Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v08/v8_254.txt

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Subject: SPACE Digest V8 #254

SPACE Digest                                      Volume 8 : Issue 254

Today's Topics:
             SPACE Digest V8 #231
----------------------------------------------------------------------

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SPACE Digest                                      Volume 8 : Issue 231

Today's Topics:
             Group for Space Camp
            Re: Shooting the Moon
            Re: Shooting the Moon
            Re: Shooting the Moon
     Re: Cometesimals (was: Millions of comets hit Earth)
             Nevada fuel plant explosion
             runway designations
           Re: Nevada fuel plant explosion
               Re: runway designations
               Re: runway designations
           Re: Nevada fuel plant explosion
           Re: Nevada fuel plant explosion
           Re: Nevada fuel plant explosion
            Re: Is it CBS or NASA?
      SRM Fuel Composition (was:Re: Nevada fuel plant explosion)
            Re: Is it CBS or NASA?
            Re: Is it CBS or NASA?
----------------------------------------------------------------------

Date: 5 May 88 03:37:42 GMT
From: ulysses!terminus![e-mail]  (Luc)
Subject: Group for Space Camp

I lead a group of folks down to adult Space Academy level II each fall.
This is a three day program leading to flights in the Shuttle simulator.

The dates we are attending this year are October 7-9.  The cost is $405
(10% off).

I need to have all the money in by June 1.

If you're interested, send email or call me at: 703-361-1290 (h)
                                                703-689-5915 (w)

++rich

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

Date: 4 May 88 20:10:14 GMT
From: aramis.rutgers.edu!athos.rutgers.edu![e-mail]  (eliot lear)
Subject: Re: Shooting the Moon

We can use Mars to solve the world's parking problem ;-)

In article <[e-mail]> [e-mail] (James Van Artsdalen) writes:
> Why do it the expensive way when you can save money for other projects?

Ohyeahsure.

It reminds me of times when the military considered ABombs as practical
solutions to all of our problems.  Remember the days of John Foster
Dulles and the French?  Does science entirely understand the intended
effects AND the side effects that would be caused by such an explosion?

After all, in the long run, which way is the expensive way?

Eliot Lear
[[e-mail]]

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

Date: 4 May 88 16:15:28 GMT
From: aplcen!aplcomm!stdc.jhuapl.edu![e-mail]  (Jim Meritt)
Subject: Re: Shooting the Moon

In article <[e-mail]> [e-mail] writes:
>1. EXPLOSION ON THE PAD: Folks, the Challenger disaster was bad, really
>bad.  But imagine if it had a nuclear warhead on board.  Bye, bye South
>Florida!  A spaceship is one of the least stable places to keep a
>warhead!

Boy, I bet you have a tough time sleeping at night!

What is the difference between:
Rocket propelled vehicle capable of lifting off of the surface of a
planet and travelling at barely suborbital velocities above the bulk of
the atmosphere and conducting a controlled re-entry

and

a spaceship?

(the first is a description of an ICBM)

What is the connection between "a nuclear warhead" on the Challenger and
"Bye, bye South Florida"?

[e-mail] 128.244.65.5  (James W. Meritt)

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

Date: 4 May 88 19:40:09 GMT
From: cfa![e-mail]  (Bill Wyatt)
Subject: Re: Shooting the Moon

In article <[e-mail]>, [e-mail] (Eric
Tilenius) writes:
[...]
> I think the Life-on-Mars opposition to this argument has been
> adequately stated, but I wanted to point out a couple of extra
> arguments against this which I sent Paul through EMAIL (did you get
> it, Paul?):
>
> 1. EXPLOSION ON THE PAD: Folks, the Challenger disaster was bad,
> really bad.  But imagine if it had a nuclear warhead on board.  Bye,
> bye South Florida!  A spaceship is one of the least stable places to
> keep a warhead!

I agree that the nuking Mars is a BAD IDEA, but the above is *very*
unlikely to be a problem. Warheads just don't go off until armed, and
they are not armed until well after launch. Remember the H-bomb dropped
accidentally from a B52 over Spain in the 60's? Remember the Titan that
blew up in its silo in Arkansas, tossing the warhead almost a mile?

Bill    UUCP:  {husc6,ihnp4,cmcl2,mit-eddie}!harvard!cfa!wyatt
Wyatt   ARPA:  [e-mail]

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

Date: Wed, 11 May 88 18:22:49 -0400 (EDT)
From: Joe Keane <[e-mail]>
X-Andrew-Message-Size: 579+0
Subject: Re: Cometesimals (was: Millions of comets hit Earth)

In some article spar![e-mail]  (Jay Freeman) writes:
> Huh??  When you whack on something hard, you expect a louder noise,
> not a different pitch, than when you whack on it more gently.  The
> analogy here is Moon <-> bell (or drumhead, or tabletop); LEM impact
> <-> little hammer blow; impact of meteoroid or cometesimal <-> big
> hammer blow.

There are some natural resonant frequencies.  A small impact tends to
stimulate the higher ones, while a large impact tends to stimulate the
lower ones.  So you don't get different pitches, just a different
distribution.

--Joe

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

Date: 5 May 88 06:43:37 GMT
From: [e-mail]  (Kian-Tat Lim)
Subject: Nevada fuel plant explosion

By now, you've all heard about the explosion at the hypergolic fuel
plant in Nevada.  This is supposed to cause further setbacks for the
already-lame U.S.  space program.  Some early questions:

1) Shuttle uses monomethyl hydrazine and nitrogen tetroxide for OMS/RCS.
    Does the reported sodium perchlorate have anything to do with
    this?  If not, shouldn't it be unaffected?

2) What fuels do other launch systems use: Titan, Scout, Ariane?

Kian-Tat Lim ([e-mail], GEnie: K.LIM1)

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

Date: 3 May 88 19:53:10 GMT
From: nbires!isis!scicom![e-mail]  (Bruce Watson)
Subject: runway designations

In the TV program SPACEFLIGHT there is a sequence of the shuttle landing
on runway 23 at Edwards (There! That got it in sci.space).  Runways are
designated by the magnetic azimuth in 10 degree increments with the 0
omitted.  Since the magnetic pole wanders have there been runways whose
designations had to be changed?

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

Date: 5 May 88 17:23:49 GMT
From: concertina![e-mail]  (Steve Hix)
Subject: Re: Nevada fuel plant explosion

If sodium perchlorate was reported, correct the reporter: that should
have been ammonium perchlorate.  It's the oxidizer used in the SRBs.  I
think most of the rest of the active ingredients is taken up with
aluminum powder.  (I assume that the binder, sort of like synthetic
rubber, is comparatively inactive.)

As to how much effect on the space program, I suppose it depends on what
percentage of the total supply of fuel comes out of that one facility.
United Technologies, just a bit south and east of here, makes the solid
booster for the Titan-4, and they sort of indicated that their supplier
is not the one who had the accident.

> 2) What fuels do other launch systems use: Titan, Scout, Ariane?

a. Titan: Hydrazine and nitrogen tetroxide for the liquid engines, and
   solid boosters using ammonium perchlorate and aluminum for the
   strap-ons.

b. Scout: Solid fuel.  Not sure what type, but guess amm.perch., etc.

c. Ariane: LOX and (?) kerosene.  Maybe LH2.

The shuttle main engines, btw, use LOX + LH2.

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

Date: 5 May 88 14:11:45 GMT
From: cat.cmu.edu![e-mail]  (David Pugh)
Subject: Re: runway designations

Yes. Two airports I know of (AGC & ZZV, I think) had their runways
relabeled. You could see the old numbers painted out beneath the new
numbers.

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

Date: 5 May 88 22:16:10 GMT
From: portal!cup.portal.com![e-mail]
Subject: Re: runway designations

Yes, Runway designations change and variation lines move, and VORs get
reset every few years.  I don't know many of the details.

One thing to remember is that runway designations are quite approximate.
For example, San Jose has three parallel runways numbered 30L, 30R and
29.  The actual runway heading is probably somewhere between them.

OAKland's 33 is actually on a heading of 326 degrees.  Consult your
local instrument approach plate for the actual runway heading.
   -edg

[e-mail]

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

Date: 6 May 88 23:20:37 GMT
From: ubvax!unisv![e-mail]  (Mike Van Pelt)
Subject: Re: Nevada fuel plant explosion

In article <[e-mail]> [e-mail] (Steve Hix) writes:
>If sodium perchlorate was reported, correct the reporter: that should
>have been ammonium perchlorate.  It's the oxidizer used in the SRBs.  I
>think most of the rest of the active ingredients is taken up with
>aluminum powder.  (I assume that the binder, sort of like synthetic
>rubber, is comparatively inactive.)

The butyl rubber binder is also fuel; it burns quite nicely, though not
as exothermic as aluminum dust.  Starstruck's hybrid rocked used butyl
rubber as a fuel and LO2 as oxidizer.

I used to have the formula for the SRB propellant.  It also contains
some epoxy (about 5%?) and about 1% iron oxide as a 'combustion
enhancer'.  (Aluminum dust + iron oxide = thermite.)

Mike Van Pelt

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

Date: 6 May 88 18:27:28 GMT
From: ulysses!thumper![e-mail]  (Phil R. Karn)
Subject: Re: Nevada fuel plant explosion

> a. Titan: Hydrazine and nitrogen tetroxide for the liquid engines, and
>    solid boosters using ammonium perchlorate and aluminum for the
>    strap-ons.

Strictly speaking, the fuel for Titan is called Aerozine-50. This is a
50-50 mixture of straight hydrazine (N2H4) plus unsymmetrical dimethyl
hydrazine (UDMH -- take off the two hydrogens on one of the nitrogens in
straight hydrazine and replace them with two methyl groups). Water is
also present in small amounts, so it's really 49.5% N2H4 + 49.5% UDMH +
1% H2O. Straight hydrazine is denser than the organic variations (i.e.,
you can cram more of it into a tank), but it is less stable and it
freezes at too high a temperature.  The Aerozine-50 mixture is a good
compromise.  AMSAT Oscar-10 used UDMH in its kick motor; Phase 3-C (due
to go up in a few weeks) will use Aerozine-50, mainly because its
greater density will result in more kick per unit tank volume. The
payload is heavier this time, but the same size tank and engine are
being used.

> c. Ariane: LOX and (?) kerosene.  Maybe LH2.

The Ariane first and second stages use UDMH + N2O4. The third stage is
cryogenic; it uses LH2 + LO2.  Kerosene is not used anywhere on the
Ariane.

It's easy to tell from a launch picture when hypergolic fuels like those
used on Titan, Ariane and Proton are being used. The plume is almost
transparent, unlike those of kerosene-fueled rockets that emit
yellow-white plumes, or solid-fueled rockets that emit lots of dense
white aluminum oxide smoke.

Phil

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

Date: 6 May 88 21:37:33 GMT
From: mnetor!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Nevada fuel plant explosion

> c. Ariane: LOX and (?) kerosene.  Maybe LH2.

Tsk, tsk, two out of three wrong.  Ariane first and second stages use
nitrogen tetroxide and one of the hydrazine variants (UDMH I think).
The third stage is LOX/LH2.  Oh yeah, and solid strap-ons for the newer
variants (also still-newer liquid strap-ons but I don't know what they
burn, probably N2O4/UDMH).

To add to the list...

d. Atlas-Centaur:  LOX/kerosene in Atlas, LOX/LH2 in Centaur.

e. Delta:  LOX/kerosene plus solid strap-ons.

 Henry Spencer @ U of Toronto Zoology
{ihnp4,decvax,uunet!mnetor}!utzoo!henry

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

Date: 5 May 88 19:15:00 GMT
From: [e-mail]
Subject: Re: Is it CBS or NASA?

>By "victims of male technology" I understood a condemnation of the
>macho attitude that led NASA not to include any sort of escape
>mechanism in the shuttle. Which of course would imply some sort of
>cowardice and fear of battle and might be misused if someone chickened
>out and pushed the "let me out" button...right???  Can't have those
>heros chickening out, can we?

>Valerie Maslak

Every U.S. spacecraft before the shuttle had an escape system.  From
what I understand, the difficulty with including one in the shuttle was
that there was no way of including a system of more than marginal
survivability that was usable in the boost phase.  (For aerodynamic
reasons an escape tower was impossible, likewise for an orbiter
separation system.  Ejection seats were used on the first flight, but
would be to bulky to provide for all the crew, and if there is one thing
NASA would not want it would be for the flight crew to punch out leaving
the passengers.)  The current system (the pole and parachutes) would
only be of use either on the pad or in gliding (and subsonic) flight,
and appears to be more of a PR scheme than anything useful, considering
that those are the two safest portions of the launch.

ami silberman

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

Date: 6 May 88 12:33:47 GMT
From: ucsdhub!hp-sdd!ncr-sd!ncrlnk!ncrwic!encad![e-mail]  (Mark
Johnson)
Subject: SRM Fuel Composition (was:Re: Nevada fuel plant explosion)

The approximate solid fuel mix used in most of the various solid rocket
motors goes something like this:

    80% ammonium perchlorate
    10% powdered aluminum (which coincidentally gives the white exhaust)
    10% HTPB (Hydroxyl-terminated polybutadiene, a polymer which serves
          as both fuel and plastic binder, and which not
          coincidentally provides a good deal of energy into the
          bargain (15-20% more than earlier solid recipes of
          polyurethane base and similar ratios).

My percentages may be a bit off, but this is basically what's used.

Mark Johnson ([e-mail])

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

Date: 10 May 88 02:01:26 GMT
From: killer!bigtex![e-mail]  (James Van Artsdalen)
Subject: Re: Is it CBS or NASA?

IN article <74700087@uiucdcsp>, [e-mail] wrote:
> Every U.S. spacecraft before the shuttle had an escape system.

In principle at least, I believe they could also extinguish the rockets,
which the shuttle can't (SRBs).

> The current system (the pole and parachutes) would only be of use
> either on the pad or in gliding (and subsonic) flight, and appears to
> be more of a PR scheme than anything useful, considering that those
> are the two safest portions of the launch.

Is the pole really useful on the pad?  Isn't there a tower in the way?
:-) Even the ejection seats originally in place were not useful in
ascent phase.

Out of curiosity, what were the windows for the previous escape systems?
How long before the rockets were moving too fast or too high?

Question: Does anyone know when SRB separation occurs, height &
velocity?  I've been having trouble finding out.

James R. Van Artsdalen

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

Date: 10 May 88 10:25:25 GMT
From: [e-mail]  (Kian-Tat Lim)
Subject: Re: Is it CBS or NASA?

In article <[e-mail]> [e-mail] (James Van Artsdalen) writes:
>Question: Does anyone know when SRB separation occurs, height &
>velocity?  I've been having trouble finding out.

According to the Space Shuttle Operator's Manual, "By the time the solid
motors consume their propellants (T + 2 minutes and 12 seconds) you have
reached Mach 4.5 and an altitude of 28 miles (45 kilometers)."

Kian-Tat Lim ([e-mail], GEnie: K.LIM1)

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

End of SPACE Digest V8 #231
*******************

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End of SPACE Digest V8 #254
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