Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_0/V13_093.TXT

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Subject: SPACE Digest V13 #093

SPACE Digest                                      Volume 13 : Issue 93

Today's Topics:
    Re: Why man rate? (was: space news from Dec 17 AW&ST)
             Pioneer 10 Update - 01/25/91
           Pioneer Venus Update - 01/25/91
      Re: MAJOR SOLAR FLARE ALERT - POWERFUL EVENT (25 JANUARY)
    Re: Why man rate? (was: space news from Dec 17 AW&ST)
    MAJOR SOLAR FLARE ALERT - POWERFUL EVENT (25 JANUARY)
      Re: Weekly World News publishes Challenger tape transcript

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

Date: 27 Jan 91 04:07:05 GMT
From: zaphod.mps.ohio-state.edu!sdd.hp.com!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Why man rate? (was: space news from Dec 17 AW&ST)

In article <[e-mail]> [e-mail] (David Cornutt) writes:
>>In the entire 30 year history of the Delta this is an accurate figure.
>>However, their success rate over the last 13 years is 98.33%...
>
>You can make the probability be anything you want if you pick and choose your
>data points.  If you only consider the last 11 flights, the Shuttle has a
>100% success rate.  This of course proves nothing...

Nonsense.  It is entirely possible to assign some degree of statistical
meaning to the shuttle's recent record.  What is lacking is very much
confidence that this accurately represents overall reliability, since there
are not very many tests involved.  Delta *does* come out ahead here,
simply because it has been launched many more times.  We have considerably
more confidence in the Delta numbers than in the shuttle numbers.

If anything, the poorer Delta reliability in its early days weakens the
case for assuming the shuttle to be highly reliable!  It is an observed
fact, from Delta and the other expendables, that early reliability is worse
than long-term reliability because the bugs are still being found and fixed.
Delta has flown often enough for considerable confidence that it is past
its "infant mortality" stage.  The shuttle has not, especially considering
its much greater complexity, which would normally be taken to require rather
more debugging.  It is entirely reasonable to discount Delta's early
troubles while not discounting Challenger.

>>Don't look now but the Shuttle *IS* being canned.
>
>If you are saying that there will be no more Shuttle flights, that's
>news to me.  Do you know something that the rest of us don't?

Of course there will be more shuttle flights.  But NRC, OTA, and others
who have studied the matter concur that an ongoing shuttle program
requires an ongoing orbiter supply.  How can you plan a launch manifest
for the things five years ahead when you don't even know *how many* of
them will be available then?  Discontinuing orbiter production amounts
to abandoning the shuttle fleet, as the remaining orbiters age (nobody
seriously expects them to last 100 flights each any more, but nobody has
any very clear idea of how long they *will* last either) and are lost
in accidents.

Without replacement orbiters, the next big accident will kill the shuttle
completely... because it will demonstrate the impossibility of planning
fleet operations without maintaining the fleet.

Or are you suggesting that there will not be another accident?

>... I was opposed to building Endeavor -- as another
>copy of the _current_ Shuttle design.  By now, we should be working on
>the next version of that vehicle...

Agreed.  But (a) we aren't, and (b) even if we were, that next version
would not be ready for use until circa the year 2000, so what do we do
until then?  You are confusing development with maintaining operational
capability, saying that we should abandon the latter because we ought
to be doing more of the former.

>...If you're saying that the Shuttle concept in
>general is a bad idea, I totally disagree.  In this day and age of
>recycling, why is everyone so anxious to build throwaway launchers?

Because we know how to make them work fairly dependably for a development
cost we are willing to pay.

>... The main
>problem with the Delta, as far as man-rating, is that steering
>of the first stage is provided solely by gimbaling of the main
>engine.  If that engine fails, the vehicle has no directional
>control and must be aborted...

???  The launcher world abounds in such single-point failure modes when it
comes to directional control.  I doubt very much that either the shuttle
or Titan can survive a failed SRB nozzle gimbal.  And every US manned
expendable was single-engined at some point during its flight.  (Redstone
from launch to burnout, Atlas after dropping booster engines, Titan after
staging, Saturn IB after staging, Saturn V after second staging.)
--
If the Space Shuttle was the answer,   | Henry Spencer at U of Toronto Zoology
what was the question?                 |  [e-mail]   utzoo!henry

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

Date: 25 Jan 91 23:19:26 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Pioneer 10 Update - 01/25/91


                       PIONEER 10 STATUS REPORT
                          January 25, 1991

     On January 14, the reference frequency used by the DSS (Deep Space
Station) transmitters was lowered by 35 Hz for the Pioneer 10 spacecraft.
This is done periodically to to compensate for the lower spacecraft receiver
rest frequency brought about by the the changing thermal environment.  On
January 17, unpredicted RFI (Radio Frequency Interference) at the 70 meter
antenna at Spain caused a 1 hour and 14 minute loss of telemetry data.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab |
  ___| | | | |__) |/  | | |___   M/S 301-355        | It's 10PM, do you know
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | where your spacecraft is?
 |_____|/  |_|/       |_____|/                      | We do!

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

Date: 25 Jan 91 23:23:14 GMT
From: usc!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Pioneer Venus Update - 01/25/91


                       PIONEER VENUS STATUS REPORT
                           January 25, 1991

     A 25-pulse precession maneuver was successfully executed on January 19
by the Pioneer Venus spacecraft.  An HGA (High Gain Antenna) adjustment was
not required because the precession moved the antenna in the desired direction.

     On January 18, a scheduled 34 meter track in Spain was cancelled due to
station antenna problems.  This prevented the loading of the spacecraft with
the commands to turn the downlink on for a subsequent Goldstone 34 meter track
on the same day.  As a result, data from both tracks were lost, as well as the
periapsis data for orbit 4427.

     On January 19, several antenna problems at the 70 meter station at
Australia, caused a 1 hour and 30 minute loss of telemetry data, and a 2 hour
and 20 minute loss of command capability.  On January 20, a power failure at
the same station caused a 1 hour and 30 minute loss of data.  This was
post-periapsis data for orbit 4429.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab |
  ___| | | | |__) |/  | | |___   M/S 301-355        | It's 10PM, do you know
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | where your spacecraft is?
 |_____|/  |_|/       |_____|/                      | We do!

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

Date: 27 Jan 91 02:42:12 GMT
From: haven!uvaarpa!murdoch!astsun9.astro.Virginia.EDU![e-mail]  (Robert W. Spiker)
Subject: Re: MAJOR SOLAR FLARE ALERT - POWERFUL EVENT (25 JANUARY)

[e-mail] (Cary Oler) writes:
>
>     A very powerful major energetic event ripped off the eastern limb of the
>sun on 25 January.
[...]

Wow!  The flares are getting so intense they're tearing the sun limb
from limb!  Is this what they mean by solar maximum?
 :-) :-)


--
Robert W. Spiker, UVa Dept. of Astronomy
+------------------------+ It is truly written that a man has five
| [e-mail]     | times as many fingers as ears, but only
| rws3n@virginia (BITNET)| twice as many ears as noses.

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

Date: 26 Jan 91 18:11:42 GMT
From: world!ksr![e-mail]  (Chris Jones)
Subject: Re: Why man rate? (was: space news from Dec 17 AW&ST)

In article <[e-mail]>, aws@ITI ("Allen W. Sherzer") writes:
>In article <[e-mail]>:
>
>++   There is no need to ask them. We HAVE sent people up on Delta's. Funny
>++   how they managed to make it do something it was never intended to do :-).
>
>+I was under the impression that Redstones and Atlases were used for
>+Mercury, and Titans were used for Gemini (and of course Saturns for
>+Apollo and Skylab) -- am I missing something?
>
>Sorry about that. I did indeed mean to say Atlas. The point remains that
>humans use tools in unintended ways all the time.
>
The effort to man-rate the Atlas was non-trivial.  In fact, the original Atlas
failed in its first flight with a Mercury on top of it, and quite a bit of
effort went into beefing up its structure and adding redundancy.  Human-rating
either the current Deltas or Titans seems to be dicey:  both have solid fuel
motors with, um, interesting firing strategies.  In fact, the Titan uses the
exact opposite of the Shuttle's ignition strategy (check out liquid fuelled
motors, and, when they're all working, fire SRBs).  It takes off under solid
propulsion only, and doesn't ignite its liquid fuelled engines until some time
has passed.
--
Chris Jones    [e-mail]    {world,uunet,harvard}!ksr!clj

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

X-Delivery-Notice:  SMTP MAIL FROM does not correspond to sender.
Date:    Sat, 26 Jan 91 12:17:34 MST
From: [e-mail] (Cary Oler)
Subject: MAJOR SOLAR FLARE ALERT - POWERFUL EVENT (25 JANUARY)
X-St-Vmsmail-To: st%"[e-mail]"

                        --  MAJOR SOLAR FLARE ALERT  --

                               JANUARY 25, 1991

                              Flare Event Summary
                           Potential Impact Forecast

                                    --------


MAJOR ENERGETIC EVENT SUMMARY

     A very powerful major energetic event ripped off the eastern limb of the
sun on 25 January.  The flare, rated a powerful class X10.8/SF flare began
at 06:23 UT on 25 January.  It peaked at an x-ray level of X10.8 at 06:35 UT
and held at an X10 level for 17 minutes.  This event ended at 09:51 (a long
duration event).  The flare was associated with strong Type II and Type IV
sweep frequency events and was also associated with strong radio emissions.
A burst of 57,000 s.f.u. was observed at 245 MHz.  The burst at 10 cm was
3,500 s.f.u.  The location of this flare was S16E78.

     The region responsible for this exceedingly powerful event is Region
6471 (near S13E61).  This region is very complex and is large in area.
Magnetic gradients in this regon are also high.  Major flaring from this
region is likely.  The potential impacts of this flare are stated below.

     In addition to Region 6471, Regions 6466 and 6462 (now nearing the
central meridian) also retain very complex parameters and high magnetic
gradients.  Any of these three regions could produce major energetic flares
which could include proton flares.  The probability for further X-class
and/or proton flares from these regions has been increased, particularly
with the appearance of Region 6471 on the east limb.  The solar flux has
responded to the enormous jump in activity and is now recorded at a level
of 283.  The background x-ray flux has jumped to levels in excess of class
C2.0.  The sunspot number has likewise jumped and is now estimated at
a value between 240 to 260 (observations are not yet all in).

     The regions now on the disk represent a very serious increase in solar
activity.  The risk for major flaring, proton flaring, satellite proton
activity and Polar Cap Absorption activity is high.  The Space Environment
Services Center is maintaining a condition YELLOW alert status for possible
PCA activity.  This recent flare did not produce any significant increases in
solar protons, but the position of this flare was too far east for solar
protons to seriously impact with the earth.  As Region 6471 approaches the
central meridian, and as Regions 6466 and 6462 move into the western
hemisphere, the risk for proton bombardments will increase.


POTENTIAL TERRESTRIAL IMPACT FORECAST

     The recent class X10.8/SF major flare is expected to produce a low to
moderate impact with the earth sometime on 28 January.  It will likely only
produce active conditions, but many area's could experience minor storming.
The long duration minor flare of 24 January is expected to produce some
increased activity today or possibly into tommorrow.  There are conflicting
reports that the activity from this minor flare may have already impacted
with the earth.  However, at the present time, we still believe the shock
(if one does indeed materialize) is still on its way and should reach the
earth sometime today or early tommorrow (27 January), UT time.

     There is a chance that a shock from the class X10.8 flare may not have
an impact with the earth.  This flare occurred relatively far away on the
eastern limb, and hence the probability for terrestrial impacts is much lower
than it would be if the flare would have occurred nearer to the central
meridian.  But it's association with strong Type II and IV sweeps is
indicative of a coronal mass ejection which could have an impact with the
earth, depending on the trajectory of the plasma cloud.

     People should be on the alert for potential increases in geomagnetic
activity over the next 24 hours, and again late on 27 January through to
about 29 January.  Impacts shouldn't be too strong (unless some other
powerful flare occurs from Regions 6466 or 6462), but middle latitude
minor storming is a possibility.

     Major flares are still possible (if not likely) over the next 24 to 48
hours.  Proton flaring is possible, as is potential PCA activity.  Radio
communications may experience significant long-duration fadeouts on HF bands
if major flares occur.  Affected area's will be restricted to the sunlit
hemisphere, and will include mostly the low and middle latitudes.
SID's/SWF's of more minor intensity are also expected as M-class flaring
increases.  Night-time propagation should be mostly normal if effects from
the minor M-class flare of 24 January do not materialize or are smaller than
expected.  Propagation on 28 January is expected to become somewhat degraded.
VHF propagation via D-layer reflection is possible during periods of major
flaring.  Also, the MUF has increased over the past 48 to 72 hours and may
provide some openings on 6 meters.

     Watch for possible future major flare alerts and/or possible geomagnetic
storm alerts.


**  End of Report **

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

Date: 25 Jan 91 05:28:55 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Weekly World News publishes Challenger tape transcript

In article <[e-mail]> [e-mail] (William K. McFadden) writes:
>So, what does it say?

--- WARNING ---

This may make you very sad.  I sure was.  Nevertheless, I think it needs
to be posted.  Hit 'n' now if you would rather not hear...


NASA's account of tapes made during the ill-fated Challenger mission ends with
pilot Michael Smith saying "uh-oh" one minute, 13 seconds into the flight.

Here is the rest: the suppressed transcript of the crew's last minutes,
captured on Christa McAuliffe's personal cassette recorder and recovered
from the shattered crew cabin.  The sex of the speaker is indicated by M or F.

T+1:15 (M): What happened?  What happened?  Oh God, no -- no!

T+1:17 (F): Oh dear God.

T+1:18 (M): Turn on your air pack! Turn on your air...

T+1:20 (M): Can't breathe... choking...

T+1:21 (M): Lift up your visor!

T+1:22 (M/F): (Screams).  It's hot.  (sobs).  I can't.  Don't tell me...
    God! Do it now!

T+1:24 (M): I told them... I told them... Dammit! Resnik don't...

T+1:27 (M): Take it easy!  Move (unintelligible)...

T+1:28 (F): Don't let me die like this. Not now. Not here...

T+1:31 (M): Your arm:... no... I (extended garble, static).

T+1:36 (F): I'm... passing... out...

T+1:37 (M): We're not dead yet.

T+1:40 (M): If you ever wanted (unintelligible) me a miracle...
    (unintelligible)... (screams).

T+1:41 (M): She's... she's... (garble)... Damn!

T+1:50 (M): Can't breathe...

T+1:51 (M/F): (Scream).  Jesus Christ!  No!

T+1:54 (M): She's out.

T+1:55 (M): Lucky... (unintelligible).

T+1:56 (M): God. The water... we're dead! (Screams).

T+2:00 (F): Goodbye (sobs)... I love you. I love you...

T+2:03 (M): Loosen up... loosen up...

T+2:07 (M): It'll be just like a ditch landing...

T+2:09 (M): That's right.  Think positive.

T+2:11 (M): Ditch procedure...

T+2:14 (M): No way!

T+2:17 (M): Give me your hand...

T+2:19 (M): You awake in there? I... I...

T+2:29 (M): Our father... (unintelligible)...

T+2:42 (M):... hallowed be Thy name... (unintelligible)

T+2:57 (M): You... over there?

T+2:58 (M): The Lord is my shepherd, I shall... not want. He maketh me to lie
    down in green pastures... though I walk through the valley of the
    shadow of death, I will fear no evil... I will dwell in the house...

T+3:15 to end (None): Static.  Silence.

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

End of SPACE Digest V13 #093
*******************