Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_4/V15NO465.TXT

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Date: Fri, 27 Nov 92 05:05:44
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #465
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 27 Nov 92       Volume 15 : Issue 465

Today's Topics:
                          Breasts in zero-g
                          Satellite Tracking
      Shuttle Performance and Titan IV (Was Shuttle Replacement)
                     Shuttle replacement (2 msgs)
                         Space suit research?
                        What comes after DC-1

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Date: 26 Nov 92 23:13:58 GMT
From: Brian Tao <[e-mail]>
Subject: Breasts in zero-g
Newsgroups: sci.space

In article <roelle.722116771@uars_mag> roelle@uars_mag.jhuapl.edu (Curtis Roelle) writes:
>
>The use of a brazier is
>still required, although the flight version differs from the
>terrestrial standard in that instead of lifting the breasts upward it
>pulls them downward, keeping them out of the face.

    I think you mean "brassiere".  Don't you use braziers to torch stuff?
OUCH!  :)  Speaking of spaceflight attire, don't the jumpsuits have some
sort of built-in "support"?  I know they are supposed to be form-fitting
so no baggy ends can accidentally snag a control switch or get caught
on a corner.  With a properly designed jumpsuit, would a bra be
superfluous in zero g?

--
-- Real name: Brian Tao (Dept. of Exobiology, University of Toronto)
-- Preferred: [e-mail] (checked daily)
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------------------------------

Date: 24 Nov 92 06:41:38 GMT
From: Ralph Buttigieg <[e-mail]>
Subject: Satellite Tracking
Newsgroups: sci.space

Original to: [e-mail]
 8> [e-mail] (Paul Mc Mullen), via Kralizec 3:713/602

 8> Does anybody know the whereabouts of a public domain (shareware)
 8> satellite tracking program, or for that matter whether they exist in
 8> this form. I would very much appreciate if anybody knows where a PC
 8> version for the IBM could be found.
 8>
 8>        Thanks in advance Paul.

 My BBS is a specific Astronomy & Space BBS.  it has several satellite
 trackers for the IBM and AMIGA. Dial [phone]

 ta
 Ralph

--- Maximus 2.01wb
 * Origin: Vulcan's World-Sydney Australia 02 635-1204 (3:713/635)

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

Date: 26 Nov 92  14:23:28
From: [e-mail]
Subject: Shuttle Performance and Titan IV (Was Shuttle Replacement)
Newsgroups: sci.space

Karl Dishaw writes:
>Has the shuttle ever lifted more than 20 tons (vs. the rated
>capacity of 30 tons)? ...

   Yes, multiple times.  For example, on each TDRS flight, the
primary payload (TDRS plus IUS stage, plus support equipment weighed
about 50,000 lbs in the payload bay.  Plus, now you have to add the
secondary and other payloads to that total.
   A note:  I've seen a couple of different interpretations here,
and if the net will indulge me, I'll define a couple of points.  A
couple of years ago I did some rather intensive set of comparative
launch vehicle manifesting, so I've been around the payload calcs
for several different types of launch vehicles.  I'm going to re-
post a posting I put up last January, with notes in [..] to update
the information....

   SHUTTLE LAUNCHES OF PAYLOADS GREAT THAN 40,000 LBS.
   The shuttle has routinely launched at least a dozen cargos with
mass more than 40,000 lbs.  For example, TDRS has single cargo
weight of about 50,000 lbs between the TDRS, IUS, and the support
equipment.  This avoids the downweight limitation by the fact that
about 40,000 lbs will be deployed from the payload bay. (But the
shuttle can land, once, with it still in the payload bay.)  Note
also there is typically about 5,000-7,000 lbs of other payloads per
mission (crew experiments, middeck locker experiments, GAS cans,
etc.). These are "secondary payloads" are are not typically listed
on the shuttle manifest.
   So the shuttle can, and has, routinely launched payloads great
than 40,000 lbs (to a standard 150 nmi altitude).

   DIFFERENCES IN "STANDARD" AND "SSF" PERFORMANCE
   I've seen a lot of unnecessary flaming about different
performance to different operational altitudes.  SSF is at 220 nmi
altitude,  while shuttle performance is standardly quoted to 150
nmi.  Titan, for example, is standardly quoted to 100 nmi.  You have
to convert the vehicles performance to a common altitude.
   As was quoted by Robert Unverzagt from the Titan IV Users Manual,
the Titan can only put 26,500 lbs into Space Station altitude, with
no margin reserve [Note: if you assume the yet-to-be-flown SRMUs on
the Titan-IV, this number increases to about 32,400 lbs.]  The
shuttle can put about 41,300 lbs to this altitude without ASRMs
(also not including performance margins), and at least 49,300 lbs to
this altitude with the ASRMs (not including the 3,000 lbs ASRM
program performance margin).  (Data from NASA SSF program briefing
"SSF Logistics Resupply", Dec 1991)  However, you typically only
plan for some lower value - including some performance reserves,
just in case.  For the shuttle this is typically 5,000 lbs, and for
the Titan-IV I believe it is 3,000 lbs.
   These numbers show to get the same lbs to SSF with Titan-IVs,
you need 15 Titan-IV flights for every 8 shuttle flights - almost a
2:1 trade off. [Or looking at differently ...
      STS (no ASRM) to Titan IV (no SRMU) = 8 : 15, assumed current
operational state-of-the-art.  If you assume the upgrades in work
for both systems, but still not operational,
      STS (w/ASRM)  to Titan IV (w/ SRMU) = 8 : 12    ]

   ORBITER RETURN PAYLOD CAPABILITY
   Orbiter return capability is totally different from orbiter
delivery capability.  The orbiter return delivery capability is
calculated on an individual vehicle and mission capability - based
upon total return landing weight.  Furthermore there is a 1-time
contingency landing capability as well as a regular mission limit.
   The limit is driven at (from memory) about 240 Klbs return
weight.  OV-102, since it is about 9,000 lbs heavier than any other
vehicle, is certified for regular returns of about 32,000 lbs of
payload. OV's-103, -104, and -105 are much lighter weight vehicles
and can accommodate higher weight payloads, typically in the 40,000
lb or higher category, on a regular basis without exceeding the
240 Klb limit.
   However, there is also a higher certified safe limit for a 1-time
contingency landing.  If the shuttle is launching a 45,000 lb
TDRS/IUS, it can't dump the payload before landing in a RTLS or TAL
abort.  And there might be a payload that won't deploy.  So the
orbiter is certified to land, once, with a gross weight at landing
of about 275Klbs, which is about a 75,000 payload on OVs -103, -104,
and -105.  After such a landing, yit would be necessary to reinspect
and recertify the landing gear, it wouldn't crash or collapse. I
called an talked to a Shuttle landing gear designer I used to work
with, and he thought an inspection would be sufficient in such an
event, based upon the data from the previous 45 [now closer to 50, I
believe] or so flights.

  Hope this data adds light to the flames.


 -----------------------------------------------------------------
 Wales Larrison                          Space Technology Investor

--- Maximus 2.00

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

Date: Fri, 27 Nov 1992 03:38:27 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

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

>Oh, and by the way, exactly HOW MUCH MODIFICATION will DCX RL-10s require?

Henry has already answered the modification question. However, I want
to point out that a similar failure will not result in loss of the DCX.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------149 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Fri, 27 Nov 1992 04:40:13 GMT
From: Dave Michelson <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
>
>Didn't Apollo eventually quit using escape rockets?

No.

--
Dave Michelson
[e-mail]

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

Date: Fri, 27 Nov 1992 02:44:26 GMT
From: Frank Crary <[e-mail]>
Subject: Space suit research?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Charles R. Martin) writes:
>Anyway, actually a significant number of people
>develop altitude sickness even at Aspen and *lower* altitudes.  Growing
>up in Alamosa, I know there were people there who never adapted and had
>to leave for medical reasons even though they were to all appearances
>healthy; Robert Heinlein's wife Ginny had altitude sickness in Colorado
>Springs that eventually forced their move to California.

That's true enough, and why I added that such adaptability could
easily be made part of the medical qualifications for spaceflight. I've
never heard of someone who adapted to the lower oxygen levels, and much
later expreienced problems. As far as I know, once someone adapts
there aren't later problems.

                                          Frank Crary
                                          CU Boulder

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

Date: 27 Nov 1992 03:44:25 GMT
From: Scott Fisher <[e-mail]>
Subject: What comes after DC-1
Newsgroups: sci.space

[e-mail] (Hugh Emberson) writes:

>The zeroth stage would be like a big SSTO with fuel tanks, lots of
>engines and guidance.  It would sit under the SSTO and act like a
>first stage booster for the SSTO.  When it was nearly out of fuel it
>would separate, fly back down and land -- ready for reuse.  The book
>says that with this the SSTO could reach GEO.

Sounds like a 747 :-)

Scott.

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End of Space Digest Volume 15 : Issue 465
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