Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v15_0/v15no068.txt

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Date: Tue,  4 Aug 92 05:09:30
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #068 (amended)
To: Space Digest Readers
Precedence: bulk


Space Digest                Tue,  4 Aug 92       Volume 15 : Issue 068

Today's Topics:
           Bono's Politics (was Re: Clinton Space Position)
                          ETs, life in space
                            Galileo issues
                             NASA Select
                        Soyuz as ACRV (7 msgs)
     Soyuz as ACRV (Posting of previous discussion data) (2 msgs)
                             Tether power
                                 TSS
                         Whales and Dolphins
                          when is the moon?

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

Date: 4 Aug 92 03:07:13 GMT
From: Greg Moore <[e-mail]>
Subject: Bono's Politics (was Re: Clinton Space Position)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Mary Shafer) writes:
>On 3 Aug 92 20:56:50 GMT, [e-mail] (Bill Higgins-- Beam Jockey) said:
>
>Bill> In article <[e-mail]>, [e-mail] (Greg Moore) writes:
>>     I went to the U2 concert in Albany NY a few months ago, and while
>> their, the lead singer, Bono made the following comment:
>
>Bill> Speaking of politics, I have heard that Bono is now running for
>Bill> Senator in California...
>
>Different Bonos.  Both singers, but one sings for U2 and the other
>was the Sonny half of Sonny and Cher.  Sonny Bono is the mayor of
>Palm Springs.
>
    Hmm, different generations of music listeners here obviously. :-)

>Isn't the U2 Bono Irish?  You can't be a US Senator if you're not a
>US citizen.

    Yes, Bono (Vox) of U2 is Irish.  Hmm, I wonder wht HE thinksof
the space prograam... should we go with Soyuz or Shuttle or Apollo?

>--
>Mary Shafer  DoD #0362 KotFR NASA Dryden Flight Research Facility, Edwards, CA
>[e-mail]                    Of course I don't speak for NASA
> "A MiG at your six is better than no MiG at all."  Unknown US fighter pilot


--
<------------------------------------------------------------------------->
Greg d. Moore                  |  [e-mail]
Green Mountain Software        |  "All that is gold does not glitter."
Carpe Diem                     |

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

Date: 4 Aug 92 01:54:44 GMT
From: John Roberts <[e-mail]>
Subject: ETs, life in space
Newsgroups: sci.space

-From: [e-mail] (Henry Spencer)
-Subject: Re: ET's, life in space
-Date: 31 Jul 92 17:43:05 GMT

-In article <[e-mail]> [e-mail] writes:
->Another point of interest. It has LONG been known that the ribosomes
->are from an ENTIRELY separate evolutionary strain. They don't even
->use the same genetic code...

-I think you mean the mitochondria (and chloroplasts, for plants).
-A ribosome is just a handful of molecules, a protein factory.  A
-mitochondrion really is a semi-independent organism, with its own
-genetics and almost certainly an independent origin.

*Most* of its own genetics - they're now dependent on the host cell for
some of their proteins. That's not to say is was always so - after all,
humans can no longer manufacture all the complex chemicals they need to
live.

John Roberts
[e-mail]

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

Date: 4 Aug 92 01:29:05 GMT
From: Henry Spencer <[e-mail]>
Subject: Galileo issues
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Cassini isn't due to flyby Jupiter until December 30, 2000.  Galileo will
>likely be not operational by then, its orbital mission around Jupiter
>runs from 1995 to 1997.  It is true that some spacecraft have lived
>well beyond their designed lifetimes, but Galileo will be in a particularly
>harsh environment in Jupiter's radiation belt...

Also, Galileo isn't going to just sit in a nice stable orbit.  It will
be expending fuel constantly to set up for one moon flyby after another,
so it will actually be getting pretty low on fuel by the end of its
nominal mission (especially since it's been expending noticeable amounts
on things like all the cooling turns).

>Ulysses will come somewhat close to Jupiter in 2004.  Same arguments as with
>Cassini plus it is not known what Ulysses' operational status will be...

Plus Ulysses isn't built for high-speed data transmission at all.  Since it
has no imaging instruments, it doesn't need it.  I believe its peak data
rate is something like 8kbps -- better than 40bps, but given that you'll
get only one quick flyby, hardly a huge advantage.
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

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

Date: 4 Aug 92 01:13:29 GMT
From: John Roberts <[e-mail]>
Subject: NASA Select
Newsgroups: sci.space

-From: [e-mail] (Gary Coffman)
-Subject: Re: NASA Select
-Date: 31 Jul 92 20:18:45 GMT
-Organization: Gannett Technologies Group

-In article <[e-mail]> [e-mail] (John Roberts) writes:
->That made me wonder - is there a "NASA Select operations" phone number that
->a viewer could use to reach operations and tell them "there's no sound"
->or "you're playing the tape backwards"? Occasionally I'm up late enough that
->such a number would be useful, and assuming replays are from NASA Headquarters,
->it wouldn't cost me much to give them a call (definitely worthwhile for an
->important press conference).

-As a broadcaster I can say with considerable assurance that the uplink
-operators are well aware of any anomalies long before you could reach
-them by phone. Generally they are running around in tight little circles
-trying to solve the problem and the last thing they need to do is answer
-a ringing phone from an irate viewer.

That depends on the level of effort being put into the nighttime broadcasts.
It doesn't apply to the local cable channels - one night "NASA Select" was
an Amiga display window, and when I called the number for the organization
responsible for that particular channel, everybody had gone home for the
night. :-)  (The main cable company did have service people, but they don't
have immediate control over the switching of that channel.)

While I don't know exactly how NASA Select handles things, I know there's
considerable variation in the broadcast industry. Television networks would
presumably keep someone there all the time. Many radio stations go to full
automation at night, some with nobody even in the building. NASA Select has
been steadily improving over the last several years, but the fact that they
never seem to have a schedule more than a few days in advance at best, and
that they often depart from the schedule even on a day-to-day basis (for
instance playing old videos rather than the live events of that day on the
midnight-4AM shift) would seem to indicate that they're somewhere "in the
middle" of that range, thus they might or might not have live crew late at
night.

The fact that there has recently been a great increase in the replay of
press briefings, etc. on the late shift is a very encouraging sign. On that
particular briefing replay, it did seem that someone started playing with
the sound about 15 minutes into the tape, which would imply that someone
actually was there, and eventually noticed and attempted to correct the
problem.

By the way, I don't mean to imply any negative comment on NASA Select.
It's an extremely valuable resource. My previous post meant just what
it said: is there a phone number to call about technical broadcast problems?
If they're busy working on it already, they don't have to answer the phone. :-)
(And I promise to be polite. :-)  :-)

John Roberts
[e-mail]

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

Date: 4 Aug 92 00:42:42 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:

>|> Sure it is. We just do what the Russians do and use it as crew transport
>|> as well.

>No problem, if that's all you need.  Are you willing to expend the
>logistics modules that would be brought up and down with a crew rotation?

I don't think we need to. We can stick some Shuttle tiles on it, put a
parachute on top, and teather it down (which saves fuel and reduces station
keeping fuel needs). It will land just like a capsule. We can easially
pay for development with the billions saved.

>|> Soyuz can stay in orbit for days if needed. All the crew need do is
>|> evacuate to Soyuz and wait until they can land on land.

>Again, no problem on the surface.  Although Soyuz has never had to
>land in water, it has missed it's target area by hundreds of miles on
>more than one occasion.

The question here is why. It could be that Russian position location
isn't good enough I was thinking of Mexico/Southern Texas as a landing

site.

>|> >If we deploy two, there is a problem of where to put the
>|> >second.  There are only so many docking ports on Freedom and most are

>|> So we add another one. Multiple Soyuz is actually an advantage. First of
>|> ...

>Serious problems here.  Again, there's just so many docking ports and
>as of a couple of months ago (the last time I saw a mission build
>plan) there just isn't an available outward facing port that can be
>used.

So put an adapter on it and add another port. We are talking about saving
billions so it is worth a lot of effort to make it work.

>Your point about the single point failure is well taken, however, four
>crewmembers simply cannot fit inside a Soyuz return module.

They can for the short time needed to get to the other one.

>Even if
>they could squeeze in for a few minutes, there would be no way to
>transfer to the other module as there is no airlock on the Soyuz and
>you certainly couldn't fit four suited crew members inside a Soyuz.  A

We use the Russian automatic docking system to dock the two Soyuz's
together.

>natural response would be "Why don't you just EVA out of Freedom's
>airlock and traverse over to the second Soyuz then?"  Again, not
>possible.  The current EMU requires a substantial pre-breath before an
>EVA can be attempted.


We use some of the savings to fund the hard suit (which they should have
done in the first place). Pre-breath won't be needed. This gives us two
ways to get the crew to the vehicle.

>|> Soyuz is also better if there is a medical emergency. With ACRV the entire
>|> station would be evacuated just because one guy got sick. Maintenance tasks
>|> wouldn't get done and time lost. With Soyuz, you just pack the sick/injured
>|> person and ship him back.

>This might be possible, but it is unlikely that any real work could be
>done with a two person crew

Currently maintenance takes two people full time. This way a maintenance
crew can remain and keep things at lease even.

>(note that one non-incapacitated
>crewmember would need to return with the injured crewmember, if not to
>pilot the vehicle, then to be on hand to help in the recovery).

Maybe not. Depends on the nature of the injury and degree of confidence
in the system.

>One other thing that hasn't been addressed here is that a universal
>docking adapter will have to be designed.  Currently NASA is looking
>into using the Russian "androgynos (sp??)" docking adapter on Freedom.
>That may be a possible solution to this problem.

I was at the Air and Space Muesuem last Saturday. They had one hanging
up connected to a Apollo and Soyuz. Maybe we can steal that :-)

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------263 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Tue, 4 Aug 1992 01:02:57 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:

>>1. Shuttle production is ended. This puts a maximum life on the fleet.

>Sure it does. Around 2010 or so. Of course, Henry is going to pop up here and
>say we'll lose one before then...

Which is foolish indeed. The Shuttle is perfect and the only bug was
fixed. Surely none will be lost.

>It's extremely difficult to believe you're a (successful) lobbyist. You can't
>beat established pork with possible contracts.

The Shuttle isn't an established contract. It is a dying program.

>members looking out for their own districts. Now, go to the district where
>Rockwell International resides, and tell the Congressmen representing that
>district you're going to pull the plug on Shuttle.

I don't need to tell them. They already know.

>>>Soyuz should be viewed as a complement TO, not a replacement FOR the Shuttle.

>>Why?

>Why. Shuttle does more than act as a taxi. You have a mobile platform which can
>retrieve large structures and

Like what?

>carry a whole bunch of people.

It carries about four people plus flight crew. I didn't know four was a
'whole bunch'.

>It has a long-time duration on-orbit.

Two weeks?

>If you have to fix Freedom, you can't do it from a tin can. You'll NEED a
>Shuttle to do it from. Not a Soyuz.

too bad we didn't have the Shuttle when we launched Skylab. We might have
been able to use it. :-)

>"But the savings will allow us to build a newer space station to replace
>everything, and apple pie!" Uh. NOT.

The architecture I am proposing will save three to four billion a year. Yes
it could pay for a newer station.

>>All I use Soyuz for is crew transport. Why do you find that unreasonable?

>No, I find it unreasonable because you concoct a

I wouldn't say 'concoct'. These are all established ideas.

> bunch of other infrastructure
>which would be new program starts and new money. Doesn't your experience with
>SSTO tell you ANYTHING about new program starts with "unproven" technology? And
>you're working with beercan money (essentially) with SSTO.

No new money is needed. The contractors will put up all the money if the
market is provided.

   Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------263 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Tue, 4 Aug 1992 01:08:46 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Mary Shafer) writes:

>AWS> At what cost? Sacrificing everything to high-speed aerodynamics just
>AWS> isn't a good idea.

>I don't know why you say this.  It sounds like a _great_ idea to me.

>Mary Shafer
>Dryden Hypersonic Aircraft Group

did I mention that part of the savings would be used by buy you your own
NASP *AND* a brand new F-15? :-)

    Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------263 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 4 Aug 92 01:27:12 GMT
From: Matthew DeLuca <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:

>>It's an example.  Replace it with any complex and delicate piece of orbital
>>equipment that we might want to retrieve.

>Like what? This piece of equipment needs to cost well over a billion $$
>before it is worth recovery with the Shuttle.

Not really...anything that we want to bring back can be worth the cost of a
flight.  LDEF, for example.  It's dollar value wasn't that amazingly great,
but the scientific value was immense.  We can bring Hubble down if we want
to, the Compton Observatory, relay satellites, you name it.  Don't forget,
as demonstrated by the recent satellite repair mission, it doesn't have to
be a dedicated mission to retrieve said object.

>But I'm feeling generous today. I'll toss in a couple of billion from
>my savings to build a Shuttle compatible return module. Just bring your
>payload to the station (hell, I'll even spring for an OTV which I can
>pay for in about a years savings). We'll stick it in and teather it
>down for recovery. I'll even give you a price break since everything
>I teather down will save me fuel.

Well, my payload is crippled, so I can't bring it to the station.  It's
good that you are going to fund an OTV, although it's a pity that you've
already budgeted yourself out until sometime in the next century.  I do
hope it can move a 40,000 pound object across 20 degrees of orbital
inclination.

Of course, we can also wonder if the station can tether 40,000 pounds out
of orbit...it certainly wasn't designed for it, and we don't even know
how to do it.
--
Matthew DeLuca                      "I'd hire the Dorsai, if I knew their
Georgia Institute of Technology      P.O. box."
Office of Information Technology                - Zebediah Carter,
Internet: [e-mail]              _The Number of the Beast_

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

Date: 4 Aug 92 01:31:26 GMT
From: Matthew DeLuca <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] writes:
>>Your point about the single point failure is well taken, however, four
>>crewmembers simply cannot fit inside a Soyuz return module.

>They can for the short time needed to get to the other one.

As tiny as Soyuz is, I bet they can't.  Soyuz is smaller than the Apollo
capsule, if my memory of the Air & Space museum is correct, and Apollo was
a tight enough fit for three.

Of course, one of the four people is injured, don't forget.

>>they could squeeze in for a few minutes, there would be no way to
>>transfer to the other module as there is no airlock on the Soyuz and
>>you certainly couldn't fit four suited crew members inside a Soyuz.  A

>We use the Russian automatic docking system to dock the two Soyuz's
>together.

That wonderfully reliable system that screwed up yet again last week?
Great.

Besides, who is undocking the Soyuz docked to the station?  I don't think
they can fly under complete autonomous control.
--
Matthew DeLuca                      "I'd hire the Dorsai, if I knew their
Georgia Institute of Technology      P.O. box."
Office of Information Technology                - Zebediah Carter,
Internet: [e-mail]              _The Number of the Beast_

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

Date: 4 Aug 92 02:22:58 GMT
From: Greg Hennessy <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

Matthew DeLuca writes
#It's an example.  Replace it with any complex and delicate piece of orbital
#equipment that we might want to retrieve.

It's still a bad example. Any complex and delicate piece of machinery
that goes up on a billion dollar per launch shuttle is almost
certainly going to be better and cheaper split into smaller peices,
launched on unmanned rockets.

As HST should have been.



--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 4 Aug 92 02:04:24 GMT
From: Henry Spencer <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:
>>>...four crewmembers simply cannot fit inside a Soyuz return module.
>>They can for the short time needed to get to the other one.
>
>As tiny as Soyuz is, I bet they can't.  Soyuz is smaller than the Apollo
>capsule, if my memory of the Air & Space museum is correct, and Apollo was
>a tight enough fit for three.

Bad example, Matthew.  Apollo maximum capacity for *reentry* was five,
that being how a Skylab rescue mission (had one been necessary) would
have been flown.  And you could squeeze several more in for orbital
maneuvering not involving high G.  (I've been in an Apollo, by the way.)
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

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

Date: 03 Aug 92  15:09:00
From: [e-mail]
Subject: Soyuz as ACRV (Posting of previous discussion data)
Newsgroups: sci.space

Allen and I did a significant thrash of this topic in January on
talk.politics.space.  After a very lively and cordial discussion
with data and analyses being thrown about from several sources, the
discussion died out on the question of reuse of payloads and
experiments on SSF.  I'm reposting my last posting (21 Jan 92)
to potentially provide a revised starting point for this
discussion... [">" indicates a previous response from Allen ...]
 . . . . . . .
[In response to Allen Sherzer...]
    I think we've again got the basis to compare numbers...(I would
preferr LCC, but annual costs will be close.) I will use your HLV
Delta costs for 2 flights. I can't buy into your cost arguments
about "FAR costs" on the Atlas II numbers, since 1) the cost quoted
is for a commercial launch, 2) $25M/flt is well below the bounds of
any current ELV (commercial or governmental), and 3) the price I'm
using matches fairly well to the Ariane IV for equivalent
capability, which definitely doesn't have to deal with the FARs. Ops
costs I will leave at $100 M/yr, which you also used.
   However, we still haven't resolved the issue of return cargos.
To return 80,000 lbs per year is not trivial. To be optimistic about
the Soyuz I will assume the Soyuz total down cargo weight capability
can be modified to match the 10,000 lbs total up capability at no
additional cost (about double or quadruple current capabilities) .
And I will assume there will be no addition to annual operating
costs to recover the Soyuzes.

    [Allen's numbers]                    [Wale's numbers]
>This gives us:
> Item                                 ****NEW NUMBERS ***
>Yearly Cost                          Yearly Costs
>Altas flights (8/yr)     $400M       Manned (6 /yr)         $600 M
>HL Delta (2/yr)          $400M [1]   Some type of HLV (2/yr) 400 M
>Operations               $100        Ops                     100 M
>Docking                  $100        Docking [A]               3 M
>Return vehicle           $300        Return Cargos  (8/yr)   800 M
>                           ----                             ------
>Total                   $1,300                             $1900 M

Note [A]: I used $100 M as a one-time cost.  Over 30 years, this is
about $3 M/yr.  (That's lost in the noise for this discussion....)

[... Net note.  This annual cost is in comparison to a shuttle cost
for flying 4 flights per year to SSF, with SSF as per the current
planning...]

This comparison looks like a wash to me - even at $500M per shuttle
launch.  Now for some sensitivity checks...
   If $300M/flt for shuttle is more accurate (which I think is
closer to reality - IMHO), then using a ELV/HLV combo is a loser by
about $700 M/yr.
   If I throw in $100 M/yr for docking (say, to support an OMV-type
system orbital retrieval system), then it is dead even, even at $500
M per shuttle flight.
   At $500M /flt for the shuttle, if we have to use 16 Soyuzes
annually as a return system (a more realistic assumption), then the
HLV/ELV combo loses (annual cost of $2700 M yields a $900M/yr higher
cost). At $300M/flt for the shuttle, assuming 16 Soyuzes/year for
return yields a higher cost for the ELV/HLV combo by $1700 M/yr.
   If we assume a new return vehicle at a 1:1 payload to vehicle
mass (very optimistic), again we have the $800M annual payload
recovery cost.  Such an annual cost is probably low since it is
quite optimistic about return vehicle capability, and does not
include any launch or recovery costs, nor any recovery of
development costs.  And we add a new development program risk.
   IF SSF ever grows to a 8 man configuration, the shuttle costs
will remain approximately the same to change crews.  However, the
ELV/HLV combo's costs will grow as 11 manned flights per year will
be needed (4x8=32, satisfied by 11 flights), increasing costs by
$500M/yr.

   IMHO, doing several new developments (HLV, Soyuz mods, man-rated
Atlas, and a new Soyuz return vehicle or new cargo return vehicle),
in lieu of using the existing shuttle system does not seem to be
justified.  At best, it might save you $100M per year (very
optimistic assumptions).  At worst, it might cost you additional
costs of at least $900M/yr to $1700/yr, plus development/technical
risk costs from those new developments.

An interesting dicussion ... and to short-circuit any "Sez you" "Sez
me" rhetoric , I think we can agree that the crux of this discussion
seems to center upon the recovery and reuse of SSF hardware.  As
such, we seem to have centered upon 3 discussion points:
   1) The amount of SSF logistics needs, and that which might be
      reused.
   2) The cost of SSF logistics hardware
   3) The ability to recover sizable payloads from space - and the
      definition and cost of systems to do so.
   In particular, 3) seems to be an interesting area for further
discussion.

I think it might be useful to move this discussion towards these
three questions, since I think we are pretty much in agreement on
the other issues.
-----------------------------------------------------------------
Wales Larrison                          Space Technology Investor
P.S. to the net.... Most of the arguements in the current thread
seem to be rehashs, so I'm pretty much staying out of the discussion
to if any new arguments come up.

--- Maximus 2.00

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

Date: 4 Aug 92 03:20:55 GMT
From: Henry Spencer <[e-mail]>
Subject: Soyuz as ACRV (Posting of previous discussion data)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>   3) The ability to recover sizable payloads from space - and the
>      definition and cost of systems to do so.
>   In particular, 3) seems to be an interesting area for further
>discussion.

One aspect of this...  Note that the COMET program is already building
a recovery capsule with a capacity of something like 750kg.  (I don't
have numbers for COMET itself handy, but that's about right for one
of the early studies I read recently.)  Unless you are desperately
concerned with bringing large objects down in one piece, it is almost
certain that the cheapest way to return payloads is to order production
quantities of these (or their Russian equivalents).
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

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

Date: 4 Aug 92 02:01:14 GMT
From: John Roberts <[e-mail]>
Subject: Tether power
Newsgroups: sci.space

-From: [e-mail] (Andrew Haveland-Robinson)
-Date: 2 Aug 92 03:43:26 GMT
-Organization: Haveland-Robinson Associates

-In article <[e-mail]> [e-mail] writes:
->The 5000 volts are induced by the Earth's magnetic field as the spacecraft
->orbits. The same principle in using magnets to enduce a voltage when you
->pass a magnet through a coil of wire.

-I can see that this will work, though it's practicality may be limited
-as it would start to slow down the shuttle if any serious power could
-be drawn.

You can also use the principle to boost the orbit from another power source
(i.e. nuclear reactor or solar power). If you have plenty of onboard
chemical power storage, you could temporarily lower your orbit (i.e. for
low-altitude experiments or for servicing by an Earth-launched vehicle),
then raise the orbit again, all with little or no expenditure of propellant.

John Roberts
[e-mail]

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

Date: 4 Aug 92 00:49:37 GMT
From: John Roberts <[e-mail]>
Subject: TSS
Newsgroups: sci.space

-From: [e-mail] (Sam Warden)
-Subject: Re: A 12 mile tether that generates 5000v?
-Date: 1 Aug 92 02:32:47 GMT
-Organization: Rick's Home-Grown Un*x

-Extracting power: now, that's the real question.  I understand quite
-well how a static p. d. is induced, but not at all how anybody's going
-to get power out of these things, the way folks are talking about.
-From whatever ion current the ends can pick up?  What kind of _usable_
-output are these things predicted to be capable of?

The commentator on NASA Select said that they hope to get about an ampere
of current - so if that doesn't result in a large voltage drop, it's
about 5000 watts.

John Roberts
[e-mail]

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

Date: 4 Aug 92 01:38:32 GMT
From: John Roberts <[e-mail]>
Subject: Whales and Dolphins
Newsgroups: sci.space

-From: [e-mail] (Edward V. Wright)
-Subject: Re: Whales and Dolphins
-Date: 31 Jul 92 16:01:27 GMT
-Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA

-In <[e-mail]> [e-mail] (John Roberts) writes:
->One theory I've heard for a "typical" mass beaching is that one whale
->in a pod (usually a young, inexperienced one) gets confused by the
->echoes in shallow water and runs aground. Its cries of distress upset
->the other whales so much that they fling themselves on the shore, either
->in a vain rescue attempt, or as deliberate suicide.

->One could perhaps view this as emotion dominating over intellect, or as a
->case of whales having values different from (most) humans.

-Oh?  So you've never heard of search parties going out looking
-for a lost person, in bad weather, although several people may
-die in the attempt?  Especially if the lost person is a child?
-Sounds very human to me.

Human search parties won't go out to rescue one person if the expected
outcome is that several people *will* die in the attempt. (Unless it's
the President or something.) There are many occasions when a search is
called off because conditions are "too dangerous". A greater level of
risk might be accepted if there are more people to be rescued, and less
risk might be taken if rescue is considered unlikely. For an organized
search, there has to be a calculation of the tradeoffs involved. (Note
that this discussion is of cases where the threat is nonhuman in nature.)

Anyway, the discussion was whether whales have *intellect* comparable to
humans, not *emotion*. Humans often have the intellectual capability to
realize that the action most strongly prompted by emotion would defeat
its own purpose if carried out. If your friend has been badly injured by
a fall from a cliff, you might feel an emotional impulse to jump off the
cliff to come to the rescue, but you realize that not only would you be
badly injured, but also you would be in no condition to help your friend
once you reached the bottom of the cliff.

If whales have strong intellects but even stronger emotions, such that
emotion prevents rational choices even more often than in humans, then
that lessens the value to humans of establishing a dialog with whales.
(Imagine an entire species made up of political extremists. :-)

John Roberts
[e-mail]

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

Date: 4 Aug 92 01:44:59 GMT
From: John Roberts <[e-mail]>
Subject: when is the moon?
Newsgroups: sci.space

-From: [e-mail]
-Subject: when is the moon?
-Date: 31 Jul 92 17:02:45 GMT
-Organization: Utah State University

-Howdy.

-I have another simple (maybe) question.

-Anybody know when the moon rises/sets during
-the next two weeks??

-Mark Taratoot   DoD#3323

It's not that simple - exact time of rising and setting is strongly
dependent on longitude and latitude, and elevation also has an effect.
Get an almanac and a calculator.

John Roberts
[e-mail]

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

End of Space Digest Volume 15 : Issue 068
------------------------------