In article <h946hk$mfe$1@news.eternal-september.org>,
Nightcrawler <Dirtydeeds@dirtcheap.net> wrote:

The only way to work under that kind of pressure is saturation, or containment, as in a
submarine type vehicle.

Prolonged saturation is out.

<snip>

Maximum record depth is 2000 feet in an "ADS" suit.

They have been deeper, but the suit depends on steel with 
copper o-rings. 

Maximum recorded depth with SCUBA is 1083 feet.

for a bottom time of around 10 minutes.

ADS suits are practical (on Earth), SCUBA is not.

The deepest saturation dive done was a simulated one to 
almost 2000 ft, 600 meters. It was not repeated because
of staggering cost. 2 months of decompression.

However, nothing will work on Venus.  The ADS suit is
rugged but is not designed for chemical or heat resistance.
The denaturing of the proteins in the human body is an extreme
risk.  There is no practical way to support the suit (currently
operates like a tethered submersible).

SCUBA will be fatal instantly.

Now that there are occupational hazard rules for saturation
diving we can use those as a reference. Maximum tolerance for
permanent habitat pressures is 10 atm, with brief excursions
to 18 atm. (90, 170 meters). Max partial pressure for oxygen 
is 0.4, max partial pressure for Nitrogen and Argon combined
is 3.2, 2.0 when performing work. So, the remaining 7.5
athmospheres is Helium. Which has a whoe ballpark of problems.

We only have three materials we have knowledge of for such
high pressure use. Steel, Aluminium 6xxx series and kevlar
epoxies. All of these corrode within seconds on Venus.

In fact, anything sent there dies.  Machine or biological.

The subject is a stupid "what if", anyway.  Sort of like the crap you
would hear from a 6 year old.

Indeed. The closest to realism observer craft would be
a dirigible, not exposed to 90 bar, but only to 3-4. 
But it would be "plankton", unmanouverable for all 
practical purposes. But it could tell us a lot about
Venus by remote sensing.


-- mrr