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Subject: SPACE Digest V11 #19

SPACE Digest                                      Volume 11 : Issue 19

Today's Topics:
          Re: Galileo Update - 02/06/90 (Forwarded)
            Imperial measurements
             Re: Galileo Mission Schedule
             Re: More Info On SSX
       Galileo Venus encounter (Re: Galileo Update - 02/07/90)
             Re: More Info On SSX
             Re: SR-71 BLACKBIRD
          Re: Galileo Update - 02/06/90 (Forwarded)
             Re: More Info On SSX
           Re: Grassroots Space "Radicals"
          Re: Spacecraft drives and fuel efficiency
         Fifth Soviet space walk done at Mir
----------------------------------------------------------------------

Date: 7 Feb 90 17:10:46 GMT
From: ux1.cso.uiuc.edu!aries![e-mail]  (James Wehmer)
Subject: Re: Galileo Update - 02/06/90 (Forwarded)

>     NASA's Galileo spacecraft will fly by planet Venus at about
>1 a.m. EST, Sat., Feb. 10, 1990, on the first leg of its gravity-
>assisted flight path to planet Jupiter.  Galileo will record
>scientific observations for playback in October.  There will be
>no live or real-time science from this Venus fly-by.
>
    Why wait eight months to download the Venus data?
    Is the Galileo mission schedual too busy to allow an earlier playback?

    Thanks, I was just wonderning.

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

Date: Wed, 7 Feb 90 15:00:26 EST
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Imperial measurements


>Subject: Re: furlongs per fortnight in space

>Does anybody know of a country other than the US that still has
>imperial measurments, as a standard?
 --------

Ha! Several people have made this mistake. The US does *not* use Imperial
measurements - that's what Canada and the UK pretend not to use :-).
(Yes, I realize that's nitpicking, but those who would make fun of our
antique measurement system shouldn't confuse it with somebody else's.)
I don't really know the name for what the US uses - probably "US Standard
or "American Standard". The British Imperial measurement system is different,
at least for volume measures. Moreover, the rest of the world does not use
the "metric system". The standard is SI, which is short for "Systeme
Internationale d'Unites" - "metric" is just a nickname nowadays. As I
understand it, there are (or recently have been) two acceptable formats
for SI expressions, chosen because they produce "convenient" values for
many everyday measures: centimeter-gram-second (arg! hate that one - and its
in all my old books!) and meter-kilogram-second (the most common one now, and
probably the "true" standard). Both of these formats suffer from an
idiosyncrasy left over from the beginnings of the system - measures are in
terms of either a hundredth of one basic unit (length) or a thousand of
another basic unit (mass). Also, common usage includes units that are not
part of SI, such as the liter (the vulgar term for the cubic decimeter).

In any event, the US standard *is* SI, and it has been for many years. The
official US standard of length is the meter, the official standard of mass
is a replica kilogram weight, and so on. The traditional measures are now
defined in terms of SI units, and are used for everyday applications. This
is usually only a problem if you want to mentally calculate how many cans
of artichokes can be boosted into orbit using a given mass of fuel, and similar
exercises. Serious calculations are generally done using SI, with the exception
of certain fields of study (such as thermodynamics, which still uses *both*
systems - the worst possible choice). Some aspects of space travel still use
the traditional units - largely a carryover from aviation. I agree it would
probably be a good idea to change this, if a way could be found to do it
all at once. As several people have pointed out, the transition would be
difficult.

I tend to post the results of calculations in "standard" units when they are
simple measures such as distance and velocity, because I think most of the
people on the list are Americans, who have a more intuitive "feel" for these
measures than the SI equivalents. Also, I tend to remember measures such as
the astronomical unit in the traditional units. For more complex calculations,
of course, it would be foolish not to convert to "metric".

The US government, through NBS/NIST, has tried to persuade the public to
convert to metric at several times, and has generally been resisted. Back in
the early 70s (?), road signs were put up along highways giving distances
in both miles and kilometers. There were complaints based on the suspicion
that the mile figures would eventually be taken down, so the kilometer
figures were taken down instead. In that climate of public opinion, do
any of you Europeans/Canadians/etc. have any ideas on how to get the
American public to switch over? (I don't think summary executions would
be acceptable. :-)

For hazardous, quick-response situations such as space travel, I have long
felt that some new synthetic measurement system would be superior to both
US standard and SI, based on the principle of KISS ("keep it simple, Stupid".)
It is very seldom that an astronaut desperately needs to know the diameter of
a bolt in terms of an eighteenth-century survey of the distance from the
North Pole to the Equator through Paris - it's more important to quickly
pick the right size wrench. Thus, bolt sizes should be "number 1", "number 2",
and so on, possibly with a similar convention for bolt length. Cabin pressure
might best be measured in "atmospheres" rather than psi or kPa. Other measures
such as seconds and Volts could remain the same. If the astronaut really
needs to know how many number 5 bolts to jettison in order to save 3 kilograms
of fuel on reentry without consultation with ground control, a conversion
table could be kept on board.

Disclaimer: I am not an official spokesman for NIST. If anyone really wants
to know, I could probably find out official government policy on measurement
systems. Also, I'm much more interested in seeing more hardware in space than
in what scale the gauges will be calibrated. :-)
                        John Roberts
                        [e-mail]

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

Date: 8 Feb 90 03:18:32 GMT
From: zephyr.ens.tek.com!wrgate!mrloog![e-mail]  (Dan Tilque)
Subject: Re: Galileo Mission Schedule

[e-mail] (Ron Baalke) writes:
>
>
>                          Galileo Schedule [abbreviated]
>
>                   02/09/90 - Venus Flyby
                       :
>                   10/29/91 - Asteroid Gaspra Flyby
                       :
>                   08/28/93 - Asteroid Ida Flyby
                       :

As I understand it, one or both of the asteroid flybys may not happen.
They will require extra fuel because they are slightly out of the way for
Galileo.  The decision to make them depends on how well the Venus flyby
goes.

Does anyone have more specifics?  That is, when will the decision be made
as to whether to make them and how much extra fuel they need for the
flybys?


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

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

Date: 7 Feb 90 14:35:16 GMT
From: eplrx7![e-mail]  (Walt Leipold)
Subject: Re: More Info On SSX

In article <[e-mail]> [e-mail] (Larry Smith) writes:
>The first SSX will probably use RL-10 rocket engines, which
>have been around a long time and are very reliable (they are
>used on the Centaur upper stage).  The anticipated cost of
>each vehicle is around $30 million,...

Do you seriously believe that you can build a reusable space vehicle
for less than a quarter of the cost of a 747?  If the gov't is going to
be a customer, you probably won't even be able to meet the payroll of
your QA dept for $30M/vehicle...

>Larry Smith for Edward V. Wright

--
"As long as you've lit one candle,                         Walt Leipold
you're allowed to curse the darkness."       ([e-mail])
--
--
The UUCP Mailer

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

Date: 8 Feb 90 02:38:31 GMT
From: van-bc!ubc-cs!eric!dssmv2![e-mail]  (Roger Fischer)
Subject: Galileo Venus encounter (Re: Galileo Update - 02/07/90)


Forgive me my ignorance but I have two questions about the Galileo
Venus encounter:

1.) Is the trajectory change towards the sun (Galileo passes on the
    outher side of the Venus) or away from the sun (Galileo passes
    inside Venus).

2.) What is the heliocentric velocity of Venus and Earth compared
    to the current and after-encounter velocity of Galileo.

Thanks for your time.....

Roger
----------------------------------------------------------------------------
Roger W. Fischer         [e-mail]         [e-mail]
..seismo!ubc-cs!mprgate!fischer     ...ihnp4!alberta!ubc-cs!mprgate!fischer

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

Date: 7 Feb 90 20:13:37 GMT
From: concertina![e-mail]  (Steve Hix)
Subject: Re: More Info On SSX

In article <[e-mail]>, [e-mail] writes:
/* Written  6:14 pm  Feb  5, 1990 by [e-mail] in m.cs.uiuc.edu:sci.space */
> I recently (2/5/90) got some interesting information on
> SSX from [e-mail] (Edward V. Wright).
> [ ... ]
> a useful payload of 9000 to 20,000 lb.
> [ ... ]
> The anticipated cost of
> each vehicle is around $30 million, yielding launch costs
> of about $50 per pound of payload in Low Earth Orbit.
> /* End of text from m.cs.uiuc.edu:sci.space */
> Forgive my math, but I get
> $30,000,000 / 20,000 lb = $1500/lb, not $50.
> For a 9,000 lb payload, it's $3333/lb. Where did you get $50/lb from?

It's reusable?

> For a 20,000 lb payload, and $50/lb, the vehicle must cost only $1million.

Mass production?    :}

------------
"...Then anyone who leaves behind him a written manual, and likewise
anyone who receives it, in the belief that such writing will be clear
and certain, must be exceedingly simple-minded..."   Plato, _Phaedrus_

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

Date: 7 Feb 90 18:12:42 GMT
From: hplabsb![e-mail]  (David Smith)
Subject: Re: SR-71 BLACKBIRD

In article <[e-mail]> [e-mail] (Nick Watkins) writes:
>
>>Hmmm, maybe we should hire the USAF to build copies of the F-1.
>
>The what? F-1 was (US) designation for the SS9 Scarp ICBM as a launcher.
>Very roughly equivalent to Titan II (Martin would probably rebuild them if
>you paid them enough ...:-) )
>
>G-1 (US) or N1 (USSR) = old moon rocket. Was this the one you meant ?

One of the most frequently asked questions in this forum is
"Why can't we restart production of the Saturn V, or at least its F-1 engine?"
That's the one I mean.
--

            David R. Smith, HP Labs
            [e-mail]
            [phone]

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

Date: 7 Feb 90 21:02:15 GMT
From: crabcake![e-mail]  (Kenneth Arromdee)
Subject: Re: Galileo Update - 02/06/90 (Forwarded)

Out of curiosity (and which I asked before): Is Galileo, when it reaches Earth,
going to take any pictures?  (Maybe they can discover life :-))
--
"Workers of the world, we're sorry!" --Soviet protestor's slogan

Kenneth Arromdee (UUCP: ....!jhunix!arromdee; BITNET: arromdee@jhuvm;
     INTERNET: [e-mail])

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

Date: 8 Feb 90 00:36:25 GMT
From: milton!maven![e-mail]
Subject: Re: More Info On SSX

In article <[e-mail]>, [e-mail] writes:
> Forgive my math, but I get
> $30,000,000 / 20,000 lb = $1500/lb, not $50.
>

Don't forget that the vehicle is reusable.  Hence you are paying only a
portion of the cost of the vehicle for each flight that it makes.  The real
cost is fuel, and maintenance + cost of vehicle/number of flights.

Or so it seems to me.

-------------------------------------------------------------------------------
Trendy footer by:
            John Stevens-Schlick
            Internet?: [e-mail]
            7720 35'th Ave S.W. Seattle, Wa. 98126
            (206) 935 - 4384
-------------------------------------------------------------------------------
My boss dosn't know what I do.

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

Date: 7 Feb 90 19:32:16 GMT
From: thorin!cassatt![e-mail]  (Jonathan Leech)
Subject: Re: Grassroots Space "Radicals"

In article <[e-mail]> [e-mail] (George William Herbert) writes:
>Can we take this into email and off the net?
>NOW?

    Heavens, whatever for?  I find it refreshing that someone with
direct knowledge of the events Bowery complains about is responding.
--
    Jon Leech ([e-mail])    __@/
    "A compact set can be controlled by a finite police force no
     matter how dumb." H. Weyl ca. 1938

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

Date: 7 Feb 90 17:25:19 GMT
From: zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!aplcen!aplvax.jhuapl.edu![e-mail]  (Jim Meritt)
Subject: Re: Spacecraft drives and fuel efficiency


Voyager is getting a pretty good MPG.

:-)


That that is is that that is. That that is not is that that is not.
That that is is not that that is not.  That that is not is not that that is.
And that includes these opinions, which are solely mine!
[e-mail]  - or - [e-mail]  - or - meritt%aplvm.BITNET

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

Date: Wed, 7 Feb 90 09:59:33 EST
From: Glenn Chapman <[e-mail]>
To: [e-mail], [e-mail],
        [e-mail], [e-mail],
        [e-mail], [e-mail]
Subject: Fifth Soviet space walk done at Mir

     On Feb. 5th at the Soviet's Mir Space Station cosmonauts Alexander
Viktorenko and Alexander Serebrov made their fifth space walk this year,
and tested their Manned Maneuvering Unite (MMU), called a "space bicycle"
or Icarus.  Again exiting the Kvant 2 module airlock station commander
Viktorenko flew the space bicycle in excess of 40 meters (131 ft.) from
Mir, and measured radiation levels at a number of points and distances from
the station.  Serebrov, who flew the MMU last time, stood by the safety
rope and check the behavior of Icarus.  The statements said that similar
space bicycles will be used on their new Mir II station (slated for mid
1990's) and with the Buran space shuttle. (Radio Moscow Feb. 4-6)
     The replacement crew for Mir will be launched on Soyuz TM-9 on Feb.
11, and the current crew will come down on Feb. 24th.  The crew for this 6
month mission will be Anatoly Solovyov (Soyuz TM-5/Mir Jun. '88 for 9 days)
and Alexander Balandin, a new cosmonaut.  It seems that the following
mission, Soyuz TM-10, scheduled for July '90, will bring up a shuttle pilot
for zero G experience.  Currently the crew suggest is Vitally Serastyanov,
Viktor Afanasyev, and Burna pilot trainee Rimantas Stankyavichus.
Serastyanov is an old time cosmonaut, selected in 1967, flew Soyuz 9 in
June 1970 for 17 days, Soyuz 18/Salyut 4 in May 1975 for 63 days and was a
manager in the Soviet Lunar Landing training program.  The flight of a
Japanese journalist to Mir has been moved up from 1991 to the fall of this
year.  Toehiro Akiyama and Ryoko Kikuchi, the two correspondents from
Japan's TSB network, have been in Russia training since Oct. '89.  (TASS
announcement Jan. 18, Spaceflight Jan '90, Phil Clark, "Soviet Manned Space
Program")
     The Soviets have a second space station still in orbit, the old Salyut
7 with the large Cosmos 1686 module attached to it.  Launched in April
1982, it was last visited in May 1986 when the Soyuz T-15 crew which first
visited Mir transferred from Mir to Salyut 7 for almost two months, then
back again. Many people have been speculating that the Russians would try
to bring Saylut 7 down in their space shuttle.  However, Vladimir
Dzhanibekov, head of cosmonaut technical training, recently said this was
just a western concept.  Dzhanibekov is the cosmonaut who rescued Salyut 7
in June 1985 when it suffered a major power system failure.  Salyut 7 is
out of fuel, drifting in a gravity gradient mode with the main station
section towards the earth, hence a high air resistance mode.  It is also
precessing, that is sinning slowly like a gyroscope that has been bumped,
so that the base end stays nearly stationary while the tip of the Cosmos
1686 module forms a circle about it.  Their main worry is that the combined
structure weights nearly 40 tonnes, and probably parts would survive
reentry.  They are currently considering sending either a special Progress
tanker which would use its engines to create a reentry over an ocean, or
perhaps mount a manned Soyuz mission to do the same.  Manned missions are
considered because of the unusual motion of the station.
     It appears that the human race is back to having a manned space
station for these plans extend for another two years.

                                                  Glenn Chapman
                                                  MIT Lincoln Lab

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

End of SPACE Digest V11 #19
*******************