Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_1/V16NO144.TXT

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Date: Fri, 12 Feb 93 09:54:44
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #144
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 12 Feb 93       Volume 16 : Issue 144

Today's Topics:
                    Advanced Solid Rocket Program
                           algorithm needed
                  Getting people into Space Program!
                        kerosene/peroxide SSTO
        Launching in a Winter Wonderland (was Re: Polar Orbit)
                        leading-edge anonymity
       New Russian Solar Sail results - data to help you see it
                      Precursors to SSF (2 msgs)
                              Probe MROs
                               Promises
                           Solar wind nits
                 So what's happened to Henry Spencer?
                      Space Grown Semiconductors
                        suicides" of sdi scien
            Today in 1986-Remember the Challenger (2 msgs)
                           Wanted- Mars Gif

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

Date: 5 Feb 1993 21:00:55 GMT
From: Doug Mohney <[e-mail]>
Subject: Advanced Solid Rocket Program
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:

>(And then there's George Koopman's offer to fund development of a hybrid
>SRB-replacement motor privately if NASA would promise to buy it after
>successful testing...  NASA, of course, ignored it.)

Not to be rude, but did he also promise a deliverable price equal to or below
the current SRBs?

Doesn't make much sense to promise something which would cost more per unit
than current tech, unless it does something wondermarvelful.


                    I have talked to Ehud, and lived.
  -- >                  [e-mail]                        < --

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

Date: Fri, 5 Feb 1993 21:08:32 GMT
From: Earl W Phillips <[e-mail]>
Subject: algorithm needed
Newsgroups: sci.space,sci.astro

Does anyone happen to have an algorithm
to convert RA & Dec to altitude & azimuth,
as measured by a compass & quadrant?

*****************************************************************
*                                    | ====@====      ///////// *
* [e-mail]|     ``________//         *
*                                    |       `------'           *
*                 -JR-               | Space;........the final  *
*                                    | frontier...............  *
*****************************************************************

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

Date: Fri, 5 Feb 1993 21:13:15 GMT
From: Henry Spencer <[e-mail]>
Subject: Getting people into Space Program!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Why can't we put some "common people" into orbit.. Why must it be PHds and
>such. It sure would get more voters involved, after all why must I as a voter
>spend money on a project for the direct benefit for some technocrat? Why not
>have a national lottery for a one time position on the Shuttle or some other
>mission into space...

It's an idea that has been raised before.  The main problem is that NASA is
dead set against it.  NASA does not really want to fly passengers at all.
(As witness the way the Citizens In Space program, which was going to fly
a teacher, then a reporter, then etc., is on permanent hold.)
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: Fri, 5 Feb 1993 21:34:55 GMT
From: Henry Spencer <[e-mail]>
Subject: kerosene/peroxide SSTO
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>> ... why kerosene and hydrogen peroxide is a better fuel
>> combination for an SSTO than LOX/LH2?
>
>I'd like to here more about that.  I assume the much higher density
>(5-6 times?) of the kerosene/peroxide combination more than
>compensates for the lower Isp, so that smaller and lighter tanks can
>be used (and that having room-temperature storable propellants makes
>the tanks easier to build and pressurize.)  But do you need more or
>larger engines to get enough thrust, for a given size payload,
>and can peroxide be pumped safely?

I don't have Mitch's paper on hand at the moment.  But yes, the general
picture is that denser propellants are a considerable win on structure
and the like, because the tanks are so much smaller.  Room-temperature
propellants aren't a big deal for the vehicle, but make operations a
good deal simpler.

The big loss by using JP-5 and peroxide is exhaust velocity.  But you
gain enough on tank weight and the like that you're still ahead.
Mitch's analysis also says that in some respects, you're in a flatter
part of the curves with JP-5/peroxide, so small shortfalls don't
matter as much.

Higher molecular weight in the exhaust is what hurts the exhaust velocity,
but it actually helps on thrust.  In that department, you're ahead.  The
same number of engines with the same size and chamber pressure will give
more thrust, not less, with JP-5/peroxide than with LH2/LOX.  Alternatively,
the engines can get smaller or you can use lower pressures, either of which
is definitely useful.

US rocket experience with peroxide was not all that good, but it was
a long time ago and there wasn't a lot of it.  The British space program,
while it still existed, got excellent results.  Kerosene and 70% peroxide
powered the Black Arrow, Britain's homegrown satellite launcher, which
put one satellite into orbit before the program was cancelled.  Peroxide
is an industrial chemical, no big deal with simple precautions (notably,
serious attention to cleanliness).  The engines used in the Black Arrow
(and in the Black Knight sounding rocket) were pump-fed.

Also of note were the peroxide monopropellant rocket engines used in the
NF-104 rocket-boosted aircraft flown by NASA and the USAF, which worked
quite well and were serviced and fuelled by ordinary USAF technicians.

There are some useful bonuses.  The flame is cool enough that there is
little or no NOx formation when it hits air.  By decomposing the peroxide
with a catalyst first, and then injecting fuel into the gas stream, you
get 100% reliable hypergolic ignition regardless of mixture ratio.  You
could vary the mixture ratio, even all the way down to straight peroxide,
if that were useful (for example, take off on straight peroxide, tuck
up your landing gear, and *then* start fuel injection... so your landing
gear is never exposed to the full-temperature flame).  Fuel injection
into a fast-moving gas stream also does wonders for mixing and combustion,
and eliminates one major class of combustion instability entirely.

As mentioned elsewhere, Mitch went so far as to sketch out a design for
a pressure-fed reusable SSTO, although Bruce Dunn has cast some serious
doubts on Mitch's weight estimates for pressurization gas.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: 5 Feb 93 15:22:22 -0600
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Launching in a Winter Wonderland (was Re: Polar Orbit)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
> In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
>>Well, Baikonur is in the middle of what amounts to a desert, I
>>believe, and the Russians typically were not launching segmented
>>solids.  They're heavily into liquid-fuel boosters, which aren't as
>>sensitive to the external temperature.
>
> Tyuratum Cosmodrome (nee Baikonur Cosmodrome) gets plenty cold in the
> winter.  The first Buran flight was launched in a subzero blizzard.

Oddly appropriate, since "Buran" (byPAH) *means* "blizzard!"

Bill Higgins, Beam Jockey              | ASTRONOMY:
Fermi National Accelerator Laboratory  | The early science of the sky.
Bitnet:           [e-mail]  | ASTROLOGY:
Internet:       [e-mail]  | How it was paid for.
SPAN/Hepnet:           43011::HIGGINS  | --Michael Rivero

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

Date: Fri, 5 Feb 1993 20:18:10 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: leading-edge anonymity
Newsgroups: sci.space,sci.astro,alt.privacy

In <[e-mail]> [e-mail] (Dances with Drums) writes:

>In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
>>In <[e-mail]> [e-mail] (Tesuji) writes:
>>>True, it may encourage irresponsible postings,
>>>especially as a novel device.  But just like
>>>the keyboard tends to reward content by
>>>not advertising race, creed, color,  age,
>>>or sex, so to anonymous postings prevent false
>>>halos (or horns) based upon one's posting site
>>>or current supposed reputation.
>>
>>No.  Instead, it gets you all the credibility that an anonymous
>>posting deserves -- i.e., none.
>>
>>>The material stands on the content, not the
>>>poster.  I look at it as taking the name
>>>off papers submitted for refereeing.
>>
>>I look at it as someone who wants to shoot of their mouth for
>>attention but doesn't have the courage to do it other thna
>>anonymously.  This is generally a symptom of immaturity.
>---

>    Really?  The police seem to think that anonymous tips are a valuable
>source of information.  Why would they recognize that anonymity may not
>be incompatible with value of information, but you give anon posters them no
>credibility.  It would seem that you have a gut reaction bias against
>anon posters regardless of the content of their posting.  This is called
>prejudice.

Frog feces.  There is some difference between an 'anonymous source'
for police or journalists (who must worry about physical harm as a
result of talking) and some little loudmouth running his mouth for the
attention and sensation he hopes to cause.  And oddly enough, I think
you'll find that police give much less weight to 'anonymous
informants' than they do to those whose identities are known.

This isn't called "prejudice" (although that's a nice try at a
strawman -- you should be bringing up Hitler and the KKK any time
now).  It's called "common sense".  Now if only our anonymous friend
could bring himself to engage in something called "adult behaviour and
responsibility".  However, I won't hold my breath wating.

>    The idea that you have to have 'courage' to post non-anonymously is
>some sorta macho game: "if you were a 'real man' you would sign your
>name (so we can later harrass and beat the *#$% out of you)."  As a
>general rule, anytime someone tells me I'm not being a "real man", or
>uses loaded words like "courage" and "immaturity" I find they are trying
>to manipulate my behaviour along some lines they find acceptable.  I
>dislike such manipulation.  I am careful to try to NOT change my behaviour,
>(including not increasing the disliked behaviour), since I desire
>to ignore such manipulating actions.

Fine.  Behave like a fool if you choose to.  People will give your
anonymous words all the weight that YOU give them by declining to be
associated with them.

>    It seems this whole little discussion got started when some anon
>poster posted an alleged transcript of the challenger crew conversations.
>If you take the attitude that 'nothing is sacred', you can just read
>that person's posting and say "Huh.  Maybe it happened that way, maybe
>it didn't."  and go on with life.  To get really upset about it seems
>to be showing a lack of perspective.  If you don't like it, ignore
>it -- maybe it will go away.

And to presume people are "really upset" or making "overreacting" is
simply stupid.  I read that person's posting, said, "What an idiot --
this is obviously false and he knows it and is just doing this for the
fun of wanting to stir things up, like some varieties of sick and
immature personality will do," and went on with life.

So, what's YOUR problem with my (and others') attitudes toward folks
like this, if you think that "nothing is sacred"?  I suggest you just
"go on with life"

--
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
[e-mail] - I don't speak for others and they don't speak for me.

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

Date: Fri, 5 Feb 1993 20:14:11 -0800
From: Glenn Chapman <[e-mail]>
Subject: New Russian Solar Sail results - data to help you see it

     Some additional information for those looking for the Russian
solar sail experiment (Znamya).  For those who have not seen the solar
sail it appears as a bright yellow flashing object some time in front
of the Mir space station.  On Feb. 4 at Vancouver, B.C. Canada it
appeared at 6:37, about 4 minutes ahead of the Mir station, which
was itself preceeded by a dimmer object - which probably is the
Progress TM-15.  The 5 degrees separation of Mir and the Progress
corresponds to about 35 km (21 miles) - about what I would expect
in this experiment.  The Znamya's lead those was 1800 km - certainly
this could only come from rapid orbital decay.  On Feb. 5th it came
some 13 minutes (+/- 1 minute) in front of Mir according to another
observer here , at 7:04 am (in an area not covered by the overcast sky).
My estimates suggest now that for Saturday it will be between 39 and 53 minutes
ahead of the Mir station values.  This corresponds to a drop of 95 Km
in altitude, to about 300 km, in just two days.  This is not unreasonable
for such a low mass object.  The Mir space station, with about the same
cross sectional area as this 20 metre diameter solar sail, falls about
1 km per day unless corrective action is taken.  The much lighter solar
sail has less energy to lose, and hence would fall faster. My initial
estimate was that the Progress/Znamya combination would fall about
20-30 km per day - Progress masses 5 Tonnes at this point, about 5% of
Mir stations mass).  Hence this is falling much faster than that estimate
and tends to confirm the statement that Znamya was separated from the
Progess.  At this rate it will burn up in just a few days.  The reason
why the solar sail is flashing is probably it has now lost its shape
and is tumbling without the mass of the Progess to stabilize it.
In some ways this makes it much easier to spot - it is just that the
time estimates are now way off from those of Mir station.
     I would have to say that more than anything else this seeing this
string of 3 objects coming one right after the other in orbit
and the flashing sail was one of the most impressive sights I have
ever seen in observing satellite objects.  If you get the chance
try to see it.


                            Glenn Chapman
                            Simon Fraser U.
                                                        School Eng. Science.
                            [e-mail]

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

Date: Fri, 5 Feb 93 21:34:07 EST
From: John Roberts <[e-mail]>
Subject: Precursors to SSF

-From: [e-mail] (Allen W. Sherzer)
-Subject: Re: Precursors to SSF
-Date: 1 Feb 93 02:09:35 GMT

-In article <[e-mail]> [e-mail] (John Roberts) writes:
->[This is really more of a response to Allen's statements in the context of
->your question - "what is being done in orbit that's expected to be useful
->for SSF?" I thought the subject was worth mentioning, separate from the current

-Playing on a toy car for a few hours and lugging an astronaut around the
-payload bay aren't my idea of good tests.

The latter obviously has nothing to do with the structural integrity of SSF,
but it's potentially helpful in turning up really big blunders in the
assembly schedule and assembly protocol. Two comments that the astronauts
made during the recent post-flight press conference:
 1) During a normal EVA, they're usually too busy trying to meet the objectives
    to notice how they meet them - a period dedicated just to practicing EVA
    techniques allows them to evaluate their abilities without distraction.
 2) Some of the things they had thought would turn out to be surprisingly
    easy turned out to be surprisingly hard. Before the experiments, most
    of the talk was on finding ways to expand the envelope of what astronauts
    are expected to be able to do on EVA (and thus influence what gets
    scheduled). There may still be some of that, but some of the things that
    had previously been thought practical may be ruled out.

The degree to which the actual Intelsat rescue mission differed from the
water tank simulations was alarming to the SSF program, and was the main
impetus for the recent addition of these tests. I agree with you that
more sophisticated tests are highly desirable.

-They ought to fly some empty modules weighted with sand and see if they can
-stick them together. They should then try and connect up a piece of the
-pri-integrated truss.

I should have mentioned the truss in my previous post. To what extent would
the payload bay assembly work done on the first flight of Endeavour
be relevant?

John Roberts
[e-mail]

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

Date: Fri, 5 Feb 93 21:54:11 EST
From: John Roberts <[e-mail]>
Subject: Precursors to SSF

-From: [e-mail] (Steinn Sigurdsson)
-Subject: Re: Precursors to SSF
-Date: 31 Jan 93 00:25:42 GMT
-Organization: Lick Observatory/UCO

-In article <[e-mail]> [e-mail] (John Roberts) writes:
- One problem for which no solution has been found yet: in-orbit fax machines.
- If SSF uses the same fax design as the Shuttle, and they want to have a
- working fax most of the time, then they'll have to ship up 52 new fax machines
- a year.

-Well, if they must stay with obsolete technology (presumably to stay
-in touch with NASA HQ and the NSC ... say, maybe that's why they keep
-breaking...)

I don't know whether the Shuttle fax is equivalent to Earth-based faxes,
or whether they just call it that because of similarity of function.

-then why not save the weight of paper and use a 9600b/fax
-modem that reads straight to file? Cut out the dead tree portion
-altogether.

They have that, plus displays to view text and probably graphics, plus
at least one other printer. I would have to guess that the fax output is
so much more desirable for some applications that when it's working they
prefer to use it, but when it jams, they can use alternative means.
I don't know about you, but when I need to handle a large amount of data
with extensive cross-referencing (for example, when I'm working on a 10-page
circuit design), I greatly prefer to get printouts of intermediate versions -
it's much more satisfying to scribble on a printout than on a CRT screen,
and you can look at a lot more "pixels" at once. Some of this may apply to
the things they print out on the Shuttle fax.

The main thing I find annoying is that you'd think they would would have
found a way to prevent jamming by now, or at least a way to get the fax
machine back in operation after it jams.

John Roberts
[e-mail]

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

Date: Fri, 5 Feb 1993 21:55:49 GMT
From: Henry Spencer <[e-mail]>
Subject: Probe MROs
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gregory N. Bond) writes:
>The Galileo updates (and similar) talk about Memory Read Outs to
>check the computers.  I presume this means they dump the entire
>contents of the memory system back down the link.
>
>If this is so, why do they do that rather than something like CRC or
>MD4 to simply verify that the memory contains what they think it
>contains?  Surely 64 bits of MD4 signature is certain enough!

Turn it around:  if you can do a complete readback, why not do so?
It's wasteful by Earthbound communications standards, but the volume
of traffic is quite small by comparison, and the reliability issues
loom much larger.  Also, often there is much more bandwidth in
the downlink than in the uplink, so the extra time needed for a
complete readback is small compared to the time needed to send the
stuff in the first place.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: Fri, 5 Feb 93 21:08:21 EST
From: John Roberts <[e-mail]>
Subject: Promises

-From: [e-mail] (Jeff Bytof)
-Newsgroups: sci.space
-Subject: Re: Clinton's Promises (space) in Charlotte Observer
-Message-ID: <[e-mail]>
-Date: 31 Jan 93 02:36:13 GMT

-Clinton has revealed himself in the last week and a half as a
-consumately political animal who tries to keep fairly easy political
-promises.

Like the one on who should be allowed to serve in the military? Yeah, I
imagine he's saying "If only they could all be this easy". :-)

-Question: did he tour NASA facilities during the campaign
-and make promises that we have on videotape???  That is the key
-to predicting the future of NASA.

I have position statements and transcripts from interviews - but some people
claim that he shouldn't be held to them. I've posted them twice already.
At this point, I think a "wait and see" attitude will be the most accurate.

One thing I found disturbing relates to the reception on the day after
the inauguration, during which Clinton shook hands with and spoke with
~2500 people. I recorded about two hours of it, and played it back while
I was doing something else, just to get a feel for what people thought
was worth mentioning to the President. (I believe these people were selected
by lottery, plus some showed up uninvited.) Anyway, the interval I listened
to probably had about 500-1000 people. Of those, many mentioned the economy,
the unemployment rate, the deficit, civil rights, and many other subjects,
but as far as I could tell, *not one* person mentioned the space program.

Since the whole event was being videotaped, I presume somebody on the staff
went through the tape and took notes on what had been discussed - that would
be the sensible thing for any politician to do. The problem is what kind of
message that sends to the new President - that hardly anyone cares enough
about space to even mention it. (Of course, many of those people may have
cared about the space program, but it could have been fifth or tenth on their
list of priorities, and they had only a few seconds to talk to the President.
Also, Vice President Gore didn't have a microphone, so I couldn't hear

what was said to him.)

Allen - I presume letters would go to the White House now?

John Roberts
[e-mail]

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

Date: Fri, 5 Feb 1993 21:41:34 GMT
From: Henry Spencer <[e-mail]>
Subject: Solar wind nits
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Tom) writes:
>Aaaand, since we were talking about solar-sails, which are just ways
>of catching momentum, it doesn't matter what you use; unlike flashlights,
>which are only really effective when they match the frequency response
>of human eyeballs.

Sorry, but it does matter what you use.  Solar sails are much more
effective when they match the nature of what's coming at them well enough
to reflect it, rather than absorbing it.  For one thing, that gives you
twice the thrust, and solar sails don't have any thrust to waste.  For
another, that lets you thrust tangentially, to make long-term changes
in your orbit.  Absorption thrust is always straight outward, which
effectively just diminishes the Sun's gravity a little bit.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: Fri, 5 Feb 1993 21:47:28 GMT
From: Henry Spencer <[e-mail]>
Subject: So what's happened to Henry Spencer?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>|I attended "Making Orbit 93"...
>
>Henry.  WOuld you be able to post your notes from the convention????

You'll see bits and pieces of it in postings over the next little while.
I probably won't get organized enough to do a coherent set of notes, even
if I could do a complete one (which I couldn't, given that there were
typically two or three things happening at once).
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: Fri, 5 Feb 1993 21:46:08 GMT
From: Henry Spencer <[e-mail]>
Subject: Space Grown Semiconductors
Newsgroups: sci.space,sci.materials

In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:
>   So, Steinn, if you have a spare few minutes might you post a brief
>   review of what the Nature article had to say?
>
>Darn, I don't suppose Henry feels like making amends for the
>frightful shortage of AvWe summaries recently...

Fraid not; my number one priority in making amends for that is to get the
AvWeek summaries flowing again...!

Besides, I don't get Nature, alas.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: 5 Feb 93 20:49:00 GMT
From: Scott E McWilliams <[e-mail]>
Subject: suicides" of sdi scien
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (fred j mccall 575-3539) writes...
>In <1993Feb3.4287.600@dosgate> "richard attenborough" <[e-mail]> writes:
>
>>JR>-About five years ago, there were quite a few suicides by scientists in
>>JR>-Europe who were asociated with the US led "strategic defense initiative."
>>JR>
>>JR>Since this corresponds extremely closely to the classic 1951 short story
If you read Sydney Sheldon's new book, called the "Doomsday
Conspriacy" you will find a synopsis of these suicides in the back
of the book.  They were scientists working on SDI and they
all committed suicides in wierd (and sometimes amusing)
ways.  It was mostly in the 1980s.  The book itself is fiction
but Sheldon tells a lot of the rumors behind that stuff.
    I personnaly don't go for the theory of alien visitations
but the book is very good and the info in back makes you wonder...

Scott McWilliams
[e-mail]
>>JR>"Breeds there a Man...?", written by Isaac Asimov, and available in the
>>JR>collections "Nightfall and Other Stories" and "Nightfall One", I'd say
>>JR>there's a significant chance that you read either this story or a reference
>>JR>to this story, and now you remember it as an historical event.
>
>>Sorry to dissapoint you, John, but I ALSO remember the news stories the other
>>gentleman was talking about. Some very "Strange" suicides DID take place among
>>some of the employess of, I believe, Marconi. They were working on SDI related
>>projects. The one that I recall in particular was the fellow who tied one end of
>>a rope around a tree, the other end around his kneck then got into his sports
>>car and floored it! Not your average suicide.(whatever average means in this
>>context.)
>
>I also remember these stories.  Marconi is the right company, but SDI
>is the wrong project.  I've heard a number of things, ranging across
>various weapons technologies, crytologic intercept and analysis, etc.
>This is the first time I've heard the claim that it was SDI related
>work they were involved in.
>
>[Why is that such an unusual way to suicide?  If you want to hang
>yourself and be *sure* the drop would break your neck, this sounds
>like a pretty good way to do it.  More 'inventive' than
>'unbelievable', but these are supposed to be quite inventive people.]
>
>--
>"Insisting on perfect safety is for people who don't have the balls to live
> in the real world."   -- Mary Shafer, NASA Ames Dryden
>------------------------------------------------------------------------------
>[e-mail] - I don't speak for others and they don't speak for me.

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

Date: Fri, 5 Feb 1993 20:34:23 GMT
From: [e-mail]
Subject: Today in 1986-Remember the Challenger
Newsgroups: sci.space,sci.space.shuttle

In article <[e-mail]> [e-mail] (The Charlatan) writes:
>
>When it Challenger disaster, occured I was in 10th grade. At my
>high school, we were writing exams. As such, the school was
>closed for regualr classes. I remember as this was my only full
>day-off from exams, I was at home do nothing in particular. Then my
>friend called, and said the Challenger blew up. I spent the rest of
>the day glued, to TV and the major networks.
>
> I still can remember everything exactly as it happened.
>The only other real jarring incident like this for me, and probably
>other Canadians of my age, was the Ben Johnson scandal in 1988.
>
>Alex
>
  So was I .  I can remember the whole thing vividly and wrote two poems
about the incident.  What made me sickest was all the lame jokes I heard
for weeks after that.  One of the greatest tragedies of our time and
probably the worst setbacks ever for the space program and all these people
could do was crack sick jokes.  I think about that incident often.  There is
a memorial to the Challenger crew at the San Antonio airport, or at least
there was when I was there in 1990 (you know how politics work and how
some people are about _moving on_; I'm waiting for someone to say that the
Vietnam War is a terrible blight on our histiory and suggest that we tear
down the wall in Washingtton and forget about the whole bloody affair and
just _move on_. <Forgive me, I tend to get carried away.>
  Anyway, at least two people are thinking of the crewmembers who were killed
in that accident.

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

Date: Fri, 5 Feb 1993 21:37:19 GMT
From: Henry Spencer <[e-mail]>
Subject: Today in 1986-Remember the Challenger
Newsgroups: sci.space,sci.space.shuttle

In article <[e-mail]> [e-mail] (Chuck Forsberg WA7KGX) writes:
>>... lowering the leak-test pressure back to its original value and
>>avoiding low-temperature launches would have been enough to make
>>launches reasonably safe, safe enough to resume a limited schedule...
>
>As I recall a number of safety related changes were made after
>Challenger, quite apart from the SRB joints and the escape pole.
>Were these significant in terms of overall safety?  In other
>words, how much safer is Shuttle for having stood down all that
>time compared to just not flying on cold days, etc.?

The shuttle undoubtedly has benefitted a fair bit from the safety review
it got during the grounding.  They fixed things that needed fixing, on
the whole.  (I have complaints about bits of it.)  However, there was
no real need to ground the fleet while that was being done.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: Fri, 5 Feb 1993 21:37:56 GMT
From: Richard Ottolini <[e-mail]>
Subject: Wanted- Mars Gif
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Bill Higgins-- Beam Jockey) writes:
>In article <[e-mail]>, [e-mail] (Kirk Marcroft) writes:
>>I'm looking for a computer generated gif of what Mars would like if
>>it were covered by 2/3 of water like Earth. It was in an issue of
>>Popular Science back in 1992.

This would be pretty easy to do with 3D computer graphics, given a
topographic map of mars.  Just threshhold and color blue altitudes
below sea level.

I have Earth and Venus topo datasets, but not Mars or the Moon.
I think Mars was available somewhere, but it had not be subsampled
to a reasonable grid size for my purposes.  Resolutions finer
than a half-degree are large and slow on my system.

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End of Space Digest Volume 16 : Issue 144
------------------------------