IPB

Welcome Guest ( Log In | Register )

Water-cooled lander
tanjent
post Aug 22 2007, 05:22 PM
Post #1


Member
***

Group: Members
Posts: 134
Joined: 30-December 05
Member No.: 628



There is a recent posting on Emily's Planetary Society blog, which must be Doug's because she's not there herself, although her name is the only name on it. The subject is using water to cool a long-lived surface probe on Venus. It sounds far more practical than any of the other proposals for landing giant atomic-powered refrigerators, or developing a whole new family of high-temperature semiconductors, etc.

But I didn't understand the whispered criticism to the effect that the Ekonomov paper assumed that the water would absorb heat only from the one watt of power driving the instrument package itself. I simply can't believe that he went to the podium and presented his model without taking into account the fact that the surface of Venus is a pretty hot place, and that the proposed probe would be absorbing the ambient heat. This is an interesting proposal and I would like to understand both the original calculation of 50 days to bring the water to a boil, and the cited flaw in the calculation. I too find it hard to believe that it would take 50 days to bring water to a boil on the Venusian surface, but where exactly is the error, and what remains after we correct it?

Doug is busy of course, but I hope he will find the time to address this when he returns, if someone else hasn't done so by then.
Go to the top of the page
 
+Quote Post
 
Start new topic
Replies
Gsnorgathon
post Aug 26 2007, 09:21 PM
Post #2


Member
***

Group: Members
Posts: 251
Joined: 23-January 05
From: Seattle, WA
Member No.: 156



Since the topic's already wandered somewhat from the OP, I'll just post this bit that I've been reminded of:


Mike Malin's Venus Geophysical Network Pathfinder: A Discovery Workshop Mission Proposal
Go to the top of the page
 
+Quote Post

Posts in this topic
- tanjent   Water-cooled lander   Aug 22 2007, 05:22 PM
- - helvick   QUOTE ..The concept is based around a 60-centimete...   Aug 22 2007, 06:32 PM
- - tty   Why start at 300 K rather than 270 K? By shielding...   Aug 22 2007, 08:41 PM
- - djellison   Unfortunately - the guy's english wasn't v...   Aug 22 2007, 09:03 PM
- - RJG   These calculations are based on the use of water. ...   Aug 22 2007, 09:59 PM
- - tasp   None of my steam traction engine information sheet...   Aug 22 2007, 11:08 PM
- - Greg Hullender   Tasp: the idea was that the water is INSIDE a glor...   Aug 23 2007, 06:16 AM
|- - marsbug   QUOTE (Greg Hullender @ Aug 23 2007, 07:1...   Aug 23 2007, 01:36 PM
|- - djellison   QUOTE (marsbug @ Aug 23 2007, 01:36 PM) A...   Aug 23 2007, 01:52 PM
- - djellison   The principle would be to have the pressure vessel...   Aug 23 2007, 12:03 PM
- - AndyG   Marsbug - you're maths is somewhat awry. Thin...   Aug 23 2007, 02:22 PM
- - marsbug   Thanks Doug and AndyG! This makes it seem a bi...   Aug 23 2007, 02:45 PM
|- - AndyG   [Excessive quote removed, hopefully before Doug ca...   Aug 23 2007, 03:23 PM
- - helvick   All the above makes sense but my understanding is ...   Aug 23 2007, 04:13 PM
- - algorimancer   I wonder whether a silica aerogel might be a bette...   Aug 23 2007, 05:36 PM
|- - rlorenz   QUOTE (algorimancer @ Aug 23 2007, 01:36 ...   Aug 24 2007, 07:39 AM
|- - AndyG   QUOTE (rlorenz @ Aug 24 2007, 08:39 AM) J...   Aug 24 2007, 08:45 AM
- - tty   If we assume that 500 W is a realistic heat input ...   Aug 23 2007, 06:25 PM
- - hendric   One idea I've always had for a Venusian balloo...   Aug 23 2007, 07:42 PM
|- - djellison   QUOTE (hendric @ Aug 23 2007, 07:42 PM) O...   Aug 23 2007, 08:52 PM
- - hendric   Aw dang, all my best ideas get stolen! First ...   Aug 24 2007, 03:04 AM
- - tasp   Thanx for clarifying what I was trying to convey. ...   Aug 24 2007, 03:10 AM
- - Greg Hullender   Taking tty's figures and using 100W instead of...   Aug 24 2007, 09:51 PM
- - djellison   That 50 days is to get up to boiling point - and t...   Aug 25 2007, 02:16 PM
|- - tty   Unfortunately to use the heat of evaporation requi...   Aug 25 2007, 05:51 PM
- - algorimancer   Of course, after the MER experience, anything less...   Aug 26 2007, 12:21 AM
- - nprev   True enough, actually; there's only so much da...   Aug 26 2007, 03:05 AM
|- - JRehling   QUOTE (nprev @ Aug 25 2007, 08:05 PM) Tru...   Aug 26 2007, 04:39 AM
- - tasp   {Going out on a limb here} Could we put a satelli...   Aug 26 2007, 02:39 PM
|- - JRehling   QUOTE (tasp @ Aug 26 2007, 07:39 AM) {Goi...   Aug 26 2007, 03:47 PM
- - ugordan   I'm no expert on radio waves by any means, but...   Aug 26 2007, 02:52 PM
- - Greg Hullender   Summary: According to a 2002 NASA publication, i...   Aug 26 2007, 06:20 PM
- - Greg Hullender   ugordan: As I calculate it, the Sun-Venus L1 point...   Aug 26 2007, 07:12 PM
- - tty   Completely mechanical seismometers were used for a...   Aug 26 2007, 07:20 PM
- - Gsnorgathon   Since the topic's already wandered somewhat fr...   Aug 26 2007, 09:21 PM
- - tasp   I think we would want a retroreflector (and to use...   Aug 27 2007, 02:25 AM
- - Greg Hullender   For some reason, NASA issued a press release yeste...   Sep 13 2007, 12:42 AM
|- - JRehling   QUOTE (Greg Hullender @ Sep 12 2007, 05:4...   Sep 14 2007, 06:20 PM
- - nnyspace   Could a liquid/solid that has a lower density chan...   Nov 7 2007, 05:58 PM
- - djellison   The problem is that the latent heat of evaporation...   Nov 7 2007, 07:05 PM
|- - nnyspace   QUOTE (djellison @ Nov 7 2007, 07:05 PM) ...   Nov 7 2007, 10:01 PM
- - dvandorn   Apollo's Lunar Rover used bee's wax to coo...   Nov 7 2007, 07:12 PM
- - AndyG   So we have wood used in Apollo hatches (is that ri...   Nov 7 2007, 08:31 PM
- - JRehling   QUOTE (AndyG @ Nov 7 2007, 12:31 PM) So w...   Nov 8 2007, 05:21 AM
- - tedstryk   Also, natural materials had been used for a long t...   Nov 8 2007, 11:32 AM
- - ugordan   QUOTE (JRehling @ Nov 8 2007, 06:21 AM) N...   Nov 8 2007, 11:45 AM
- - nnyspace   Speaking of biomaterials, fats, fatty acids and gl...   Nov 8 2007, 06:15 PM


Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 25th November 2014 - 01:40 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.