Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_5/V15NO501.TXT

Internet Message Format | 1993-07-13 | 31KB

Date: Fri,  4 Dec 92 09:50:40
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #501
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri,  4 Dec 92       Volume 15 : Issue 501

Today's Topics:
                        Autorotation (2 msgs)
                      Comparative Launcher Costs
                             DC-X status?
                     DCX Transportation on Earth
       Detonavion vs Deflagration (was Re: Shuttle replacement)
   NASA has 5 hand grenades still on the moon from Apollo missions
                         NSSDC Data on CD-ROM
                         physiology in zero-G
                    Pop in space, dumpster diving
                         Rumors about Hubble
                            shuttle costs
                           shuttle downtime
                     Shuttle replacement (3 msgs)
           Terminal Velocity of DCX? (was Re: Shuttle ...)
                          unpowered landings
         Voyager's "message"... What did it *say*?!? (2 msgs)

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
    "Subscribe Space <your name>" to one of these addresses: listserv@uga
    (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: Thu, 3 Dec 1992 17:52:59 GMT
From: Ed Faught <[e-mail]>
Subject: Autorotation
Newsgroups: sci.space

In article <[e-mail]> [e-mail]
(Mary Shafer) writes:
>Were emergency autorotations as deadly as you claim, we'd have a
>number of empty desks at NASA and elsewhere.  My uncle got his first
>Purple Heart (and a Silver Star) when his medevac helicopter was shot
>down in the Korean War--but he got the Purple Heart for being shot,
>not for any injury from the autorotation.

I believe I'll add my two cents to this thread. There are so many variables
involved in autorotating a helicopter that it would be difficult to determine
beforehand whether the maneuver would be survivable. Just one example: is the
helicopter in question a Bell jet ranger or a Boeing CH-47? I can tell you from
personal experience that autorotating these two machines requires very
different mindsets.

The most dangerous type of flight for a helicopter is the hover, when the
engines are using maximum power, the rotors are at maximum angle of attack, and
the air is "dirty". The altitude required to enter an autorotation from a hover
is naturally going to enter into the problem, as well as whatever load may be
slung underneath. I've successfully punched off a load and autorotated a
Chinook to one side from a thirty foot hover. If the load had been a telephone
pole, I would have been higher, but the pole may have fallen on top of me!
Fortunately the only problem we had was that the guys at the firebase got
squashed banannas for lunch that day.
--
Ed Faught  WA9WDM  [e-mail]
 Superconducting Super Collider Laboratory

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

Date: Thu, 3 Dec 1992 20:08:12 GMT
From: Donald Lindsay <[e-mail]>
Subject: Autorotation
Newsgroups: sci.space

[e-mail] (Mary Shafer) writes:
>Well, after 21-1/2 years of full-time permanent employment in flight
>test,...

I made no claim to knowledge as extensive as yours.

>Were emergency autorotations as deadly as you claim,

I also made no claim that emergency autorotations were deadly. Try
reading my post again. I said that they weren't always possible.

This thread has got less and less to do with space, so if you insist
on rebutting what I *did* say, you can have the last word.

--
Don        D.C.Lindsay    Carnegie Mellon Computer Science

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

Date: 3 Dec 92 19:45:55 GMT
From: Henry Spencer <[e-mail]>
Subject: Comparative Launcher Costs
Newsgroups: sci.space

In article <[e-mail]> @fuug.fi:[e-mail] ("F.Baube x554") writes:
>> At $20,000 a pound for Pegasus compared to $8500 a pound for Shuttle,
>> Pegasus is the most expensive launcher, not the cheapest.
>
>This can't be a valid comparison, can it ?

If all you care about is poundage to orbit, it's valid.  Of course,
typically the two launchers are serving different markets, so the
comparison is dubious for most purposes.

>For another, isn't it a near-tautology that you can save money
>by using a reusable low(er)-complexity airplane to get over
>most of the atmosphere and gravity well ?

Pegasus could potentially be quite cheap if it were bigger (although that
would raise the problem of finding a suitably large launch aircraft).
The main reason it costs so much is diseconomies of scale.

OSC is hoping to make Taurus -- which is a wingless Pegasus atop an MX
first stage -- competitive on price per kilogram with bigger launchers.
Taurus does have rather more payload than Pegasus.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: 3 Dec 92 18:39:19 GMT
From: [e-mail]
Subject: DC-X status?
Newsgroups: sci.space

> In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>In article <[e-mail]> [e-mail] (Matthew Kaiser) writes:
>>>what's the status on the DC-X and Y?
>>
>>DC-X:  under construction for flight in spring.

Ok, but at what stage in construction...
Are they bending metal yet?  (I would think so, 4 months is not that far off...)
Do they have the airframe built?
Are the fuel tanks bolted into place?
Are the motors delivered?  (Tested?  Installed?)

Just what is the sequence of steps for actual construction of this thing...?

            John.

(Oh, yeah, while I am asking obnoxious questions, does anybody have a real
sequence of the test flights, what is expecxted of each one, and how they will
progress, {and how fast...} )

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

Date: 3 Dec 92 18:56:08 GMT
From: Henry Spencer <[e-mail]>
Subject: DCX Transportation on Earth
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (James Thomas Green) writes:
>I suppose this would apply more to the DCY/1/...
>
>Once the vehicle was on the ground, how would it be transported from
>the landing site (say Edwards AFB) to the launch site (say Florida)?

If it would fit in a Super Guppy, you could move it that way.  Otherwise,
you'd have to fly it under its own power.  That's what they do with
aircraft, even highly experimental ones, if they won't fit inside a
heavy cargo jet.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: 3 Dec 92 19:30:42 GMT
From: Pat <[e-mail]>
Subject: Detonavion vs Deflagration (was Re: Shuttle replacement)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (John D. Boggs) writes:
>>> At least in the language of supernovae research, a detonation involves
>>> a flame front that propogates supersonically, whereas a deflagration has
>>> a subsonically propogating flame front...
>>
>>Hmm.  And just how fast *does* sound move in space?
>
>In vacuum, there is no sound.  In space, there is, because space is not a
>perfect vacuum.  (Admittedly, in most regions of space you need pretty
>sensitive instruments to notice the difference.)
>
>In any case, either detonation or deflagration involves propagation of
>a flame front *through a combustible medium*, so the point is moot.

Um,  as i understand it a deflagration doe snot have a over-pressure
wave associated with it.  Forest fires are no fun, but firemen have
lived through fire waves with only Mylar fire blankets for protection.
A detonation requires protection from the shock wave that causes
concussive injury.  Not that i'd like either,  but a fire wall is
survivable.  The challenger was not destroyed by the relatively
mild combustion of her spilled fuel products,  she was destroyed by
aero stress.  had challenger been carrying Hypergolic fuel in the
ET,  you'd need a sieve to find the parts.  Gary has been going on
and on about Flaming rockets crashing into disneyworld. a vehicle
crashing with deflagrating fuels is much less damaging then a SCUD
missile with a TNT warhead.

pat

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

Date: 3 Dec 92 17:30:26 GMT
From: Curtis Roelle <roelle@uars_mag.jhuapl.edu>
Subject: NASA has 5 hand grenades still on the moon from Apollo missions
Newsgroups: sci.space

O.K.  So for whatever reason you can fire a gun in space.
BIG DEAL, enough already -- WHO CARES?  Now back to the original topic ...

[e-mail] (Edmund Hack) writes:

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

>>What are 5 hand grenades doing on the moon and why would NASA
>>send them up with the astronauts???

>The "hand grenades" ar probably the small mortar rounds from the active
>seismic systems that were sent up.  They had a few mortar rounds that
>were fired off (after the crew left, I think) to produce shock waves for
>analysis.  Similar charges are used in oil exploration, except they are
>emplaced in holes drilled in the ground.

Since the original post was discussing valuable space junk one must assume
that the explosive devices referenced above were unused.  The question I
ask is, why weren't they detonated?  Did the lunar-based seismic experiment
fail before all experiments were performed?  Did the mortar jam?  Did
the rounds just bounce (say, because the triggers were designed for one-g)
and so the shells are just laying on the ground?

Curt Roelle

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

Date: 4 Dec 92 01:45:06 GMT
From: Ron Baalke <[e-mail]>
Subject: NSSDC Data on CD-ROM
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (dan herpst) writes...
>In article <[e-mail]>, [e-mail] writes...
>>In article <[e-mail]>, [e-mail] (Robert J. Kinder) writes...
>>
>>Since you can get all 12 of the Voyager CD-ROMs for only $86, I'd suggest
>>that you get the whole set.
>
>     Where can I get these for $86???
>
>     I would love to get a set!
>

     There are twelve CD-ROMs that contain about 30,000 images taken
by Voyager 1 and Voyager 2 on their encounters with Jupiter, Saturn, Uranus
and Neptune.  There are also 66 Magellan CD-ROMs containing over 30,000
images of Venus.  The CD-ROMs are available to the general public at the
NSSDC (National Space Science Data Center) at the Goddard Space Flight
Center.  The "nominal" charge is $20 for the first CD-ROM, and $6 for any
additional CD-ROM in an a set.  However, NSSDC may waive this charge for a
small amount of data requested by bona fide research users, government
laboratories, etc.  School teachers who are unable to pay may be helped on a
case by case basis, and/or as resources permit.  Researchers funded by NASA's
Solar System Exploration Division can also obtain the CD-ROMs through the
Planetary Data System at JPL.  NSSDC can be contacted at:

        National Space Science Data Center
        Request Coordination Office
        Goddard Space Flight Center
        Greenbelt, MD  20771

        Telephone: [phone]

        Email address:   [e-mail]

     NSSDC also provides the following software to display the images:

        o IMDISP       (IBM PC)
        o Browser      (Macintosh)
        o Pixel Pusher (Macintosh)
        o True Color   (Macintosh)
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | The 3 things that children
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/  |_|/       |_____|/                     | space, dinosaurs and ghosts.

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

Date: 3 Dec 92 18:54:44 GMT
From: Henry Spencer <[e-mail]>
Subject: physiology in zero-G
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
>The topic of sanitary facilities for females in space suits is very seldom
>discussed by NASA officials, but from occasional remarks I gather that what
>is used is basically the "adult diaper" that is sold in drug stores everywhere
>for people who suffer from incontinence...

Actually, at least at one time *everybody* wore one of those when suited up,
because urination isn't the only potential problem when EVAs last hours.

Bear in mind, also, that Gemini flew missions up to 14 days long with no
sanitary facilities at all.  They used diapers.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 03 Dec 92 18:11:35 EST
From: Tom <[e-mail]>
Subject: Pop in space, dumpster diving

Tor Houghton (Maybe David Toland) sez:
>>> If a blob of, say Coke, was floating weightlessly in space (inside a
>>> spaceship - normal air pressure), would the "fizz bubbles" go from the
>>> centre to all directions?

Bill Higgins sez:
>When cosmonaut Anatoly Artsebarski visited Chicago last summer I
>learned that he had tested soda pop aboard Mir.  I gather that he
>didn't like it much, but he didn't talk about specifics.

I imagine it would be disconcerting.  First, the lack of gravity means
that the expansion in the stomach that gets relieved by burps wouldn't
be caused by gas, but a gas/liquid mixture.  So, if you succumb to
the urge to burp, actually, you'd barf.  (I hate when that happens...:-)

Soon, your average caffeine-loving space-naut would learn to avoid
burping, which means the gas would pass through the intestinal system,
and in a closed atmoshperic system, too!  Yuck!  I can see it now:
"New, caffiene-free, sugar-free, carbonation-free Pepsi!  The
pop they drink in space!  Just like brown water, but we can it and
put our logo on it!" :-)

>Bill Higgins sez;
>...I was in the VIP
>bleachers  at the Cape, near the garbage dump.  (Since I was a guest
>and on my best behavior I resisted the temptation to go
>dumpster-diving for space hardware.)...

About dumpster-diving:  One of our faculty recently moved out, and, not
wanting to store a bunch of (perceived) crap, threw a bunch of stuff
out.  Some friends of mine went looking for folders, and one
guy came out with an autographed picture of the crew for the Apollo 11
mission!  What luck!  Anyway, my boss thought it was no big deal,
which prompted a short and uninformed discussion about the monetary
value of said autographed picture (which Steve wasn't selling :-)

Anyone have any idea how much something like that would go for?
They must be kinda rare...

-Tommy Mac
-----------------------------============================================
Tom McWilliams              | What a tangled web we weave, when at   ". |
[e-mail]      |              ,  .first we .practice .*'  .|
[phone] -or- 353-2986|            '. '  . . to decieve    ,      |
a scrub Astronomy undergrad | After that, the  ,          +             |
at Michigan State University| improvement is tremendous! '.  , .'       |
------------------------------===========================================

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

Date: Thu, 03 Dec 92 18:03:32 EST
From: Tom <[e-mail]>
Subject: Rumors about Hubble

I heard the strangest rumor recently.  The doubt factor is pretty high,
but I'm curious if anyone has anything to add about the reality or origin
of the rumor.

It goes something like this:  HST is actually in perfect working condition,

but the military shanghied it, with the bad-mirror cover story, for the
purpose of inspecting a recently discovered radio signal coming from
space, presumably from IET's.

You're buyin' it, right? :-)  Does this sound familiar to anyone, or
is it a total crock?  One way or the other, how do you know?

-Tommy Mac
-----------------------------============================================
Tom McWilliams              | What a tangled web we weave, when at   ". |
[e-mail]      |              ,  .first we .practice .*'  .|
[phone] -or- 353-2986|            '. '  . . to decieve    ,      |
a scrub Astronomy undergrad | After that, the  ,          +             |
at Michigan State University| improvement is tremendous! '.  , .'       |
------------------------------===========================================

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

Date: Thu, 3 Dec 1992 18:25:33 GMT
From: Henry Spencer <[e-mail]>
Subject: shuttle costs
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Richard A. Schumacher) writes:
>Nonsense. It will never cost less than $500 million to launch a shuttle.

It probably could be done, actually.  However, I concur that it won't be.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 3 Dec 1992 19:04:39 GMT
From: Pat <[e-mail]>
Subject: shuttle downtime
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Pat) writes:
>>I believe that once they lost one shuttle they suddenly discovered that the
>>shuttle had a significantly high risk of loss due to any of a number of
>>problems many of which were fixed at the same time...
>
>The accident focussed quite a bit of attention on safety issues, and got
>some action taken on several worrisome problems.  The paranoia ultimately
>escalated, mind you, well beyond reasonable levels.  Had the shuttle been
>an aircraft, it probably would have resumed flying -- subject to some
>restrictions and precautions -- after a considerably shorter downtime.
>--
>MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
>              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry


I can't remember, but i thought they needed to requalify either the
SSME's or the Turbo-pumps.  and that took a significant time period.
I seem to recall hearing something along the lines that the original assumptions
for pump behavior were not correct and they needed to retest and modify them.
I am sure henry will shed some light on this.

On the other hand.  shortly after the STS 51-l loss, the new calculations
indicated an expected loss rate of 1/25 for the shuttle fleet.  in fact this
was a major grounds for criticizing and stagerring SSF launches, and was a driver
for looking at using HLV's to lift SSF.

If the three year down, has helped push down this loss rate then i am all for it
in fact, we are at flight 52 and no sign of blowing up one.  if this means
we have cut the loss rate,  we are in good shape.
Henry, you'd be the expert.  has the expected loss rate of orbiters dropped
due to the system improvements, or is it still sitting at 1/25?

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

Date: 3 Dec 92 19:14:27 GMT
From: Pat <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>The fact that no widebody has ever had to ditch at sea shows just how rare
>total power loss is.
>--

When they certify Twin Jets for commercial passenger flights over oceans,
they use the acronym ETOPS Extended Twin Engine OPerationS.  Wags
prefer the acronym Engines Turn Or Passengers Swim. also
Engines Thrust Or People Sink.

Actually how many instances of total power loss have their been?
The brits lost one after an engine fire on a 757 and the pilot
then shut down the remaining good engine.  Their was Gimli and
and an incident when a US airliner lost all engines when a mechanic
forgot an o-ring on all foour engines.   there was also the avianca?
(Columbian airline)  that ran out of fuel enroute to JFK.
Have their been any other isntances?  i am sure the military has lost a
few this way also.

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

Date: Thu, 3 Dec 1992 18:23:53 GMT
From: Henry Spencer <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>I was wondering if anyone else was going to mention that gaffe.
>I mean, TEN PEOPLE???
>Okay, you've crewed the fire truck... now who's going to fuel the DC? :-)

How many people does it take to connect a couple of hoses and push the
buttons to start the pumps?
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: 3 Dec 92 19:58:53 GMT
From: Pat <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>In article <[e-mail]> [e-mail] (Pat) writes:
>
>Yes, the real crime was treating Shuttle as an operational system after
>so few flights. No commercial aircraft would be certified operational
>after so few takeoffs and landings. Shuttle is still significantly
>more risky than any operational aircraft, yet we fly it now. My point
>is that the incremental risk for flying it with some of the potential
>problems unfixed may not have been that much higher than the risks
>it endures now, after the fixes.
>
Well, NASA declared it operational after 4 flights.  take it up with them.
one reason we dont have so much trouble in civil aeronautics is that
most things can be reshuffled.  passengers can be put on other planes,
cargo can go by rail or sea or other birds.  As far as the tisk of
soem the problems.  thats a pretty narrow argument, NASA, Rockwell,
Thiokol, Martin and Henry can thrash that one out.

>>Gary  i think you should study under what conditions risk is applied,
>>before you grandly declare it was a risk averse america.
>>Remember,  we ground entire airline fleets and military birds when
>>problems are detected and fixes are applied.  the AH-64 spent half its
>>life until 1988 grounded for one problem or another.  the F-14s spent
>>months flying under restricted conditions because they kept stalling
>>and falling into the water.  the DC-10 spent months grounded after
>>chicago.  they forced groundings of 747s pening emergency inspections
>>of cargo hatches after the UAL problem..... operational aircraft are
>>always restricited until they know and understand the problem.  we dont
>>want anymore comets.
>
>This is all true too. But *when necessary* military aircraft do fly
>without the fixes. The losses are accepted as part of the cost of
>getting the mission done. Shuttle grounding, at a time of Titan
>troubles put national security at risk. I think we were down to
>our last KH-12.

So what....  i think the disintigration of the CIS/USSR/Pick your name
only proves my point.  National security is a big thing and the
loss of any one single system only incrementally affects it.
also, in 1987, we were down to our last KH-11.  those flews on titans.
the reason we had trouble in the KH class was because they were developing
the KH-12 to fly on the shuttle and the program was draining money from
the 11.  they could have kept flying 11's
but they were expecting the 12 to fly on a certain date.
shuttle troubles and delays on the 12 pushed this back leaving us with
decaying orbital asssets.
this is similiar to the problem with GOES.  GOES NEXT wiped all resources
and it's still not ready to fly.  if we werent getting weather data
from Defense and european sats we'd be screwed.  And believe me, that
is at least as large a national problem as a delayed KH-12 flight.



> A lot of money was spent, and a lot of time was
>used to fix numerous *potential* problems as well as the proximate
>problem. The question is whether these potential risks were sufficient
>to offset the costs to the missions of the delays incurred. Normally
>when an aircraft is grounded, there are alternatives available so that
>the mission can continue. At the time of the Shuttle grounding, there
>was no alternative for many payloads. There still isn't in some cases.
>One failure seems insufficient to cause a total halt in space launches
>when the previous record was 100% successes. Being risk averse isn't
>bad, but being too risk averse can be. There's such a thing as carrying
>zero failure tolerance too far.
>
>Gary


at 1.5 billion an orbiter,  it's a big risk.  look at risk management in nukes....

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

Date: 3 Dec 92 19:23:07 GMT
From: Pat <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Josh 'K' Hopkins) writes:
>[e-mail] (Gary Coffman) writes:
>
>>To shut me
>>up, all you need to do is agree to launch and land this thing away from
>>major population centers. It's not an airliner, and it likely can never be
>>an airliner. If it's a cheap launcher that ocasionally crashes or goes
>>boom in an uninhabited spot, that's good enough for me.
>
>DC isn't an airliner with wings and jets, but it's not a rocket with low
>margin engines and flight history of zero either.  It's something in between.
>To shut us up, you're going to have to show us why, given reasonable estimates
>of vehicle reliablity, you require it to live up to rocket standards and not
>airliner standards.  I think most of us agree that the RSO for a rocket is an
>important job, but that the current accident rate of airliners doens't
>necessitate them.  Just why can't a launcher be an airliner anyway?
>
>--

RSO's are important safety people, but you cant have an RSO/Emer Self Dest
on a vehicle with an integral crew and passengers.  The X-15 had no
ESD that i know of, nor do experimental aircraft (Fighters/bombers).
Henry is the expert, but what he tells me is the ESD is not to destroy
the vehicle but to ABSOLUTELY 100% GUARANTEE the termination of vehicle
thrust under emergency conditions.  the idea is to keep the vehicle
from pushing beyond the safe range area.
If DC-1 has reliable ways of terminating thrust during launch,  then that
capacity will be controlled by the pilots.

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

Date: Thu, 3 Dec 1992 18:34:38 GMT
From: Henry Spencer <[e-mail]>
Subject: unpowered landings
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>... Even a Harrier can dead stick to a runway
>landing if it loses engine power in flight.

If there's a runway handy, and if there isn't too much of a crosswind, and
if neither thunderstorms nor icing are present.

Of course, if we rephrase the situation, to "if it loses one engine in
flight", then the situation is a dead-stick landing for a Harrier and an
entry in the maintenance log after a normal landing for a DC-1.

It's easy to find circumstances where a DC-1 would crash and a Harrier
wouldn't.  It's also easy to find circumstances where the situation would
be reversed.  The question is not whether situation X leads to a crash
for a particular craft; the question is the overall likelihood of failures
leading to crashes for that craft.

Total power loss is extremely rare in multi-engine turbine aircraft.  It
also appears to be quite rare in multi-engine rockets.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 3 Dec 1992 18:07:53 GMT
From: Jochen Bern <[e-mail]>
Subject: Voyager's "message"... What did it *say*?!?
Newsgroups: sci.astro,sci.space

In <[e-mail]> [e-mail] (Rick Miller, Linux Device Registrar) writes:
>Does anyone know (or know who knows, or where to find out) what the heck
>the "message" on Voyager's gold plate was supposed to 'mean'?  In case I'm
>naming the wrong vehicle, I'm talking about a rectangular plate on which
>is inscribed a man, a woman, a simplification of the vehicle itself, a
>chart of our solar system showing the vehicle's flight-plan, and a couple
>other things.

>Are these facsimilies of spectrometer readings?  The codes along the
>radial lines of the starburst pattern are even *more* complex... and I
>can't make heads nor tails of the two circles linked by a line just above
>the starburst.

Others already pointed out that these Lines are binary Numbers. I don't know
what the Readings for the Planets mean, but I've read the following Explanation
for the Starburst:

The Starburst Codes are supposed to "origin" from the Earth's Position and to
point to a Number of Pulsars carefully chosen. The Numbers give a high-preci-
sion Measurement of the appropriate Pulsar's Frequency. This enables the Reader
of the Message to identify the Pulsars, compute the approximate Position of
the Earth, and the Time when the Spacecraft was launched - since the Pulsars'
Frequencies change (drop) at a computable Rate.

Hope that helps,
                                J. Bern
--
 /  \  I hate NN rejecting .sigs >4 lines. Even though *I* set up this one. /\
/ J. \ EMail: bern@[TI.]Uni-Trier.DE / ham: DD0KZ  / More Infos on me from /  \
\Bern/ X.400 Mail: S=BERN;P=Uni-Trier;A=dbp;C=de  /   X.400 Directory, see \  /
 \  /  Zurmaiener Str. 98-100, D-W-5500 Trier    /     X.29 # 45050230303.  \/

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

Date: 3 Dec 92 20:11:03 GMT
From: Doug Ingram <[e-mail]>
Subject: Voyager's "message"... What did it *say*?!?
Newsgroups: sci.astro,sci.space

>In <[e-mail]> [e-mail] (Rick Miller, Linux Device Registrar) writes:
>Does anyone know (or know who knows, or where to find out) what the heck
>the "message" on Voyager's gold plate was supposed to 'mean'?

    It says, "We've just elected an actor President of the most
powerful nation on Earth!  SEND HELP!"

:)

Doug Ingram -- [e-mail] // "Carpe Datum."

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

End of Space Digest Volume 15 : Issue 501
------------------------------