

Orbiter Mass: 1018 kg

Fuel Mass: 898 Kg

Mass Ratio: Fuel/Orbiter = 1:1.3

NASA's figures for the cost of water transported to the Moon $50,000/
pound (about $23,000/Kg), clearly another market here.



NASA seem very cagey about the precise details of the ion-drives.
This mission was also launched on Russian-made rocket motors.


Jan





On 29 Jun 2009, at 16:37, Ueli Scheuermeier wrote:

> Jan, as far as I understand you've just reinvented the "solar
> dynamic" electricity source.
>
> Ueli
>
> --- On Mon, 6/29/09, EOS Mars
> Program<eos.mars.program@...> wrote:
>
> From: EOS Mars Program <eos.mars.program@...>
> Subject: [NEAmines] Heat Differentials
> To: NEAmines@yahoogroups.com
> Date: Monday, June 29, 2009, 3:28 PM
>
> A thought about how one could use the temperature differential
> between sunside and nightside on a spacecraft.
>
> If an external sunside heat collector contained a volatile liquid
> that could be superheated to pass into a turbine generator in the
> bowels of the craft, and the output cooled by radiators on the
> nightside, power could still be generated if the solar panels had to
> be furled during a solar flare episode.
>
> Or am I missing something here?
>
> Jan