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Subject: SPACE Digest V11 #434

SPACE Digest                                     Volume 11 : Issue 434

Today's Topics:
            space news from April 23 AW&ST
          Re: space news from April 9 AW&ST
             Re: HST Solar Panels
             Cape York Space Port
              Re: Soyuz TM-9 Problems ?
             Re: HST Solar Panels
             Re: HST Solar Panels
   Re: Carnegie Mellon University develops planetary robot for NASA
----------------------------------------------------------------------

Date: 21 May 90 04:11:59 GMT
From: cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: space news from April 23 AW&ST

[Aviation Week & Space Technology subscription address is 1221 Ave. of
the Americas, New York NY 10020 USA.  Rates depend on whether you're
"qualified" or not, which basically means whether you look at the ads
for cruise missiles out of curiosity, or out of genuine commercial or
military interest.  Best write for a "qualification card" and try to get
the cheap rate.  US rate is $64 qualified, higher for unqualified.
It's weekly, it's thicker than Time or Newsweek, and most of it has nothing
to do with space, so consider whether the price is worth it to you.]

The Orbiter Lifting Facility from Vandenberg will be taken out of storage
and moved to Palmdale, to make it easier to transport orbiters to and from
the Rockwell facilities there.  (Previous practice has been to tow the
orbiters by road from Palmdale to Edwards.)

"Of Soviet efforts to crach the commercial launch business, [DepSecCommerce
Thomas Murrin] remarked, `That's the kind of peace dividend I don't believe
we anticipated.'"

NASA's Aerospace Safety Advisory Panel echoes previous comments from OTA
and others, telling NASA that another major shuttle accident is likely
during the next hundred flights.  (OTA's comments were that, assuming
shuttle reliability is 98% -- something we don't know with confidence
yet -- there is a 50% chance of losing another orbiter by 1993 and a
72% chance of losing one before space station assembly *starts*.)  ASAP
says there have been quite a few improvements since Challenger, but also
areas where improvements could be had and no effort is being made.  The
panel wants to see more effort on the main engines, a complete redesign
of the nozzle and igniter joints in the SRBs, and a hard look at whether
the proposed automated insulation process for the ASRMs can be made to
work with available resources.  ASRM is well off in the future and should
not be an excuse for stopping work on the current SRBs, much less the
SSMEs.  The "large-throat combustion chamber" for the SSMEs would
reduce stress in the engines and considerably improve safety, but it
is not even officially part of the engine-improvement project -- it's
just a technology study.  Recent studies clearly show that the orbiter
structure does not consistently have the 1.4 factor of safety it was
meant to have, particularly in the wings, and action on this is needed.
25 orbiter windows so far have been pitted by debris impact, 11 of
them badly enough to require replacement, and ASAP recommends either
stronger windows or a determined effort to fly the orbiter in attitudes
where the windows are less exposed to debris strikes.  There is no
systematic plan for structural overhauls of the orbiter fleet, and
any airliner engineer will tell you that such planning is necessary
to keep a fleet flying safely.  NASA has not thought hard enough about
safety problems resulting from human error and poor human interfaces.
Finally, there is little evidence of serious contingency planning for
the possibility of a major interruption in shuttle operations after
the space station is underway.

ASAP had quite a bit to say about the space station too.  There seems
to have been no attempt to do overall safety analysis of the station.
The decision to use existing space suits is a mistake, the panel says,
and the higher-pressure suit should be considered urgent.  The current
station design has two shuttle docking ports, but it is not possible
to dock two orbiters simultaneously, because the ports are too close
together!  If there's ever a problem with separating an orbiter from
the station, the station is in trouble, particularly if something else
is wrong at the same time and the crew *have* to reach that one port.
The panel says this configuration is "an unacceptable risk" and one
of the ports should be moved.  (Lenoir says the problem is known but
not yet dealt with.)  Funding limitations have scaled back software
verification facilities for the station, and given the station's heavy
reliance on software, this is a mistake.  The combination of long lead
times for station spare parts and limited launch capacity to transport
them up may make timely repairs very difficult; NASA needs to include
spares stocks and availability of launch capacity for them in the
"launch commit" criteria for the station.

Indonesia's Palapa comsat goes into space for the second time, aboard
a Delta this time, April 13.  The launch slipped four days due to the
(aborted) launch of Discovery carrying the HST:  the Cape normally
wants 48 hours between launches to reconfigure tracking etc.  David
Braverman, VP of Hughes (builders of Palapa), says this is a bad sign.
Foreign customers, he says, feel that commercial launches get rather
higher priority at Kourou, Baikonur, or Xichang than at the Cape.
He says nobody disputes that HST had priority in this case, but it's
generally perceived that the US government feels free to preempt
commercial launches whenever it pleases.  He says US commercial launch
firms need solid government support if they are going to compete with
"subsidized" launch industries elsewhere, and "That support to the
present has been nothing but lip service.".

Col. John Wormington, commander of the Cape, says that the Cape's old
facilities will probably limit expendable launches to 20-25 a year.
The equipment is manpower-intensive and the system is not very robust.
He says pads are the "choke points", because far too much work needs
to be done after the hardware arrives on the pad -- typically 2-3
months of it.  The problem has been aggravated since Wormington banned
60-hour work weeks, which had become routine but were increasingly
seen as an unacceptable safety risk.  He says, for example, that
McDonnell Douglas wants to launch 12 Deltas a year, but without
unacceptable pressure on staff, the most they can expect is 10.

TRW gets USAF contract to build (up to) twelve experimental lightweight
satellites over the next six years.  They will go up on "small launch
vehicles" [can you say "Pegasus"?] starting in 1992.

One week after Asiasat 1 went up from Xichang, 80% of its capacity has
already been leased, and the rest is expected to go within a week.
This is a lot better than its backers expected, and they are already
looking at a second satellite.  Their original target for leasing all
of Asiasat 1's capacity was 1992!

NRC says it is not in the US's best interest to undertake a joint manned
mission to Mars with the USSR:  the program would be hostage to political
changes, neither nation is likely to give the other full responsibility
for major technologies, and the mechanisms for cooperation are rudimentary
as yet.  NRC advises a cautious start based on initial projects that are
"resilient to unforeseen technical and nontechnical problems", and urges
more cooperation with "more traditional scientific collaborators".  The
panel did reiterate an earlier call for the US to get moving on a Mars
sample return, and observed that the US has no firm Mars plan stretching
farther than 1992 (the launch of Mars Observer).

Launch of the Japanese journalist to Mir has been set for Dec 2.  West
Germany has reached agreement for an eight-day Mir mission by a German
astronaut in 1992.

Head of USAF Space Command says the US cannot place satellites into orbit
quickly, and prescribes [of course] that the military should operate its
own launchers rather than relying on contractors.

Lawrence Livermore to start fabrication of inflatable-space-structure
prototypes within a year.  Lowell Wood says that DOE will announce the
formal establishment of a DOE space-exploration budget soon.

Wood sharply criticizes NASA, saying its approach to human exploration
of space is far too slow and costly to ever get the necessary political
support.  "All but the youngest of today's adult Americans will have
died of old age before we can put a permanent human presence on Mars...
the root canal approach to manned exploration... Everyone recalls that
we've already gone to the Moon in eight years, moving out from a standing
start in technologically far less advanced times.  Americans therefore
treat pending proposals to return to the Moon 12 or 15 or 20 years from
now as nonstarters..."

Wood says that a key aspect of his proposals is to reduce the long-term
pre-planning of scientific experiments, with follow-on science organized
in response to initial exploration, rather than by predetermining decades
of research beforehand.
--
Life is too short to spend    |     Henry Spencer at U of Toronto Zoology
debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 21 May 90 00:17:55 GMT
From: zaphod.mps.ohio-state.edu!know!samsung!munnari.oz.au!metro!cluster!softway![e-mail]  (Greg Rose)
Subject: Re: space news from April 9 AW&ST

In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:
>In article <[e-mail]> [e-mail] writes:
>
>>as the start of a CANZUS Space Alliance.  (CANZUS = Canada, Australia, New
>>Zealand and United States).
>
>But if there's nuclear material (RTG's or reactors) aboard the satellites to
>be launched, won't New Zealand wimp out? (Only a half-smiley, folks.)

Strange, one of the smallest, most isolated countries in the world
stands up to one of the biggest and most powerful (and who the party
of the first part relies upon for defence) and tells them that they don't
want their nuclear weapons thanks, AND YOU CALL THIS WIMPING OUT?
I'd like to see a lot more of this.

(When was the last time you told the gang of muggers where to get off...:-)

By the way, New Zealand objects far more to the nuclear weapons than
to the nuclear stuff in general. But bear in mind that they don't need
nuclear power stations, so why bother with figuring out how to cope
with nuclear accidents?  My understanding of their policy is that they wouldn't
have any real problem with shooting reactors up (as opposed to
shooting up reactors) from somewhere else, if they thought they were
reasonably safe.

>Matthew DeLuca
--
Greg Rose - assistant test pilot - Softway Pty Ltd
PHONE: [phone] FAX: [phone] NET: [e-mail]

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

Date: 20 May 90 08:47:19 GMT
From: tornado.Berkeley.EDU![e-mail]  (George William Herbert)
Subject: Re: HST Solar Panels

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Wesley Cole) writes:
>>How different are space craft solar panels from panels that can be purchased
>>commercially?  ...  I'm sure that NASA panels must be space flight
>>certified (very resistant to vibration, heat, etc) but do they use the
>>same process to convert sunlight to electricity at the same efficiency as
>>earth bound panels?
>
>The underlying process is definitely the same.  Space solar arrays are
>generally different from ground ones in being optimized for light weight
>and radiation resistance, subject to constraints requiring them to be
>resistant to vibration, extreme temperatures, etc.  I don't know how the
>efficiencies compare offhand -- the extra constraints are balanced, to
>some extent, by cost-is-no-object engineering.

Some stuff about solar cells...

The solar sells that are currently in use are standard, though very high
quality silicon cells.  More advanced amorphous silicon and GaAs cells are
in the pipeline, but not yet standard for flight use.

The average effeciency of mid-seventies silicon cells was twelve percent;
of the solar flux of 130 watts/sq. ft. (or 1.4 kW/m^2).  More recent
cells have pushed fifteen percent; various difficulties with technology
make it unlikely that there will be big leaps in the near future.

Solar cells are degraded by the radiation that is inherent to the space
environment; the average space-hardened solar cell loses 5% of it's output
per year of exposure.  The hardening usually is simply a layer of quartz
or saphire as shielding, plus some optical coatings.

The power to weight density of most solar cells is around ten watts/lb.
(twenty two watts/kg).  Costs run anywhere from $400 to $800 in 1980 terms
per watt of output for the entire array.

-george

Ps- space/astro funnies
When NASA announced that they would make some observing time on the Hubble
available to amateur astronomers, they must have counted on some pretty wierd
proposals, but one in particular was amusing: someone wanted to take a SDI
laser and vaporize the surface off asteroids, watching with the spectrometer
on Hubble to determine the composition of the released gases...

As part of a class I was helping teach this last semester, someone took this
general idea a step further as part of their term project...worked out the
numbers on a pulsed laser to do that sort of spectroscopic study on the
martian surface from low mars orbit.  The fact that it was even close to
working scared most of the class.  The "SDI-grade laser" joke kept running
on and on, gaining momentum with occational design checks that showed it wasn't
as insane or unworkable as you might think...

Following a recent conversation, a variant of this finally reached the peak
of wiggy-ness...With the National Space Council and it's chair, Dan Quayle,
having issued a public call for proposals on how to advance the space program,
we drew up a joke proposal to...
[those in NASA asked not to take this too seriously 8-) ]

...use a SDI orbiting laser to vaporise parts of NASA HQ in washington, DC,
looking for any evidence of direction of purpose in the spectrographic
observations to be taken by the Hubble as it passed over.... 8-)

[mary, albion, peter, eugene; please forgive me 8-) ]
*******************************************************************************
George William Herbert              JOAT For Hire: Anything, Anywhere: My Price
   UCB Naval Architecture undergrad: Engineering with a Bouyant Attitude :-)
-------------------------------------------------------------------------------
"Who?" the man managed.                    Whip me, Beat Me, Make me learn C...
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"...and all we want is a jack into your    ========== [e-mail] OR
custodial system." -neuromancer            """""""" [e-mail]

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

Date: 20 May 90 14:40:06 GMT
From: swrinde!zaphod.mps.ohio-state.edu!know!samsung!munnari.oz.au!metro!cluster![e-mail]  (Andrew Taylor)
Subject: Cape York Space Port

In article <[e-mail]> [e-mail] (Henry Spencer)
writes:
>Cape York has started work on an environmental impact statement, with
>construction to begin immediately on final approval in 1992.  A Soviet
>satellite might be the first payload launched, in 1995.  Full operation,
>in 1997, would start at five launches per year.

It should be noted that final approval is far from a formality. My uneducated
guess is that there is a greater than even chance that the project will be
stopped on environmental grounds. Cape York is such an ecologically important
area that the environmental impact statement (EIS) may be unfavourable,
even given the (relatively) low impact characteristics of a spaceport.

Neither would a favourable EIS be sufficient, the likely bitter opposition
of conservation groups could well see the spaceport stopped. I can only
guess that the political climate when the project started made approval
seem more likely.

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

Date: 20 May 90 19:07:13 GMT
From: usc!samsung!xanth!xanth.cs.odu.edu![e-mail]  (Frank C. Paterra)
Subject: Re: Soyuz TM-9 Problems ?

In article <[e-mail]> [e-mail] (Steven Bellovin) writes:

   The next Kvant launch is going to include a ladder and some tools for
   the Mir crew to use to try to repair the blankets.  (The purpose of
   the ladder is to give them something to hang onto; there are no handholds
   on the outside of the Soyuz.


I hope they remember to send some [duct|gaffer] tape :-)

--
Frank Paterra
[e-mail]

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

Date: 20 May 90 22:47:40 GMT
From: swrinde!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: HST Solar Panels

In article <[e-mail]> [e-mail] (Richard A. Schumacher) writes:
>>intense solar activity last fall knocked several years off the lives of
>>some satellites...
>
>CNN has just reported that film aboard the shuttle during the HST
>deployment mission was fogged by radiation. Can this have knocked a few,
>well, weeks, anyway, off the lives of the crew? ...

It undoubtedly shortened their lifetimes slightly and raised their chances
of certain types of cancer slightly.  As I recall, NASA's official career
radiation exposure limit is based on a modest increase in cancer probability
and a two-year generic reduction in life expectancy.  Nobody has yet been
retired due to hitting the limit, that I know of.

The crew to wonder about, actually, is the bunch that did the Galileo
deployment.  They were up during some of the solar uproar last fall, and
I'm told they reported cosmic-ray light flashes in their eyeballs, most
unusual for low orbit.
--
Life is too short to spend    |     Henry Spencer at U of Toronto Zoology
debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 20 May 90 06:14:56 GMT
From: convex![e-mail]  (Richard A. Schumacher)
Subject: Re: HST Solar Panels

[e-mail] (Henry Spencer) writes:
>intense solar activity last fall knocked several years off the lives of
>some satellites.  (Satellites in all but the highest Earth orbits usually

CNN has just reported that film aboard the shuttle during the HST
deployment mission was fogged by radiation. Can this have knocked a few,
well, weeks, anyway, off the lives of the crew? (No details of total
dose or source were provided, naturally.)

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

Date: 20 May 90 09:53:41 GMT
From: tnc![e-mail]  (JOHN BASHAW)
Subject: Re: Carnegie Mellon University develops planetary robot for NASA

>     Planetary rovers must be able to make autonomous decisions
>because of the long transmission times for commands between Earth
>and planetary surfaces -- about 45 minutes one way to Mars.  "The

correct me if I'm wrong (I know you will :) ) but according to my
calculations one-way light time to mars varies from ~13 minutes to ~29
minutes, even as an average, 45 minutes seems a tad out of line for
round-trip time, much less one-way.

                         John Bashaw

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

End of SPACE Digest V11 #434
*******************