Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_0/V15NO074.TXT

Internet Message Format | 1993-07-13 | 38KB

Date: Thu,  6 Aug 92 05:00:08
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #074 (amended)
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu,  6 Aug 92       Volume 15 : Issue 074

Today's Topics:
              ACRV Mission Requirements, and Commentary
          Energiya's role in Space Station assembly (3 msgs)
                        ETs and Radio (2 msgs)
                  Fermi Paradox vs. Prime Directive
          Hubble used for spying? + other neat info (2 msgs)
                        Reentry Size of Apollo
                            Soyuz as ACRV
     Soyuz as ACRV (Posting of previous discussion data) (2 msgs)
                                 SSF

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
    "Subscribe Space <your name>" to one of these addresses: listserv@uga
    (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: 04 Aug 92  21:47:08
From: [e-mail]
Subject: ACRV Mission Requirements, and Commentary
Newsgroups: sci.space

ACRV Mission requirements
   There are 3 fundamental mission requirements for an ARCV:
   1) Return of a sick or injured crew person.
   2) Escape from a damaged station.
   3) Shuttle unavailable.
  Now for a discussion of each basic requirement.  A couple of years
ago I was involved with one of the industry teams looking at ACRVs
and investigated these in some depth.
   1) Return of a sick or injured crew person.  This requirement may
arise at any time, and would also require the return of a second
crew person with the sick/injured person to act as an attendant.  A
typical timeline for this would be about 24 hours from declaration
of medical emergency to having them on the ground and in a hospital.
   As a point of comparision,  the US has about 21,000 manyears of
experience in nuclear submarine operations, which is roughly
equivalent to space station operations.  They've required about 44
crew evacuations, which would translate into 1 or 2 needed medical
evacuations over 30 years of a 4 man space station.
   2) Escape from a damaged station.  The time line on this can be
as little as 20 seconds or so or as long as 6 months.  It can be
broken down into retreat, isolation, preparation, departure, loiter,
and return.  If there is a major emergency on SSF, the crew first
retreats into a safe area (such as another module), and then tries
to isolate the problem (by such as closing the hatches).  If they
can't stop it there, they retreat into ACRV and isolate ACRV from
SSF.  If then, they have to leave SSF, they prep the vehicle (a few
minutes), separate from SSF, and establish a safe orbit away from
SSF and wait for a deorbit opportunity.
    I have a problem with this requirement - I have a hard time
figuring out what could be such a significant problem that retreat
and isolation into another module wouldn't solve - and that keeps
the crew alive long enough to get into the ACRV. If SSF doesn't use
isolation and "safe haven" capability other than ACRV, SSF is even
more screwed up. [Aside: SSF does have this capability, although I'm
fuzzy if this capability will be operationally equipped or used.]
"Safe haven" removes the 20 second "slam and scram" contingency and
makes 2) a resupply issue rather than a need for a return vehicle.
"Safe haven" capability on SSF with independent power and ECLSS with
skip cycle supplies needs to be compared to an ACRV.
   3) Shuttle unavailable.  This imagines another Challenger
disaster and the grounding of the shuttle fleet for a longer period
than the on-board logistics can maintain the crew at SSF.  SSF is
stocked for a "skip cycle" contingency, so it is equiped with
consumables to last 1 additional cycle if one resupply is missed.
There would then be at least 3 months to prepare for departure.
    Again, I have a problem with this requirement.  If there was
another Challenger-type problem, they would launch anyway to reach
stranded folks on SSF.  Just launch when it was warm....  I see this
requirement as a resupply requirement, rather than a return vehicle
requirement.  If the crew can be kept resupplied, they can be
maintained on orbit in reasonable safety and health for a period up
to at least a year (from Mir experience) - which should be enough
time to get the problem fixed.

    To summarize this,  I think there are a variety of methods to
solve the ACRV problem other than a dedicated down crew vehicle -
such as is currently planned for the ACRV.  1) as stated above, is a
legitimate requirement - but is 1 or 2 incidents over 30 years worth
several billions of cost?  The need for a medical evac can be
greatly reduced by putting a good health maintenance/ medical
facility on SSF.  Since I think we need to establish the data for
long-term human habitability on-orbit as a SSF priority, making room
for such a facilitiy and using it in conjunction with on-going
medical and life sciences research should be a priority.  And
cheaper than a billion $ ACRV used once or twice...
   For 2), emergency escape, a safe haven concept is already in the
design.  I think equipping and operating to this, plus the
capability of unmanned resupply would solve 2) a lot cheaper than a
dedicated return vehicle.
   For 3), unmanned resupply capability would also satisfy much of
this requirement.  Providing a second manned capability to SSF would
completely satisfy it.  Since SSF will not have permanently manned
capability (PMC) until after 2000 (as per current plans) and will
not require ACRV capability until PMC, we should look at what else
might be available.  As a first stop gap capability, use of 90-day
LDO space shuttles would work.  From the preliminary data I've seen,
modififying the entire shuttle fleet to 90-day LDO capability would
cost about $300M, with very little impact on recurring ops costs.
   Similarly, Soyuzes launched on ELVs into 28.5 deg inclination
orbits could satisfy this requirement.  Or, if Hermes or HOPE are
available they would also satisfy 3).  Over the next decade post
2000, this requirement could also be met by NASP, SSTO, PLS, or
Sanger - or other manned transportation systems.

    Anyway, enough flame.  My personal preference is to use a 90-day
LDO as a stop gap, add an unmanned ELV resupply system for SSF, and
have a fly-off competition between NASP, SSTO and a ELV/manned
return vehicle combination (Titan/HL-20, Atlas/ Soyuz, Ariane/
Hermes) for a multi-year guaranteed market with demonstration to
take place in 2003.  That'd give commercial firms 10 years to demo
and develop, and for Congress to incrementally appropriate funding
into an escrow account for the multi-year market guarantee and to
provide termination liabilty to the firms.  Downside risk is the
$300 M to provide minimal capability with LDO, and upside potential
is proving out several alternative manned transportation systems
with commercial development and operation.
 ------------------------------------------------------------------
 Wales Larrison                         Space Technology Investor


--- Maximus 2.00

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

Date: Wednesday, 5 Aug 1992 09:19:53 CET
From: "Hugh D.R. Evans" <[e-mail]>
Subject: Energiya's role in Space Station assembly
Newsgroups: sci.space

In article <[e-mail]>, [e-mail]
(Gerald Cecil) says:
>
>to why one would NOT want to orbit the Space Station at an inclination > 28.5
>deg is the increased radiation load at higher latitudes.  I have a hard time
>believing that the situation is much worse if one spends a little time at 45
>degs, but are there any magnetospheric experts out there who would like to
>comment?  I thought that most of the nasty stuff drifts in from several RsubE
>under normal circumstances, except during intense storms when it can penetrate
>to ~1 RsubE ... still comfortably far away and 30 degs from the geomagnetic
>pole.  Or, is the problem stuff that drifts UP from the ionosphere?  How do
>the fluxes compare to the load in the South Atlantic Anomaly that the Space
>Station has to encounter in any case?  Finally, how does the shielding on the
>Space Station compare to that on Skylab (which flew at 55+ degs)?  True,
>Skylab was occupied during a solar Min (the next Max is what nailed it), but
>was radn shielding a real concern?

SSF is shielded very well, due to its low altitude, from solar flare protons by
the Earth's magnetic field.  Since the solar flare protons are generated
in bursts and are not a constant source of radiation, their overall
contribution to the long term total dose is quite small.  The majority of the
dose received will be in the form of the Van Allen radiation belt protons
as the SSF passes through the SAA.  Here we are lucky due to
solar max (which causes the atmosphere to expand leading to the increased
absorption of radiation belt particles) as the trapped particle fluxes are
less in general.  So, SSF will actually fly in a gentler radiation environment
than Skylab ( my previous calculations of ~26 rads/30 days was intentionally
pessimistic and took solar min conditions;  solar max conditions gives ~13
rads/30 days for the 40 deg orbit compared to ~4 rads/30 days for the 28.5 deg
orbit at solar max.  To provide the necessary shielding on SSF for the 40 deg
orbit would require more than 20mm of Al, as opposed to the 4mm currently
planned.

As to whether or not the radiation environment and shielding was considered for
Skylab, I don't know.  However, if someone can send me the orbital details
of Skylab (apogee, perigee, inclination ) I could compute the shielded dose.

Regards
Hugh.

ESTEC                   * Inet:   [e-mail]
P.O. Box 299            *     or  [e-mail]
2200 AG Noordwijk       * SPAN:   ESTCS1::HEVANS
The Netherlands         * BITNET: HEVANS@ESTEC

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

Date: 5 Aug 92 13:29:15 GMT
From: Gerald Cecil <[e-mail]>
Subject: Energiya's role in Space Station assembly
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Hugh D.R. Evans) writes:
> ...  SSF will actually fly in a gentler radiation environment
>than Skylab ( my previous calculations of ~26 rads/30 days was intentionally
>pessimistic and took solar min conditions;  solar max conditions gives ~13
>rads/30 days for the 40 deg orbit compared to ~4 rads/30 days for the 28.5 deg
>orbit at solar max.  To provide the necessary shielding on SSF for the 40 deg
>orbit would require more than 20mm of Al, as opposed to the 4mm currently
>planned.

Thanks for this useful info! So we are now up to 7200+ kg of extra shielding
PER MODULE (assuming 2.2m radius x 12 m long modules).  Still comfortably
doable w/ Energiya, but I admit kind of pushing the point.  However, there's
certainly an inclination above 28.5 deg that minimizes the added shielding and
maximizes Energiya payload. We need to quantify the payload loss associated
with any ballistic coast.  Basically, you must minimize the horizontal
velocity while Energiya travels more than 4500 kms down toward the equator (at
high altitude to minimize thermal loads/frictional losses), until it reaches
the correct orbit inclination, then `dogleg' and light 'er up. Does anyone
have notes on Energiya engine performance?  (State budget cuts have killed
our subscription to Spaceflight.)

Re the radiation loads: if you get 4-13 rads/30 days INSIDE a Space Station
module, how much worse is the cumulative exposure during the assembly phase,
in suits?  Presumably you want to keep this well below 80 rads/30 days if
the 50% mortality dose is 250-300 rads/30 days.
--
Gerald Cecil 919-962-7169  Dept. Physics & Astronomy
U of North Carolina, Chapel Hill, NC 27599-3255 USA
-- Intelligence is believing only half of what you read; brilliance is
   knowing which half. ** Be terse: each line cost the Net $10 **

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

Date: 4 Aug 92 18:18:48 GMT
From: Bruce Watson <[e-mail]>
Subject: Energiya's role in Space Station assembly
Newsgroups: sci.space

In article <[e-mail]| [e-mail] writes:
|In article <[e-mail]|, [e-mail] writes:
|| In article <[e-mail]+, [e-mail] (Gerald Cecil) writes...
||[e-mail] writes...
||+- The cross plane maneouver from 51 degrees down to 28.5 degrees has an
||+- enormous penalty in payload.  This is why you will NEVER see a Soyuz at
||+- SSF orbit unless it is on Energia.  The payload penalty will drop Energia's
||+- delivered payload to around 50,000 pounds.  I do not know the dynamics and
||+- this estimate is based on what I have read in generalities regarding that
||+- Energia could at best only deliver a Soyuz to SS Freedom. Anybody have
||+- Delta V numbers for such a plane change?
||+
|
|Forgive me for being a naieve European, but it seems to me that the obvious way
|of using an Energia (or several) to get the Space Station launched, and
|avoiding the problems of launching into several different orbital inclinations,
|is to build an Energia launcing platform at KSC. This would inevitably be

The solution is to put SSF into an orbit with an inclination of 51.6 degrees.
That way launches from Baikonur, KSC, Kourou, Cape York, Tangeshima,
Tai Yuan, Sriharikota, and Alcantara can get to it. The only ones that
couldn't is Plesetsk (too far north), Vandenberg (azimuth constraints,
too close to greater Los Angeles), and Negev (can't launch west).

|--
|================================================================================
|Dave Clements, Oxford University Astrophysics Department
|================================================================================
|clements @ uk.ac.ox.vax            |  Umberto Eco is the *real* Comte de
|dlc      @ uk.ac.ox.astro        |           Saint Germain...
|================================================================================


--
 __________________________________________________________________________
|[e-mail]|    "Another Case of too many scientists and     |
|Bruce Watson            |     not enough hunchbacks." -- Gary Larson      |

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

Date: 4 Aug 92 03:39:58 GMT
From: Kent Schumacher <[e-mail]>
Subject: ETs and Radio
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>> Assume Einstein is right. Interstellar flight takes longer than the
>> time available since the Universe began to visit all the stars. Or,
>> we are the *first* technological civilization to evolve in the
>galaxy.
>> Or, technological civilizations self destruct.
>>
>
>
>Or they discover nanotechnology and after a few millenia of play (if
>they don't manage to turn the galaxy and themselves into cases of
>beer first), join a universal mind that could literally watch every
>sparrow fall...

Cyberspace and virtual reality could clip a few civilizations as well.
Why play in the real universe, when there's a fake one just around the
corner?


--
---
I've spent so much on this computer, I can't afford a signature
Kent Schumacher

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

Date: Wed, 5 Aug 92 12:59:23 BST
From: [e-mail]
Subject: ETs and Radio

Synchronicity strikes again.

In the June 5 Science:

    H. Mitchell Waldrop, "Finding RNA Makes Proteins Gives 'RNA
    World" a Big Boost", p1396-97

    Norman R. Pace, "New Horizons for RNA Catalysis", p1402-1403

    Harry F. Noller, Vernita Hoffarth, Ludwika Zimniak, "Unusual
    Resistance of Peptidyl Transferease to Protein Extraction

    Procedures", p1416-1419

    Joseph A. Piccirilli, Timothy S. McConnell, Arthur J. Zaug,

    Harry F. Noller, Thomas Chech, "Aminoacyl Esterase Activity
    of the Tetrahymena Ribozyme", p1420-1424

In a nutshell, it this recent work is making it look as if RNA does
it all. And I do mean ALL.

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

Date: Wed, 5 Aug 1992 12:15:47 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Fermi Paradox vs. Prime Directive
Newsgroups: sci.space

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

>>... One can imagine something like the "non-interference rule"...

>The hard part is making it stick for many millions of years, and be
>sufficiently airtight that there are no leaks whatever.

This was settled back in the early 80's. There has been no contact
because the mice won't permit it. Nobody has tried to get around it
because the whole galaxy wants to know the question to the ultimate
answer. :-)

   Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------261 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 5 Aug 92 05:42:52 GMT
From: [e-mail]
Subject: Hubble used for spying? + other neat info
Newsgroups: sci.space,sci.astro

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

>In article <[e-mail]>
>[e-mail] (E.J. du Toit) writes:
>
>>Can the Hubble telescope be rotated to view the earth's surface and what
>>could be seen (resolution)?
>
>No.  The Earth is too bright, even at night.  Pointing Hubble at Earth
>(or even the moon) would burn out (or seriously endanger) the Faint
>Object Camera.

I attended an excellent lecture by Dr. Eric Chaison of the Space Telescope
Science Institute that was given in Cleveland, Ohio in November last year.
This same question was asked by the audience and the answer is yes, you can
use Hubble to view the Earth's surface. In fact, it is routinely done for
calibrating the instruments. Fortunately for the scientists, they made the
minimum exposure time long enough such that all you see is a big blur,
otherwise the U.S. military and C.I.A. would want to start using it! There
was also a mention of the backup mirror made by Kodak (which was not flawed).
It is currently sealed inside a big box and no-one is allowed to look inside
the box. Makes you wonder if the Kodak mirror is still on the Earth or up
there spying on Saddam Hussein!

I wrote down details of the rest of the talk on my little dinner card. Here's
what I can make out of it. The solar panels are apparently oscillating up to
28 cm peak to peak for about 3 seconds after passing through the day/night
terminator with up to 1 m oscillation on one solar panel which was
supposed to have been observed by U.S. spy sats (KH-11 or KH-12). The cause
is due to the use of stainless steel on the deployment rods. Someone forgot
to take into account the coefficient of expansion of stainless steel as Hubble
passed from day to night and vice versa. The scientists are worried that stress
may break the rods. If that happens, you can kiss Hubble goodbye because it
would loose attitude control and half its power. However, the engineers say
that this won't happen and that Hubble will survive until the repair mission
in December 1993.

There is also a theory that the oscillations may have contributed to the
failure of the 2 gyros, since they are being worked harder to compensate for
the oscillations. The real cause of the gyros failing has been determined as
using integrated circuits that wern't made radiation hard enough for the Van
Allen belts and South Atlantic Anomaly. The real bummer is that apparantly
these chips are also used on U.S. spy sats where they had failed before Hubble
was launched. This information was not passed onto NASA because of the secrecy
behind the spysats. There is also another gyro which is drawing a high current
but is still usable.  Hubble has 6 gyros and requires 3 for science operations.
If 2 more gyros fail Hubble will be put into a safe non-science mode to await
repair (a set of very reliable, but coarse accuracy gyros are used).

Another fault is in the Wide Field Planetary Camera (WFPC). Apparrantly,
lanolin was used on the rivets which outgassed. The gasses settled onto the
mirror and lanolin is opaque to ultraviolet! The camera can still see in
visible though. The main mirror is 2 microns flatter at the edge which is
causing all the spherical abberation. To overcome this, 85% of the halo in each
image of a star is thrown away to obtain high resolution. This means that
Hubble can see bright objects really clearly, its the faint ones that Hubble
has trouble seeing.

There was also a lot discussed on the upcoming repair mission. The first thing
that has to be done is to replace the solar panels with ones that don't vibrate.
The next job is to replace the broken gyros with two new units (there are 2
gyros per unit). After that, a new and improved WFPC will be put in. The last
thing to be put in is the COSTAR. The COSTAR will replace the High Speed
Photometer and will deploy 5 pairs of 5 cent size mirrors before the other 3
instruments (the WFPC has its own corrective optics). This will clear up 90%
of the problem. If the corrective mirrors are more than 3% out of alignment
the images will be as bad as they were before, so great accuracy is required.
Unfortunately, the COSTAR was designed so that it could replace only the HSP.
If one of the other instruments were to fail, the astronauts could end up
pulling a perfectly good HSP to correct for a failed instrument! The Goddard
High Resolution Spectrograph is having power supply problems and that's
another job for the astronauts to fix! What is worrying the scientists is that
the astronauts won't have enough time to fix all of Hubbles problems. Only
four 6 hour EVA's are planned, with one EVA left as reserve!

Other info on Hubble was its pointing accuracies, resolutions, and observation
times. The WFPC has 0.1 arcseconds resolution, the Faint Object Camera has 0.03
microns. Pointing accuracy is 0.007 arcseconds and the jitter due to the solar
panels is approximately 0.1 arcseconds and has to be compensated for by the
gyros. Hubble also only can get 30 minutes of data in each 96 minute orbit
since the rest of the time is spent looking at the Earth.

All the above information was given at the talk and in speaking with
Dr. Chaisson after his talk. I hope I have not made any errors, but this
was over 8 months ago and I have only my little card to go by and my sometimes
not so perfect memory.

--
Steven S. Pietrobon,  Australian Space Centre for Signal Processing
Signal Processing Research Institute, University of South Australia
The Levels, SA 5095, Australia.      [e-mail]

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

Date: 5 Aug 92 13:09:35 GMT
From: Jim Mann <[e-mail]>
Subject: Hubble used for spying? + other neat info
Newsgroups: sci.space

In article <[e-mail]> [e-mail]
writes:
> I attended an excellent lecture by Dr. Eric Chaison of the Space
Telescope
> Science Institute that was given in Cleveland, Ohio in November last
year.
> This same question was asked by the audience and the answer is yes, you
can
> use Hubble to view the Earth's surface. In fact, it is routinely done
for
> calibrating the instruments. Fortunately for the scientists, they made
the
> minimum exposure time long enough such that all you see is a big blur,
> otherwise the U.S. military and C.I.A. would want to start using it!

Why?  Would Hubble give them better pictures than the spy satelites
that are designed for viewing the earth's surface? I doubt it.

--
Jim Mann
Stratus Computer   [e-mail]

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

Date: 04 Aug 92  21:45:44
From: [e-mail]
Subject: Reentry Size of Apollo
Newsgroups: sci.space

Hi Henry

>>As tiny as Soyuz is, I bet they can't.  Soyuz is smaller than the
>>Apollo capsule, if my memory of the Air & Space museum is correct,
>>and Apollo was a tight enough fit for three.
>
>Bad example, Matthew.  Apollo maximum capacity for *reentry* was
>five, that being how a Skylab rescue mission (had one been
>necessary) would have been flown.  And you could squeeze several
>more in for orbital maneuvering not involving high G.  (I've been
>in an Apollo, by the way.)

   Actually, the Apollo maximum capacity for reentry was SIX.  A
couple of years ago on a project at work we dug out an Apollo
configuration for a 6-crew capsule done by North American.  It
basically added a second row of couches under the basic three.  This
was built and tested, including suited ingress/egres tests (I saw
the films of this, and found and talked to one of the designers and
test participants - he was still working for Rockwell/North
American!)  The problem with the 6 crew configuration was the
counches on the baseline Apollo were designed to "stroke" on impact
to reduce the impact load on the crew.  For the 6-crew configuraion,
no stroking could be allowed.
   The 5 crew verson I believe your're thinking of was the Skylab
rescue configuration, where a kit was prepared for a Skylab rescue
mission, if needed.  5-crew was selected rather than 6, since it was
felt only 5 people would be needed on the mission (a 4 crew
configuration was also examined, but they wanted to preserve the
option for a backup pilot/medical specialist), and the option to
allow stroking of one couch was still desired (to attenuate the
impact on an injured crewperson) and removable pins to either lock
the strut or allow it to stroke were designed in.
 -------------------------------------------------------------------
 Wales Larrison                         Space Technology Investor

--- Maximus 2.00

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

Date: Wed, 5 Aug 1992 12:13:21 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

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

>Basically, you gotta stop the shuttle *cold* in order to grab the money you
>want. And it ain't gonna happen cuz shuttle is booked through 1998-2000 to
>build Freedom.

I'll try again, please read it this time: there is no need to stop Shuttle
since the contractors have already offered to assume development risk if the
market is there. All we need to is agree to buy the cheaper services if and
when they are available.

>You refuse to recognize the problems NASA has with examining Soyuz as a limited
>use vehicle (ACRV).

And you don't see the rapid changes happening at NASA. The problems are
nowhere near as bad as you claim.

>You have yet to address how you're going to shutdown Rockwell International..

I don't need to. Look at employment numbers at the relevant Rockwell plants
and you will see it is happening even as we speak.

    Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------261 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 04 Aug 92  21:43:28
From: [e-mail]
Subject: Soyuz as ACRV (Posting of previous discussion data)
Newsgroups: sci.space

Hi Henry!

>>   3) The ability to recover sizable payloads from space - and the
>>      definition and cost of systems to do so.
>>   In particular, 3) seems to be an interesting area for further
>>discussion.
>
>One aspect of this...  Note that the COMET program is already
>building a recovery capsule with a capacity of something like
>750kg.  (I don't have numbers for COMET itself handy, but that's
>about right for one of the early studies I read recently.)  . . .
   Beg to differ, but COMET provides a return capsule with maximum
return capability of about 150 kg.  Total mass on orbit is about 750
kg (of the return system), with about a 30 day lifetime.
   There are also several competitors for COMET around - NIS
offering the CHEOPS system, and CARINA from Italy as being the two
most real.  (NIS is using a derivative of the US DoD recoverable
payload system, and CARINA is in the final design stages).  Not to
mention the Chinese return system, and some surplus Russian/Soviet
systems being marketed for whatever hard currency they can get.
   The problem is cost -- COMET is now projected to be about $30M +
per launch for that 300 lbs.  That's about $100,000 /lb! Even if
they manage to cut the costs by a factor of 2, that's still about
$50,000 /lb.  The other systems (with the notable exception of the
Russian/Soviet system) are in the same $/lb ball park.  Russian/
Soviet systems are somewhat lower - but I am somewhat suspicous of
their cost numbers since the quoted costs I've seen don't even match
the launch costs being put forward by other Russian launch firms.

>Unless you are desperately concerned with bringing large objects
>down in one piece, it is almost certain that the cheapest way to
>return payloads is to order production quantities of these (or
>their Russian equivalents).
   I've looked at payload return from orbit from a couple of
different ways - either as paying products or to get cost savings
from reuse of hardware.
   As a point of comparision, the most commonly produced satellite
in the Western world is the GM/Hughes HS-376 communications
satellite, of which 40 have been made or ordered.  It costs about
$30,000 per pound, dry (not including propellants), and is primarily
standard, "mass produced" structure and tankage.  You can also
derive costs of $30,000/lb or higher by looking at other satellites
with reasonable production runs (Transit/Nova, DSP, GPS, etc.)
   One-of-a-kind satellites (like HST or Galileo) can run up to
$100,000 or more per pound. And some DoD satellites are rumored to
cost even more on a $/lb basis.  While some cost savings seem to be
reasonable for economic production quantities, comparision to
historical data would indicate a bottom of the cost savings for
satellites and orbital hardware with current technology of about
$20-30,000/lb.   With current LEO launch costs of only $3,000-5,000
/lb, payload cost dominates in the overall program.
   Since most LEO satellites and payloads are one-of-a-kind, their
costs would be higher.  This would indicate a potential market for
cost savings -- if we can return payloads at a reasonable $/lb.

   The crux of the previous discussion Allen and I had turned upon
cost deltas from expending or reusing SSF hardware.  SSF is
currently planning to run a logistics mission to SSF every 90 days,
carrying fresh crew, experiments, and housekeeping supplies.  It
should be noted Mir does approximately the same, although it
transfers a lesser amount of supplies due to the limitations of the
Soyuz/Progress system.  Allen and I agreed to use the existing SSF
program as a baseline, and the logistics data I used was from a SSF
program briefing entitled "SSF Logistics Resupply" from Dec 1991.
   I re-dug the briefing up, and it indicates approximately 82,000
lbs of logistics resupply to be provided annually (total up weight
of about 160,000 lbs if you include the weight of the logistics
carriers, tankage, rack structures, etc.).  Of these, about 54,400
lbs are of equipment planned to be reused (experiments, etc.), or
about 60 "racks" of experiments using a common SSF metric.
   If you figure these experiments cost $30,000/lb to procure (at
the low end of the range derived above) then they represent about
$1.6 BILLION per year to replace if they are not reused.  I think a
reasonable argument can be made $30,000/lb for such items is low -
since these are one-of-a-kind experimental apparatus, and the mass
doesn't include standard, cheap hardware for utilities (provided by
SSF), or cheap mass-produced hardware such as tankage or support
structure (since I've already subtracted the mass of the logistics
module and rack structure).  Reusing "racks" of experiments should
be capable of being done at about $1,000/lb or less (primarily
destowing, storage, updating, and reintegration/verification).
    Even if I'm high by a factor of 3x, those racks of experiments
represent about $500 M in annual expenses which will have to be
added back into program costs if they are not reused.
    Again, this indicates a need for a cargo return vehicle from SSF
with significant down cargo capabilities. Such a capability should
be added to any evaluation of use of Soyuz at SSF.
    If time permits, I'll add another message on ACRV unique
requirements for return missions, and another on cargo return
vehicles.
 ----------------------------------------------------------------
 Wales Larrison                         Space Technology Investor


--- Maximus 2.00

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

Date: 5 Aug 92 12:08:13 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Soyuz as ACRV (Posting of previous discussion data)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Allen and I did a significant thrash of this topic in January on
>talk.politics.space....

I'm deleting most of this and just want to comment on a few points.

>   However, we still haven't resolved the issue of return cargos.
>To return 80,000 lbs per year is not trivial.

Since January I have spoken with an engineer who works on Freedom. He says
that very little will be brought back and that the biggest single object
is a stationkeeping engine which weighs about 15K pounds. Aside from that
vast majority of what will be returned is trash which we can simply teather
down and let it burn up. It sounds like Dale's comment about putting the
stuff in a shoe box is about right.

From this I conclude that slapping some Shuttle tiles on a logistics
module and adding a parachute will do for recovery. I assert that the
operational costs of such a system will be a small fraction of the
savings.

>This comparison looks like a wash to me - even at $500M per shuttle
>launch.  Now for some sensitivity checks...

I am also assuming that with this system in place the entire Shuttle
program is phased out. This will save a lot more money while providing
more capability.

>   IF SSF ever grows to a 8 man configuration, the shuttle costs
>will remain approximately the same to change crews.  However, the
>ELV/HLV combo's costs will grow as 11 manned flights per year will
>be needed (4x8=32, satisfied by 11 flights), increasing costs by
>$500M/yr.

The increase should be less than that. Remember we are using single
unit prices for our Atlas launches. This plan would roughly double
Atlas production and tripple it if crew goes to 8. In addition, we
are buying services, not using government procurement.

This should greatly reduce the Soyuz launch costs.

>   IMHO, doing several new developments (HLV, Soyuz mods, man-rated
>Atlas, and a new Soyuz return vehicle or new cargo return vehicle),
>in lieu of using the existing shuttle system does not seem to be
>justified.  At best, it might save you $100M per year

If it means Shuttle can be phased out it should save $3 to $4 billion
per year.

>plus development/technical risk costs from those new developments.

These costs are carried by the developer. We are not buying hardware,
only paying for a service.

    Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------261 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 4 Aug 92 18:27:10 GMT
From: Bruce Watson <[e-mail]>
Subject: SSF
Newsgroups: sci.space

In article <[e-mail]| [e-mail] (John Roberts) writes:
|
|-From: [e-mail] (Gerald Cecil)
|-Subject: Re: Energiya's role in Space Station assem
|-Date: 3 Aug 92 14:53:53 GMT
|-Organization: University of North Carolina at Chapel Hill.
|
|-So, my question: why is the Space Station being assembled in a 28.5 deg.
|-orbit?  This locks out ANY participation by the CIS launch complexes for only
|-a few % gain in payload.  (This also excludes the obvious benefit to earth
|-observations of an orbit at 40+ degs, perhaps an important selling point to
|-soon-to-be VP Gore.)  Concerns re abort sites are irrelevant, in that NASA
|-has happily launched Shuttles to higher inclination orbits in the past.
|
|To add to the arguments presented by others, re a higher inclination:
|
|Pro: A larger percentage of the taxpayers could watch it pass overhead.
|     (At least, I *hope* that would be pro. :-)
|
|Con: Higher inclination orbits are not as well protected from radiation
|     as the lower inclination orbits of the same altitude. Long-term

False.

|John Roberts
|[e-mail]


--
 __________________________________________________________________________
|[e-mail]|    "Another Case of too many scientists and     |
|Bruce Watson            |     not enough hunchbacks." -- Gary Larson      |

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

End of Space Digest Volume 15 : Issue 074
------------------------------