Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_3/V13_349.TXT

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Subject: SPACE Digest V13 #349

SPACE Digest                                     Volume 13 : Issue 349

Today's Topics:
      One Small Step for a Space Activist...  Vol 2 No 4
        Self Unloading Lunar Transport Vehicle
         Re: Let's build Freedom on the Moon
              Re: Solar Eclipse
              Re: Solar Eclipse
              Re: SPACE Digest V13 #344
    Re: One Small Step for a Space Activist...  Vol 2 No 4
              Re: Solar Eclipse

Administrivia:

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

Date: Tue, 2 Apr 91 09:16:12 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: One Small Step for a Space Activist...  Vol 2 No 4


                  One Small Step for a Space Activist...
                                      by
                            Allen Sherzer & Tim Kyger

                          In Search of Ancient Engines

One interesting old myth about the space program is what happened to the
Saturn V. Some say the parts and plans were lost; others say they were
deliberately destroyed to protect Shuttle. Congress has recently been holding
hearings on the NASA budget and interesting things are coming to light.

Rocketdyne put together a presentation to brief the Synthesis Group on what it
would take to build F-1s again (the F-1 was the first stage engine for the
Saturn V). It turns out that all required plans and drawings exist and that
several flyable engines still exist in environmentally controlled storage.
Sources say that for about $100 million in startup costs a 58 engine lot could
be built, with an average cost of $12.7M each, in 4.5 years. These engines
would be rated at 1.8M pounds of thrust (compared to 1.5M for the Apollo-era
engines), they would be throttable, and perhaps even be restartable.

ALS on the other hand wants to build the Space Transportation Main Engine
(STME). This engine will cost $2-3 BILLION to develop, and will cost about $5M
a copy; its designed to produce 600,000 pounds of thrust. (Keeping the STME
program going is Senator Howell Heflin's (D-AL) highest legislative priority
this year).

These new F-1s will cost 15% less per copy to build (measured by $$ per pound
of thrust) and have 5% of the development costs of STME. NASA wants a heavy
lift vehicle, guess which engine NASA is going to build?

                               Legislative Roundup

                             Spaceport Financing Act
HR-1358, the Spaceport Financing Act, was recently introduced by Reps Bacchus
(D-FL) and Shaw (R-FL). This bill will extend to spaceport bonds the tax
status currently enjoyed by airport bonds. This is similar (but not as far
reaching) as the equivalent provisions in last years Omnibus Space
Commercialization bill of Rep. Bob Walker (R-PA). The bill has been referred
to the House Ways and Means Committee for action.

Things to do:
1. Write your Congresscritters and ask for support of this bill. This is
especially important if your Representative is on Ways and Means.

                                      SSX
As we reported recently, SDIO is working on several SSX-like launcher concepts.
Of the four submitted two are vertical launch and landing, one is horizontal
launch and landing, and another is vertical launch horizontal landing. These
vehicles can be ready for launch in five years and will launch Atlas class
payloads for 1/10 the cost of an Atlas.

The budget for this project has been cut for next year. This means that it is
likely that only one instead of two alternatives will be funded and that
suborbital testing will slip by a year.

                                     SEI
Some members of the House Space Subcommittee are beginning to object to the
open-ended funding and schedule for SEI. They would like to see real schedules
and budgets. We can help make this happen by writing our Congresscritters and
encouraging them to demand that they be given real schedules and plans. (SEI
is in last place behind Mission to Planet Earth, SS Freedom, and ALS in the
funding battles).

                                 Synthesis Group
Expect to see Stafford's Synthesis Group report issued around May 1. Published
reports say they will recommend four options for Mars. One is a direct trip;
the other three build a Lunar base first. This report will be a good focus
point for activists. Get a copy of the report and read it; it's important.

One important aspect of the report is an emphasis on nuclear propulsion. All
four options require it and as we reported last month DoE has money in next
year's budget for it. So far so good, but activists will have an important role
to play when the effort is ramped up. Eventually the antinuclear people will
get wind of this and raise hell. Activists did a good job dealing with this
over the RTG issue and we will need to do it again. If you see a letter
opposing space-based nuclear power in your local paper, write a reply. If we
respond vigorously early on with reason and not hype, we can favorably shape
the discourse.

                               The Great Exploration
Many of the technologies needed for SEI are being worked on by DoE. This will
This will make it easier to get Great Exploration technologies (low cost
launchers and inflatables) into SEI, which could reduce cost and schedule.
Expect to see a lot of SEI funding inside DoE in the near future.

Despite this, the Appropriations Committees will be reluctant to fund civil
space with DoE funds (despite the fact that DoE is a member of the Space
Council). The showdown will happen in a few months. Grassroots help will be
needed to show support.

Things to do:
1. MEET with your Representative and Senators. Ask them to write a letter to
Rep. Bevil (D-AL) and Senator Johnston (D-LA) supporting this new program.

2. If you talk with your Senator about DoE efforts in civil space please
don't give the impression that this effort will hurt NASA. NASA's support in
the Senate is very strong. In fact, when supporters of commercial space
legislation last year told senators that the legislation would get NASA out of
the launch business, it made it a lot harder to get the bill passed. Instead
tell them that DoE involvement will help leverage NASA's efforts (which it
will) and that this effort is in line with the Augustine recommendations.

                   Omnibus Space Commercialization Act
The Omnibus Act is still pending and it may or may not have been 'dropped in
the hopper' by the time you read this. This bill promises to enact into law
many good ideas; get ready to push for it.

                             Tidbits
Sources inside General Dynamics say GD's internal management has killed their
SDIO SSTO (SSX) effort... Word in the street in DC is that NASA should expect
a $1 billion cut in the 92 appropriation...

Allen Sherzer: [phone] (W) [phone] (H) [e-mail] (net)
Tim Kyger: [phone] (W) [phone] (H) [phone] (voice mail)
p

   Allen

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

Date: 2 Apr 91 19:08:50 GMT
From: ccncsu!longs.LANCE.ColoState.EDU![e-mail]  (Jay Nestle)
Subject: Self Unloading Lunar Transport Vehicle


    I am currently designing a self unloading reusable
transport vehicle and wanted to throw my ideas at the space
readers for responses.  Please email me.

    My vehicle is designated L-SURV for lunar self
unloading reusable vehicle.  Basically this vehicle would
operate from LLO to lunar surface and back.  This would
assume a transfer platform of some kind in lunar orbit and
reliable OTVs.  Would a design of making the L-SURV capable
of OTV between LLO and LEO be more practical?  Basically this
means adding an aerobrake and more fuel for the round trip.

    The self unloading is going to be done with cabling
holding the payload (station derived modules or cargo pallets)
that will be severed or disconnected with exploding bolts.  Does
anyone know where explosive bolt information can be obtained?
Also has anything like this been done in the past?  Especially
in space.

    The propulsion will be attached to the sides of the
vehicle, this is so the payload can be "dropped off" the
bottom.  This is structurally more complex but with the
added simplicity of unloading we felt this was the best.

    Please feel free to discuss these proposed ideas and
keep me informed on what you all think!  Thanks!

                Jay Nestle

[e-mail]

   "Save the earth, develop space."  -  Bumper Sticker

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

Date: 3 Apr 91 01:03:49 GMT
From: hub.ucsb.edu!ucsbuxa![e-mail]  (Charles Frank Radley)
Subject: Re: Let's build Freedom on the Moon



The NASA 90 day study proposed exactly that ..  a lunar base
composed initially of Freedom modules.

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

Date: 3 Apr 91 02:25:46 GMT
From: phoenix![e-mail]  (Jon Edelson)
Subject: Re: Solar Eclipse

In article <[e-mail]> [e-mail] (John Roberts) writes:
>So for eclipses, I imagine it would be a slightly lesser degree of the same
>risk. Viewing the sun even during a partial eclipse is never recommended
>unless you know what you're doing and use a projection system or a filter
>approved for your particular application.

Watch out for this one, some years ago there was an eclipse in my home
town, and on the news was info about viewing.  One of the things
mentioned was that if you are not careful to use the proper filter, the
visible intensity of the light would be reduced to the point where you
could (comfortably) look directly at the sun, yet the level of IR or UV
would be high enough to cause damage.  Maybe John could post his projector
design.

-Jon Edelson ([e-mail])

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

Date: 2 Apr 91 09:55:54 GMT
From: elroy.jpl.nasa.gov!sdd.hp.com!wuarchive!waikato.ac.nz!aukuni.ac.nz![e-mail]  (GuyonAlanEdward Roche )
Subject: Re: Solar Eclipse

In <31530@usc> [e-mail] (Steve Robiner) writes:

>Can someone out there who has seen (well, maybe not directly) a total
>solar eclispe describe to me what it and the sky look like at the time?

>Questions:

>Does the whole sky turn very dark (or just a circular area around the
>sun/moon?  Can one see the stars in that area?

Not actually sure on this one, but I think the whole sky goes dark.

>Is it truly more dangerous to look at an eclipse than looking at the
>normal sun?  It can't possibly be any brighter.  The only danger I can
>see is that while viewing the relatively dark eclipsed sun, the moon
>moves out of the way, and one's dialated eye is caught off gaurd and
>exposed to the sun's full brightness.  Is there any other danger
>beyond that?

As I understand it, though the sun might not look very bright during a
total eclipse, the intensities at non visible wavelengths ( infra-red )
are, and it is very easy to cause much damage to the retina without knowing

>Has the sun's corona been observed above the Earth's atmosphere?  If not,
>isn't possible that it is merely an atmospheric phenomenon, just light
>scatering and refracting around the edges of the moon.

No the Corona is a real part of the sun caused by light emitted and reflected
by particles that are continuously streaming away from the sun.
(refracting around the sun ? HOW?)

>How big is the Moon's shadow on the Earth?  I would guess it's nearly the
>size of the moon, but there must be some refraction of light around the
>edges of the moon, making the totally dark shadow of the moon somewhat
>smaller.

The Umbra of the shadow (the bit that sees no sunlight) is sometimes quite
large and sometimes isn't there at all (see annular eclipse)

>Is the moon, during a full total eclipse, exactly the same apparent size as
>the sun, or is it larger?

the orbit of the moon is not circular it is ecliptic, which means sometimes
it may seem larger (when it is close to the Earth) and other times it may
seem smaller(when it is farther away).


Hope this is of some assistance

       /-------------\
       | Guyon Roche |
       \-------------/
--
New administrater uofa.

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

Date:         Tue, 02 Apr 91 15:48:00 EST
From: Tom McWilliams <[e-mail]>
Subject:      Re: SPACE Digest V13 #344

Re;  Railguns, EM launchers

No one has given a good explanation of how to beat the frictional problems
of a PURE gun-style launcher.

No matter how aerodynamic you make it, friction won't come down below roughly
.25 This is not ablative friction, but just skin-adhesion friction (I can't
remember the right term).  Even if you make 'real long and thin', you'll just
raise your coefficient, since you've raised the surface area.

Since friction only becomes a real problem at high sppeds, consider this idea
for the application of gun-type launchers:

Use a short rail, with moderate acceleration to put a fully-loaded, already-
been-tested-and-budget-approved chemical rocket moving up at around, say,
300mph, then fire the rockets.

Remeber the Saturn V?  It put about 200,000lbs into LEO.  It also burned about
1 ton of fuel PER SECOND as it was leaving the pad.  If it takes, say 20 s to
get up to 300mph, a partial rail-gun system could save 10 tons, or about 20%.
400mph could save, roughly, 35%, etc.

Now, combine that with the HOTOL concept, saving all the wieght of the O2, the
haviest part of the fuel anyway, for a payload savings around, say, 90%.

And that's not even talkin' 'bout the vechicle itself, or possible reusability.
I'm just an armchair aerospace engineer, after all.

Could you handle the acceleration up to 400mph over, say 5mi?  Could you afford
the easments?, etc.  I think so.  R&D?  The rockets we have.  HOTOL is really
just a plane with o2 systems.  Railguns are converted roller coasters. Of
course there's more to it than I make it sound, but there is far less invloved
than when you start from scratch, with say, laser or nuclear.

The fact that I can think of this, yet find no reference of the combination of
similar technologies to yeild better launch efficiencies elsewhere, is my proof
that the chemical rocket is not streched to it's limits, or fully explored.
BTW:  That's a ditto for EM, Rail, Hotol, Reusability, etc.

P.S>  I think chemical rockets will never, ever, have a market outside of LEO.
      My personal favorites are the ion rocket and solar sail.

Tommy Mac          I sure hope I get to see if I'm right!
18084tm@msu
Acknowledge-To: <18084TM@MSU>

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

Date: 3 Apr 91 01:06:02 GMT
From: hub.ucsb.edu!ucsbuxa![e-mail]  (Charles Frank Radley)
Subject: Re: One Small Step for a Space Activist...  Vol 2 No 4



I am puzzled about complaints that nobody is proposing
"real" hardware and schedules for SEI.    The following
paragraph answers the question - everybody has been holding off
waiting for the synthesis report.......

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

Date: 2 Apr 91 20:07:35 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!jarthur!nntp-server.caltech.edu![e-mail]  (David Palmer)
Subject: Re: Solar Eclipse

[e-mail] (David Tholen) writes:
>An eclipsed Sun is no more dangerous to look at than a normal Sun.  The added
>danger simply stems from the fact that people have a reason to look at the
>Sun during an eclipse, but not at other times.  Having said that, let me
>emphasize that both a normal Sun and an eclipsed Sun are indeed dangerous
>to look at directly.  Don't do it, if you value your eyesight.

WRONG.

When the sun is only a little way out from behind the moon, your
eyes tend to be fully dilated.  This allows 50 times as much light
per in as before.  Although the sun, when 98% covered, has
fifty times less light coming from it, this means that the same
amount of light hits your retina.

However, the light, instead of falling in a 1/2 degree circle,
is compressed in a thin cresent.  This gives you fifty times
the light per unit area on your retina.  So in one second,
that area gets as much heat as you would get by
staring at the sun, without moving your eyes, for about a minute.
It is, of course, much worse when all that heat comes at once.

A lot of people have crescent-shaped burns on their retinas from this.


--
        David Palmer
        [e-mail]
        ...rutgers!cit-vax!gap.cco.caltech.edu!palmer
    "Operator, get me the number for 911"  --Homer Simpson

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

End of SPACE Digest V13 #349
*******************