Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_2/V11_212.TXT

Internet Message Format | 1991-07-08 | 17KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/Ea64dYq00VcJ83BE4D>;
          Tue,  3 Apr 90 03:01:57 -0400 (EDT)
Message-ID: <Ia64d-C00VcJ83=[e-mail]>
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Tue,  3 Apr 90 03:01:30 -0400 (EDT)
Subject: SPACE Digest V11 #212

SPACE Digest                                     Volume 11 : Issue 212

Today's Topics:
           Payload Status for 04/02/90 (Forwarded)
      Re: Fun Space Fact #1: Launcher Development Costs
               Re: Solar Cells
            Saturn V gone forever?
             How does Comet Austin look?
          Re: Will we lose another orbiter?
              Re: Strange flash of light
             Re: Shuttle Designs
                 Re: Needles
         HST orbit (was Re: Comparative Costs to LEO)
----------------------------------------------------------------------

Date: 2 Apr 90 20:11:37 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Payload Status for 04/02/90 (Forwarded)


    Daily Status/KSC Payload Management and Operations 04-02-90.


    - STS-31R HST (at pad-B) -

    The HST to orbiter interface verification test was completed
    Friday.  HST battery charging was started third shift
    Saturday and will continue through today.  HST confidence
    testing was started third shift Sunday and will continue
    through Tuesday.


    - STS-35 ASTRO-1 (at OPF) -

    Igloo leak checks and DDU reinstallation were completed
    Friday.  On Saturday ASTRO was powered up and retests of the
    RAAB, DDU, and HDRR were successfully completed.  Today non-
    power up closeouts will be performed.


    - STS-40 SLS-1 (at O&C) -

    Preps for rack and floor installation into the module were
    worked Friday and Saturday and will continue today.
    Troubleshooting of the fire suppression system was also
    worked on Friday.


    - STS-42 IML-1 (at O&C) -

    Racks 4, 7 and 11 staging operations were worked on Friday.
    Racks 5, 7, and 11 staging operations along with module
    cable clamp inspections were active Saturday.  Racks 3, 5,
    7, and 11 staging operations, module cable clamp inspections
    and pyrell foam replacement are scheduled for today.


    - STS-45 (Atlas-1)-

    On Friday hardpoints were installed on pallet 2.  Cold plate
    support structures, flight trunnion, and handrail
    installations were active Saturday.  Pallet joint kit
    installation on frames 1 and 4 will be active today.


    - STS-55 SL-D2 (at O&C) -

    Rack 12 staging activities were worked on Friday and will
    continue today.


    - HST M&R (at O&C) -

    ORUC cable installation will be active today.

------------------------------

Date: Mon, 2 Apr 90 13:44:47 CDT
From: [e-mail]
Subject: Re: Fun Space Fact #1: Launcher Development Costs

> [e-mail]  (SERRE GLENN)

> How is the present design more complex than the original design of
> the shuttle?  More engines, higher Isp, more computers, what?

I posted an (overly) long exposition on just why increasing size
means increasing complexity some time back.  Rather than repost it,
I'd suggest you simply think about the increased number of
connection points, supports, wire runs and tiedowns, ducts, tubes,
etc. that are necessary in a larger scale version of something.

If that doesn't make what I'm talking about clearer for you, EMail
me and I'll send you a copy of the original article.


==============================================================================
| Fred McCall  ([e-mail]) | "Insisting on perfect safety is for  |
| Military Computer Systems           |  people who don't have the balls to  |
| Defense Systems & Electronics Group |  live in the real world."            |
| Texas Instruments, Inc.             |                     -- Mary Shafer   |
+-------------------------------------+--------------------------------------+
|  I speak for me.  I don't speak for others, and they don't speak for me.   |
==============================================================================

------------------------------

X400-Received: by /PRMD=inria/ADMD=atlas/C=FR/;
    Relayed; 31 Mar 90 09:57:54+0100
X400-Received: by /PRMD=SWITCH/ADMD=ARCOM/C=CH/;
    Relayed; 31 Mar 90 09:56:28+0200
Date: 31 Mar 90 09:56:28+0200
From: Joseph C. Pistritto <[e-mail]>
Subject: Re: Solar Cells

>Mailer: Elm [revision: 64.9]

Solar Cell facts (from my recent forays into ground based solar
photovoltaics):

1) Solar flux at ground level is about 800 W/m2 (this figure is
        used by most manufacturers).  At LEO, I believe the
        figure is 1Kw/m2, but I'm not real sure.  This, by the
        way is referred to as the "solar constant", even though
        it isn't...

2) Currently mass produced Si solar cells (civilian market), claim
        efficiencies of 6-14%, there are 3 kinds commercially
        available:
                1) Monocrystaline - single crystal silicon wafer
                cells - commerical efficiency 14%.  These appear
                solid deep blue.  Wouldn't surprise me if you could
                get a percent or two more thru selection, (milspec).

                2) Polycrystaline - multi-crystal silicon wafer,
                cells - commercial efficiency 12%, slightly cheaper.
                Appears to be a collection of blue 'flakes'.

                3) Amorphous - noncrystaline silicon - new process,
                These are a uniform brown color - commercial
                efficiencies 6-8%.  These are much cheaper to produce
                than types 1) or 2), but this fact doesn't seem to
                be reflected in the market prices, at least here in
                Europe.

3) There are other kinds of cells as well, (non-Si based), but these
        have only smaller or specialized markets.  Cadmium-sulfide
        comes to mind.  I think the first solar cells were CdS, actually,
        but I'm not sure.  Efficiency is real low though (4%?).

4) Gallium Arsenide (GAs) is in general safer from radiation effects
        than Silicon, which is why the military is so interested in
        GAs based computers, etc.  (GAs also has a higher electron
        transport speed than Silicon, which would make for both more
        efficient solar cells (less time for electrons/holes to
        recombine), and faster computers.  Maybe this also is why
        it's radiation resistance is higher, but I'm no solid state
        physicist.

5) Normal Silicon solar cells as used on satellites seem to decay at the
        rate of several percent (2-3%) per year due to on-orbit radition
        exposure.  For instance, the Magellan spacecraft has already lost
        3-4% of its solar generating capacity due to solar flares (recent
        activity is admittedly higher than normal, we're at a cycle peak).
        A certain number of cells also fail due to thermal stress on the
        electrodes & mountings, and I imagine at launch time as well.

--
Joseph C. Pistritto ([e-mail] -or- cgch![e-mail])
 Ciba Geigy AG, R1241.1.01, Postfach CH4002, Basel, Switzerland
 Tel: [phone] (work) [phone] (home)   GMT+2hrs!

------------------------------

Date: 1 Apr 90 02:44:16 GMT
From: venus![e-mail]
Subject: Saturn V gone forever?


     I recently attended a panel discussion in which someone commented
that the technical blueprints for the Saturn V launch vehicle have disappeared;
that noone at NASA knows where they are (or have gone).
     I find this incredibly hard to believe.  Does anyone know if this is
actually true?  And if so, is there any more of story behind the disappearance,
or are the blueprints *just gone*?

------------------------------

Date:     Sun,  1 Apr 90 12:21 CST
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject:  How does Comet Austin look?
Original_To:  SPACE

Anybody been able to see Comet Austin yet?  It's been pretty cloudy in the
Chicago area...

     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |                      Bill Higgins
 \       /                      Fermi National Accelerator Laboratory
   -   -                        Bitnet:                [e-mail]
     ~                          Internet:             [e-mail]
                                SPAN/Hepnet/Physnet:         43011::HIGGINS

------------------------------

Date: 1 Apr 90 13:57:53 GMT
From: eru!luth!sunic!mcsun!ukc!icdoc!syma![e-mail]  (Nick Watkins)
Subject: Re: Will we lose another orbiter?

In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>It was NASA's responsibility to inform the public about the safe
>flight rate of the system, not recklessly exceed it in a futile
>attempt to preserve the myth of the shuttle's economic viability.  It
>was NASA's responsibility to be honest about the potential
>capabilities of the shuttle when it was being sold.  But, as Keyworth
>noted, NASA is the only government adgency that outright lies.
I am intrigued by the spelling, is adgency a contraction of advertising
agency ...:-). Seriously though, the assertion that the CIA, DoD, State
Department, (and the NSA & NRO) never lie is one that I find a little
hard to swallow. Perhaps this is  caused by the reading of too much Seymour
Hersh et. al. on my part.
 Maybe Keyworth  puts the boundary between lying and dissembling in a different
place to where I would. Let he he who has enough brilliant pebbles to
spare cast the first stone ...

Nick

"This operation is rather like the periscope of a submarine" - Mike
Collins, July 1969.
--
Dr. Nick Watkins, Space & Plasma Physics Group, School of Mathematical
& Physical Sciences, Univ. of Sussex, Brighton, E.Sussex, BN1 9QH, ENGLAND
JANET: [e-mail]   BITNET: [e-mail]

------------------------------

Date:     Mon, 2 Apr 90 15:06:26 CST
From: Will Martin <[e-mail]>
Subject:  Re: Strange flash of light

I finally located a newspaper article on the event that cited various
local astronomy types as stating the flash was definitely caused by a
meteor. It didn't have much technical detail, and spent most of the
space discussing historic meteoric events.

Regards, Will

------------------------------

Date: Mon, 2 Apr 90 13:31:36 CDT
From: [e-mail]
Subject: Re: Shuttle Designs

> agate![e-mail]  (William Baxter)

> >Fact 1:  The Shuttle is significantly bigger and has much more
> >delta-v capacity than the original design.
>
> The original 'design' was not well defined.  It was, for the most
> part, a set of promises about performance. (e.g. $100/lb to LEO,
> fully reusable)

It seems to have been well enough defined so that at least two
people on the net (Henry Spencer and myself) seem to have at least a
somewhat clear picture of what it would have been like.

> >Fact 2:  This redesign made the Shuttle much more complex.
>
> You are comparing existing hardware with a bunch of promises.

So is it your contention, Mr. Baxter, that nothing that was said
until after the first hardware was flying matters?  I thought that
the thing that everyone was so upset about was the difference
between "promises" and what got delivered.

Or do you just want to pick and choose which events count and which
don't?

> >Fact 3:  This increase in complexity increased the maintenance
> >requirements drastically.
>
> Comparing apples and hypothetical oranges is irrelevant.  What's the
> total launch cost of the 'original design,' and what is the unit cost
> per kilo?  How much will it cost to build?  How does the maintenance
> schedule differ from that of the existing Shuttle?

Then so is *any* plan, proposal, or anything like that, Mr. Baxter,
including yours.  It is this very blindness about the overall
picture of the budgetary process and how systems get developed and
evolve that seems to be a continuing weak point of your whole
position.

I certainly don't have those figures handy, not being associated
with either NASA or a major contractor with them (SuperJim's
innuendoes notwithstanding), but having some idea of what sort of
detail goes into any kind of proprosal to a government agency, I
have no doubt that there are at least first cut estimates of a lot of
those things.

I thought you just said that nothing said before the first one flew
(of whatever it was) mattered ("comparing existing hardware with a
bunch of promises")?  You can't have it both ways, Mr. Baxter.

At least not if your intention is to try to be intellectually honest.

> New promises to Congress are commonly known as Space Station Freedom,
> National AeroSpace Plane, Advanced Launch System, and the Moon-Mars
> Thing.

"Moon-Mars Thing".  I like that.  Nice technical project name there.
;-)

[And as for your munging of my signature, while it's no doubt
'cute', there is a word for statements which are placed in quotes
and purport to be those of someone else, but which are not.  They are
commonly called "lies" in most parts of the country.  There is also a
name for the person who does it, just as there is a name for those
who resort to personal attack when their position proves to be
intellectually bankrupt.  I'll leave the net to draw its own
conclusions about you from that; and I'd like to thank you for
showing us all your true colors and once again validating my prior
remarks about your propensity for putting people on "enemies lists"
and just how one goes about getting put there.]

> William Baxter


==============================================================================
| Fred McCall  ([e-mail]) | My boss doesn't agree with anything  |
| Military Computer Systems           | I say, so I don't think the company  |
| Defense Systems & Electronics Group | does, either.  That must mean I'm    |
| Texas Instruments, Inc.             | stuck with any opinions stated here. |
==============================================================================

------------------------------

Date: 1 Apr 90 03:09:58 GMT
From: wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Needles

In article <[e-mail]> [e-mail] (Brian or James) writes:
> Does anyone out there have information on an early (late fities
>to mid-sixties) project to place millions of needled in LEO as a
>passive radio relay. I *think* it was DOD related (a stop gap
>technique to use if the US comsats got fried)...

Ah yes.  Project West Ford.  It was copper wires, actually, not needles.
The idea was indeed to orbit a passive radio reflector that could not be
shot down or destroyed in any simple way, for wartime military use.
It was tried once in orbit, over the protests of the astronomers.  As I
recall, basically it didn't work all that well, and the idea was dropped.
--
Apollo @ 8yrs: one small step.|     Henry Spencer at U of Toronto Zoology
Space station @ 8yrs:        .| uunet!attcan!utzoo!henry [e-mail]

------------------------------

Date: 3 Apr 90 01:32:01 GMT
From: zaphod.mps.ohio-state.edu!uwm.edu!ogicse!zephyr.ens.tek.com!wrgate!mrloog![e-mail]  (Dan Tilque)
Subject: HST orbit (was Re: Comparative Costs to LEO)

[e-mail] (Henry Spencer) writes:
>[e-mail] (Robert McGwier) writes:
>>If the world wanted to put stuff in a 250km high, 28 to 58 degree inclination
>>orbit, your numbers would be meaningful.  Since BY FAR, most of the
>>LEO shots are polar...
>
>Um, you've forgotten a goodly assortment of science missions -- e.g. the
>Hubble telescope -- which merely want to get into orbit and don't greatly
>care which orbit.  Space is not just comsats and spooks.

Minor nit: they don't much care what orbit HST gets into except for it's
altitude.  There's an interesting article in the April Sky & Telescope
about the deployment of HST.  It's written by the Mission Specialist who
will actually run the Arm (Steve Crawley, I think his name is).  In it he
says the shuttle will try for about 570 Km altitude, which is as high as
the shuttle can go with that load and still have some reserve fuel left.

The main reason they want the high altitude is due to the current high
level of solar activity which degrades low orbits.

---
Dan Tilque    --    [e-mail]

------------------------------

End of SPACE Digest V11 #212
*******************