"The best vacuums available on Earth are less than 10 -8 Pa, less than 10e-13 atmospheres!" Not QUITE true...

Space/Science » in reply to Tom is wrong

"The best vacuums available on Earth are less than 10 -8 Pa, less than 10e-13 atmospheres!" Not QUITE true...

R.L. — 7/17/2005 8:41:40 AM (archived)

You can get lower than that but the methods you use get more and more extreme...

A good turbo pump can get you down to 10^-9 or 10^-10 torr in a stainless steel chamber- this assumes you havent left a fingerprint in the chamber, cleanliness is essential... To get lower you need other interesting technology such as ion pumps or sublimation pumps... I used a LN2 cooled Titanium sublimation pump.

Hydrogen dissolved in the steel is a major outgassing contaminant as is water at these pressures... CO is also a contaminant...

To reduce the pressure further you can chill the walls of your chamber so the gasses 'freeze' to the walls... I vaguely remember hearing about a chamber made of copper chilled to liquid helium temperatures that (I think) claimed to reache an atomic density comperable to intergalactic space...

The whole thread (116 posts)

NASA will be scraping space science missions... - Chris Vancil - 7/15/2005 7:46:26 PM
- Chris is mostly correct - Gary - 7/16/2005 5:19:51 AM
  - It is not "flags and footprints", it is CAPS - E.P. Grondine - 7/16/2005 4:50:30 PM
    - re: It is not "flags and footprints", it is CAPS - Chris Vancil - 7/17/2005 1:54:45 AM
      - re: It is not "flags and footprints", it is CAPS - E.P. Grondine - 7/17/2005 8:10:04 AM
        
        re: It is not "flags and footprints", it is CAPS - Chris Vancil - 7/17/2005 8:37:14 AM
        
        CAPS - E.P. Grondine - 7/17/2005 4:50:43 PM
        
        re: Craps...snake eyes! - Chris Vancil - 7/17/2005 8:43:48 PM
        
        Well I'd Give It To You But - Mark Eby - 7/18/2005 2:01:36 AM
        
        Arggh! - Mark Eby - 7/18/2005 2:16:15 AM
        
        re: Arggh! - Chris Vancil - 7/18/2005 9:31:53 AM
        
        crapped out - E.P. Grondine - 7/18/2005 1:50:35 AM
        
        re:The Debate Here... - Chris Vancil - 7/18/2005 2:33:22 AM
- Just an idiot Moonbat... - Joe2700 - 7/15/2005 9:11:49 PM
  - re: Just an idiot Moonbat... - Chris Vancil - 7/16/2005 12:14:19 AM
    - I call B*** S***, Chris - E.P. Grondine - 7/16/2005 2:17:33 AM
      - re: I call B*** S***, Chris - Chris Vancil - 7/16/2005 5:33:38 AM
        
        An added gotcha... - Gary - 7/16/2005 5:46:27 AM
        
        Space.com addresses lunar base issues - Daniel - 7/16/2005 6:11:17 AM
        
        re: Space.com addresses lunar base issues - gbaikie - 7/16/2005 8:47:34 AM
        
        So did the House Space Subcommittee: CAPS: 32-0 - E.P. Grondine - 7/16/2005 3:03:40 PM
        
        Hello - Mark Eby - 7/17/2005 3:28:47 AM
        
        and Hi! - E.P. Grondine - 7/17/2005 7:27:22 AM
        
        So You Got Nothing As Usual - Mark Eby - 7/17/2005 2:28:25 PM
        
        And as usual, you're able to see nothing, and understand even less - E.P. Grondine - 7/17/2005 5:01:55 PM
      - ***As moderator, I have to ask you two a question*** - ModBob - 7/16/2005 2:40:24 AM
        
        Mars Cult - Spacegirl2100 - 7/16/2005 6:42:28 PM
        
        re: Idiot Moonbat.... - Joe2700 - 7/17/2005 12:43:31 AM
        
        I'll take Griffin over Zubrin. - Mark Eby - 7/17/2005 3:17:55 AM
        
        re: Cultism Views Warped. - Chris Vancil - 7/16/2005 8:12:01 PM
        
        re: Cultism Views Warped. - Spacegirl2100 - 7/17/2005 1:53:49 AM
        
        re: Cultism Views Warped. - Chris Vancil - 7/17/2005 6:27:25 AM
        
        Appropriate That You Don't Use A Real Name - Mark Eby - 7/16/2005 7:55:55 PM
        
        re: Appropriate That You Don't Use A Real Name - Spacegirl2100 - 7/17/2005 1:51:54 AM
        
        Yeah what's with not using your real name!?!?!?!? - Buck Galaxy - 7/17/2005 8:55:57 PM
        
        Clearly You Are Hand Waving - Mark Eby - 7/18/2005 1:42:06 AM
        
        re: Yeah what's with not using your real name!?!?!?!? - Chris Vancil - 7/17/2005 9:23:47 PM
        
        Oh So You Like - Mark Eby - 7/17/2005 2:59:16 AM
        
        Sexist as well... - Spacegirl2100 - 7/17/2005 5:53:13 AM
        
        No - Mark Eby - 7/17/2005 2:38:30 PM
        
        "Weak-minded women " and you're not? (n/t) - Chris Vancil - 7/17/2005 7:35:23 AM
        
        ***AHEM*** - ModBob - 7/17/2005 7:39:12 AM
        
        for what it's worth - Daniel - 7/17/2005 9:53:44 AM
        
        Thanks for pointing this out.... NOW do they care to explain 'themselves'? (n/t) - ModBob - 7/17/2005 10:19:19 AM
        
        Very Strange - Mark Eby - 7/17/2005 2:55:03 PM
        
        jumpy conclusions - Daniel - 7/17/2005 8:05:30 PM
        
        Merely Idle Speculation Not Conclusions - Mark Eby - 7/18/2005 1:13:46 AM
        
        re: She flung that sword at herself. (n/t) - Chris Vancil - 7/17/2005 7:42:07 AM
        
        ***Just a Warning*** - ModBob - 7/17/2005 7:52:18 AM
        
        re: ***Just a Warning*** - Chris Vancil - 7/17/2005 8:13:24 AM
        
        re: Appropriate That You Don't Use A Real Name - Joe2700 - 7/17/2005 12:52:25 AM
        
        Sure Kid You're A Real Mars Advocate - Mark Eby - 7/17/2005 2:47:38 AM
        
        Sonny, where were you when it started? - Joe2700 - 7/17/2005 2:56:10 AM
        
        re: Sonny, where were you when it started? - Mark Eby - 7/17/2005 3:12:11 AM
        
        re: Sonny, where were you when it started? - Joe2700 - 7/17/2005 6:53:36 AM
        
        Why the heck would you want to dive down a gravity well in the first place? - Tom Brosz - 7/16/2005 5:48:46 PM
        
        Leave it to Tom to be the most reasonable viewpoint here - Buck Galaxy - 7/17/2005 8:41:04 PM
        
        Cool - E.P. Grondine - 7/17/2005 8:17:04 AM
        
        Easy Natural Resources, Safety, & Potential - Mark Eby - 7/16/2005 11:59:46 PM
        
        re: Easy Natural Resources, Safety, & Potential - Tom Brosz - 7/17/2005 8:01:16 AM
        
        Partly Right - Mark Eby - 7/17/2005 3:02:46 PM
        
        re: Why the heck would you want to dive down a gravity well in the first place? - gbaikie - 7/16/2005 10:04:32 PM
        
        re: Why the heck would you want to dive down a gravity well in the first place? - gbaikie - 7/16/2005 10:25:47 PM
        
        re: Why the heck would you want to dive down a gravity well in the first place? - gbaikie - 7/17/2005 1:30:51 AM
        
        Tom is wrong - gbaikie - 7/17/2005 4:25:16 AM
        
        "The best vacuums available on Earth are less than 10 -8 Pa, less than 10e-13 atmospheres!" Not QUITE true... - R.L. - 7/17/2005 8:41:40 AM
        
        The Shuttle Test Unit I worked on for Gravity Probe B used ion pumps - Tom Brosz - 7/17/2005 8:59:15 PM
        
        re: "The best vacuums available on Earth are less than 10 -8 Pa, less than 10e-13 atmospheres!" Not QUITE true... - gbaikie - 7/17/2005 10:33:25 AM
        
        re: Lunar Sourcebook data - ken murphy - 7/17/2005 4:54:46 AM
        
        So Why Not Provide The Link? - Mark Eby - 7/17/2005 3:37:28 PM
        
        re: So Why Not Provide The Link? - ken murphy - 7/17/2005 4:07:17 PM
        
        Sorry Thought Your Were Referring To A PDF or Word File (n/t) - Mark Eby - 7/17/2005 4:13:42 PM
        
        re: Why the heck would you want to dive down a gravity well in the first place? - ken murphy - 7/16/2005 6:20:46 PM
        
        I might be wrong about the vacuum level. - Tom Brosz - 7/17/2005 7:56:27 AM
        
        re: Why the heck would you want to dive down a gravity well in the first place? - Mark Eby - 7/17/2005 3:23:27 AM
        
        I designed and built an experimental vacuum chamber... - R.L. - 7/17/2005 8:21:58 AM
        
        re: I designed and built an experimental vacuum chamber... - Mark Eby - 7/17/2005 2:53:31 PM
        
        re: ***As moderator, I have to ask you two a question*** - Mark Eby - 7/16/2005 3:01:35 PM
        
        Forgot Another Key Issue - Mark Eby - 7/16/2005 4:18:59 PM
        
        Compare & Contrast Question - ken murphy - 7/16/2005 5:39:37 PM
        
        re: Compare & Contrast Question - Chris Vancil - 7/17/2005 7:34:01 AM
        
        Uh The Moon Does Have A Far Better Vacuum Than Mars - Mark Eby - 7/17/2005 3:05:39 PM
        
        re: I'm not say it doesn't. I question his Nanotech need for "perfect" lunar vacuum. All his points are flawed. (n/t) - Chris Vancil - 7/17/2005 8:51:56 PM
        
        re: Compare & Contrast Question - Chris Vancil - 7/17/2005 6:42:10 AM
        
        re: Compare & Contrast Question - Mark Eby - 7/17/2005 4:30:43 AM
        
        You're right! I'm sold! - ken murphy - 7/17/2005 5:20:46 AM
        
        Boy Did You Miss The Point - Mark Eby - 7/17/2005 3:17:17 PM
        
        Hey Thanks For Giving Me More Ammo - Mark Eby - 7/16/2005 6:21:14 PM
        
        re: Hey Thanks For Giving Me More Ammo - ken murphy - 7/16/2005 7:37:53 PM
        
        re: Hey Thanks For Giving Me More Ammo - Mark Eby - 7/17/2005 3:43:53 AM
        
        Still Waiting... - ken murphy - 7/17/2005 4:34:10 AM
        
        And On The Data Provided - Mark Eby - 7/17/2005 4:41:58 AM
        
        re: And On The Data Provided - ken murphy - 7/17/2005 5:32:42 AM
        
        You're Economics Are A Joke - Mark Eby - 7/17/2005 3:25:35 PM
        
        re: You're [sic] Economics Are A Joke - ken murphy - 7/17/2005 4:47:26 PM
        
        Great - Mark Eby - 7/17/2005 5:21:59 PM
        
        re: Great - Chris Vancil - 7/17/2005 9:05:03 PM
        
        re: And On The Data Provided - Joe2700 - 7/17/2005 6:49:44 AM
        
        re: How to Make Friends & Influence People - ken murphy - 7/17/2005 5:30:24 PM
        
        Let's See - Mark Eby - 7/18/2005 1:37:07 AM
        
        Uh 9:30 PM to 9:34 PM (n/t) - Mark Eby - 7/17/2005 4:37:36 AM
        
        re: Hey Thanks For Giving Me More Ammo - Spacegirl2100 - 7/16/2005 7:08:50 PM
        
        Hello - Mark Eby - 7/17/2005 3:45:24 AM
        
        I agree with you entirely here: there is no economic justification for manned Mars missions - E.P. Grondine - 7/16/2005 4:33:37 PM
        
        re: I agree with you entirely here: there is no economic justification for manned Mars missions - Joe2700 - 7/17/2005 12:55:18 AM
        
        There is no economic justification for manned Mars missions - E.P. Grondine - 7/17/2005 5:27:36 PM
        
        re: There is no economic justification for manned Mars missions (that Ed knows) - Chris Vancil - 7/18/2005 2:49:40 AM
        
        re: ***As moderator, I have to ask you two a question*** - E.P. Grondine - 7/16/2005 4:06:24 PM
        
        Is There Any Point Reading Past The First Paragraph? - Mark Eby - 7/16/2005 4:31:37 PM
        
        Hell, Mark, you haven't even made it past the first paragraph? - E.P. Grondine - 7/16/2005 4:44:07 PM
        
        re: Are you off meds? - Chris Vancil - 7/17/2005 7:13:09 AM
        
        As usual: Mark is both perceptive and correct - Gary - 7/16/2005 3:47:35 PM
        
        Amazing: Mark and Gary agree - E.P. Grondine - 7/16/2005 4:27:01 PM
        
        Holy F**K! Mark, Gary and EP agree! - Adam - 7/18/2005 5:53:02 AM
  - Or What A Dingbat Thinks (n/t) - Mark Eby - 7/15/2005 10:44:43 PM
    - re: Or What A Dingbat Thinks - Joe2700 - 7/17/2005 12:48:11 AM

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