Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_2/V16NO211.TXT

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Date: Mon, 22 Feb 93 05:00:13
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #211
To: Space Digest Readers
Precedence: bulk


Space Digest                Mon, 22 Feb 93       Volume 16 : Issue 211

Today's Topics:
                   "DOES AMERICA SAY YES TO JAPAN"
              extreme responses to Challenger transcript
          How many RPM's around his own axle can human take?
                Mars Rescue Mission, what if! (3 msgs)
                        McElwaine disciplined!
                McElwaine disciplined! (somewhat long)
                NASP (was Re: Canadian SSF effort ?? )
                       Nobody cares about Fred?
                           PEGASUS QUESTION
               Pressure fuel delivery, ideas regarding
       Reliable Source says Freedom Dead, Freedom II to be dev
    Reliable Source says Freedom Dead, Freedom II to be developed
                              Rocketeer
                          Sabatier Reactors.
          Spy Sats (Was: Are Landsat Satellites receivable?)
                       SSTO/DC-X in the Media..
                   Titan or Bust! (Saturn Moon)...

    Welcome to the Space Digest!!  Please send your messages to
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----------------------------------------------------------------------

Date: Sat, 20 Feb 1993 23:00:03 GMT
From: Josh Hopkins <[e-mail]>
Subject: "DOES AMERICA SAY YES TO JAPAN"
Newsgroups: sci.space

[e-mail] (Andre Robotewskyj) writes:

>Hello,
>    Over the past few months, a paper entitled, "Does America Say Yes
>To Japan?" (Louis Leclerc 1992) has been circulated over various computer
>networks and BBS's.

My first thought was that this was a little out of place.  But then I thought
about what's happened to station this week.

I imagine, however, that the paper takes a rather different atitude then the
last few days would suggest is accurate :-)
--
Josh Hopkins                                          [e-mail]

    You only live once.  But if you live it right, once is enough.
            In memoria, WDH

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

Date: 11 Feb 93 14:12:46 GMT
From: [e-mail]
Subject: extreme responses to Challenger transcript
Newsgroups: sci.space

In article <[e-mail]>, [e-mail]
(Jason Cooper) wrote:
>
> > >My posting was not libelous, obscene, or otherwise criminal.


Could someone please repost it? Thanks.

 _______________________________________________________________________
| Alex Alexander          |    The views expressed here are my own.     |
| LaserMaster R&D         |---------------------------------------------|
| Minneapolis, MN 55344   |    "Your only validation is in living your  |
| [e-mail] |      own life; vicarious existence is a     |
| [phone]          |       fucking waste of time." -- Axl Rose   |
 -----------------------------------------------------------------------

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

Date: Sat, 20 Feb 1993 17:46:50 GMT
From: [e-mail]
Subject: How many RPM's around his own axle can human take?
Newsgroups: sci.space,sci.med

I am not sure if this is the right group, but as space technology has
also studied the limits of human, I'd guess there was somebody who knew:

How many RPM's around his own axle can a human take?

Let's take two cases: a human is sitting on a round table, under which
is an electric motor, and then the same but standing on it?

Some animals are known of being capable of taking very hard rpm's
without suffering visible damage, but I would rather not to prefer being
my own test subject in this matter!

I need this information to designing an amusement park -type of thing,
which will only be for "real fun" as opposed to the very lame apparates
found in amusement parks. Of course I will finally test these on myself,
but I needed practical guidelines along which I should be able to make
safe tests.

--
[e-mail] | PGP 2.0 key available | PGP 2.0 avain saatavilla

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

Date: 20 Feb 1993 22:15:27 GMT
From: "Kevin W. Plaxco" <[e-mail]>
Subject: Mars Rescue Mission, what if!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Frank Crary) writes:


>That really depends on the nature of the problem. There is a paper
>on rapidly sending small (under 10kg) packages to Mars within one
>month.


Yowzers.  One month?  10Kg?  Do tell!

-Kevin

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

Date: Sat, 20 Feb 1993 19:12:33 GMT
From: Frank Crary <[e-mail]>
Subject: Mars Rescue Mission, what if!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Wierd question? What is the mission to Mars fails, and the astronauts are
>stranded, maybe not int he end, but early on. What steps would be done if
>anything to rescue them??

That really depends on the nature of the problem. There is a paper
on rapidly sending small (under 10kg) packages to Mars within one
month. So it's very possible to send a stranded astronaut the three
vital parts he needs to fix his rocket. However, if you mean
"stranded" as in (say) "all the fuel in his rocket leaked out"
(i.e. where a rescue would require tens of tonnes of new rocket/life
support module/whatever...) There isn't alot that could be done.

>Scenario if early in the mission, mabe a fly by resupply mission (space drop
>versus air drop?).

For heavy payloads (i.e. where you can't use as much fuel as you like)
the orbital mechanics prevent any sort of rapid rescue. It is only
possible to send things from Earth to Mars once every two years, and
the transfer takes about nine months. So, once launched, an astronaut
couldn't expect anything (major) from Earth for almost three years.
Of course, three years isn't forever: It wouldn't cost a mission
much to include extra life support supplies, making it possible to
wait until a rescue could arrive (a typical mission would be about
500-days long anyway, because of the same requirements of orbital
mechanics...) Also, missions can be designed to minimize these
risks: While you can't send supplies _after_ the astronaut has
left, you can send them before. In fact, the timing of transfer
orbits and launch windows insures that pre-positioned supplies
would have already reached the Martian surface before the astronaut
left Earth: You can send vital equipment ahead and make sure
it gets there safely before deciding to send the astronaut...

>If later in the mission, namely on the way home. what is there available to
>help them home..

Just about nothing: Any rescue would have to reach him _and_ match
his velocity. That would require an essentially impossible amount
of fuel.

                                                        Frank Crary
                                                        CU Boulder

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

Date: Sat, 20 Feb 1993 19:20:40 GMT
From: Frank Crary <[e-mail]>
Subject: Mars Rescue Mission, what if!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Herman Rubin) writes:
>>Wierd question? What is the mission to Mars fails, and the astronauts are
>>stranded, maybe not int he end, but early on. What steps would be done if
>>anything to rescue them??

>Very little.  The Scott expedition to the south pole died.  Any frontier
>is a dangerous place.

However, the Shackelton expedition didn't, nor did Amendsen's: Risks
can be minimized by carefull planning and having enough sense to
give up and cut your losses, when serious problems come up...
(More exactly, good judgement about when a solution can be improvised
on the spot and when it can't.)

>Would the astronauts have the mobility to get to the supplies?

They wouldn't need much mobility: A resupply/resuce mission should
be able to land within 250m of them (closer, if they have a radar
transponder and meterological instruments so that the atmospheric
conditions are well known...)

                                             Frank Crary
                                             CU Boulder

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

Date: 20 Feb 93 18:15:00 GMT
From: Andrew Koenig <[e-mail]>
Subject: McElwaine disciplined!
Newsgroups: sci.skeptic,sci.space,sci.astro,sci.space.shuttle

It always worries me when someone is stomped on because of what he says,
even if what he says is unadulturated gibberish.  Are we so thin-skinned
that we can't just ignore stuff we don't want to see?

Being suppressed doesn't make you Galileo, but there are an awful lot
of crackpots out there who think it does.
--
                --Andrew Koenig
                  [e-mail]

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

Date: 20 Feb 93 23:15:37 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: McElwaine disciplined! (somewhat long)
Newsgroups: sci.skeptic,sci.space,sci.astro,sci.space.shuttle

[e-mail] (Russell J. Pagenkopf) writes:

>In article <[e-mail]> [e-mail] () writes:
>>It always worries me when someone is stomped on because of what he says,
>>even if what he says is unadulturated gibberish.  Are we so thin-skinned
>>that we can't just ignore stuff we don't want to see?

>* SOAPBOX ON *

>I must agree with you Andrew.  Just because *you* (newsgroups in
>general) don't agree with what someone has to say doesn't mean you have the
>right to CENSOR him/her.  Yes, I agree that sometimes some of the posts can be
...

Maybe it's about time a lot of these people learned about
a newsreader called 'nn'.

--
Phil Fraering         |"...drag them, kicking and screaming,
[e-mail]|into the Century of the Fruitbat." - Terry Pratchett,
                       _Reaper Man_

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

Date: 20 Feb 1993 19:44:50 GMT
From: CLAUDIO OLIVEIRA EGALON <[e-mail]>
Subject: NASP (was Re: Canadian SSF effort ?? )
Newsgroups: sci.space

> Aerospace Daily also reports that NASA research
> on advanced subsonic and supersonic transport aircraft would
> get a big increase under Clinton's budget plan, with $550
> million more programmed in fiscal years 1994-97, and another
> $267 million scheduled for FY '98.

What about NASP???

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

Date: 20 Feb 93 18:44:05 GMT
From: Pat <[e-mail]>
Subject: Nobody cares about Fred?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Hugh Emberson) writes:
|>>>>> On Thu, 18 Feb 1993 23:10:13 GMT, [e-mail] (Brad Whitehurst) said:
|
|BW> In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
|>Some of the specific R&D projects I have worked on include: SeaFire
|>Fire Control System (Navy), Integrated CNI Avionics (USAF), a Digital
|>Map system I can't remember the name of (USAF), Pilot's Associate (DARPA/
|>USAF), Emergency Procedures Expert System (TI IR&D), Multi-Agent Planning
|>(TI IR&D), Mission Planning Workstation (TI IR&D).
|>
|BW>     Welll, Allen, I'm just a lowly mechanical engineer (hate those
|BW> li'l electrons!!), but I would propose that there are some qualitative
|BW> differences in forging a large, mechanical assembly out of steel,
|BW> aluminum, and composites, compared to primarily software
|BW> constructions.  [...]
|
|Actually constructing large programs is not much different, if its
|done properly.  If its not done properly then the mess is a lot worse.
|
|There is a whole branch of computer science called "software
|engineering" which aims to make the construction of large programs as
|much like constructing a bridge as possible.
>
>Hugh


I would argue, that it is easier to design large mechanical assemblies
of steel, composites and aluminum and fabricate them to spec then to build large
software programs.

Engineering especially mechanical and civil are fields dating back
to babylonian days.  Most of the material interactions in a mechanical
structure can be well understood and there are ASME/ ASTM/ ASCE/ PE
standards regarding design and fabriacation.  also finite element
analysis gives a good understnading of real world behaviors prior
to design.  Then most structures have a solid  testing program
to verify performance.

Computer systems suffer from poorly understood requirements,
difficult planning and impossible test.  most major systems
involving software have had major software problems.  the structure
part tended to work better then the software part.

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

Date: Sat, 20 Feb 1993 17:55:15 GMT
From: [e-mail]
Subject: PEGASUS QUESTION
Newsgroups: sci.space

> Lawrence Curcio writes:
>
> Not to beat this to death, but regarding the marginal velocity supplied
> by the B52:
>
> First, it was my impression that this was more than a couple of hundred
> kph. Also, the altitude-for-velocity function is remarkably convex, once
> one gets out of dense atmosphere. That is, there are increasing altitude
> returns to marginal velocity, as velocity increases. Therefore, 600-1000
> kph more or less could make a difference in capability, IMHO.


        I don't think anyone is (seriously) suggesting "a couple of hundred
kph", although one poster may have used this term dismissively.  200 kph is
about 120 mph, which will be lower than the stall speed of any large plane
used as a carrier.

        I suggested 200 m/s, which is 720 kph, or about 450 mph.  This will
vary however depending on the launch profile which is chosen.  One approach
is to fly as high as you can horizontally, maximizing speed, and dropping the
rocket.  The rocket must then do an aerodynamic or thrust vectored pullup to
start climbing.  An alternative is to dive the carrier vehicle, then pull the
whole vehicle up into a steep climb before "lofting" the rocket.  This gives
a better launch angle, at the expense of velocity.  Some proposals have
included putting a rocket assist in the tail of the carrier vehicle to help
the climb. Imagine a 747, whose engines normally generate something like
200,000 or 250,000 lbs thrust, augmented with an SSME with an atmospheric
thrust of about 400,000 lbs thrust - now there's a high performance vehicle!


--
Bruce Dunn    Vancouver, Canada   [e-mail]

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

Date: Sat, 20 Feb 1993 18:10:42 GMT
From: Frank Crary <[e-mail]>
Subject: Pressure fuel delivery, ideas regarding
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>a. Transfer fuel from thin-walled main tank to theoretical smaller, thick-walled
>>   secondary tanks by *light* pressure-feeding.
>>b. Close valve between main tank and secondary pressure tanks.
>>c. Pressure-feed fuel from secondary pressure tanks...

>This is a reciprocating pump of a slightly unusual type.  Gas consumption
>should not be significantly higher than for a straight pressure-fed system,
>but it's not clear to me why it has much of an advantage over a reciprocating
>pump powered by a turbine or something on that order.

If the rocket is going to make several burns, the idea has some advantages:
The fuel could be pumped slowly from the main tank to the pressurized
tank, between burns. Since this wouldn't require much of a pumping
rate, the pump could be substantially lighter than that of a normal
rocket's pump.

                                                     Frank Crary
                                                     CU Boulder

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

Date: 20 Feb 93 22:43:39 GMT
From: Josh Hopkins <[e-mail]>
Subject: Reliable Source says Freedom Dead, Freedom II to be dev
Newsgroups: sci.space

[e-mail] (CLAUDIO OLIVEIRA EGALON) writes:

>Do they already have a date for deployment of SSF II???

No.  They don't even have any money.  Just wait a few months and see what
happens.


--
Josh Hopkins                                          [e-mail]

    You only live once.  But if you live it right, once is enough.
            In memoria, WDH

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

Date: Sat, 20 Feb 1993 17:53:23 GMT
From: tomas o munoz 283-4072 <[e-mail]>
Subject: Reliable Source says Freedom Dead, Freedom II to be developed
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Pat) writes:
|>
|> SO if we re-do SSF , how should we do it.
|>
|> Are trusses inherently more costly and problematic?
|> certainly it allows larger growth.
|>
|> Should we look at something made from ETclusters along
|> with Pre-built modules and inflatable zones?

I feel that a total scrapping of the current work is very irresponsible.
The SSF program is currently undergoing its CDR for flights MB1 - MB7
and UF1.  At the end of this CDR around the end of summer beginning of
fall, the design will be ~90% done.  This is a huge milestone.  Despite
the bad press, a lot of good, sound work has already been done.

|> Should we look at higher altitudes and and steeper inclination orbits?
|>
|> If we went to 48?? degrees, we could still launch from KSC
|> yet also get Russian access for not a lot of cost?

I concur here.  The only things that would have to be worked out is
the resupply/return capability and the logistics between US & CIS.

|> I do like the idea of a 4.8 billion dollar go
|> certainly that's a much more do-able and defendable figure.

NASA can do two things to save a lot of money and still have a station
with the current schedules and work:
    1. Only build up to MTC [MB7 - first 8 flights] and delay/scrap
       everything after that.  This would leave the station with a
       fully functional laboratory, a node, & ability to grow.

    2.  Only build the first two flights and use an EDO/LDO Shuttle
        as its laboratory.  This configuration provides power for
        EDO/LDO orbiter stays, and provides prop to maintain altitude.

Now, if the object of Clinton's redesign is to scrap the "Republican"
station and put up a distinctly "Democrat" station, well then the cost
issue is not about doing the right thing.

--
========================================================================
Tom Munoz     |   [e-mail]

Thought for the day [plagiarized from someone else]:

Engineers think equations are an approximation of reality.
Physicists think reality is an approximation of the equations.
Mathematicians never make the connection.
========================================================================

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

Date: Sat, 20 Feb 1993 22:07:37 GMT
From: Joe Cain <[e-mail]>
Subject: Rocketeer
Newsgroups: sci.space

    I wanted to illustrate something simple about rocketry to my
planetary geology class (there is a chapter in our text "Exploring the
Solar System: Space Travel" which includes a small section on Rocket
propulsion with nothing informative except that each solid booster for
the Shuttle has a thrust of 11,790,000 Newtons.

    I thought I might consider the olde Buck Rogers or Rocketeer
back packs and let them compute how much fuel would have to be
expended to keep a 100 kg payload hovering. e.g. 80 kg person and
maybe 30 kg backpack. In order to do this I need to have a reasonable
figure for what maybe a relative jet velocity might be. I have seen
figures from 2000 to 5000 m/sec. Assuming say the 1950's idea of
running something on alcohol (burned not ingested) what is a
reasonable exhaust velocity? Alternately, I have seen a demo of an
experimental flight unit, James Bond variety. What velocities are
usual for such modern "man rated" devices?

The expression I would be using would be a = v mdot/m where a is
acceleration, v the exaust speed relative to the rocket, mdot the
decrease of mass per time, and m the instantaneous mass being
accelerated. Is this too simple?

    I assume we can show that to get more than an extra g over
gravity you would burn all the fuel you can carry in a very few
minutes. Now if you had a VERY bright flashlight...



Joseph Cain        [e-mail]
[e-mail]        scri::cain
[phone]        FAX [phone] or -0098

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

Date: 20 Feb 1993 14:11:01 -0500
From: Pat <[e-mail]>
Subject: Sabatier Reactors.
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
|In article <[e-mail]> [e-mail] (Pat) writes:
|>In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:
|>|In article <[e-mail]> [e-mail] (Pat) writes:
|>|>In article <[e-mail]> [e-mail] (Henry Spencer) writes:
|>|
|>|>|In fact, you could
|>|>|*probably* fuel an empty Centaur from residual propellants in the shuttle's
|>|>|own external tank, and dispense with the fuel dump.  [...]
|
|Yeah, except we'd use that fuel getting the ET into orbit, and we'd have
|to design and install scavenging pumps in the ET to get to the fuel in
|micro-G, etc. The ET isn't designed to supply fuel except under acceleration.

Then we should be doing flight test programs to qualify and design
pumps that could do exactly this.  IF Shuttle is this great workshop
then why cant we install some compressors and some refrigerators
into it to recover residual propellants.?
I have a workshop in my back yard, I don't have to spend billions of
dollars sticking a 1 hp air compressor in there.

The ET isn't designed to do lots of things but clever engineers have
lots of plans to use them for other things.
 Come on gary.  you dont think, the idea is impossible, so we should
be doing it.  we need to have the hardware base in place for
futture  projects.

aOh and according to wingo, the shuttle doesn't use any extra propellant
keeping the ET attached going up.  Dennis, correct me if i am
misquoting you.


|
|>|>If people are going to defend the shuttle as this marvelous
|>|>workshop,  then i suggest we see it do some real workshop
|>|>type activities.  Refueling satellites is a very reasonable
|>|>mission,  and it seems beyond the shuttles capacity.
|>|
|>|Read what he wrote.  It's not that the Shuttle is incapable of doing it, it's
|>|that NASA doesn't want to try it.  Two different things entirely.
|>|
|>|(Do note, however, that "modest unknowns" is Spencer-speak for "we're
|>|clueless"; it's not just a matter of hooking up a pump and pumping away.
|>|We should learn to do it, though...we have to sooner or later.)
|>|--
|>|Matthew DeLuca
|>
|>I agree. I don't see any reason why it couldn't be tried,
|>but NASA is constitutionally unable to do such basic experiments.
|
|No, NASA is just terrified that if they did it Allen Sherzer would
|scream in his best McElvane speak that the Evil NASA spent a BILLION
|dollars to duplicate what any gas station in the SOVIET UNION could
|do for pennies. And that it was all a PLOT to kill SSTO.
|

Red Herring artgument gary.  and it stinks like a fish.
Besides, fuel transfer technology especialy of Cryogenics is a must do
for the DC-1 project.  The DC-1-OTV and LLM  both require in orbit
fueling.  IF Shuttle picked up the developement cost it's only
help the DC-1's case.
Besides  Do you really mean to say that all those high government officials
are afraid of little old alan?

|>All those people who glorify NASA should push to see Shuttle
|>used for such basic technology research studies.
|
|NASA is a government agency, so by definition it is already glorified,
|however, they are doing basic research. The Drop Physics Module on
|a recent flight was designed to find out how liquids behave in micro-G.

That's an apples and oranges argument gary.  playing with a couple cc's
of water and glycerine on sticks is as far from pumping hundreds of pounds
of LH2/LOX  as breeding chickens and doing DNA recombinant experiments.

We need to know how to move large quantities of fuel through hoses,
valves, pumps, compressors and refrigerators in vacuum, in orbit.

Many brute force assumptions (WE call them engineering assumptions)
can be made to model the actual physics.  while it may be elegant to
know the behavior of a drop on a stick (Surface tension effects)
it's maybe not relevant due to scaling factors in bathtub quantities.

Engineering developement is oftentimes very different from theoretical
physics studies.  look at theoretical mechanics.  it's only now we have
the math to accurately describe  solitons and catenaries.  but bridges
were built for centuries before then.

IF we used your reasoning,  it's only now we would build the
brooklyn bridge.


|That's applicable to any liquid transfer system that may be designed.
|They also did an experiment to refuel a satellite's thrusters on one

If i understand,  they did a simulation using nitrogen gas.
and it's nice, but they only did one or two experiments in 60
missions.  Sherzer is right on when he says every!  shuttle misison
should have carreid a couple of suits and had the astronauts out
there playing with hardware in vacuum.

They should have been carying small tank systems up there and
practiced setting up fueling lines and pumping and transferring
liquid nitrogen, oxygen and hydrogen.

And the EDO pallet is nice, but it's a passive system.
what about pumps and refrigerators.  ?

|flight. The extended duration orbiter will have cryogenics stored on
|a pallet in the bay. Etc. Remember that if NASA didn't have a zero
|risk attitude, they'd just carry a fueled Centaur in the bay like they
|originally planned.
|
|Gary


And this is exactly the problem.  If NASA was willing to take risks,
they'd carry the centaur,  they'd have an EVA program, THey'd be ou;there
doing experiments on ET refueling and recycling.
But no they don't because they are afraid.  Afraid of risk, afraid
of political pressure.  they have their budget and they have their
glorious manned space program and everyone is happy and cozy and
nothing is changing.

Gary,  Do you have a problem with risk?  your business is based on
risk.  people build things and then you test them.  if the designers
were so perfect, we wouldn't need testing shops like yours.

pat

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

Date: Sat, 20 Feb 93 18:47:49 GMT
From: Dean Adams <[e-mail]>
Subject: Spy Sats (Was: Are Landsat Satellites receivable?)
Newsgroups: sci.space

[e-mail] (Martin Connors) writes:
>[e-mail] (Henry Spencer) writes:
 >> We could tell you, but then we'd have to kill you. :-)
That phrase rings a bell..<heh>

 >> Nobody who knows is going to be able to talk about it in public.  The
 >> very *name* of the National Reconnaissance Office was classified until
 >> quite recently
Which was a pretty ridiculous situation to say the least.

 >> The diffraction limit will make it impossible to do better than a few
 >> centimeters with visible-light optics that fit in current launcher
 >> payload shrouds.
Yep...  I have not seen many serious estimates beyond about the 6" range.

 >OK I will confess why I posted this. I saw Patriot Games (video) the
 >other days and found the portrayal of CIA operations using satellites
 >unrealistic to say the least.

Actually, I thought they had most of the basic stuff down pretty well...
although some was certainly exaggerated at least a bit.  Advanced KH-11 birds
are supposed to have "near real time" imaging capability, but that probably
does not translate into the continuous view they portrayed.  The BIGGEST error
however was that their operation was at NIGHT, and these satellites are normally
placed into sun-synchronous polar orbits to optimize their daylight coverage.
I do not believe they have a significant nighttime imaging capability.

 >I heard through the grapevine that there was an instance of imaging
 >individual tiles on the Space Shuttle, which is likely possible from
 >a mountain site with guide star techniques to correct atmospheric effects.
 >But what would be routinely visible to a spy sat looking down?

That report has been around a while...  DoD's GROUND based tracking assets
were certainly used and perhaps even one of their airborne platforms, but
it may just be the press jumping to conclusions to think any satellites were
involved.  KH-11 orbits are not all that much higher than the shuttle, which
would make an intercept pretty tight, and besides the optics are obviously
optimized for resolving ground targets.

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

Date: 20 Feb 93 19:31:45 GMT
From: CLAUDIO OLIVEIRA EGALON <[e-mail]>
Subject: SSTO/DC-X in the Media..
Newsgroups: sci.space

I have been reading that SDIO's funding will be cut and I was wondering is it
going to affect DC-X???

  [e-mail]

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

Date: Sat, 20 Feb 1993 18:26:58 GMT
From: Frank Crary <[e-mail]>
Subject: Titan or Bust! (Saturn Moon)...
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>...I couldn't
>>bare the thought of pinning my entire career on a single spacecraft
>>that has (I can't emphasize this enough) *SEVEN* years in which
>>to breakdown before I see any data.

>The outer solar system is a *big* place. Nuclear rockets might make
>it a little smaller, but anyone intending to work with outer planet
>data just has to have more patience than you exhibit. And, unfortunately,
>more stable funding than our space program exhibits.

Even using chemical rockets, a transfer orbit to Saturn shouldn't
take more than five years. (The outer solar system is big,
but not quite that big.) I think Cassini is using another series of
Earth and Venus flybys like Galileo (I have no idea why: I'd think
a direct launch on a Titan IV would be possible...) If more advanced
propulsion (nuclear thermal or nuclear electric) were available,
I'd expect the transfer time to drop below three years (or the payload
to increase dramatically, which ever you prefer...)

                                                    Frank Crary
                                                    CU Boulder

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

End of Space Digest Volume 16 : Issue 211
------------------------------