Lunar rover, how cheap using Lunokhod technology

Pat Flannery wrote:
:
:The isotope heater is a lot simpler idea as it doesn't tie the rover
:down to one area, or force it to dig new burrows to shelter itself in as
:it moves along over the surface from month to month.
:

It also means that you don't have to worry about the space and
complications of the rover having an excavator that can dig
rover-sized holed.

Simple solutions are best...


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

On Dec 5, 8:28 pm, Fred J. McCall wrote:
"David Smith" wrote:
:
:Would it help to have a rover (or an ancilliary machine) that could
:basically dig a hole for them to hide in for the night? Would that be
:easier to keep warm?
:

Not much, unless they could dig really, really deep. The ground is
essentially a really big heat sink. It's not cold because the
(non-existent) atmosphere gets cold. It'd cold because EVERYTHING
gets cold.

--
"Rule Number One for Slayers - Don't die."
-- Buffy, the Vampire Slayer

What's the full earthshine IR w/m2 worth?

~ BG

:The isotope heater is a lot simpler idea as it doesn't tie the rover
:down to one area, or force it to dig new burrows to shelter itself in as
:it moves along over the surface from month to month.
:

It also means that you don't have to worry about the space and
complications of the rover having an excavator that can dig
rover-sized holed.

There's only one problem with RTGs, but its a big one down here in the US.
We've run out of the isotope that they use...

It's pretty stupid, really. The US shut down and _scrapped_ the facilities
to process the fuel more than 10 years ago, during the Clinton
administration. The isotope is produced only in Russia now and we haven't
bought any more from them in many years. The last remaining bit from our
last purchase is going to MSL.

That's why New Horizons launched with only one RTG, instead of the two it
was designed for. That's why Juno is being designed to use high efficiency
solar cells instead of RTGs.

On Dec 4, 8:09*am, Dr J R Stockton wrote:
In sci.space.policy message ,
Wed, 3 Dec 2008 20:56:28, Vincent D. DeSimone
posted:



Remember, nighttime on the lunar surface lasts 14 days. *You're going to
need batteries to store keep-alive power from what the solar panels can
accumulate during daytime. *Plus, it gets mighty cold at night. *You'll need
those batteries to provide power for heaters, as well (perhaps supplemented
by radioactive decay heaters).

Give it a garage for use at night. *Maybe multi-layer insulation,
deployed after landing. *Or foam insulation - the rover could be landed
within a foam hutch, or foam bricks could be formed after landing.

The penalty of needing to return to base, or of carrying the garage,
seems worth paying if needed to ensure operation over several lunar
days.

--
*(c) John Stockton, nr London, UK. *Turnpike v6.05 *MIME.
*Web *URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
* Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
*No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

Multi 'wrinkled' layers of reflective mylar, in a form like an
unbrella that could be raised, extended and lowered like a shell over
the rover, might have less mass than cardboard for the same area.

This was very effective on the LEM. Helium was initially ruled out as
a pressurizing gas because it was thought the tanks wouldn't stay
cold. Like a badly wrapped present, the slightly separated layers act
like a super thermous in the vacuum.

On Dec 6, 6:01 pm, Totorkon wrote:
On Dec 4, 8:09 am, Dr J R Stockton wrote:



In sci.space.policy message ,
Wed, 3 Dec 2008 20:56:28, Vincent D. DeSimone
posted:

Remember, nighttime on the lunar surface lasts 14 days. You're going to
need batteries to store keep-alive power from what the solar panels can
accumulate during daytime. Plus, it gets mighty cold at night. You'll need
those batteries to provide power for heaters, as well (perhaps supplemented
by radioactive decay heaters).

Give it a garage for use at night. Maybe multi-layer insulation,
deployed after landing. Or foam insulation - the rover could be landed
within a foam hutch, or foam bricks could be formed after landing.

The penalty of needing to return to base, or of carrying the garage,
seems worth paying if needed to ensure operation over several lunar
days.

--
(c) John Stockton, nr London, UK. Turnpike v6..05 MIME.
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

Multi 'wrinkled' layers of reflective mylar, in a form like an
unbrella that could be raised, extended and lowered like a shell over
the rover, might have less mass than cardboard for the same area.

This was very effective on the LEM. Helium was initially ruled out as
a pressurizing gas because it was thought the tanks wouldn't stay
cold. Like a badly wrapped present, the slightly separated layers act
like a super thermous in the vacuum.

There is a lot of incoming and local secondary/recoil IR to deal
with. Therefore artificial shading and otherwise terrific insulation
must be included along with h2o2 for cooling and energy.

Too bad none of that nifty oven-wrap mylar stops X-rays or gamma from
getting through, and/or prevents the creating of more secondary/recoil
forms of radiation that are not exactly DNA friendly.

~ Brad Guth Brad_Guth Brad.Guth BradGuth BG / “Guth Usenet”