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Subject: SPACE Digest V11 #211

SPACE Digest                                     Volume 11 : Issue 211

Today's Topics:
          Re: Will we lose another orbiter?
           Payload Summary for 03/30/90 (Forwarded)
              RE: SPACE Digest V11 #178
             Re: Comparative Costs to LEO
             Velikovsky's Theory
                JUNK IN SPACE
----------------------------------------------------------------------

Date: 29 Mar 90 19:16:58 GMT
From: samsung!cs.utexas.edu!hp-sdd!ncr-sd!ncrlnk!ncrcce!ncrons![e-mail]  (Wayne D. Johnson)
Subject: Re: Will we lose another orbiter?

In article <[e-mail]> [e-mail] (Lou Adornato) writes:
=>        One of the root causes of the Challenger accident, was public pressure
=>to launch on schedule.  This was caused by the public's inability to understand just
=>how complex and demanding launching an experimental aircraft can be.  Once people
=>stop taking technology for granted, they start learning.  Maybe in the long run Challenger
=>will have made us stronger by making us see the danger in having 90% of our population
=>(and 100% of our policy makers) technologically illiterate.

I disagree.  It was not public pressure that was forcing NASA to fudge on safety
It was NASA's impression of congress's impression of the public.  Both
impressions probably are faulty (IMHO).

=>In the light of basic probability, I don't see how a lower "risk" factor can be justified.
=>
=>Consider a single component with a reliability of 99.9999% (which is pretty good even
=>for a small, simple component, like a rivet).  The chance of this part failing is
=>one in 10,000.  If there are 1000 of these parts, then there is 1 chance in 10 that
=>one of them will fail.  If you put a million of them into the system, then you have
=>to expect that 100 of them _will_ fail.  In order to maintain a 98% safety margin, you
=>have to increase the per-unit reliability by _three_ orders of magnitude.  Do you have
=>any idea how to make a rivet 1000 times more reliable?  Keep in mind that making it heavier
=>might reduce the reliability of some other component.

That is assuming that the mission will fail if any of the parts fail.  The
main reason for redundant systems is to limit the failure rate by increasing
the number of parts that may fail.  By having 3 redundant engines, failure of
1 critical part in 1 engine will not cause a "failure".  You probably know all
of this, I'm just thinking out loud.

=>Yes, they should, no smileys about it.  Basic spares management policy would be to have
=>a new orbiter ready after 50 flights (25 would be better), and then put it in "hot" storage

It might be a good idea to think about updating the design to start removing
some of the risks as we are building a new shuttle.
--
Wayne Johnson         |  Is a baby's life worth more than the right to
NCR Comten, Inc.      |  make a choice?  Babies are people too.
Roseville MN 55113    +-----------------------------------------------------
(Voice) 612-638-7665   (E-MAIL) [e-mail]

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

Date: 31 Mar 90 14:24:13 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Payload Summary for 03/30/90 (Forwarded)


                                Payload Status Report
                                Friday, March 30, 1990

          George H. Diller
          NASA Kennedy Space Center



          HUBBLE SPACE TELESCOPE

               The installation of the telescope into the payload canister
          was completed on Friday, Mar. 23.  Transportation of HST on the
          ten-mile trip from the Vertical Processing Facility to launch pad
          39-B began just after midnight on Sunday morning, Mar. 25.  It
          arrived at the pad at dawn.

               Removal of the protective cocoon from around the telescope
          and opening of Discovery's payload bay doors was rescheduled by
          one day to Tuesday, Mar. 26, to deal with insects.  Midges, an
          insect resembling a small mosquito, was observed on the payload
          bay doors of the orbiter.  Some escaped into the payload
          changeout room.  Those remaining were vacuumed off.  Seven traps
          were placed in the PCR.  Collectively, a total of 40 midges were
          removed from the facility.

               Because the cocoon remained in place around HST there was no
          path for the midges to enter the telescope.  The cocoon removal
          did not begin until traps provided confidence that there was not
          additional risk.  At 4:30 a.m. on Wednesday, Mar. 28, the traps
          were removed.  Telescope installation was rescheduled for one day
          later to schedule crews and permit some Space Shuttle ordnance
          work to be accomplished.

               The transfer of the Hubble Space Telescope into the payload
          bay of Discovery began at 10:40 a.m. on Thursday, Mar. 29.  The
          HST was locked into the first of four payload bay retention
          latches at 3:55 p.m. and into the last latch at 4:40 p.m.
          Electrical connections were established between the HST and the
          orbiter overnight and this morning, leading to a 6.5 hour
          Interface Verification Test scheduled to begin at the start of on
          second shift at 4:00 p.m. to verify those connections.

               At midnight on Sunday morning, Apr. 1,  a 52-hour of Pad
          Confidence Test will begin as a final check of the telescopes's
          systems and its onboard science instruments.

               These tests will also verify remote communications
          capability to the Space Telescope Operations Control Center
          (STOCC) at NASA's Goddard Space Flight Center in Greenbelt, Md.,
          the Huntsville Operations Support Center (HOSC) at the Marshall
          Space Flight Center in Huntsville, Alabama, and the Lockheed
          plant at Sunnyvalve, Calif.  The STOCC will be able to receive
          data and send commands through Discovery's communications systems
          which are connected to the Hubble Space Telescope in the payload
          bay.  The HOSC and Lockheed Sunnyvale will be monitoring the
          spacecraft systems.

               The final work to be performed will be approximately 132
          hours of battery charging scheduled to be completed 68 hours
          before launch, after which the payload bay doors of the orbiter
          are to be closed.



          GAMMA RAY OBSERVATORY

               Weight and center of gravity measurements have been
          completed to determine whether any refinements need to be made.
          Observed offsets will be compensated for by repositioning the
          orbit adjust thrusters or by ballasting certain locations of the
          spacecraft.

               Testing with the Payload Operations Control Center (POCC) at
          the Goddard Space Flight Center was completed late Tuesday.
          These tests simulated procedures to be used later when GRO is in
          the payload bay of Atlantis, and again for a predeployment
          checkout exercise.  As part of this exercise, all science
          instruments were operated during the "34 Hour Test."   This was
          essentially an end-to-end test which allowed data flows to be
          sent to science investigators at other NASA centers or
          laboratories which sponsor one of the GRO instruments.

               Also part of the exercise was a test of the Ephemeris
          program and associated spacecraft computers.  This was two
          consecutive software loads of a program which deals with the
          predicted orbital characteristics of the Gamma Ray Observatory.
          This is used by the satellite to control certain on-orbit
          spacecraft activities based on the satellite's geographic
          location.  Trouble shooting became necessary early in the test to
          resolve issues with computer updates of internal clock software;
          however, this allowed engineers to perform and complete the test
          successfully.  Portions of this test may be repeated later.

               Yesterday, checks began of the other onboard computer
          software.  These programs were used during functional testing of
          the observatory's instruments, and the software associated with
          them can now be refined.




                                PAYLOAD STATUS REPORT
                                FRIDAY, MAR. 30, 1990


          Patricia E. Phillips
          NASA Public Affairs,
          Kennedy Space Center

          ASTRO-1/STS-35
          (OPF)

               The ASTRO-1 astrophysics payload has successfully  completed
          an  extensive  series  of testing in Columbia's payload bay.  The
          test team moved smoothly through the Crew  Equipment  Integration
          Test (CEIT),  the interface verification test (IVT), and the end-
          to-end test.  The series of tests confirmed  that  communications
          between  orbiter  and payload are operational,  as are communica-
          tions  between  orbiter,  payload,  KSC,  Marshall  Space  Flight
          Center,  Goddard Space Flight Center,  Johnson Space Center,  and
          satellite relays.

               During the testing,  a signal conditioning box that  handles
          data between the orbiter and the payload experienced a failure of
          one circuit. This box, called a Remote Amplifier and Advisory Box
          (RAAB),  immediately switched to its redundant circuit, and test-
          ing was completed without any impact.

               Following completion  of  testing,  engineers  and  managers
          decided to replace the unit,  which is housed near the top of the
          ASTRO-1 igloo.  The "remove and  replace"  procedure  was  worked
          overnight Mar. 28/29. Operations went so smoothly that retests of
          the new RAAB and its linkages were underway by 4 a.m. Mar. 29 and
          completed that same day.

               Pre-flight  processing  for  ASTRO-1 will include regularly-
          scheduled BBXRT servicing,  as well  as  continued  contamination
          control and temperature monitoring.


          SPACELAB LIFE SCIENCES (SLS-1)/STS-40
          (O&C Building)

               The  floor  assembly and racks were moved to Test Stand 2 on
          Mar.  29 in preparation for integration there with  the  Spacelab
          module.  The integration is scheduled to begin Monday.

               STS-40 Mission Commander Bryan O'Connor was on hand Mar.  29
          as technicians began moving the components to Test Stand  2.  The
          combination  of  moving  elements and integration with the module
          will take several days.

               A replacement for a low-G centrifuge that  experienced  tem-
          perature  fluctuations was installed.  The new unit,  an upgraded
          one, successfully passed retesting.

               SLS-1 will be launched in August aboard Columbia.



          INTERNATIONAL MICROGRAVITY LABORATORY (IML)/STS-42
          (O&C Building)

               Technicians continue the buildup  and  integration  of  com-
          ponents  and  racks for IML,  scheduled to fly aboard Columbia in
          December.

               An international mission,  IML will have a  crew  of  seven.
          Five international space science research organizations are work-
          ing  with  NASA  on  IML:  the  European Space Agency (ESA),  the
          Canadian Space Agency (CSA), the French National Center for Space
          Studies (CNEW),  the West German  Research  and  Development  In-
          stitute  for  Air  and  Spacecraft (DLR),  and the National Space
          Development Agency of Japan.

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

Date: Sat, 31 Mar 90 23:37 EST
From: [e-mail]
Subject: RE: SPACE Digest V11 #178

How can I be removed from this list?  The mail is overwhelming my
account!

                                        HELP!
                                        Don Winters

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

Date: 1 Apr 90 03:13:13 GMT
From: wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Comparative Costs to LEO

In article <[e-mail]> [e-mail] (Robert McGwier) writes:
>If the world wanted to put stuff in a 250km high, 28 to 58 degree inclination
>orbit, your numbers would be meaningful.  Since BY FAR, most of the
>LEO shots are polar...

Um, you've forgotten a goodly assortment of science missions -- e.g. the
Hubble telescope -- which merely want to get into orbit and don't greatly
care which orbit.  Space is not just comsats and spooks.
--
Apollo @ 8yrs: one small step.|     Henry Spencer at U of Toronto Zoology
Space station @ 8yrs:        .| uunet!attcan!utzoo!henry [e-mail]

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

Date: 28 Mar 90 21:51:15 GMT
From: eru!luth!sunic!mcsun!ukc!reading!cf-cm!cybaswan![e-mail]  (Steve Hosgood)
Subject: Velikovsky's Theory

As many of you probably know, a guy called Immanuel Velikovsky published
a couple of books in the 1950's entitled "Worlds in Collision" and "Ages in
Chaos". Maybe he wrote others too - it's not important.

He postulated that several times in recent (i.e recorded) history, the
orbits of Mars and Venus were disturbed wildly, and those planets
came in close contact with the earth. The resulting tidal forces, and spin
changes and orbit changes for the earth caused such legends as the Biblical
flood and others to be written - based on fact. Indeed, unless he does
a serious lying job, it seems that many cultures have a flood myth, and many
claim that the sun stopped in its tracks one day (or maybe that the night was
very long if they were on the other side of the planet).

Things are quieter these days, and it seems highly unlikely that Mars or
Venus should have strayed from their orbits. However, it seems that current
thoughts are that the planetary orbits are chaotic in nature (mathematically
chaotic, that is), and maybe in the light of this , strange things
could have happened once or twice. Maybe they will happen again, though
the nature of chaos probably prevents a sensible prediction.

Certainly, Venus has a retrograde spin, and it seems Mars *may* have had
running liquids on its surface recently enough that the sandstorms have
not yet removed the evidence. Both of these facts seem a bit odd, yet are
known to be true.

Has Velikovsky's theory held up under attack from supercomputer simulations
in recent years? Any info? Enquiring minds would like to know.

THanks for your time reading this.
Steve

[e-mail]
or
[e-mail]

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

Date: 2 Apr 90 06:36:17 GMT
From: zaphod.mps.ohio-state.edu!unix.cis.pitt.edu![e-mail]  (Filip G.)
Subject: JUNK IN SPACE


    Greetings. I have heard a few times that man has launched

    so many sattelites and other "junk" into orbit that, in the

    future, there might be problems with having collisions. And,

    in my humble opinnion (IMHO), things are getting worse. For

    example, correct me if I'm wrong, do the NASA people have to

    worry about "unexpected", old, non-functional, satellites

    "tumbling" to earth in a collision path with a newly deployed

    satellite. It seems to me that instead of building a space

    station, NASA should worry about "cleaning up" the earth's

    orbit and not "polluting" it more. Also, in the news, I

    heard that the "promised" space station would require

    billions in maintenance. Are those expenses due to all that

    "junk" in space, or particles of thereof? Please correct

    me if I'm wrong, but the only "safe" way to exist in space

    for any period of time would be to "quickly" invent/implement

    a "force" field or shield. (Like StarWars or StarTrek...:-)

                Tell me what you think...

                [e-mail]

--
_______________________________________________________________________________
"The FORCE will be with you. Always." It *IS_ with me and has been for 8 years.
Filip Gieszczykiewicz "..of future fame...." "Ok! so I have a dream..."
FMGST@PITTVMS  or  [e-mail]

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

End of SPACE Digest V11 #211
*******************