Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V08/V8_265.TXT

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

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail
Received: from andrew.cmu.edu via trymail for [e-mail]
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/andrew.cmu.edu.5177.1.0>;
          Sat,  9 Jul 88 23:24:03 -0400 (EDT)
Received: by andrew.cmu.edu (5.54/3.15) id <AA05173> for ota+space.digests; Sat, 9 Jul 88 23:22:42 EDT
Received: by angband.s1.gov id AA07907; Sat, 9 Jul 88 20:23:11 PDT
    id AA07907; Sat, 9 Jul 88 20:23:11 PDT
Date: Sat, 9 Jul 88 20:23:11 PDT
From: Ted Anderson <[e-mail]>
Message-Id: <[e-mail]>
To: [e-mail]
Reply-To: [e-mail]
Subject: SPACE Digest V8 #265

SPACE Digest                                      Volume 8 : Issue 265

Today's Topics:
          Re: Some more launch loop stuff...
          Re: Some more launch loop stuff...
              Re: Bureaucracy vs.  space
              Mir elements, epoch 25 May
            Re: Mir elements, epoch 25 May
               Re: Space Station Names
               Re: Space Suits
               RE: SPACE Digest V8 #240
            Re: Naming the space station.
              Re: Nuclear bombs
           Tours of NASA Ames during Usenix
                 Space Digest
            skin tight space suits
          Re: Some more launch loop stuff...
----------------------------------------------------------------------

Date: 1 Jun 88 02:49:17 GMT
From: mnetor!utzoo!utgpu!water!watmath!looking![e-mail]  (Brad Templeton)
Subject: Re: Some more launch loop stuff...


What ever happened to the good old fashioned 500 mile linear acellerator?

At 3.5g for 3 minutes 20 seconds you hit orbital velocity.
You have to correct to circular with a reaction rocket later of course,
and you have to also get back the velocity you lose to air.

But the point is we could build such a thing.  500 miles isn't that
long, with mass production techniques.  If it costs $20 million per
mile to build, that's only $10 billion -- lots less than the
space scuttle program.  Share it with the Russians, Japanese, Canadians
and ESA even if it costs $100 million per mile.  Float it at sea and
have it shoot up the Rockies or the Andes.  Stretch it over the
desert.  Use it as a supercollider when it isn't busy launching.

The launch loop would fail in a bad way.  Geostationary towers can't
stand because they would be hit by satellites.  I think it's this
or super fast scramjets, folks.
--
Brad Templeton, Looking Glass Software Ltd. - Waterloo, Ontario 519/884-7473

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

Date: 1 Jun 88 16:13:05 GMT
From: mnetor!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Some more launch loop stuff...

> ... Also, the segments wouldn't wind up in Earth orbit.
> They would go into solar orbit.  Nothing like having a few thousand
> one kilo chunks of iron flying about in an earth intersecting solar
> orbit. :-(

Not to worry, there are millions of one-kilo-sized nickel-iron meteorites
out there already.

The only reason space junk is a concern in Earth orbit is that near-Earth
space, especially the most interesting regions, isn't very big.  We can't
totally disregard the issue elsewhere, but given the natural background
level already present, it will be a while before it's a real concern.
--
"For perfect safety... sit on a fence|  Henry Spencer @ U of Toronto Zoology
and watch the birds." --Wilbur Wright| {ihnp4,decvax,uunet!mnetor}!utzoo!henry

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

Date: 1 Jun 88 16:31:04 GMT
From: mnetor!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Bureaucracy vs.  space

> Agreed, but Henry's original posting was comparing shuttles with cargo
> planes, not with expendables.

True, but it doesn't affect my point, which is that the cargo environment
for the shuttle is not severe enough to explain the massive difference
in paperwork.

> ... it is perfectly
> reasonable for those regulations to be stricter than for expendables,
> given that the shuttle is manned, reusable, and more delicate than an
> expendable.

Sure.  But several orders of magnitude?  The Hercules is also manned and
reusable, if a bit more durable.  By the way, I think you're overestimating
the robustness of expendables; no space-launch system is made any heavier
than it absolutely needs to be.  If anything, the shuttle has to be more
robust than expendables.

> As for being manned, it doesn't matter how much risk the astronauts are
> willing to take for the glory of NASA.  Every manager or engineer on
> the ground still is morally required to worry about their safety ---
> much, much more than what he would be expected to worry in the case of
> an unmanned vehicle.

The same comment applies to airlines.  They seem to find it possible to fly
cargo and people at reasonable costs with reasonable paperwork... but then,
they have incentive.  They have to be useful, or they go broke.

> As for reusability, in an expendable launch the only party who really
> needs to worry about payload safety is the payload owner, since he is
> the only one who stands to lose in case of an accident...

Ho ho.  Sorry, wrong.  The launcher supplier has to worry about the effects
of a failure on future business.  This is *not* a trivial issue, especially
with production volumes as low as they are today.  (That is, he can't just
say "well, we had a failure, but with 357 successes in the last three years,
we can quite safely say that it was a fluke and our booster is still amply
reliable".  The airliner builders have a bit of an advantage here.)  At the
very least, the launch outfit has to have iron-clad proof that the failure
was the satellite's fault, and that's not easy to get.  The Soviets might
have commercial Proton business by now if they hadn't had those failures.
With volume so low and costs so high, it doesn't take many failures for
customers to decide that your launcher is jinxed.  Expendable builders get
to worry a lot about payload safety.  However, unlike NASA, they do have
to be useful, so they have some incentive to keep things under control.
--
"For perfect safety... sit on a fence|  Henry Spencer @ U of Toronto Zoology
and watch the birds." --Wilbur Wright| {ihnp4,decvax,uunet!mnetor}!utzoo!henry

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

Date: 1 Jun 88 20:07:00 GMT
From: [e-mail]
Subject: Mir elements, epoch 25 May


Satellite: Mir
Catalog id 16609
Element set 212
Epoch: 88144.82886303
Inclination:  51.6140 degrees
RA of node: 192.4097 degrees
Eccentricity:  0.0022899
Argument of perigee:   5.3494 degrees
Mean anomaly: 355.2223 degrees
Mean motion: 15.75455582 revs/day
Mean motion acceleration: 0.00019094 * 2 revs/day/day
Epoch Revolution: 12999

Semimajor axis:    6721.43 km
Apogee height*:     358.66 km
Perigee height*:     327.88 km


        Source: NASA Goddard via T.S.Kelso's `Celestial RCP/M'

* Apogee and perigee altitudes are referred to the mean radius of the
  Earth (6378.15 km), and not to the local radius of the geoid.  They
  are only approximate, and should not be used for orbit prediction.

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

Date: 1 Jun 88 20:16:00 GMT
From: [e-mail]
Subject: Re: Mir elements, epoch 25 May


Sorry about the delay on this posting; I was in Denver for the
National Space Society convention.

During the convention, I observed Mir visually twice, on Saturday and
Sunday evenings.  Since it arrived exactly when predicted (+/- a few
seconds, perhaps) I surmise that as of Sunday night, 10:20pm MDT, the
Soviets had not yet reboosted and dumped Progress 36.  One may expect
that they will in short order, as they plan to launch a visiting Soyuz
this week and will need to clear the rear docking port of Kvant to
accomodate it (The side ports cannot be used until the first Star
module with a remote manipulator system is on-orbit).

Kevin Kenny            UUCP: {ihnp4,pur-ee,convex}!uiucdcs!kenny
Department of Computer Science    ARPA: [e-mail]
University of Illinois
1304 W. Springfield Ave.
Urbana, Illinois, 61801        Voice: [phone]

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

Date: 24 May 88 04:12:15 GMT
From: nfsun!ditka!formtek!darth!pitt!cisunx![e-mail]  (Robert Garwood)
Subject: Re: Space Station Names

In article <[e-mail]> [e-mail] (Mike Smithwick) writes:
>And now the question you've all been staying up late for: what the
>heck are they going to name the Space Station??

How about just painting it white with the following in
large black letters :

"Space Station"


Why pay more for a brand name when generic will do?


Bob Garwood
"I don't have a .signature file."

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

Date: 22 May 88 22:37:36 GMT
From: [e-mail]  (Kevin William Ryan)
Subject: Re: Space Suits


   Someone mentioned the 'skin suit' style space suit, and asked for some
references.  Enjoy them courtesy of J.E. Pournelle, in Vol. 2, No. 3 of the now
defunct _Destinies_.

   NASA Report CR-1892, Development of a Space Activity Suit, by James Annis
and Paul Webb.  Ask your congresscritter, and he should send you one - that's
how I got my copy (since misplaced in one of my moves...).

   The suit is basically a multilayer (seven in this version) tight leotard.
Pressure maintained is ~170 torr around the torso, tapering to ~100-120 torr
at the extremities.  Multiple layers are preferable for ease of construction
(one layer is not required to support all that pressure), ease of tailoring,
and of course redundancy.  Pressure integrity is kept around the head by a
bladder extending over the torso, providing constant volume while inhaling.
Cooling is provided by sweat (quite efficient cooling, what with instant
evaporation).  Loss of several pints expected in average EVA.  Heating was
planned by electrical resistance heaters in on oversuit - said oversuit also
to provide radiation and thermal protection.
   Dexterity in the test suits was far far superior to the existing semi-hard
suits.  (Interesting parts included 'rounders' where the human body had
concavities and flats, such as the backs of the hands, in order to allow the
suit to exert pressure.)  Estimated cost for the seven layer suit, including
silk underlayers for ease of donning was $2000 1974 dollars, compared to the
rather extreme cost of period and present suits.  Present shuttle suit costs
~$200K.
   Difficulties included _individual_ tailoring, including a need for a new
suit if the owner changed weight by more than a few pounds, and the task of
putting on seven layers of _tight_ leotards.  Note also the low pressure in the
suit, 170 torr compared to the present shuttle pressure of 760 torr, which may
require compression - decompression cycles.  Tailoring and donning problems
were expected to be reduced with more experience, plus some work on user-
friendly zipper pull handles.
   The overall design was thus a multilayer leotard, oxygen tank, battery and
radio backpack, covered by a heavy silvered coverall with sweat vents.  Very
light, cheap, and providing (compared to any other design) incredible freedom
of movement.  Also a large safety margin - a tear would simple cause pain,
swelling, and edema (sp?  Swelling of the skin due to vapor pressure of under-
lying fluids.).  Not instantly fatal decompression and loss of suit enviornment
unless the helmet or torso bladder are ruptured.

  An excellent design.  NASA never picked up on it for reasons completely
unknown to me.  Perhaps somebody was instinctively repelled by the thought of
expensive astronauts floating around in expensive skivvies?...

                                                    kwr

   "Jest so ya know..."

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

Date:     Thu, 02 Jun 88 00:04:24 -0900
Reply-To: <[e-mail]>
Sender: <[e-mail]>
From: Scott Dennis, Computer Support   <[e-mail]>
Subject:  RE: SPACE Digest V8 #240

Well, then she was probably pretty lucky!  Darn cars don't even see motocycles..
  Well, I'm hittin' the hay.  I'll see you in the morning at about 10, then!

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

Date: 26 May 88 17:39:43 GMT
From: hall!pai![e-mail]  (Eric Johnson)
Subject: Re: Naming the space station.

In article <[e-mail]>, [e-mail] writes:
> How about "Fred"?
>
>             --Net.Rabbit

Count mine as another vote for

Space Station Fred


--
Eric F. Johnson          | Phone [phone]             | Are we
Prime Automation,Inc     | UUCP: ihnp4!umn-cs!hall!pai!erc   | having
12201 Wood Lake Drive    | UUCP: sun!tundra!pai!erc          | fun
Burnsville, MN 55337 USA | BIX:  erc                         | yet?

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

Date: Thu, 2 Jun 1988 14:40-EDT
From: [e-mail]
Subject: Re: Nuclear bombs

I'd also suggest those interested dig through back issues of Life,
around 1959-61 for a picture of a hole in the ground in a Carolina farm
field after it was accidentally dropped from a B-52 or B-57. Triggers
made a good size crater and caused some local cleanup problems, but the
last time I drove through the Carolina's they were quite well
populated...

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

Date: Thu, 2 Jun 88 14:40:33 pdt
From: Eugene N. Miya <[e-mail]>
Subject: Tours of NASA Ames during Usenix

I go on vacation and my mailbox, etc. fills.  gezz....

Several of you have written to tell me you would like tours of the
Ames Research Center while you are visiting SF during Usenix.
Contrary to popular belief, my job isn't to read mail and news,
I am supposed to be doing development and research.

I wish I could really help a lot of you, but it's too short a notice
for me to do anything with a large group of you.  It's not clear to me
that I will be going to Usenix for more than an a day (there's just not
that much on the program to interest me).  I've also been asked to
convey a NASA Internal Unix User Group meeting, so this puts severe
time contraints on me.  If you guys had suggested this 6 months ago...
Actually, Ames is pretty boring stuff, no mission controls, no high
performance aircraft (well, a couple of Harriers, F-104s and T-38s).
Tours are only given during daylight (working hours) on strict
time schedules.  FOREIGN NATIONALS TAKE 1 week to 1 month to clear
in advance since this is a Government reservation, this includes
English speaking nations (sorry Bob and others).  So I have to turn
you guys down in a blanket way, there's just too many of you on too short
a notice.  Now if you win a Field's or Nobel Prize, and you have time to
stop by to give a talk, I'm sure they can make exceptions for you.
Next conference, have the local arrangements communittee reach by 6 months
in advance.  Contact the Public Information Office (get the phone
as a exercise for the reader [remember this one?]) if you still want to try,
we are 40 minutes South of SF on 101 (terrible drive during rush hour)
it's the Moffett Field exit (the first street exit after Stierlin
[Silicon Graphics and E&S and Pyramid, and Bridge?] and Rengdorff [
SUN Microsystems].
Another gross generalization from

--eugene miya, NASA Ames Research Center, [e-mail]
  resident cynic at the Rock of Ages Home for Retired Hackers:
  "Mailers?! HA!", "If my mail does not reach you, please accept my apology."
  {uunet,hplabs,ncar,ihnp4,decwrl,allegra,tektronix}!ames!aurora!eugene
  "Send mail, avoid follow-ups.  If enough, I'll summarize."

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

Date:     Thu, 2 Jun 88 14:37 AST
From: <[e-mail]>
Subject:  Space Digest

Please send me Space Digest Volume 8, Issue 230. Thank you.      gf

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

Date: 2 Jun 88 14:48:17 GMT
From: mtunx!whuts![e-mail]  (WARMINK)
Subject: skin tight space suits

All this discussion about the skin-tight pressure suits reminds me of the
suits worn (?) by the adventurous space men & women on the covers of
those old science fiction magazines...
--
------------------------------------------------------------------------------
"Please continue the petty bickering,  |  Stuart Warmink, APT UK Ltd.
 it is most intriguing"    Cmdr. Data  |  <ihnp4>!whuts!sw, Whippany NJ USA
-----------> My opinions are not necessarily those of APT UK Ltd. <-----------

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

Date: 2 Jun 88 14:58:16 GMT
From: mtunx!whuts![e-mail]  (WARMINK)
Subject: Re: Some more launch loop stuff...

In article <[e-mail]>, [e-mail] (Brad Templeton) writes:
>
> What ever happened to the good old fashioned 500 mile linear acellerator?
> At 3.5g for 3 minutes 20 seconds you hit orbital velocity.
> You have to correct to circular with a reaction rocket later of course,
> and you have to also get back the velocity you lose to air.

Don't forget about air resistance - quite substantial at orbital velocity
and near sea level, not to mention the frictional heating effects!
--
------------------------------------------------------------------------------
"Please continue the petty bickering,  |  Stuart Warmink, APT UK Ltd.
 it is most intriguing"    Cmdr. Data  |  <ihnp4>!whuts!sw, Whippany NJ USA
-----------> My opinions are not necessarily those of APT UK Ltd. <-----------

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

End of SPACE Digest V8 #265
*******************