Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_4/V15NO495.TXT

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Date: Thu,  3 Dec 92 05:25:36
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #495
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu,  3 Dec 92       Volume 15 : Issue 495

Today's Topics:
                             Autorotation
                      DC Terminal Fall Velocity
  Environmental group to sue NASA to stop rocket motor fuel testing
        flywheel electricity generator for satellites (2 msgs)
                    Fwd: Robot To Explore Volcano
   NASA has 5 hand grenades still on the moon from Apollo missions
   Satellites more expensive on STS? (was Re: Shuttle replacement)
     Seeking info on Tours of External Tank factory in Louisiana
                     Shuttle replacement (4 msgs)
                      Space probe to pass Earth
             Voyager's "message"... What did it *say*?!?
                        What comes after DC-1
            What is the SSTO enabling technology? (2 msgs)

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

Date: Wed, 2 Dec 1992 20:40:38 GMT
From: Donald Lindsay <[e-mail]>
Subject: Autorotation
Newsgroups: sci.space

[e-mail] (Edward V. Wright) writes:
>>4. Autorotation doesn't work worth a damn. The way I've heard it, if
>>the engine goes out, maybe the pilot of the helicopter will get very
>>lucky and be able to autorotate...
>
>In that case, there must be an awful lot of ghosts walking around.
>Every helicopter pilot is requried to practice and demonstrate
>autorotation in order to get his license.

Hah. It works nicely under certain well-known circumstances, and
the practice is carefully done in just such circumstances.

In real life, the pilot doesn't get to choose when his problem will
occur. For example, helicopters which spend a lot of flight time
lifting construction materials (towers and such) are unlikely to be
able to autorotate.
--
Don        D.C.Lindsay    Carnegie Mellon Computer Science

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

Date: 2 Dec 92 18:03:15 GMT
From: Thomas Clarke <[e-mail]>
Subject: DC Terminal Fall Velocity
Newsgroups: sci.space

In article <96#29v=@rpi.edu> [e-mail] (Michael V. Kent) writes:
> In article <[e-mail]> [e-mail] (Gary Coffman)
writes:
> From the SSTO fact sheet I picked up at the Northeast Space Developemnt
> Conference:
>                           DC-X                DC-Y
>                           ----                ----
> Empty Weight:           22,760 lb          104,100 lb
> Gross Liftoff Weight:   41,630 lb        1,279,000 lb
> Vehicle Height:             39 ft              127 ft
> Width at Base*:             11 ft               40 ft
>
>* My estimates based on the listed height and drawings of both
> vehicles.  There is no guarrantee that the drawings are to scale.

Therefore, assuming Cd=1, the empty sea-level
terminal fall velocities are:

DC-X:  154 m/sec or 350 mph

DC-Y:  90.5 m/sec or 206 mph

Assuming Isp=300, then fuel needed to land is approx

DC-X:    1220 lbs

DC-Y:     5570 lbs

Sounds like the DC-Y is the easier problem since it is
less dense and falls more slowly.

Of course the tanks-full fall velocites are 472 mph and
720 mph (supersonic?, simple equations break down:-)
respectively so its best to burn off excess fuel in case
of an abort.

--
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
[phone], FAX: [phone], [e-mail]

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

Date: 2 Dec 92 18:06:23 GMT
From: Henry Spencer <[e-mail]>
Subject: Environmental group to sue NASA to stop rocket motor fuel testing
Newsgroups: sci.space,talk.politics.space,talk.environment

In article <[e-mail]> [e-mail] (Matthew Kaiser) writes:
>the Russians use liquid fueled boosters with no problems
>why don't we?

Because the president you elected, and the congress you elected, thought
it cost too much money.

The only reason the shuttle uses solid boosters is because they were a
little bit cheaper to develop.  NASA originally considered them strictly
an interim solution until funding for liquid-fuel boosters could be found...
but it's never been found.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Wed, 2 Dec 1992 18:05:09 GMT
From: Matthew Kaiser <[e-mail]>
Subject: flywheel electricity generator for satellites
Newsgroups: sci.space

say i found an article (i've forgotten where) about
a possible flywheel in space to generate electricity
continuously virtually forever.

what ever happened to the idea?

matthew
[e-mail]

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

Date: 2 Dec 92 19:12:06 GMT
From: Dave Jones <[e-mail]>
Subject: flywheel electricity generator for satellites
Newsgroups: sci.space

Matthew Kaiser ([e-mail]) wrote:
> say i found an article (i've forgotten where) about
> a possible flywheel in space to generate electricity
> continuously virtually forever.
>
> what ever happened to the idea?
>
> matthew
> [e-mail]
>
Went the way of other perpetual motion machines, I imagine.  While a
rotating object in space will continue to rotate virtually forever, any
kind of energy extraction must slow it down. (First Law of
Thermodynamics)

A rotating object would have as much energy as you put into it.  This would
involve using a primary source like a rocket to spin it up, then extracting
electricity as the object rotated in some kind of magnetic field.  Given
that there are excellent primary sources of electricity for space use
(solar, nuclear and fuel cell) you'd hardly want to fool with a massive
flywheel, even if the rotation were frictionless and the magnetic field came
for free (i.e. Earth's own field).

Now if the flywheel got its energy from a different source, that'd be
a whole new ballgame.....but there's no other source that I can think of,
other than a mass-stream coming from higher up the gravity well (more of
a space-waterwheel, really)


--
||------------------------------------------------------------------------
||Dave Jones ([e-mail])|Eastman Kodak Co. Rochester, NY  |

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

Date: Wed,  2 Dec 1992 14:25:10 -0500
From: Samuel John Kass <[e-mail]>
Subject: Fwd: Robot To Explore Volcano
Newsgroups: sci.space

I promised I'd post again if any news about Dante came around campus...
So here's the latest.
    --Sam

-- Disclaimer:  Everything is true. - [e-mail]               --
-- A Math/CS major at Carnegie Mellon University --  Beward the fnords.  --


---------- Forwarded message begins here ----------

Date: Wed,  2 Dec 1992 12:57:13 -0500 (EST)
Subject:Robot To Explore Volcano

A NEWS RELEASE FROM THE CARNEGIE MELLON DEPARTMENT OF PUBLIC RELATIONS

Carnegie Mellon Robot Will Leave for Antarctica
To Explore Crater of Mt. Erebus, an Active Volcano

    PITTSBURGH--A team of researchers from Carnegie Mellon University's
Robotics Institute will leave for Antarctica Dec. 10 with a unique,
eight-legged walking robot named Dante they have built to explore the
crater of Mt. Erebus, a live volcano.

The purpose of the expedition, which is sponsored by NASA and the
National Science Foundation, is to test robotic technologies under
extremely harsh conditions as a precursor to exploring Mars, and to
gather information about Mt. Erebus and its emissions that up to now has
been impossible to obtain.

Mt. Erebus is the only easily accessible volcano in the world that
contains a permanent lava lake inside its crater. It's an important
source of information, but scientists have been stymied in their
attempts to gather data because the volcano erupts without warning.
Dante will be able to collect valuable data without exposing researchers
to a live volcano's hazards.

Four scientists from Carnegie Mellon and four from the New Mexico
Institute of Mining & Technology (NMT), Socorro, N.M., will accompany
Dante on its odyssey. Carnegie Mellon's principal investigator, William
L. "Red" Whittaker, an internationally known robotics expert, will lead
the expedition with NMT's Philip R. Kyle, a 20-year veteran of volcanic
research in Antarctica.

James Osborn, project manager at Carnegie Mellon, will operate a
"mission control" station at the Goddard Space Flight Center (Greenbelt,
Md.), with two-way data communication and live video feedback from the
frozen continent via a NASA satellite link.

After arriving in Antarctica, the researchers will set up a base station
two kilometers (1.4 miles) from the rim of Mt. Erebus' crater. Dante
will be transported to the top of the 12,447-foot-high mountain on a
cart equipped with an electric winch. The cart, which researchers named
Geryon, is one of several references to Dante Aligheri's classic
"Inferno," where Erebus was a region of darkness in the underworld to
which dead souls were sent.

When Geryon reaches the mountaintop, controllers at the base station
will order Dante off the cart. Other researchers will anchor its
lifeline, a one-quarter-inch-wide tether containing power and data
wires, to the edge of the crater, and position the robot for its descent
into the mountain.  The tether, which also is attached to the cart for
communication purposes, will slowly unreel as Dante "sees"~and feels its
way down the sheer crater walls with the help of a laser range finder,
3-D video cameras and "eyes" in its robotic feet. For much of the
expedition, Dante's onboard computers will receive instructions from
operators at the base station and it will interpret those commands into
robot actions.

It will take Dante 24 to 36 hours to make the 850-foot descent to the
crater floor. If all goes well, it may stay as long as eight-hours,
measuring gas composition, recording temperatures of the lava lake and
retrieving samples of hot gases and aerosols directly from vents near
the lake. Information will be transmitted to the base station and on to
the mission control station at Goddard Air Force Base.

For the return trip, Dante must reverse its course and climb up the
crater walls using the tension on the tether for support.

"The Erebus mission offers an opportunity to test technologies developed
during more than seven years of research on Carnegie Mellon's autonomous
driving (NavLab) and Mars exploration (Ambler) projects in a very harsh
environment," said Whittaker. "Both NASA and the National Science
Foundation consider this Antarctic expedition a precursor to planetary
exploration by robots, since it most closely approximates
extraterrestrial environments. Missions to the Moon and Mars will
require robots to withstand harsh conditions, operate for extended
periods and understand and navigate challenging terrain. The Erebus
project will provide useful insights for designing more capable robots,
developing effective human/robot interactions and planning future
missions."

According to Kyle, volcanoes may play an important role in diminishing
earth's ozone layer. He said recent measurements suggest Erebus may be a
key source of sulfur dioxide, hydrochloric and hydrofluoric acids in the
Antarctic atmosphere. The gases may remain in the atmosphere long enough
to mix into the stratosphere and contribute to the destruction of the
ozone layer.

###

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

Date: 2 Dec 92 17:02:54 GMT
From: [e-mail]
Subject: NASA has 5 hand grenades still on the moon from Apollo missions
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] ("Phil G. Fraering") writes:
>Ordinary firearms wouldn't work in a vacuum anyhow.
>The gunpowder couldn't burn. The same might be true at high
>altitudes on the Earth's surface, as I've heard that in a
>particular South American city (I think it was La Paz, Bolivia),
>there's not enough oxygen in the air for them to really require
>a fire department.

The propellant in modern firearms does not need oxygen from the air to work,
the oxidizer is built in.  Oxygen from the air is negligible in helping
to fire a gun.

However, having said that, I read that black powder (the old style gunpowder,
not used in most modern firearms) will not ignite in a vacuum, NOT because
it needs the oxygen from the air (it is built in), but because it needs the
pressure.  It works just fine in an atmosphere of argon or any other inert gas.

-Mike

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

Date: 2 Dec 92 13:22:07 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Satellites more expensive on STS? (was Re: Shuttle replacement)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] writes:
>
>>For small satellites on the shuttle (microsats), the Shuttle is far
>>cheaper than its competition.
>
>No, it isn't cheaper it's just that NASA found some suckers (us) to pay the
>extra. If you where forced to pay the true cost, you would buy the cheaper
>Pegasus.

At $20,000 a pound for Pegasus compared to $8500 a pound for Shuttle,
Pegasus is the most expensive launcher, not the cheapest. If the launcher
only carries one 200 pound payload, Pegasus is cheaper, but if the flight
is fully booked, Shuttle wins easily. For one small payload, Scout is cheaper
than Pegasus.  If you need a 700 pound payload though, neither Pegasus or
Scout is cheap at any price.

>>Who cares if it is subsidized Allan
>
>I care since I am the one paying the subsidy. Given a choice between
>a) spending billions of my money and shutting down commercial space or
>b) saving billions, reducing costs, and opening up the space frontier
>I prefer b.
>
>I wonder if you could tell us just why you prefer a?

Because the choices aren't a or b. The choice is satisfying government
demand for launch services. Government is *the* major customer for
launch services. Private program management might make that cheaper than
civil service management, but Rockwell already does that for Shuttle.

Gary

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

Date: Wed, 2 Dec 1992 19:10:38 GMT
From: Jim Sims <[e-mail]>
Subject: Seeking info on Tours of External Tank factory in Louisiana
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Karl R. Stapelfeldt) writes:

> One space facility in the central gulf coast I haven't been to is
>the Michaud assembly facility where the Saturn 1st stage was built

 that's Michoud

>where shuttle external tanks are now built.

>    Are tours of the ET assembly line offered ?

 not that I know of - call 'em and see - Martin Marietta (504)
 555-1212 (information for that area code)

>    Are they interesting ?  What do you get to see ?

 Like I said - I'm not aware of organized public tours when I worked
 there (>6 yrs ago), but I can't imaginewhy you couldn't get to *most*
 of the plant without any kind of clearance. The foam-spraying areas
 were all behind NASA controlled access areas when I was there, but I
 dont recall any other areas I had to go through gates to get to
 (other than the whole facility).

>    How to I get to Michaud ?

 Michoud - take Interstate 10 east from New Orleans, and take the exit
 for Michoud, turn left on Old gentilly Road. It's on the right-hand
 side about 2 miles down, cant miss the Saturn V first stage lying
 down just off the road, inside the fence. Go just past that to a
 little visitor parking lot and entrance.

>    Do I need to write ahead for arrangements ?

 probably - call first and see

>Thanks in advance to anyone on the net who can help.

 sorry to not be more help - it's been a while, and having acess to
 everything, I never had the need to find out about tours...

jim
-------------------------------------------------------------------------------
 [e-mail]                               The MITRE Corporation
 DECUS AI SIG Symposium Representative            7525 Colshire Drive   MS Z421
 the opinions are mine, who'd wanna claim 'em?          McLean, Va.   22102

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

Date: 2 Dec 92 18:37:51 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

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

>Are the payload/pallet integration costs included in DC flight costs,
>or are they offloaded onto the customer?

On the customer I assume.

>Standards help, of course,
>but payload integration costs are a significant part of spaceflight

Indeed. The DC design will encourage payload designers to conform to
their standards and at the same time not hamper (more than now) those
who need/want a different interface.

   Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------143 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Wed, 2 Dec 92 23:03:33 GMT
From: [e-mail]
Subject: Shuttle replacement

> It seems to me that the launch requirement for something of the DC class
> is small enough that there will only be a few built, and those flown
> fairly infrequently. At least they will fly at nowhere near the schedule
> rates of airliners. What I'm questioning here is whether airliner grade
> ground servicing can work with such a system. It would take many years
> of flight experience to feel confident that all the catastropic failure
>


Max Hunter's own words are that he is not out to build a hanger queen like
the space shuttle. This bird is meant to get the pants flown off it. If DC-X
works, and then DC-Y works, the DC-1 will be open for business to carry
passengers into orbit.

And before you talk about it being dangerous... well, as far as I'm
concerned, *LET* all the chickenshits stay on the ground. Who needs them out
there anyway? I certainly don't expect an operational DC-1 to be any less
safe than commercial airtravel in the 1920's. Otherwise it won't be built.

If grandpa and grandma had the guts to do travel in their day, then so do I
in mine.

--
=======================================================================
Give generously to the        Dale M. Amon, Libertarian Anarchist
Betty Ford Home for                    [e-mail]
the Politically Correct     Greybook:  [e-mail]
=======================================================================

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

Date: 2 Dec 92 19:11:28 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

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

>>In ten years of operation this is the first year where Shuttle has gotten
>>even close to projected flight rates.

>So than now as the system has matured and the probabiltiy of launching when
>they say they will has been reached, you want to kill the system.

Since it is still three times more expensive than the alternative it does
seem a good thing to do.

>Also the
>cost reductions that are now being implemented that will reduce further the
>cost of launch you want to throw away. Makes a lot of sense Allan

If you can document to me that these reductions will reduce costs by a
factor of three, I'll change my mind.

>>Maybe even not then. It depends on the cost of failure.

>The cost of failure for communications satellites is not simply measured
>by the cost of the hardware and launch vehicle.

Sure. There is always replacement costs and opportunity costs.

>Intelsat was willing to pay the big bucks to NASA to retrieve I VI

Hold on there! They paid what amounts to the scrap value of the satellite.
You and I paid the bulk of the rescue costs. They did it to get out of
the cost of a new satellite and luancher. All in all an excellent deal
for them but only because they got some suckers to pay the actual costs.

>Therefore Allan old boy
>please add the cost of the loss of revenue, both in actual dollars lost

Done. Shuttle still comes up short. Had Intelsat been forced to pay the
actual costs, they would have found it cheaper to wait for the new
satellite and launch it themselves.

>as well as the permanent loss in market share to other satellite vendors.

Intelsat is a monopoly. They needn't worry about market share and competitors.

>>One reason Hubble is unique is that Shuttle eats almost a third of
>>NASA's budget. I hope you consider this when measuring Shuttle utility.

>Got any idea what you mean by this remark?

As Daniel Gouldin said: "Shuttle is eating our lunch!". The opportunity
cost of spending a third of NASA's budget on an operational system which
doesn't work is astounding.

>You sure as heck could not have
>gotten HST up to that altitude with anthing less than NLS II or Shuttle

Titan could have come very very close. With the money saved, we could
build another Hubble.

>>If YOU where paying for Hubble, which would you pick?

>I would pay the trucking company that could get it to the orbit that I want.

I note that you didn't consider cost. Why am I not suprised?

>>>    Allen, they haven't made a profit in 6 years (since Challanger).

>>Largely because they are forced to compete with government subsidized
>>competition.

>No Allan if you remember no commercial sats are going up on the Shuttle.
>Where is this government competition?

Does the word 'Airiane' ring a bell?

The fact that the largest user of launch services refuses to use cheaper
commercial services just makes it worse. Of course, the free world sure
was lucky recently when a half billion dollar Shuttle flight was used
to launch a 400 pound satellite!

Sure we could have used a Pagasus which would have been 50 times cheaper
and helped reduce costs. But then it's good we had those people on board
to do, well, stuff to support the luanch.

>From the info I have the Delta II line would shut down without the government
>that you detest so much not paying for GPS on a regular basis.

Don't misunderstand me. I have no problem with government building
satellites. That is a requirement for government to do its job. The
problem is when they stifle competition by using its own far more
expensive facilities when cheaper commercial facilities can be used.

>No as I have just pointed out, any of the American launchers including the
>Delta II, Atlas II, and Titan III, IV and V, depend on the government dole.

No, not the dole. Launching GPS so the military can function is a proper
function.

>>One thing we need to do to make progress is understand the mistakes of
>>the past and then have the courage to correct them.

>What we need to understand is that this whole industry is still in an infantile
>stage that REQUIRES the input of government funds to survive.

No problem. However, it also requires policies which promote privitazition
so that a day will come when it doesn't need government funds. The policies
you advocate do not lead to that end. This means that without change space
will always be expensive. NASA hasn't reduced the cost of access to
space in 30 years. Even it's new cheaper vehicle (NLS) is more expensive
than the alternatives. the only cost reductions we have seen have come
from the private sector with NASA fighting these reductions all the way.

>You have not even addressed the other end, the HLV end of the spectrum.

I have several times. We can develop low cost HLV's in a few years for
the cost of a single Shuttle flight should we feel the need. The private
sector is ready to do it.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------143 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 2 Dec 92 21:10:25 GMT
From: "Michael V. Kent" <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

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

>Also the
>cost reductions that are now being implemented that will reduce further the
>cost of launch you [Allen] want to throw away.

Does anyone have details on what the Assured Shuttle Availability Program
entails?

>>>    Allen, they haven't made a profit in 6 years (since Challanger).

>>Largely because they are forced to compete with government subsidized
>>competition.

>No Allan if you remember no commercial sats are going up on the Shuttle.
>Where is this government competition? The reason is that MacDac offered a
>ver low price to uncle air force that is below manufacturing costs. Then
>to recover a profit they added a clause that if the first 18 flights of
>GPS (which is a government contract that MacDac follows you magic formula)
>are successful MacDac gets a col 72 million. Well they have almost made it.
>the first 17 have made it to orbit, but MacDac chickened out. They negotiated
>for a lesser amount for 12 successful launches. Made much less money than
>they would have. No guts no glory I guess.

I think the real reason for this was that insurance costs were eating up the
profits.  I remember reading (in AvWeek?) that insurance premiums are deter-
mined by the _industry_ success rate, not the success rate of the launcher in
question.  When GD blew up a couple of Atlases, the premiums soared to 20%
the cost of the launch.  I do know that the contract that lessened the award
fee also caused the Air Force to self-insure their Navstars.

Mike

--
Michael Kent              [e-mail]        Rensselaer Polytechnic Institute
"Interviewing during a recession is a lot like faking an orgasm.  You have to
pretend you're interested all the while getting badly screwed." - Anonymous
Tute-Screwed Aero, Class of '92                               Apple II Forever!

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

Date: 3 Dec 92 00:56:52 GMT
From: Ron Baalke <[e-mail]>
Subject: Space probe to pass Earth
Newsgroups: sci.space

In article <[e-mail]>, phoenix.Princeton.EDU!carlosn (Carlos G. Niederstrasser) writes...
>In article <[e-mail]> [e-mail] (UPI) writes:
>>
>>     Galileo will pass within about 68,000 miles of Earth's moon at 10:58
>> p.m. EST Dec. 7 and pass within 190 miles of Earth at 10:09 a.m. EST the
>> next day.
>>     Scientists plan to use the pass by the atomic-powered, $1.4 billion
>> spacecraft to calibrate the probe's instruments by using the various
>> sensors and cameras to study and photograph the Earth and moon.
>
>190 miles ?!?!  Isn't that even closer than the normal shuttle orbit?  Are they
>missing a few zeroes?

190 miles is correct, with an accuracy of about +/- 4 miles.  This is no
suprise, the VEEGA trajectory was planned out 5 years ago.  A trajectory
correction was performed over the weekend, and the spacecraft is right
on course with no further corrections needed.  All we have to do right now is
sit back and collect the science data.  Even thought the closest approach for
the Earth isn't until December 8, the Earth encounter has already started.
The science instruments are already on and sending back data.

>And on a 'whine' note, once again the press trying to scare ignorant fools by
>stating that the spacecraft is atomic-powered.  Was that reference really
>necessary in the context of the article?  I think not!

This is a misconception that the press often reports.  Galileo has two
RTG's as its power source, which converts the heat from the natural
decay of plutonium into electricity.  The RTG's are not nuclear reactors.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     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: 2 Dec 92 21:29:13 GMT
From: "Rick Miller, Linux Device Registrar" <[e-mail]>
Subject: Voyager's "message"... What did it *say*?!?
Newsgroups: sci.astro,sci.space

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.

What bothers me is that I, a *native* of the world it came from, can't
decipher what the crazy 'code' is that everything is written in.  For
example, here's the labling for our nine planets:

    Mercury:    |-|-
    Venus:        |--||
    Earth:        ||-|-
    Mars:        |--||
    Jupiter:    |----||
    Saturn:        ||-||
    Uranus:        ||-||
    Neptune:    ||-- -||-
    Pluto:        ||-||

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.

Does *anyone* know what this was *supposed* to mean???

Rick Miller   <[e-mail]> | <[e-mail]>   Ricxjo Muelisto
Occupation:  Husband, Father, WEPCo. WAN Mgr., Discus Sys0p, and  Linux fan

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

Date: Wed, 2 Dec 1992 17:21:55 GMT
From: Henry Spencer <[e-mail]>
Subject: What comes after DC-1
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>I can't point to a source at the moment, but I have seen references to
>the Shuttle being a stage and a half system, since all the engines fire
>at liftoff, and two (the SRBs) are jettisoned during flight. The SRBs are
>more like strap-ons (i.e., Delta or Titan) than another stage (Stage 0?)

Actually, the Titan strap-ons are referred to as stage 0, mostly because
they were added as an afterthought to a design that already had a stage 1.

I'd be interested to know where you saw the shuttle referred to as 1.5-stage.
It doesn't meet the normal definition of this.  You can't really have a half
stage with solid-fuel rockets, since their tankage is part of their engines.

The NASA documents that I've seen refer to the shuttle as two-stage.  (In
fact, the NSTS Reference manual describes ascent in terms of two stages,
divided at SRB burnout.)
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: 2 Dec 92 17:41:15 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: What is the SSTO enabling technology?
Newsgroups: sci.space

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

>>RL-10s seem to do just fine.

>    But are they reused?

Each RL-10 is tested with something like 20 starts and stops. There is
nothing in their design which prevents starting and stopping  an arbitrary
number of times.

RL-10's have been started, stopped, and re-started in space several times.
There is no reason they can't be re-used.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------143 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Wed, 2 Dec 1992 13:04:29 GMT
From: Gary Coffman <ke4zv!gary>
Subject: What is the SSTO enabling technology?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>
>PS. SSME upgrades are paid for with out tax $$. RL-10 upgrades are paid for
>    by the private sector.

I think you meant *with* tax $. I would note that tax dollars come from
the private sector too. While I worship at the shrine of private enterprise
from time to time, the important question is who's willing to spend the
money. The source of the money is always from the pocket of the productive.
There are three main sources of launch services demand.

(1) science payloads, government financed.
(2) military payloads, government financed.
(3) comsats, commercially financed.

The government dominates the demand side. On the supply side, all
launch vehicles are provided by private enterprise in the US.
Launch *services* are split between government personnel and private
contractors. The government dominates demand, but private enterprise
makes up the bulk of supply. Money talks. As long as the government
is the main source of demand, the government will determine the
shape of the market, not the suppliers of launch services.

"Build it and they will come" is movie myth.

Gary

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End of Space Digest Volume 15 : Issue 495
------------------------------