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Subject: SPACE Digest V13 #495

SPACE Digest                                     Volume 13 : Issue 495

Today's Topics:
         Re: "Bussard Ramjets" AKA duct space drives
         Re: "Bussard Ramjets" AKA duct space drives
     One Small Step for a Space Activist... (Vol 2 No 5)
            SPACE Digest V13 #475
            SPACE Digest V13 #475
       PLEASE REMOVE ME FROM THE DL,  THANX IN ADVANCE
               Re: mars orbiter
            Re: Terraforming Venus

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription requests,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 4 May 91 07:31:03 GMT
From: agate!lightning.Berkeley.EDU![e-mail]  (Frank Crary)
Subject: Re: "Bussard Ramjets" AKA duct space drives

In article <[e-mail]> [e-mail] writes:
>I thought one of the problems in astrophysics at the moment was the
>uniformity of the interstellar medium. Or am I getting it confused with
>the M.B.R. ?

You are right that the uniformity of material in the universe is a BIG
problem in astrophysics (Cosmology more specifically). But you have the
wrong scale. The problem is that the universe is much more uniform than
expected, in terms of galaxy-sized clumps and gaps. For an interstellar
ramjet, the interstellar medium should be uniform on the scale of a few
million km. This level of nonuniformity could quite easily be possible.

                     Frank Crary
                     UC Berkeley

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

Date: 4 May 91 21:12:04 GMT
From: usc!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: "Bussard Ramjets" AKA duct space drives

In article <[e-mail]> [e-mail] writes:
>>As far as the uniformity of the ISM, all astronomical methiods of measuring
>>its density give results which are the average over, at least, light years.
>>Local density clumps are not detectable at this time.
>>
>I thought one of the problems in astrophysics at the moment was the
>uniformity of the interstellar medium. Or am I getting it confused with
>the M.B.R. ?

You are.  The problem -- on a vastly larger scale than anything relevant
to a Bussard ramjet -- is that the universe is very lumpy while the
microwave background radiation is very smooth, and it is difficult to
explain the evolution of such a lumpy universe from such a uniform
Big Bang.
--
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  [e-mail]  utzoo!henry

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

Date: Wed, 1 May 91 08:33:40 -0400
From: "Allen W. Sherzer" <[e-mail]>
Subject: One Small Step for a Space Activist... (Vol 2 No 5)


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

NASA's budget is now about as big as it is going to get in this decade. We may
continue to see small increases, but nothing major. This places an upper bound
on how many large programs NASA can undertake. NASA has room for three large
multi-billion space programs this decade. Currently these are Freedom and
Mission to Planet Earth. The third is the National Launch Development Program
(NLDP). No other major initiatives realistically can be expected before the
next century (unless things somehow change radically).

NLDP is a program to develop the next generation of Heavy Lift Vehicles (HLV)
and is sponsored by the Air Force and NASA. NLDP will develop a family of
launch vehicles lifting up to 160,000 pounds to LEO for $300/pound.

Is NLDP worth the money invested and the opportunity cost the US will invest
in it? Will it work? Currently it looks like the answer is no. The Air Force
and NASA seem to have very different views of the NLDP vehicle. The Air Force
wants a Titan IV follow on and NASA wants an HLV. A recent story in the April
15 Aviation Week also says that NLDP costs will go up from $300/lb to $500 to
$1,000/lb. It can only go up from here.

What we are seeing now is something very similar to what happened when NASA
began development of the Shuttle. The systemic problems which made the Shuttle
so expensive and unreliable are still there. The Shuttle was designed by a
committee with conflicting goals; so far NLDP is no different. NLDP will fail
for the exact same reasons the Shuttle failed.

What alternatives are there to the ten year, $14+ billion NLDP? We have written
about some recently. Companies have offered to build HLV's for about 5% of
NLDP's development cost and in half the time if the government will just buy
the launches. For $1 billion we could have two different HLVs with operational
costs far better than NLDP. If we were to build these other alternatives, we
would have $13 billion to spend on other projects. Furthermore, Title II of
last years NASA authorization act (which we all worked so hard for) seems to
make NLDP development moot; why develop it if you can't buy it? For that
matter why develop it when you can just buy it for far less?

If we build NLDP, we will spend the rest of the decade and have nothing to show
at the end. We will have no infrastructure to speak of and none on the
horizon. Get a copy of the Sept. 90 Aerospace America and read the article on
the Zenith Star Launch Systems. Meet with your Congresscritters and ask them
to spend our money where it will do some good.

We must stop spending dollars on what could be had for pennies.

                               Legislative Roundup

                                      ISDC
At this years Space Development Conference I will be running a workshop on
legislation. The workshop will outline what goes into legislation, how it
gets passed and how you can draft your own space legislation.

As an optional second part, a group will be formed to use the lessons learned
to pass a real piece of legislation. Current plans are to make the new version
of the Omnibus Commercial Space Act the bill we work for. If you would like to
help out, and are not going to ISDC, drop one of us a line and we will get
you busy.

                                Synthesis Group
As of this writing (April 24) the Synthesis Group report is being finalized.
It may will be out when you see this. Reports indicate that they will recommend
their own Heavy Lift Vehicle using what amounts to a Saturn V at the core and
SSME derived strap on boosters.

In other news, Rep. Lamar Smith (R-TX) added some special language into the
Report on the NASA Authorization bill for this year. This report language
will require NASA to maintain a core Synthesis Group made up of current
members. The NASA administrator is required to consult with them on enacting
the Synthesis Group recommendations. This will make it a lot harder for NASA
to put the Synthesis report on the back burner.

Things to do:
1. Get a copy of the report and read it. If you like what you read, write to
the Administrator of NASA and tell him. Ask him to support it and work to see
it enacted.

2. Write to the Vice President and the Space Council. Ask them to enact the
Synthesis proposals and push for funding.

                             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. Ask him/her
to cosponsor.

                       Omnibus Space Commercialization Act
The bill is close to completion and is in the hand of the House office of the
Legislative counsel. These guys are bunch of lawyers who will read the bill and
recommend changes to make the bill easier to interpret. Expect it to go 'in
the hopper' around May first. We will provide a summary of the bill next month
(assuming it is on schedule).

                             Tidbits
The NASA Authorization bill will go to the full house May first. By June first
the Senate should be done as well... In testimony before the House the military
seems to have done an about face on NASP. They now see lots of use for it which
should ease the funding battles... Rep. Rohrabacher (R-CA) got an amendment to
the NASA Authorization changing the name of one account from "Expendable launch
vehicles and services" to "Launch services". The report language makes it very
clear that the name was changed to show NASA that Congress is serious about
Title II.

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

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

ReSent-Message-ID: <Added.Ic7jvc200UkTEZTk9=@andrew.cmu.edu>
Resent-Date:  Wed, 01 May 91 13:36:26 EDT
Resent-From: Tommy Mac <[e-mail]>
Resent-To: [e-mail]
Date:         Sun, 28 Apr 91 02:01:50 EDT
Reply-To: [e-mail]
From: [e-mail]
Subject:      SPACE Digest V13 #475
Comments: To: [e-mail]
To: david polito <[e-mail]>, Tom McWilliams <[e-mail]>

Re: Screwed up Galileo

>>Perhaps a more sensible approach would be to jettison the reentry
>>probe, change the second gravity assist and salvage some science by
>>abandoning Jupiter and converting to a multiple asteroid flyby
>>mission.  It could repeatedly swing by earth and/or mars to be
>>directed onto flybys of new asteroids.  With luck, we could get
>>pictures of half a dozen or so, with the data from each encounter
>>played back over the low gain antenna at the next flyby of earth.

>I dunno about this one.  Getting a look at the atmospheric composition
>of Jupiter from the 'top' of the atmosphere on down to where the probe
>stops transmitting would seem (to me) to be worth a *lot* more than
>a few extra asteroid encounters, especially considering that the original
>encounters can still be done.  Not to mention, the extra detail (as compared
>to Voyager) we can get on the moons of Jupiter is worth a lot, especially
>for Io and Europa.  Dropping all this for a few measly asteroids seems to
>be a waste.

Sure dropping Jupiter for a 'few measly asteroids' would seem to be a waste.

But dropping Jupiter for the most abundant, accessible resources and plantetary
science specimens in the Solar System is a FANTASTIC idea.

Remember that, unlike the Planets, we can (eventually) study every gram of the
Asteroids, given the time and determinantion.  We will never study the interior
of any of Jupiter's moons, let alone Jupiter.

This not only means the Asteroids would make better scientific specimens, but
also means we can recover all the heavy metals (i.e. gold, iron, lead, copper)
that are forever hidden at the center of the other planets.

And finding those heavy metals could be the incentive that private industry
needs to get their butts busy building a space infrastructure.

You would like to see a space infrasturcture wouldn't you?

Tommy Mac
Acknowledge-To: <18084TM@MSU>

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

ReSent-Message-ID: <[e-mail]>
Resent-Date:  Wed, 01 May 91 14:11:08 EDT
Resent-From: Tommy Mac <[e-mail]>
Resent-To: [e-mail]
Date:         Sun, 28 Apr 91 02:01:50 EDT
Reply-To: [e-mail]
From: [e-mail]
Subject:      SPACE Digest V13 #475
Comments: To: [e-mail]
To: david polito <[e-mail]>, Tom McWilliams <[e-mail]>

Subject: Re: Alexander Abian wants to blow up the moon?

>>       Very late last night (around 4 or 5 AM) I tuned in to CBS's
>>"Nightwatch" news program in the middle of a "debate" between Bevan
>>French of NASA and some crazy loon at Iowa State University named
>>Alexander Abian.
>>       My question is basically... who IS this Abian guy and what
>>exactly is he trying to say?

>While standing in the checkout line last month with my bag of Doritos,
>waiting for the cashier to figure out the price on a bar of soap for the
>customer in front of me, I had the good luck to spy a copy of the Weekly
>World News, with the headline 'SCIENTIST WANTS TO BLOW UP MOON!' in type
>large enough to announce the advent of World War III.

>Basically, this guy wants to blow up the moon in such a manner as to
>have a large chunk drop into the Pacific, thereby knocking the planet
>into a 0 degree (as opposed to the current 23.45 degree) axial tilt,
>making it springtime forever over a large chunk of the earth and bringing
>happiness to all.  How he plans to do this wasn't made clear.

>There weren't any sidebars or graphs, though, so I discounted the article
>entirely. :-)

Despite the lack of Sidebars and Graphs (I think USA Today had some :-), this
kook is totally serious, or at least hard up for publicity.

In this weeks Newseek, he got on the 'funny/stupid quotes of the week' page.
He was talking about how we are victims of the 'celestial dictatorship' or some
such revolutionary jargon.

Aside from the possibility of cruching a highly poplulated area with moon-parts
or creating a mile-high tidal wave, or all the other stupid parts of this guys
idea there are other associated 'difficulties'

Even if it did work, the plan would

A) level the entire surface of the Earth due to the tourque induced as the
   angular momentum vector is wrenched 23 degrees.
B) Freeze most of the Planet because the new rings would shade most of the
   Earth for years and years.

However, that does not mean that nuclear explosions on the Moon would be all
bad.

1)  Wouldn't it make a hell-uv-a fireworks show?  Better than an eclipse!

2)  We could induce a spin on the moon!  Then we could study the far side
    without those costly probes and rockets.

3)  Better than testing the potentially dangerous things here!

Tommy Mac   :-)
Acknowledge-To: <18084TM@MSU>

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

X-Ns-Transport-Id: 0000AA00268C396B2BDC
Date:     Wed, 1 May 1991 21:53:01 PDT
From: [e-mail]
Subject: PLEASE REMOVE ME FROM THE DL,  THANX IN ADVANCE

To the owner,

Please remove me from the dl.  I can't seem to be able to do it myself.

Thanx in advance,

           Lisa

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

Date: 2 May 91 16:23:45 GMT
From: sdd.hp.com!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: mars orbiter

In article <[e-mail]> [e-mail] writes:
>As the original Viking Missions to Mars were winding down, there were already
>plans and a launch date to send the next set. Vikings 3 and 4 were to
>be similar to the first 2, with the addition of a detachable remote vehicle...
>The project was placed on indefinate hold after the Challenger Incident.

Um, really?  References, please.  There was talk of various Viking followons,
but as far as I know, all of them died long before Challenger.  (Remember,
Challenger happened ten years after the Viking landings.)
--
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  [e-mail]  utzoo!henry

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

Date: 2 May 91 17:58:49 GMT
From: news-server.csri.toronto.edu!helios.physics.utoronto.ca!aurora.physics.utoronto.ca![e-mail]  (Christopher Neufeld)
Subject: Re: Terraforming Venus

In article <[e-mail]> [e-mail] writes:
>>
>Since venus receives about twice? as
>much solar energy as Earth the water has vaporized which causes the
>huge atmospheric pressure, while on mars it may be frozen out in the
>polar caps and soil.
>
   Venus' high atmospheric pressure is not due to a huge mass of water
in the atmosphere. There is very little water in the atmosphere because
it tends to photodissociate and then the hydrogen leaves for deep space.
The atmosphere is primarily carbon dioxide, freed up from surface rocks
which tend to evolve it if heated in the absence of water.

>I think the main issue here is to first heat up the
>martian surface by throwing in some CFC's or something similar, or possibly
>permanently shielding venus from the sun. After the atmosphere is
>normalized by human standards then we can worry about wether or not it's
>or not and how we would go about cleaning up that.
>
   Heating up the martian atmosphere would not increase the atmospheric
pressure. It's not just PV=nRT, V=constant type problems from high
school chemistry. If anything the pressure would decrease marginally as
more atmosphere escaped into space. Similarly for Venus, the atmospheric
pressure is not going to decrease until the temperature drops to below
the liquification temperature of CO2 at the relevant pressure.

>    Also when people talk about bombarding  either mars or venus with
>comets. Where are they going to come from and how are they going to get here?
>Is their any evidence that their actually is an oort cloud, or is this
>just a nice hypothesis?
>
   The Oort cloud would be a long way to go for water. Comets dropped in
from the Oort cloud would also take tens of thousands of years to get to
the inner solar system if they were dropped in by simply cancelling
their orbital motion about the Sun. You'd have to get out and push it
all the way in if you were in a hurry. It might be more practical to
extract hydrogen from the gas giants, or water from their satellites.

>Mark Wieczorek


--
 Christopher Neufeld....Just a graduate student  | Flash: morning star seen
 [e-mail]    Ad astra! | in evening! Baffled
 cneufeld@{pnet91,pro-cco}.cts.com               | astronomers: "could mean
 "Don't edit reality for the sake of simplicity" | second coming of Elvis!"

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

End of SPACE Digest V13 #495
*******************