Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V09_3/V9_355.ZIP/V9_355

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Date: Mon, 10 Apr 89 05:16:42 -0400 (EDT)
Subject: SPACE Digest V9 #355

SPACE Digest                                      Volume 9 : Issue 355

Today's Topics:
        Re: more on Liberty Bell 7 (and other s'craft)
                  Re: Ozone
              Re: Magellan's Trajectory
        Was: Discovery - UFO Close Encounter?
        Re: more on Liberty Bell 7 (and other s'craft)
              Re: Hubble Space Telescope
               constant-boost rocketry
          Re: Building a fusion-based rocket
     Re: Room Temperature fusion - possible indications?
              Information needed
     Re: Room Temperature fusion - possible indications?
     Re: Room Temperature fusion - possible indications?
              Space News, Apr 6
----------------------------------------------------------------------

Date: 7 Apr 89 17:19:48 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: more on Liberty Bell 7 (and other s'craft)

In article <[e-mail]> [e-mail] (Tom [Chris] Murphy) writes:
>>plutonium-powered thermionic generator of Apollo 13's LEM.
>
>HUH?  All American (and probably all Soviet) manned spacecraft use
>fuel cells for electrical generation.  The U.S. doesn't make much use
>at all of nuclear-powered satilites, except for deep-space probes.

ALSEP, the Apollo Lunar-Surface Experiment Package, carried starting
with Apollo 13, used an isotope generator so that it could continue to
operate (and keep warm, for that matter) in the lunar night.
--
Welcome to Mars!  Your         |     Henry Spencer at U of Toronto Zoology
passport and visa, comrade?    | uunet!attcan!utzoo!henry [e-mail]

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

Date: 7 Apr 89 09:06:15 GMT
From: portal!cup.portal.com![e-mail]
Subject: Re: Ozone

[e-mail] (Stephen Hutchison) writes:
>Could some kind person clarify this for me?  I've been told by an acquaintanc
>who I would expect to have some knowledge of chemistry, that the Ozone layer
>gets rebuilt at night (since catalysts work both ways) and that it may
>actually
>be rebuilt somewhat in excess of the day's losses.  Has anyone tested this?
>He seemed convinced it was true and adequately explained the difference
>between
>the expected readings and the actual measurements.

     The ozone layer is produced by the action of ultraviolet light on
oxygen in the upper atmosphere.  Thus, it is replenished during daylight,
not at night.
     I don't know what you mean by "since catalysts work both
ways".  First of all, not all catalysts work "both ways", and secondly
(if I may assume that you are referring to "catalytic" destruction of
ozone by chloride radicals) the process by which chloride radicals (from
chloroflourocarbons) destroy ozone would definitely not be occur in the
reverse spontaneously.

Jim Kowalczyk
[e-mail]

[What a cross-post!  Only group missing was sci.chem :-)
 I will only see follow-ups in sci.misc and sci.chem]

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

Date: 7 Apr 89 14:39:38 GMT
From: [e-mail]  (Matthew T. DeLuca)
Subject: Re: Magellan's Trajectory

In article <[e-mail]> [e-mail] (Tom [Chris] Murphy) writes:
> (Galileo will take some 2.5 years to get to Jupiter I believe.)

That was the original flight time, I believe.  The new time, with the Venus
double-loop, will be on the order of 5.5 years.

--
--------------------------------------------------------------------------------Matthew DeLuca                      :
Georgia Institute of Technology     : Certainty is the lot of those who
ARPA: [e-mail]        :           do not question.
--------------------------------------------------------------------------------

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

Date: 7 Apr 89 15:34:39 GMT
From: m2c!ulowell!tegra![e-mail]  (Johnathan Vail)
Subject: Was: Discovery - UFO Close Encounter?

In article <243a1438@ralf> [e-mail] writes:
   In article <[e-mail]>, [e-mail] (Paul Rodman) writes:
   }In article <[e-mail]> [e-mail] (Steve) writes:
   }>When Apollo 13 had an electrical fire, loss of some power and system
   }>failure, they said "uh, Houston, we have a problem." somewhat toned
   }>down for public consumption.
   }I belive the quote was "Uh, Houston, we have a problem here.".
   }
   }I think toned down due to the nature of the Astronaut saying it, not for
   }any worry of public consumption.

   Then again, when Challenger exploded, the special report on CBS started with
   "There has been a major malfunction...."

I remember a half hour or more after the fact the term "apparent
explosion" being used by NASA.  The disclaimer being they had not
verified whatever data that would confirm there was an explosion.

BTW (getting a bit farther off track) I was amazed and impressed
watching the tapes of the control room.  Talk about cool.  Just a
second or two of silence then the controller with something like:
"lock you consoles, get hardcopy of your screens, protect all your
data sources, fire off a message to the press..."

Another tense time was when they almost aborted to Spain when it
looked like some kind of valve in the main engines was bad.  The
controller (a woman whose name I forgot) made the quick decision to
continue which turned out to be correct as the indicator or sensor was
the part that was bad.

If anyone has details here I would like to refresh my memory on this.
(sorry, no dynamic refresh....)

"The crux of the biscuit, is the apostrophe" -- This is the dog talking...
 _____
|     | Johnathan Vail  | tegra![e-mail]
|Tegra| [phone]  | N1DXG @ 145.110-, 444.2+, 448.625-
 -----

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

Date: 7 Apr 89 14:32:00 GMT
From: [e-mail]  (Matthew T. DeLuca)
Subject: Re: more on Liberty Bell 7 (and other s'craft)

In article <[e-mail]> [e-mail] (Stuart Warmink) writes:
>
>(By the way, other than the new shuttle, the Soviets have always used solar
>power and/or batteries for their manned spacecraft.)

Soviet RORSAT's (Radar Ocean Reconaissance SATellite) use nuclear reactors for
power, since the power consumption of a powerful radar is quite impressive.
If nothing else, the Soviet satellite that came down in Canada in 1979 was
nuclear, and the Canadians were less than pleased with the radioactive debris
strewn across the Yukon.  Also, the Russians are saying that they want to
sell their new Topaz reactor to other nations for space applications.

--
--------------------------------------------------------------------------------Matthew DeLuca                      :
Georgia Institute of Technology     : Certainty is the lot of those who
ARPA: [e-mail]        :           do not question.
--------------------------------------------------------------------------------

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

Date: 7 Apr 89 19:44:27 GMT
From: phoenix![e-mail]  (Matthew B. Kennel)
Subject: Re: Hubble Space Telescope

In article <[e-mail]> [e-mail] (Greg Hennessy) writes:
>In article <[e-mail]> (Philip Verdieck) writes:
>#
>#What are the capabilities for rotating this baby and using it for
>#spying purposes???
>
>Not much, since the detectors are sensitive enough to burn out. A
>KH-11 or KH-12 will do the job for you though.
>
>-Greg Hennessy, University of Virginia
> USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
> Internet:      [e-mail]
> UUCP:        ...!uunet!virginia!gsh7w

My father, who is on various NASA committees, claims that a KH-11/12
is essentially a Hubble Telescope pointing down.  2-3 meter primary,
>2 gigadollars, many tons.  I suspect that it's not the optics on
the space telescope that make it unsuitable for spying, but the lack
of encryption for the beamed-down data.

Does the space telescope have cryostats?  By "burn out" do you mean
boil away?  (i.e. does do IR?)  Or are CCD's damaged permanently from
high fluxes?  What happens if a 10 GeV proton decides to deposit
its energy in the CCD chip?

Matt Kennel
[e-mail]

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

Date: 7 Apr 89 17:36:33 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: constant-boost rocketry

In article <[e-mail]> [e-mail] (Tim J Ihde) writes:
>Of course further research is needed here, but maybe .5G would be good
>enough?  Or .25?  I can't believe these problems (originally we were talking
>about immune system difficulties in extended free fall, I believe) magically
>appear at 1G - epsilon.

Probably not.  But our experience with partial gravity is a total of a few
man-days in 1/6 G.  (And you thought our experience with free fall was
limited...)  How much you need is an open question.
--
Welcome to Mars!  Your         |     Henry Spencer at U of Toronto Zoology
passport and visa, comrade?    | uunet!attcan!utzoo!henry [e-mail]

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

Date: 7 Apr 89 17:47:44 GMT
From: tektronix!psueea!psu-cs![e-mail]  (Sandy Michael)
Subject: Re: Building a fusion-based rocket


Why on Earth do you want a fusion powered _rocket_?  Sounds like a total
waste of energy. ;*)

How about a fusion powered electricity generator powering an ion drive!!!

Real big Deuterium tanks and a load of Palladium and reactor shielding and
all that fun stuff.  Depending on the size of the tanks to payload ratio
you could get into some relativistic effects even.  Maybe .1 c if you're
cheap with the deuterium.  For probes with light payload you might get
some stuff to the nearer stars by 2100.

What technology do you see the Earth having by the year 3000?
Michael Sandy
[e-mail]

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

Date: 6 Apr 89 21:19:27 GMT
From: att!mtuxo!rolls!attdso![e-mail]  (Tim J Ihde)
Subject: Re: Room Temperature fusion - possible indications?

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
<In article <[e-mail]> [e-mail] (James C. Benz) writes:
<>Well, if you are going to assume *lots* of relatively free fusion energy,
<>why not just accelerate at 1G or some appreciable fraction thereof, until
<>you are halfway there, then turn around and decelerate at the same rate?

<Because the power requirements are not merely high, but staggering, if
<the fuel consumption is to be kept sane.  . . . way up in the terawatts . . .
<. . . 1% inefficiency means you have to dissipate gigawatts of heat.

Hmmm . . . good point.

Of course further research is needed here, but maybe .5G would be good
enough?  Or .25?  I can't believe these problems (originally we were talking
about immune system difficulties in extended free fall, I believe) magically
appear at 1G - epsilon.

--
Tim J Ihde                INTERNET:   [e-mail]
[phone]                UUCP:        att!attdso!tim
"Blimey - this redistribution of wealth is more complicated than I'd thought!"
        - Dennis Moore and various Presidents

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

Date: Fri, 7 Apr 1989 14:40-EDT
From: [e-mail]
Subject: Information needed

I and a coauthor are nearing the end of draft 2 of a rather large SF
novel (10 years in the making), and I need a few pieces of information.

What would be the appearance of the plume from an antimatter rocket
using Hydrogen? I would presume the Hydrogen comes out the nozzle as a
plasma of protons and electrons that gradually recombine and give off
EM.

Can anyone describe the appearance of such a plume?

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

Date: 7 Apr 89 17:33:28 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Room Temperature fusion - possible indications?

In article <[e-mail]> [e-mail] (Jim Meritt) writes:
>}>why not just accelerate at 1G or some appreciable fraction thereof...
>}
>}Because the power requirements are not merely high, but staggering, if
>}the fuel consumption is to be kept sane.  I did the calculation in sci.space
>}a week or two ago; it was way up in the terawatts, as I recall...
>
>Maybe terawatt-hours? terawatt is, I believe, power, not energy....

They asked about power, so I answered with power.  Terawatts.  A constant-
boost system needs a constant amount of power (ignoring possible throttle
changes as vehicle mass changes), which can be calculated fairly easily.
In this case it wasn't necessary to figure total energy requirement; it
sufficed to show that the continuous power requirement was enormous, hence
extremely difficult to handle.

>And as such, while the momentary power requirements would be in terms of
>watts, that would say nothing about the energy requirements (except,
>perhaps, for peak load).

Energy requirement dictates how much fuel you have to carry.  Power
requirement dictates how heavily-built the engine and support hardware
must be.  The former tends to be the dominant problem with chemical rockets
and the like, but the situation changes for high-energy systems.  It's not
hard to figure out that a fusion rocket will have really major cooling
problems, for example.  Constant-boost systems are especially bad because
if you're going to thrust for days at a time, your fuel consumption has
to be pretty low, which means you have to put *lots* of energy into that
small amount of fuel to get reasonable thrust.  (An equivalent way of
looking at it is that constant-boost systems reach very high velocities,
which is expensive in either fuel or energy -- your choice.)

(PS:  Why are you talking about "momentary" power requirements for a
constant-boost system?)
--
Welcome to Mars!  Your         |     Henry Spencer at U of Toronto Zoology
passport and visa, comrade?    | uunet!attcan!utzoo!henry [e-mail]

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

Date: 7 Apr 89 08:21:27 GMT
From: gondor.cs.psu.edu![e-mail]  (Mark A. Sobolewski)
Subject: Re: Room Temperature fusion - possible indications?

>In article <[e-mail]> [e-mail] (Henry Spencer) writes:
><In article <[e-mail]> [e-mail] (James C. Benz) writes:
><>Well, if you are going to assume *lots* of relatively free fusion energy,
><>why not just accelerate at 1G or some appreciable fraction thereof, until
><>you are halfway there, then turn around and decelerate at the same rate?
>
><Because the power requirements are not merely high, but staggering, if
><the fuel consumption is to be kept sane.  . . . way up in the terawatts . . .
><. . . 1% inefficiency means you have to dissipate gigawatts of heat.

    For the record... I get 1 gigawatt for a 20 kilo-ton (metric) mass
accelerating at 1g.  (P=E/t, delta(v)=g*delta(t) (1 second),E=0.5mv^2,
20,000,000kg)  (minimum power consumption of course).

    While not a very large ship....  It still has enough room
for a lifesystem, fusion plant, super-conductors (to push against the
interstellar flux, possibly)  with room left over for landing vehicles.

    Don't expect one in 10 years.  But I would not be surprised if I see
one made in my lifetime.

------------------------------------------------------------------------------
Mark Sobolewski   "If you're going to lose anyway, you might as well win."
[e-mail]      #include<std.disclaimer>

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

Date: 7 Apr 89 15:44:00 GMT
From: cfa!cfa250![e-mail]  (Jonathan McDowell)
Subject: Space News, Apr 6


Jonathan's Space Report

Apr 6, 1989 (No. 10)


The Swedish Space Corp. broadcasting satellite, Tele-X, was launched
on Apr. 1 by Ariane 2 flight V30 from Kourou, South America. It is
now in geostationary orbit.


Preparations continue for the launch of Soyuz TM-8 on Apr 19
and Space Shuttle mission STS-30 on Apr 28.

The Soviet Kosmos-1993 recon satellite landed on March 27 after a two
month mission.


All a bit quiet, really..  I bet something really exciting happens while
I'm away down in DC for the weekend.

---------------------------------------------------------------------------
(c) 1989 Jonathan McDowell, all rights reserved
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------------------------------

End of SPACE Digest V9 #355
*******************