Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_0/V13_063.TXT

Internet Message Format | 1991-06-28 | 18KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/QbaIFk:00WBwAEr05l>;
          Sun, 20 Jan 91 02:19:12 -0500 (EST)
Message-ID: <[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Sun, 20 Jan 91 02:19:06 -0500 (EST)
Subject: SPACE Digest V13 #063

SPACE Digest                                      Volume 13 : Issue 63

Today's Topics:
            Re: Voyager Update - 01/16/91
             Re: THE BLUE PLANET
              Galileo Update - 01/17/91
          Re: What is cosmological constant?
               MAJOR SOLAR FLARE ALERT
         NASA Headline News for 01/18/91 (Forwarded)
              Magellan Update - 01/18/91
              Re: US buys Soviet reactor
           Re: space news from Dec 17 AW&ST

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: 18 Jan 91 01:43:49 GMT
From: sun-barr!newstop!texsun!convex![e-mail]  (Richard A. Schumacher)
Subject: Re: Voyager Update - 01/16/91

Oh, give it a rest. We all knew Ron meant "grams" by "Gm",
just as we knew you meant "measurement" even though you
spelled it "mesurement".

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

Date: 18 Jan 91 16:48:21 GMT
From: agate!bionet!uwm.edu!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!euclid.jpl.nasa.gov![e-mail]  (Peter Scott)
Subject: Re: THE BLUE PLANET

In article <[e-mail]>, [e-mail] (Daniel Fischer) writes:

> A technical question: there are two kinds of giant-screen cinemas, one with
> a flat screen ('5 stories high' or so go the ads), the other one working inside
> a planetarium dome - which one of these is the actual 'IMAX' system?

The first one.

>Is the
> generic term for the planetarium-based version OMNIMAX?

Yes.

> And: do both versions
> use exactly the same footage (with square-sized 70x70mm-frames - the Dutch
> 'Omniversum' sells samples to visitors)?

No.  They're different frame formats.

--
This is news.  This is your       |    Peter Scott, NASA/JPL/Caltech
brain on news.  Any questions?    |    ([e-mail])

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

Date: 17 Jan 91 18:14:06 GMT
From: snorkelwacker.mit.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Galileo Update - 01/17/91


                         GALILEO STATUS REPORT
                           January 17, 1991

     Yesterday, the Galileo spacecraft's operating mode was successfully
changed from dual-spin to all-spin followed by a planned sun acquisition to
maintain the required sun pointed attitude for thermal control reasons.

     Today, the CDS "B" (Command Data Subsystem) memory activity is in process.
This activity is similar to that successfully performed last week for the
CDS "A" copy activity.

     Tomorrow, Spacecraft activity will include a sun acquisition activity and
cruise science memory readouts for the EUV (Extreme Ultraviolet Spectrometer),
MAG (Magnetometer) and DDS (Dust Detector) instruments.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 17 Jan 91 19:10:36 GMT
From: [e-mail]  (Troy E Daniels)
Subject: Re: What is cosmological constant?

In article <[e-mail]>, [e-mail] writes:
|> Can someone give me a brief explanation of "cosmological constant"?
|> I have the understanding that this is a base energy density for
|> "empty" space; as opposed to a base energy level (vacuum energy level)
|> for "empty" space.  Is this correct?  To what would this base energy
|> level be due?  Uncertainty leading to a background cloud of paired
|> virtual particles?
|>
|> Thanks.
|>
|> Mike McGinnis                                 "Rust never sleeps."
|> Academic Computing Center                           -The Second Law of
|> University of Kansas                                 Thermodynamics
|> Lawrence, Kansas  66045

The cosmological constant was originally introduced by Einstein in order to
allow a steady-state universe.  As the universe turned out to be expanding, it
turned out to be one of Einstein's biggest mistakes.

Then particle physicists realized that the universe should be filled with lots
of virtual particles, who, individually have a negligible gravitational effect, but taken collectively should have a huge effect.  (There was recently an article in Scientific American, or a similar magizine about this.)  These virtual particles can have one of two effects, something like positive or negative curvature, and it should be HUGE.  For one effect, light should be seriously deflected after travelling only 100m or so.  The other effect was equally obvious, and is equally unobserved.  One real big




 question in cosmology is why is it so small.  If you can answer that question, you can probably get a Nobel prize.

Troy Daniels
[e-mail]

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

Date:    Fri, 18 Jan 91 01:27:12 MST
From: [e-mail] (Cary Oler)
Subject: MAJOR SOLAR FLARE ALERT
X-St-Vmsmail-To: ST%"[e-mail]"

                        --  MAJOR SOLAR FLARE ALERT  --

                               JANUARY 17, 1991

                              Flare Event Summary
                           Potential Impact Forecast

                                    --------


MAJOR ENERGETIC EVENT SUMMARY

     A major solar flare erupted off of the sun beginning at 14:55 UT,
peaking at 15:02 UT and ending at 15:41 UT (event duration was 46 minutes).
The flare was rated as a respectable class M6.9/1B energetic event.  It was
associated with a 350 s.f.u. (solar flux unit) Tenflare and a significant
Type II sweep frequency burst event.  The region responsible for this flare
was Region 6455, which has exploded in growth over the past 24 hours.  It now
covers an area of approximately 330 million square kilometers and contains
17 visible spots within its boundary.  It currently consists of a Beta type
magnetic configuration in a type DAI optical pattern.  It's location as of
18 January at 00:00 UT was S14W07.  The location of the flare was S11W04.

     Other regions currently visible are Regions 6444 (N15W50) and 6447
(S07W23).  Region 6444 continues to span very large areas (3,840 million
square kilometers with an angular extent of 21 degrees) and is by far the
most impressive optical region visible, but has not succeeded in producing
any flaring more energetic than class C x-ray events.  Region 6447 is also
quite impressive optically, but has become nearly dormant in flare output.

     Solar activity should remain mostly low to moderate.  No further major
flaring is currently anticipated from Region 6455, although there is
obviously a slight risk that it may produce surprisingly energetic activity.
However, the data presently indicates that major flaring from this region
will probably cease, although M-class flaring remains a possibility in this
region, as well as in Regions 6444 and 6447.


POTENTIAL TERRESTRIAL IMPACT FORECAST

     The association of this major flare with a strong Type II radio sweep
indicates the distinct possibility that this event produced a coronal mass
ejection.  It is certainly well placed for producing terrestrial impacts,
however it is important to note that no Type IV continuum radiation
accompanied the Type II sweep.  Hence, terrestrial impacts will likely remain
relatively low.

     There is a moderate to high probability that this flare will produce a
sudden magnetic impulse within the next 48 hours or so followed by increased
levels of geomagnetic activity and corpuscular radiation.  However, the
geomagnetic activity is expected to remain confined to mostly unsettled to
perhaps active levels.  There is a risk of minor storming over high
latitudes.  Middle latitudes should remain mostly unsettled with potential
periods of active conditions.  Worst case scenario's indicate potential minor
storming over middle latitudes and major storming over high latitudes,
however this projection is considered inaccurate considering the data
collected thus far.

     Auroral activity should increase coincident with the increase in
geomagnetic activity sometime late on 19 January or 20 January.  Activity is
expected to be mostly moderate over high and middle latitudes.

     Radio propagation conditions will likely witness decreased signal
quality and increased fading, noise and distortion associated with the
arrival of any enhanced corpuscular radiation.  However, the conditions are
not expected to be severely degraded.  Relatively good DX should still be
possible despite the expected increase in geophysical activity.

     VHF auroral backscatter communications may become possible for high and
northerly-middle latitude locations on 20 January, depending on the actual
intensity of auroral and geomagnetic activity achieved.  Any backscattering
will likely be localized and sporadic.

     It is entirely possible that we won't experience any geophysical
impacts.  However, the data would seem to indicate otherwise.  Terrestrial
impacts from this flare are currently expected to be relatively low, but
should be measurable.


**  End of Report **

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

Date: 18 Jan 91 20:34:40 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 01/18/91 (Forwarded)


             Headline News
Internal Communications Branch (P-2) NASA
Headquarters

  Friday, January 18, 1991    Audio Service: 202 / 755-1788

This is NASA Headline News for Friday, January 18, 1991

At the Kennedy Space Center, scheduled operations continue in
the Orbiter Processing Facility.  Water spray boiler servicing
is complete on Discovery.  Testing and checks of the
hydraulic system and the orbital maneuvering pods also
continue on schedule.  During helium purge operations
yesterday, engineers determined there may have been hydraulic
fluid introduced into the high pressure oxidizer turbopump on
main engine number three.  A technical assessment of the
potential problem and further evaluations will be made today.

And on Atlantis, also in the OPF, hydraulic fill and bleed
operations were completed successfully last night, as were
checks of the nose wheel steering mechanism.  Main engine
installation is scheduled to begin this weekend.

In the Vehicle Assembly Building, ground service equipment has
been installed in Columbia's payload bay.  Columbia is
scheduled to be moved to the OPF later this month,
following the rollover of Discovery to the VAB.

  * * * * * * * * * * * * * * * * * * * * * * * * * *

Also at Kennedy, initial testing of the Tethered Satellite
has been underway.  Hardware associated with the TSS
deployer is currently being integrated onto the orbiter pallet.
The first fit check of the satellite with the deployer is scheduled
to begin today, and will last about a week.

Payload technicians yesterday completed alignment of the two
sun sensors aboard the Gamma Ray Observatory.  Earlier
this week, workers removed GRO's test batteries and reinstalled
the six nickel cadmium flight batteries.  The spacecraft was
powered up yesterday as part of preparations for today's tests
of the instrument switching unit -- the device which controls
electrical signals to the various equipment bays inside GRO.

Final assembly, functional testing, and radio frequency system
testing of the Inertial Upper Stage for TDRS-E has been
completed by the Air Force/Boeing test team at Cape Canaveral
Air Force Station.  IUS buildup operations are scheduled to be
completed in mid-February.  Due to the possibility of limited
military aircraft availability, TDRS-E could be shipped early
to KSC from the TRW plant in California.

  * * * * * * * * * * * * * * * * * * * * * * * * * *

The Combined Release and Radiation Effects Satellite
released a lithium canister last night into the Earth's
magnetosphere.  The next scheduled release is Saturday, Jan.
19, during one of the following times: 8:42 pm, 9:21 pm. 10:45
pm and 11:54 pm through 3:07am Sunday morning.  The first
three times are opportunities for barium releases, the latter
window is an opportunity for lithium or a large barium release.


Here's the broadcast schedule for Public Affairs events on NASA
Select TV.  All times are Eastern.  **indicates a live program.

Tuesday, 1/21/91
    12:00 pm    NASA productions.

Wednesday, 1/23/91
     9:30 am    **STS-39 Flight Director briefing from JSC.
    11:00 am    **STS-39 DOD payload briefing from JSC.
     2:00 pm    **STS-39 crew briefing from JSC.





All events and times may change without notice.  This report is
filed daily, Monday through Friday, at 12:00 pm, EST.  It is a
service of Internal Communications Branch at NASA
Headquarters.  Contact:  CREDMOND on NASAmail or at
202/453-8425.


NASA Select TV:  Satcom F2R, Transponder 13, C-Band, 72
degrees West Longitude, Audio 6.8, Frequency 3960 MHz.

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

Date: 18 Jan 91 22:25:06 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 01/18/91


                          MAGELLAN STATUS REPORT
                            January 18, 1991

     The Magellan spacecraft and its radar system continue to perform
nominally.  All of the STARCALS (star calibrations) and DESATS (desaturations)
of the past 24 hours were successful with few star rejects.

     Yesterday, the Sun loss fault protection limit was raised from 11 to 30
minutes.  Later today, the weekly mapping command sequence, M1019, and its
associated parameter files will be sent to the spacecraft.  This is the last
occulted mapping sequence in the current Earth occultation period.  It shortens
the mapping pass by slightly less than 7 minutes in order to accommodate an
Earth occultation of about 48 minutes.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 11 Jan 91 19:04:40 GMT
From: julius.cs.uiuc.edu!wuarchive!sdd.hp.com!caen!math.lsa.umich.edu!sharkey!cfctech!teemc!fmeed1![e-mail]  (Russ Cage)
Subject: Re: US buys Soviet reactor

In article <[e-mail]> [e-mail] (Robert McGwier) writes:
>There is one helluva big difference between an RTG and a full fledged
>nuclear reactor.  An RTG has a relatively small amout of (say) PLutonium
>encased in special pellet coatings put together is such a way that
>they generate heat which makes electricity from thermocouples.  A nuclear
>reactor is one where you have quite a bit of nuclear material [....]

There's another one.  A nuclear reactor can use uranium as fissile
material, and does not have to be run before launch.  This means it
can be launched "cold", without any significant amount of fission
products in it.  If the launch fails, and the reactor falls into
the ocean, it can contribute only a little more uranium to the
vast amounts already dissolved there.  This worst-case is even
better than the (already good) safety of RTG's.  (This assumes
the reactor cannot start itself given seawater for a moderator.
If it is broken into pieces by the range safety devices, this
can be assumed.)
--
Russ Cage    Ford Powertrain Engineering Development Department
Work:  itivax.iti.org!cfctech!fmeed1!cage   (CHATTY MAIL NOT ANSWERED HERE)
Home:  [e-mail]  (All non-business mail)
Member:  HASA, "S" division.

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

Date: 17 Jan 91 23:26:21 GMT
From: bonnie.concordia.ca!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: space news from Dec 17 AW&ST

In article <[e-mail]> [e-mail] ("Allen W. Sherzer") writes:
>>...the committee's recommendation to terminate orbiter production.
>>[And rightly so -- it's a thoroughly dumb idea, if the shuttle fleet is to
>>continue to be a significant part of NASA planning.]
>
>I think it is clear that the Shuttle will no longer be a significant
>part of NASA planning. But then, with a man-rated HLV costing far less
>than the Shuttle and a space station, there is little need ...

Uh, where is this "man-rated HLV"?  I don't see it in current inventory.
And if it's not, then the Shuttle *does* figure in NASA's plans for this
decade, at least, and that means replacement orbiters will be needed.
Maintenance of the shuttle fleet requires an orbiter supply, and said
maintenance can be abandoned only when the fleet itself is about to be
abandoned.  That won't happen soon.

The practical consequence of this, if the decision sticks, is that the
shuttle fleet *is* being abandoned, well before any replacement is ready.
Nobody can make sensible plans for a fleet of unknown size.
--
If the Space Shuttle was the answer,   | Henry Spencer at U of Toronto Zoology
what was the question?                 |  [e-mail]   utzoo!henry

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

End of SPACE Digest V13 #063
*******************