Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v16_1/v16no164.txt

Internet Message Format | 1993-07-13 | 30KB

Date: Fri, 12 Feb 93 18:41:16
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #164
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 12 Feb 93       Volume 16 : Issue 164

Today's Topics:
                Antimatter/Atomic Booms for Jettison!
                        Challenger transcript
                    hardware on the moon (2 msgs)
                     HST repair mission (2 msgs)
        Launching in a Winter Wonderland (was Re: Polar Orbit)
                        leading-edge anonymity
                 Payload Hit For Polar Orbit (2 msgs)
                         Peekskill Meteorite
                Pegasus Launch Successful this Morning
        Pt 1/2: FREE-ENERGY TECHNOLOGY For Spacecraft (2 msgs)
         SS Freedom and Supercollider again on chopping block
                 Supporting private space activities
       Tethers for electricity generation (was Re: Beanstalk?)
                           What was ASSET?

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
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----------------------------------------------------------------------

Date: 9 Feb 93 19:24:33 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Antimatter/Atomic Booms for Jettison!
Newsgroups: sci.space

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

>Way to handle anti-matter or atomic engines/rockets. Do it the same way the
>Enterprise does it.. Put them on booms and if they go critical jetteson them..

A reactor goes critical whenever it's in operation.  What
you mean to say is "supercritical."  However, that happens
less often in real life than it does on Star Trek.

You would probably want your engines on a long boom anyway,
however, because it makes radiation shielding much easier.


>Or put them behind the space craft and jettison them.. or combine them..

>==================
>                 \ -----------
>                   |__________|

>Engine on top

Well, if you mount an engine that way, its line of thrust is
not through your center of mass.  So when you start it up,
it will spin your ship like a pinwheel.

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

Date: Tue, 9 Feb 1993 19:28:57 GMT
From: Jochen Bern <[e-mail]>
Subject: Challenger transcript
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>      I don't think that it is seriously disputed that the 51L crew
>      was alive after the breakup at 73 seconds. Its the anonymously
>      posted "transcript" that angers the audience. Even if it is
>      true (more evidence against than for) its posting here was in
>      questionable taste, at best.

Just my .02 (perhaps less biased since I'm no US Citizen):

-- There *is* public Interest in what happened to the Crew after the Ex-
   plosion. Reason: It's the *only* Shuttle Explosion we've had so far,
   so all our Knowledge is based on this one. Suppose that there are
   Lots of People out there which might have good Ideas (eg., Escape
   Sys Designers), it's not a very good Idea to present forged Facts
   to them.

-- There is *no* well-founded public Interest in the Content of the Tape
   *if* the Tape contains what the initial Poster said it contains.

-- There *would be* public Interest in the Content of that Tape if, eg.,
   we could conclude from it that the Commander tried to get back Control
   over the Shuttle, and failed due to whatever technical Reason.

Thus, for anybody having a Copy or a Transcript of the real Tape (if there
is one) and not willing to publish it completely, just answer two Questions:

a) Was the Crew killed, unconscious, or ready to take any Actions when the
   ET had blown up?
   (If you want to design an Escape System, this makes the Difference
   between "forget it", "make it automatic" (and, thus, unsafe), and
   "make it and put it under manual Control".)

b) Did they try to save themselves? If yes, how and why did they fail?

>      Worse, the anonymous poster presented the transcript as fact,
>      The person who posted the transcript was either:
>       A) Carrying an axe to grind against the space community,
>       B) Exceedingly naive, or
>       C) Looking for a quick thrill.
>      This the net can do without.

Correct. In the Beginning, I would have added "or D) better informed than
we are", but this would have been a more academic Possibility and I think
that it has been proven false meanwhile.

Regards,
                                J. Bern
--
 /  \  I hate NN rejecting .sigs >4 lines. Even though *I* set up this one. /\
/ J. \ EMail: bern@[TI.]Uni-Trier.DE / ham: DD0KZ  / More Infos on me from /  \
\Bern/ X.400 Mail: S=BERN;P=Uni-Trier;A=dbp;C=de  /   X.400 Directory, see \  /
 \  /  Zurmaiener Str. 98-100, D-W-5500 Trier    /     X.29 # 45050230303.  \/

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

Date: Tue, 9 Feb 1993 18:08:40 GMT
From: Ed Faught <[e-mail]>
Subject: hardware on the moon
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer)
writes:
>most of the seismometers and other instruments were alive until
>they were deliberately turned off in 1977.  (That was when the money
>for collecting and analyzing the data ran out.)

As I recall they were turned off during the successful Apollo-Soyuz rendezvous
in order to keep the action in the background. I still believe it was a
monstrously stupid thing to do.

--
Ed Faught  WA9WDM  [e-mail]
 Superconducting Super Collider Laboratory

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

Date: Tue, 9 Feb 1993 19:20:16 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: hardware on the moon
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Henry Spencer) writes:

>But not from the Moon itself.  The Moon's gravitational field is very
>lumpy, thanks to the mascons (heavy spots in its crust).  It is not
>particularly well mapped, but so far as we know there is no such thing
>as a stable lunar orbit in the long term.  They all get perturbed enough
>to intersect the surface eventually.  Designs for lunar orbiters have
>to include quite substantial amounts of orbit-correction fuel.

When NASA wanted to build a second Skylab and put into orbit
around the Moon, they estimated it would have a lifetime of
something like 60 days.

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

Date: 9 Feb 93 10:46:41
From: Steinn Sigurdsson <[e-mail]>
Subject: HST repair mission
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:


   >There's a faint rumour that the "return-to-Earth" option
   >for the HST mission has been re-opened and that a committee [sic]
   >has been set up to look at that option [again].

   >Anyone know whatsup? Are there new concerns over the EVA
   >schedule or is this out of the blue.

   >|  Steinn Sigurdsson

      Returning Hubble is a last ditch option, but that has been the
      case all along, there is no change in the timetable.

Ok, let me firm this up. "What's New" last friday claimed
the GAO was pushing for a new analysis of returning Hubble
and that a committee had been set up to review the matter again,
I've also heard analogous rumours from other sources, but they
might all go back to "What's New". So, in the last week,
has the possibility of HST return as primary objective been
opened for review and if so who would be suitable for receiving
comments?

BTW the conventional wisdom, as I understand it, is that if
HST is returned it will most probably never fly again, and
as far as I'm concerned it is far better used as is then returned
 - a successful repair is of course the best possibility.

|  Steinn Sigurdsson    |I saw two shooting stars last night        |
|  Lick Observatory    |I wished on them but they were only satellites    |
| [e-mail] |Is it wrong to wish on space hardware?        |
| "standard disclaimer"    |I wish, I wish, I wish you'd care - B.B. 1983    |

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

Date: 9 Feb 1993 19:53:19 GMT
From: Doug Mohney <[e-mail]>
Subject: HST repair mission
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] writes:
>
>>>   According to last week's "Space News", Endeavour on December 2...
>
>>And some of you people think this could be done with a Soyuz.
>
>Hmmm... I can't think of anybody who thinks it can be done with only
>a Soyuz. I do however know of lots of people who think it can be done
>with any of the inexpensive space station ideas out there combined
>with one of the several OTV concepts also out there.

> Both could be
>developed and operated for a fraction of what Shuttle costs simply
>to operate. Not only is it a lot cheaper but returns several times
>the science as both Shuttle and Fred put together.

You forgot your smoke and mirrors, Allen.

The real problem I have with your handwaiving is, while you make these
grand claims of killing Shuttle to solve all the problems of U.S. manned space
flights:

    A) You piss away your time promoting politically unsupportable
       schemes, like Soyuz on Atlas, while

    B) You have to beg for money and flash a panic alert to keep DC
       development going.

    C) You have never, ever, EVER addressed how you are supposed to
       circumvent the aerospace lobbying machine.


>More importantly, it is cost effective. We will likely spend more
>on Hubble repair then it would cost to simply build another and
>send it up on a ELV.

Oh really? So, how much is time worth to a science researcher who has time
booked on Hubble?  How much time do you lose while you try to get another
replacement built and launched?

> Cheaper approaches will not only make it far
>easier to do (a station with a OTV could have scheduled the reapir
>long ago)

Not that you address how the money was supposed to appear magically.

> but will actually make it cost effective. (I realize that
>you don't like cost effective solutions but they will make space
>more popular).

Sure.  Implementation of said "cost effective" solutions has, in a
word, sucked.

Why don't you just come out of the closet and say you want to kill every NASA
employee above a GS-14 or so?


                    I have talked to Ehud, and lived.
  -- >                  [e-mail]                        < --

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

Date: Tue, 9 Feb 1993 18:29:17 GMT
From: [e-mail]
Subject: Launching in a Winter Wonderland (was Re: Polar Orbit)
Newsgroups: sci.space

Leigh Palmer ([e-mail]) wrote:
: In article <[e-mail]> ,
: [e-mail] writes:

: >My wife has Renault's Syndrome [sp?], a problem with blood flow to the
: >hands which gives her perpetually cold fingers.

: I think that's Reynaud's Syndrome (but I'm not sure, either); it is not
: uncommon. I've got it, too.

: Renault's Syndrome is indicated when an otherwise sane person suddenly
: buys a French car.

No, it must be some other disease.  My wife suddenly buys pick-up
trucks.  Twice, now.  Maybe it's related: Dodge Disease?  S-10-itis?

-- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office
      [e-mail]  [phone]

     "Instant gratification takes too long." -- Lisa Jenks

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

Date: 9 Feb 93 14:38:15 GMT
From: [e-mail]
Subject: leading-edge anonymity
Newsgroups: sci.space,sci.astro,alt.privacy

In article <[e-mail]>, [e-mail]
(Jason Cooper) writes:

> I really had to reply to some of the JUNK being posted here about
> anonymity.  To say that anonymous stuff is automatically junk _IS_
> prejudice, plain and simple.

I have not seen that said in the articles which I have read.  I think that the
spirit of the objections raised against anonymous posting was that it allows
the medium to be abused by unscrupulous posters.


>                               The reason people post anonymously is so
> that they don't have to put up with some of the CRAP I've seen around
> here.  If you think this guy's just out to stir things up, why are you
> giving him what he wants?  _HE_ never stirred things up.  If you took a
> look around you, you'd see that, in fact, YOU have been the ones stirring
> things up!
>
>                                                         Jason Cooper


Instead of making this a "free-er medium" by allowing posters to "protect
themselves" with anonymity, simply require that all posters be prepared to
discuss their sources of information and take the heat for unsubstantiated
dribble.  This seems to be the way things are currently done;  the "crap" to
which you refer is simply this newsgroup's "selective pressure" against stupid
posters making stupid postings.

Remember, this is a newsgroup for posters writing about SCIENTIFIC issues.
Anonymous discussion of scientific issues leads to bad science.


Aaron Christopher
Ball State Univ.



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

Date: Tue, 9 Feb 1993 19:07:24 GMT
From: "Kieran A. Carroll" <[e-mail]>
Subject: Payload Hit For Polar Orbit
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Rickel) writes:
>
>In article <[e-mail]>, "UTADNX::UTDSSA::GREER"@utspan.span.nasa.gov writes:
>|> We know that kinetic energy varies with the square of the velocity.  Orbital
>|> velocity at 300 km altitude is about 7700 meters/second, while the velocity of
>|> the surface of the Earth at the equator is about 460 m/s...
>
>OK, what is important is delta-V.  Using your numbers:
>
>Equator launch - equatorial orbit    7240 m/s
>Equator launch - retrograde equ. orbit    8160 m/s
>Equator launch - polar orbit        7714 m/s
>Pole launch - polar orbit        7700 m/s
>
>Pretty clearly, the differences in velocity needed for polar orbit from the
>equator or polar orbit from a pole are pretty insignificant.  Anyway,
>plucking numbers out of the air, let's assume that you always need an
>additional 1.5 km/sec to make orbit (atmospheric effects), and that your
>effective exhaust velocity is 4.4 km/sec.
>
>So the table now goes
>
>Launch        delta V        effective    required
>type        (km/sec)    delta V        mass ratio
>                (km/sec)
>
>E - E        7.24        8.74        7.29
>E - RE        8.16        9.56        8.78
>E - P        7.714        9.214        8.12
>P - P        7.7        9.2        8.09
>
>Using these numbers, the penalty for equatorial launch into polar orbit vs
>polar launch into polar orbit is on the order of 0.4%.
>
>
>david rickel
>[e-mail]


Thanks for posting these numbers; they've motivated me to
pull a book off the shelf and see what they turn into.

I'll start by assuming that your numbers are good. Then, I'll
apply them to a vehicle of the sort that has been proposed
for launch from a near-polar launch site. Bristol Aerospace
has been working on the "Orbital Express" launcher for awhile,
the concept being to launch it from Poker Flats (as I
understand it). This is roughly "Scout-class", being about 500 lb
to LEO, so lets use Scout numbers.

From a book titled "The Encyclopedia of Space Technology"
(Crown Publishers, New York, 1981), I finda table that says
that a Scout D has a wet weight of 47,000 lb, and can deliver
390 lb to a 300 km orbit. Probably better numbers are available,
but lets use these for convenience.

Consider your case E-P. Assume that
launch weight = 47,000 lb.
Since Mass Ratio = 8.12,
therefore Dry weight = 47,000/8.12 = 5788.2 lb,
and Fuel Load = 47,000/7.12 = 41211.8 lb.
Since Payload = 390 lb,
thus, structural weight = 5788.2-390 = 5398.2 lb
(i.e. the weight of the launch vehicle, minus the combined
weight of the payload and the launch vehicle's fuel load).

So, let's use this as the baseline. Now, consider launching the
same vehicle from close to the north pole---your P-P case.
The launch vehicle structural weight is assumed to be
unchanged, at 5398.2 lb. Assume that the all-up
weigth is also the same, at 47,000 lb. The slightly-
improved mass ratio of 8.09
results in a dry weight of 47,000/8.09 = 5809.6 lb,
for a fuel load of 41190.4 lb. (i.e. assume that we are free
to adjust the total amount of fuel in the vehicle).
Thus, payload weight = 5908.6-5398.2 = 411.4 lb.
This is 5.5% more than in Case E-P.

Thus, a very small change in mass ratio corresponds here
to a much larger change in payload. This is because the payload
mass is such a small fraction (0.83%) of the dry weight;
thus, payload is very sensitive to slight changes in dry weight.

Note that for a typical spacecraft, the operating payload might
amount to 50% of the spacecraft weight, and maneuvering fuel
perhaps 5% of the spacecraft weight. Case 2 thus allows
an increase in payload size of perhaps 11%, or a doubling in the
amount of maneuvering fuel. This might correspond to increasing
a commercial spacecraft's revenue by 11%, or doubling its
lifetime, neither of which is a negligible effect.

Of course, your mass ratios don't take into account the
effects of staging, or a myriad of other smaller effects that
go into calculating the true performance of a real launch
vehicle. However, I believe that my main conclusion is
relatively insensitive to these (please correct me if I'm wrong!).
What Prof. Tennyson claimed appears to me to be true---there
is a significant advantage to be had from launching into polar orbit
from near the poles. (Hopefully, this will outweight the significant
>disadvantages<. For example, at Churchill the sounding rockets
were launched from >indoors<, due to the horrifyingly low
temperatures, high winds and blizzards that are common there during
much of the year.)
--

     Kieran A. Carroll @ U of Toronto Aerospace Institute
     uunet!attcan!utzoo!kcarroll [e-mail]

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

Date: 9 Feb 93 20:31:37 GMT
From: Dave Stephenson <[e-mail]>
Subject: Payload Hit For Polar Orbit
Newsgroups: sci.space

Just a quick comment. I thought that Bristol and Thiokol had parted
company on the 'Orbital Express'. The Bristol stages did not have the
performance that Thiokol was shooting for. The problem with all small
rocket launchers is the specific cost. The fixed charges, launch site
etc. make them expensive in terms of pounds in space. It is cheaper
to hitch a ride (if one is going!) with a big commercial launcher putting
a payload into polar orbit.
The other problem is that most studies I have come across estimate there
is a world market for 1 small solid fuelled launcher, and there are
so many nations and countries with plans for their own small launcher.
The cheapest small launcher was arguably the British Black Arrow liquid
fuelled launcher, but that is a sad story.
--
Dave Stephenson
Geodetic Survey of Canada
Ottawa, Ontario, Canada
Internet: [e-mail]

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

Date: 9 Feb 1993 18:59 UT
From: Ron Baalke <[e-mail]>
Subject: Peekskill Meteorite
Newsgroups: sci.space,sci.astro,alt.sci.planetary

The meteorite that went through the trunk of the car in Peekskill, New York,
last October is on display at the Best Western Executive Inn in Tuscon,
Arizona.  The car is also on display in the front of the hotel.  The meteorite
is in the room of Lang's Fossils & Meteorites.  The meteorite has been
sliced up and sold in smaller pieces, and about 12 pounds of the original
27 pound mass still remains.  A cast of the original meteorite is in the lobby
of the hotel.  Small fragments of the meteorite (about 1 gram) and a
copy of the local newspaper with the meteorite story are availabe for $25.
The going price for both the remaining 12 pound meteorite and the car is
$125,000.   The car and the meteorite will continue to be on display until
February 14.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Never yell "Movie!" in a
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | crowded fire station.
|_____|/  |_|/       |_____|/                     |

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

Date: Tue, 9 Feb 1993 20:18:54 GMT
From: Jeffrey J Bloch <[e-mail]>
Subject: Pegasus Launch Successful this Morning
Newsgroups: sci.space

As seen on NASA Select this morning, Pegasus
successfully launched a Brazilian communications
satellite at approximately 9:30AM EST. Launch
looked nominal, except for someone saying
15 seconds before drop, "Abort!, Abort!", due
to an apparent loss of contact with the command
receiver that controls the vehicle destruct.
However, moments later, the count proceeded and
just as Pegasus dropped from the B-52, someone
else on the net said, "Did someone say 'Abort'?".


                Jeff

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

Date: 9 Feb 93 18:15:01 GMT
From: Eric Van Drunen <[e-mail]>
Subject: Pt 1/2: FREE-ENERGY TECHNOLOGY For Spacecraft
Newsgroups: sci.space

Unfortunately, Migma was included with the rest of the junk in that post.

More realistic info:  Migma should theoretically work (really!).  I mean, I'm
sure if you got some plasma physicists together they could argue over it, but
there are no solid reasons why it shouldn't work.  What needs to be done is to
have it constructed and tested.  Tokamaks were supposed to work long ago, too,
but nasty problems appeared.  Migma reactors have been built (I think there have
been more than one.), but none have reached break-even.  Obviously, if it had
would they have turned it off?  It lost funding long ago (about 10 years?), and
right now the people involved are trying to get private funding.  The last machine
built is sitting 100 yards from me gathering dust.

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

Date: Tue, 9 Feb 1993 18:22:11 GMT
From: Rob Healey <[e-mail]>
Subject: Pt 1/2: FREE-ENERGY TECHNOLOGY For Spacecraft
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Bogdan Eremia) writes:
|>  mm>               One other energy source should be mentioned
|>  mm>here,
|>  mm>          despite the fact that it does not fit the
|>  mm>definition of Free
|>  mm>          Energy.  A Bulgarian-born American Physicist named
|>  mm>Joseph
|>  mm>          Maglich has invented and partially developed an atomic FUSION
|>  mm>          reactor which he calls 'Migma', which uses  NON-radioactive
|>  mm>          deuterium as a fuel [available in nearly UNLIMITED quantities
|>  mm>          from sea water], does NOT produce radioactive waste, can be
|>  mm>          converted DIRECTLY into electricity (with-OUT energy-wasting
|>  mm>          steam turbines), and can be constructed small enough to power
|>  mm>          a house or large enough to power a city.  And UNLIKE the
|>  mm>          "Tokamaks" and laser fusion MONSTROSITIES that we read about,
|>  mm>          Migma WORKS, already producing at least three watts of power
|>  mm>          for every watt put in.  ["New Times" (U.S.
|>
|>
|>     Just one question....why aren't we using these already?
|>
    Assuming the process actually works, which projects do you think
    get the funding bucks, small and useful or huge and esoteric? Which
    one's make you shine in the eyes of your piers? Certainly not the
    small, unglamourous stuff...

    In watching the allocation of money at my old alma mater alot of
    small, doable projects were usually overlooked in favor of bigger,
    riskier projects that would get more press and more impressive looking
    papers in the journals. Remember, the name of the game in the
    research community is to get published not actually implement
    things that are practical although unglamourous and mundane journal
    copy... B^(.

        -Rob

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

Date: Tue, 9 Feb 1993 18:05:08 GMT
From: Rob Healey <[e-mail]>
Subject: SS Freedom and Supercollider again on chopping block
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Andy Cohen) writes:
|> In article <[e-mail]>, [e-mail]
|> (Jeff Bytof) wrote:
|> >
|> > I just heard on the radio that the Space Station and the Supercollider
|> > are up for discussion by Clinton officials.  The broadcast gave
|> > little in the way of details.  The report mentioned the "30 billion
|> > dollar pricetag" for the space station.  Curiously, Clinton's job
|> > stimulus package is pegged at $31 billion...
|> >
|>
|> Now....just imagine how that would look!!!
|>
|> Clinton kills SSF and eliminates over 100,000 (according to Space News and
|> AV week) jobs for a job stimulus package!!!!
|>
    Minor technical point, Clinton can't do squat in the kill dept., only
    CONGRESS can do that. All he can do is recommend. What we need to
    do is recommend that our Congress critters NOT listen to such
    advise. Maybe point out the Aerospace industry is where all those
    high tech Military jobs are going to have to go.

|> GREAT!!!  Put the educated scientists and engineers out of work for the
|> high school drop outs!!!

    Actually, that's what Reagan effectivly did in the eightys. Eliminated
    many high paying jobs and substituted more low paying jobs and
    called it progress... Maybe Clinton got more than jelly beans when
    he visited Reagan... B^(.

    Somebody should probably point this out to them although it should
    be an obvious no brainer. Also, where do they plan to put the
    military workers if they destroy the Aerospace industry? More
    McDonalds and BK jobs? B^(.

        -Rob

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

Date: Tue, 9 Feb 1993 19:14:20 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Supporting private space activities
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Henry Spencer) writes:

>I don't know how fast the braking is, but clearly there are limits.
>In any case, I was using "baby ducks" as the scaled-down equivalent of
>all the other vehicles that accompany the crawler when it rolls out.
>They keep their distance, because they know full well what happens if
>they get under those treads, but you still want to be able to see
>something like a stalled car up ahead.

That makes sense.  Knowing that KSC area is also a wildlife
sanctuary, I took your statement literally.

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

Date: Tue, 9 Feb 1993 20:01:52 GMT
From: Jochen Bern <[e-mail]>
Subject: Tethers for electricity generation (was Re: Beanstalk?)
Newsgroups: sci.space

In <[e-mail]> [e-mail] (David Smith) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>In article <[e-mail]> [e-mail] writes:
> >as well. Shuttle had an experiment to try it out. Remember the stuck
> >reel? The main problem is the return circuit. It takes two wires to
> >make a light as we say in the electrical contracting business. A tether
> >moving through a magnetic field has a current induced into it, but a
> >return wire would have an equal and opposing current induced into it,
> >so no net current would flow. To get around that, you use brush discharge
> >contactors to use the global circuit as your return path. One of the
> >things our stuck reel satellite was supposed to test was how well that
> >would work.
> >
> What about a coaxial cable?  I should think a current would be generated in
>the sheath but the center conductor would be shielded?  Or am I forgetting
>my physics here?

If I'm not very much mistaken, the Experiment wasn't meant to tap a mag-
netic but an electric Field. There *are* electric Level Differences in
the Atmosphere's Layers. If so, the Tether would be rather like reaching
out for the other Pole of a Battery. :-) The second "Wire" would then be
the Mechanism which builds up the Voltage in the Atmosphere.

If I'm right, I would think that the Tether would have been insulated with
open Contacts at both Ends, thus delivering the Voltage to the Shuttle
instead of just short-circuiting the Atmosphere. Could somebody check
this?

Regards,
                                J. Bern
--
 /  \  I hate NN rejecting .sigs >4 lines. Even though *I* set up this one. /\
/ J. \ EMail: bern@[TI.]Uni-Trier.DE / ham: DD0KZ  / More Infos on me from /  \
\Bern/ X.400 Mail: S=BERN;P=Uni-Trier;A=dbp;C=de  /   X.400 Directory, see \  /
 \  /  Zurmaiener Str. 98-100, D-W-5500 Trier    /     X.29 # 45050230303.  \/

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Date: 9 Feb 93 18:06:33 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: What was ASSET?
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Dave Michelson) writes:
> I was just glacing through the Proc. X-15 First Flight 30th Anniversary
> that Mary sent out some time ago...
>
> On page 57, Richard Hallion refers to the ASSET program.  What was that?

It was a program that launched scale lifting bodies on ICBMs to test
hypersonic aerodynamics.  An article in one of the *JBIS* history
issues  covered it in the past 10 or 12 years.  Also, I believe some
of the hardware is on display in the (miniscule) section devoted to
space in the Air Force Museum near Dayton, Ohio.  Wish I could tell
you more, but perhaps a few clues are better than nothing.

During the first and second stage         Bill Higgins
flights of the vehicle, if a serious      Fermi National Accelerator Laboratory
irretrievable fault should occur and      [e-mail]
the deviation of the flight attitude of   [e-mail]
the vehicle exceeds a predetermined       SPAN/Hepnet: 43011::HIGGINS
value, the attitude self-destruction
system will make the vehicle
self-destroyed.
     --Long March 3 User's Manual
     Ministry of Astronautics, People's Republic of China (1985)

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End of Space Digest Volume 16 : Issue 164
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