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Thu, 15 Nov 1990 02:16:44 -0500 (EST)
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Date: Thu, 15 Nov 1990 02:16:12 -0500 (EST)
Subject: SPACE Digest V12 #554
SPACE Digest Volume 12 : Issue 554
Today's Topics:
Re: Payload Status for 11/08/90 (Forwarded)
Cassini Investigation Team (Forwarded)
Re: CRAF/Cassini Update - 11/09/90
Re: Space Station Work Package #3
Re: LLNL size and Fred micrograv environment
Administrivia:
Submissions to the SPACE Digest/sci.space should be mailed to
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In article <7034.273fd310@abo.fi>, mlindroos@abo.fi writes:
|> In article <1990Nov11.001924.10302@jato.jpl.nasa.gov>, baalke@mars.jpl.nasa.gov (Ron Baalke) writes:
|> >
|> > CRAF/Cassini Status Report
|> > November 9, 1990
|> > ...take the Huygens probe about 3 hours to parachute all the way down to the
|> > surface of Titan; if the probe survives the landing, valuable data will
|> > continue to be transmitted back for about 30 more minutes. No more data will
|> > be returned to the Cassini orbiter from Huygens on any subsequent orbits, as
|> > the battery onboard Huygens will have rundown by then.
|> >
|>
|> 30 minutes! Why can't we send an advanced long-life, Viking-style probe
|> to Titan instead?! The Viking lander was "only" about twice as heavy as the
|> Huygens probe will be so the lack of a powerful-enough launcher surely cannot
|> be the reason? Is this just because of financial considerations again, or...?
The reason is maybe that we have NO data of the condition down there:
- Is there any *solid* ground ?
- pressure ?
- temperature ?
So with no information, it seems difficult to design a long-life probe.
A similar(?) problem occured on Venus, where the probes Venera 11-14 lasted only a few hours. The first ones didn't reached the ground because theirs parachutes where destroyed by the acid atmosphere.
On mars, the informations where much more complete, because the ground had been observed by many orbital probes: it was visible.
There was an excellent article in the ESA journal (?), some month ago about "Cassini Probe Huygens Entry techniques" .
--
-- E-mail: Henry.Thomas@irisa.fr
Henry Thomas - IRISA Campus Universitaire de Beaulieu 35042 RENNES CEDEX FRANCE
