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Date: Fri, 16 Feb 90 01:39:18 -0500 (EST)
Subject: SPACE Digest V11 #50

SPACE Digest                                      Volume 11 : Issue 50

Today's Topics:
			more standards (long)
		    Hipparcos: The present status
Truly promotes science and math during National Engineers Week (Forwarded)
		    Re: Galileo Update - 02/12/90
		  Re:   HASA select & Operacio 9000
		       Re: inter stellar travel
----------------------------------------------------------------------

Date: Thu, 15 Feb 90 19:35:22 EST
From: John Roberts <roberts@cmr.ncsl.nist.gov>
Disclaimer: Opinions expressed are those of the sender
	and do not reflect NIST policy or agreement.
Subject: more standards (long)


>From: skipper!bowers@ames.arc.nasa.gov  (Al Bowers)
>Subject: Re: measurement standards (aerospace)

>Having lived in Australia for 3+ years and going to school there I
>must agree that the U.S.'s reluctance to accept the SI system is not
>doing us any good.  

Of course it's not. 

>>> - To some extent, when designing physical systems, recurring decimal
>>>places can be avoided, hence round off errors can be reduced.
>>For shame! That's one of the few areas in which the "standard" system really
>>shines, since it was a major design criterion. For instance, express 1/3
>>of a foot in inches (4). Now try 1/3 of a meter in mm (333.33333333333...).
>This is not really a valid argument as an engineer would NEVER spec
>something as 1/3 of a foot!

Why not? If you have a space one unit wide, and you have to fit three
identical thingamajigs into it side by side, what is the maximum allowable
width of a thingamajig? When I was in mechanical drawing class back in
high school, we used all sorts of odd units and fractions, including tenths
of a foot.

As I mentioned before, I was simply correcting an erroneous statement, not
promoting "standard" units. An analogy to the original statement would be
"Potatoes are better for you than cheese, because potatoes are rich in
complex carbohydrates, contain no cholesterol, and are made from pure fresh
milk". I agree with the general argument, but not that specific detail.
In a measurement system, you can have good divisibility or good consistency
of units, not both. "Standard" chose one approach, metric the other. In the
modern context, the metric approach is better.

>>>I am told that America is the most inwardly looking nation on the planet,
>>>and boy does it show!!!   
>I'm afraid I have to agree.  Both my in laws are in education and tour
>Europe every summer.  I always hear from them about how the Europeans
>don't do things the way they are supposed to be done.  This from
>American educators!  In my family (mixed race) we were taught to
>respect others and their customs and beliefs.  I grew up on three
>continents (never learned a language other than English though) and I
>wish that kind of perspective could be taught here at home.

And America is undoubtedly the most universally popular target of "clever"
remarks! This is probably related to the many interactions between the US
and other countries. A person selected randomly from the planet is unlikely
to have a sudden urge to insult Australia, unless of course he's from
New Zealand. :-)

Still nobody has defined "inwardly looking" in a way that makes sense in this
context. It's true that many Americans place a high value on their own
traditions, and tend to be somewhat uneasy about the unfamiliar, but that's
true to some extent in most nations. On the other hand, American consumers
can hardly bear to buy anything made in the US, largely because the word
"imported" carries great status. The US contains a great number of immigrants,
both legal and illegal (millions of each). Americans spend a vast amount of
money on aid to poverty-stricken countries, and even more to keep soldiers
running around all over the planet.

If you want to identify a "most inwardly looking" nation, how about China?
I think it's still true that most Chinese have never *seen* a person not
from China.

>I seriously doubt that 90% of the people on this net could tell you
>the capitol of Australia and the state it resided in (FYI Canberra in
>the Australian Capitol Territory, the state bit was to throw you off)
>or what country Singapore is in, or find Lebanon on a map or ...  I
>could go on and on but I'd only depress myself.  Now go to another
>country, and ask their school children if they have heard of
>Sacramento.  Or Seattle, or Minneapolis, or Dallas-Fort Worth.  We as
>a nation are too self centered.

That's an unfair judgement - Americans are mostly ignorant of geography
in general. They may understand US geography slightly better, because they're
more likely to travel to US locations. Remember that going to another country
is a much bigger deal starting from Kansas than starting from Paris. Also
remember that geography has not been a life-or-death matter for most Americans
since the 1860's. (By the way, Dallas-Fort Worth is an airport, not a single
city, though I admit it's pretty big. :-)

>>I think things are headed in that direction - it's just slower in some fields
>>than in others. Also remember that the US is not the only country to stick to
>>"peculiar" standards. Europe has been blocking an international standard on
>>HDTV television broadcast format unless it's PAL-compatible (or SECAM?) while
>>the US and Japan are willing to settle on an extension of NTSC. 
>So from this I gather NTSC is 'RIGHT' but PAL or SECAM is 'WRONG'!?!
>Listen to yourself!  Our demand for compatibility is okay but yours
>isn't!  Haven't you read a thing that Greg has written!?!

There's a fundamental difference between measurement standards and technical
standards. Both measurement systems work about the same, though metric is
less awkward to use. A technical standard affects the actual performance
of a machine, etc. It is my opinion that PAL has features built into it
that are reasonable for standard broadcast, but which would place unnecessary
limitations on HDTV broadcast. Europe has an incentive to resist NTSC
because of its installed investment, separate from any technical issues.
I point out that the US is not the only nation sticking to some standards
for other than pure technical merit, and you think that means I think they
should be judged differently. That's not true - I think they should be judged
the same.

One of the reasons PAL was established was that Europe had standardized on
50Hz AC power. I believe this happened after the US had developed a 60Hz
power standard. I don't know of any clear technical reason for Europe to
have changed to 50Hz.

Anyway, to pick a more Australian example for Greg, why do you Australians
persist against all reason in driving on the wrong side of the road, as do
the UK and a few other countries? :-) The answer is obvious - people are
used to it, and it would cost a lot to change over. Just so with our "standard"
measurement system.

>>>Anyway, to sum up, stop making excuses, start making changes, put a bit
>>>of effort in , and maybe, just maybe you will be able to talk technical
>>>with the rest of the world in twenty years or so!
>The U.S. will have to do what was done in Australia, pass a law making
>SI or metric the standard and make our current system illegal.  Phase
>outs and partial change overs will not work.  Bite the bullet and do it!

There will have to be a major change in public attitudes first. If Congress
voted in such laws now, they'd probably get thrown out of office in the next
election. Maybe it will happen in the same way as the recent political changes
in Eastern Europe - huge pro-metric rallies in Washington, Administration
forced to resign, mile markers on highways torn down! :-)

>>Haven't you folks in metric countries wondered why your integrated
>>circuits have a pin spacing of 2.54mm? :-) :-) :-) :-)
>...you believe you're making a joke... 

That part wasn't a joke. US companies pioneered the technology, and once a 
large base was installed, there was no technical reason to change it.

>Albion H. Bowers  bowers@elxsi.dfrf.nasa.gov  ames!elxsi.dfrf.nasa.gov!bowers
>         NASA Ames-Dryden Flight Research Facility, Edwards, CA
>                  Aerodynamics: The ONLY way to fly!

Much of this is drifting from the topic of space. If you want to promote
the use of SI on the space station, you should argue that the space station
is to be a site for serious scientific research, which should always be done in
metric. (Let the flight-control portions stick to "standard", if they want.)
Probably the best way to change public attitudes toward metric is to encourage
the news media to go to an all-metric format. After several years, people will
automatically think in metric.
                       John Roberts
                       roberts@cmr.ncsl.nist.gov

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

Date: 15 Feb 90 13:44:37 GMT
From: mcsun!hp4nl!esatst!neil@uunet.uu.net  (Neil Dixon)
Subject: Hipparcos: The present status

The following is reproduced from ESTEC News, without permision.

---------------------------------------------------------------------
Published by ESTEC Public Relations Office  14 Feb. 1990

Hipparcos: The present status

Subsequent to the perigee raising manoeuvres performed last September,
the satellite operations have continued smoothly after much intensive
work by the ESOC Operations Team and members of the Project Team. The
outlook for the mission is much better than it was in the days and
weeks following the apogee boost motor failure. It Is worth noting
that, while the present elliptical orbit has posed many unforeseen
operational difficulties and will inevitably result in a somewhat
degraded scientific mission (compared with the nominal mission for any
given operational lifetime), a geostationary orbit was not mandatory
from the point of view of the astrometric measurements, and this
explains why it has been possible to implement a revised mission.

In the new orbit, the satellite was commissioned and its overall
performance was found to be nominal or better than specified.

On 1 November 1989, the nominal scanning law acquisition was completed
and the satellite is now following its pre-defined scanning of the
celestial sphere. Further payload calibrations were carried out
between 1-25 November and the nominal mission commenced on 26
November. Star observations (more than 10 000 stars are observed each
day, along with some minor planets - even Venus has already been
observed) are now proceeding routinely.

Ground station data coverage is now provided by a combination of the
Darmstadt, Perth (Australia), and Kourou ground stations. A fourth
station at Goldstone, USA, is planned to be operational by the end of
March thus raising the coverage from the present value of about 70% to
about 90%.

The most critical parameter in any assessment of the expected
scientific accuracy of the revised Hipparcos mission is still the
satellite lifetime, which will be determined by the degradation of the
solar panels due to the high-energy proton radiation environment in
the present elliptical orbit. Estimates now suggest that a total
lifetlme of about 30 months might be achievable - this estimate has
been continually refined as further satellite measurements are
accumulated and as progress has been made in matching the on-board
measurements to the theoretical predictions.

A further complication with the present orbit is that the eclipse
durations experienced by the satellite can be much longer than the 72
minute maximum expected for the nominal mission. The first such
extended eclipse period will be encountered around February and March
1990, with eclipses lasting up to about 100 min. Plans are being
formulated to ensure the survival of the satellite throughout these
periods, and to maximise the amount of scientific data acquisition and
engineering check-outs that can be carried out during this eclipse
period.

It is evident that the payload performance in all areas is extremely
good, with the instrumental parameters and (along-scan) star positions
already being determined to milli-arcsecond precision. There is still
some way to go before the mission can be considered to be a complete
scientific success, but in terms of satellite performance and
operational procedures made necessary through the implementation of
the 'recovery' mission, the future is looking promising.
-- 
Neil Dixon <neil@yc.estec.nl> UUCP:...!mcvax!esatst!neil, BITNET: NDIXON@ESTEC
Thermal Control & Life Support Division (YC) 
European Space Research and Technology Centre (ESTEC),
Noordwijk, The Netherlands.

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

Date: 14 Feb 90 23:33:12 GMT
From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov  (Peter E. Yee)
Subject: Truly promotes science and math during National Engineers Week (Forwarded)

Terri Sindelar
Headquarters, Washington, D.C.                   February 14, 1990

RELEASE:  90-25

TRULY PROMOTES SCIENCE AND MATH DURING NATIONAL ENGINEERS WEEK

     NASA Administrator Richard H. Truly, selected as an "All-
Star" engineer, will help launch National Engineers Week 1990 
Discover(E) program by participating in a press conference on 
Tuesday, Feb. 20.  Discover(E) is a first-ever student outreach 
program conducted by and for the engineering profession.  

     The kick-off press conference will be held at Jefferson 
Junior High School, 7th & H Sts., S.W., Washington, D.C., on 
Tuesday, Feb. 20, from 10:30 - 11:30 a.m.  Also participating will 
be Stephen D. Bechtel, Chairman, Bechtel Group, Inc., and Honorary 
Chairman of National Engineers Week 1990 and Raul Allegre, place-
kicker for the New York Giants.  The three engineers will discuss 
their views of the future of the engineering profession and the 
U.S.'s ability to compete technologically.

     During the press conference, results of a nationwide junior 
high school student survey about life in the 22nd Century will be 
released.  The survey, conducted by the National Engineers Week 
Committee and "Science World," addresses questions like "Will 
Americans be living in space?" and "What will be the most common 
way to get rid of waste materials?" 

     During Engineers Week, Feb. 18-24, over 5,500 engineers will 
visit junior high schools nationwide, reaching more than 500,000 
students, to inspire them to study math and science.

     National Engineers Week is supported by a number of national 
engineering organizations to bring visibility to the profession. 
The event is celebrated during the week of George Washington's 
birthday.  Washington was a military engineer and land surveyor 
responsible for establishing the first U.S. engineering school, 
which later became the U.S. Military Academy at West Point, N.Y.

     Other All-Stars include, Astronaut Mary Cleave; Deputy 
Secretary of Commerce Thomas Murrin; Secretary of Energy James 
Watkins; National Science Foundation Director Erich Bloch; 
Chairman and CEO of Rockwell International Donald Beall; and 
Chairman and CEO of Amoco Corporation Richard Morrow.

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

Date: 15 Feb 90 14:07:48 GMT
From: bu.edu!xylogics!barnes@eddie.mit.edu  (Jim Barnes)
Subject: Re: Galileo Update - 02/12/90

In article <1990Feb15.001749.1516@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>
>In any case, we don't get to see the Galileo Venus images for quite a
>while yet, since they'd take too long to transmit through the low-gain
>antenna.

A local radio station news bit stated that several images of Venus had
been successfully returned by Galileo.  This is contrary to all that I
had read here and in other sources.  Can anyone confirm/deny the news
report?
----
  Jim Barnes (barnes@Xylogics.COM)    | <This space for rent.>
                                      |

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

Date: Thu, 15 Feb 90 10:48:09 PST
From: pjs@aristotle.Jpl.Nasa.Gov (Peter Scott)
Subject: Re:   HASA select & Operacio 9000

 di4007@ebccuab1.bitnet (Jordi Iparraguirre) writes:

>On the other hand, On Feb/18/1990 will begin in Catalonia (Europe)
>OPERACIO 9000. In this operation, a man called Emili Reyes will be living
>alone in a grot for 9000 days. He will be monitored by doctors, and his unique
>link with the surface world will be a computer (Mac). Doctors want to study
>human reactions in front the lonelyness, and among others, they will simulate
>delay comunications as on a space trip to Mars.

Unfortunately the last person to do this just committed suicide; according to
her husband, her isolation in the cave was the cause, although the authorities
disagree.  Even though this guy has previous extended spelunking :-) experience,
perhaps they ought to be wary before trying to break the previous record...?

Peter Scott (pjs@grouch.jpl.nasa.gov)

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

Date: 15 Feb 90 13:43:11 GMT
From: wuarchive!cs.utexas.edu!mailrus!umich!ox.com!itivax!vax3!aws@decwrl.dec.com  (Allen W. Sherzer)
Subject: Re: inter stellar travel

In article <1990Feb14.200816.25598@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>>I know a few years back there was discusion about particles that might 
>>travel faster than the speed of light.

>They are still a sort of vague theoretical possibility, but it takes some
>serious contortions to get around all the theoretical problems, and there
>is the major objection that nobody's ever seen one.

I was under the impression that the theory required that they all be
created at the big bang and that they can never go below c. If so, then
we will never see them.

>>	At the speed of light it would take a little over 4 years to reach 
>>the nearest star. What are the chances that it would have a planet that
>>man could live on....
>
>Uncertain.  One would prefer to know before starting the trip. :-)  Current
>theory is that planets are normal around Sun-like stars.  The chances for
>habitable planets are harder to figure.

I read an article in Astronomy on this a few years back. They thought Tau
Cetti would be the closest posibility. Anything closer was eihter not a
sun like star or was part of a binary system (and thus considered unlikely
to form planets).

>Of course, the space-colony enthusiasts would reply "who needs planets?".

Yep. We took three million years to climb out of this gravity well. Why
would we want to jump into another?

    Allen
----------------------------------------------------------------------------
| Allen W. Sherzer     | Cthulhu for President -                           |
|  aws@iti.org         | If you're tired of choosing the LESSER of 2 evils |
----------------------------------------------------------------------------

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End of SPACE Digest V11 #50
*******************