HDTenEightyP/NetNews huggingface dataset:
From: fcrary@ucsu.Colorado.EDU (Frank Crary)
Subject: Re: Cassini Undergoes Intensive Design Review
Keywords: Cassini, JPL
Organization: University of Colorado, Boulder
Date: Fri, 11 Dec 1992 18:28:29 GMT

In article <1992Dec10.232527.643937@locus.com> hayim@locus.com (Hayim Hendeles) writes:
>>     After flybys of Venus (twice), Earth and Jupiter as it loops
>>around the sun to pick up energy, Cassini will arrive at Saturn
>>in November 2004, beginning a four-year orbital tour of the
>>ringed planet and its 18 moons. The Huygens probe will descend to
>>the surface of Titan in June 2005.

>Pardon my asking an ignorant question, but I can't understand why it
>should take 7 years to get to Saturn. When Voyager went to Jupiter and
>Saturn, it took (if I recall correctly) 4 years and a Jupiter flyby to
>make it to Saturn. Here, you are using 4 flybys, and it's taking you 7
>years! 

After the Challenger failure, NASA added a safety requirement that 
nothing launched in by a space shuttle may use liquid fuels. That
means Cassini must use lower-energy solid rockets instead. As a 
result, a direct launch to Saturn (or a single Jupiter fly-by on
the way) is not possible. A long VEEJGA series of fly-bys of the
inner planets is required to gain suffiecient energy.

>I would think that if you were to adjust the launch date so that
>Jupiter and Saturn were in the same relative positions as they were in
>1977 (when Voyager was launched), you could do the same trick again (in
>the same 4 years).

While the Earth/Jupiter/Saturn geometry is different, I don't think it
it sufficiently worse (in terms of time and energy) than that of the
Voyager fly-by. In any case, waiting for the optimum geometry isn't
really possible: It would take many decades...

                                              Frank Crary
                                              CU Boulder

Newsgroups: sci.space
From: ewright@convex.com (Edward V. Wright)
Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
Date: Tue, 15 Dec 1992 18:06:18 GMT
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1992Dec9.175236.8649@ke4zv.uucp> gary@ke4zv.uucp (Gary Coffman) writes:

>SSTO masses 100 times it's payload while a supertanker's payload masses
>100 times the vehicle mass. 

No it doesn't.  The dry weight of an SSTO is very small.  Most of
the loaded weight is liquids.  Just like a supertanker.  Tankers
do not (normally) draw fuel from their cargo stores because a) the
customers don't like that and b) crude oil has a tendancy to explode
if you use it as bunker fuel.  That does not change the fact, however,
that a supertanker, like an SSTO, is mainly a big liquid storage tank.
From: sysmgr@king.eng.umd.edu (Doug Mohney)
Newsgroups: sci.space
Subject: Re: DoD launcher use
Date: 16 Dec 92 20:22:19 GMT
Reply-To: sysmgr@king.eng.umd.edu
Organization: Computer Aided Design Lab, U. of Maryland College Park

In article <1992Dec16.092029.27518@ke4zv.uucp>, gary@ke4zv.uucp (Gary Coffman) writes:

>aircraft is low and the cost is much less. The military, like everyone
>else has to pay attention to costs, even if their threshold is higher
>than most other users. Wars can be lost by simply running out of money
>as surely as losing on the battlefield

Then, gary goes on to say...

>. With a serious opponent, your space assets would be priority targets. 

So, uh, gary, where are the serious opponents supposed to afford A-SATs? hmm?

If you can kill recon planes, it's damn sight harder to kill sats.

Furthermore, you assumed that the KH-11 is the benchmark (also known as
the Szabo yardstick) without the resultant drop in costs which would occur if
you could rapidly deliver sats to orbit. 

You don't have to add lots of fuel, thrusters, and other sensors, treat the
camera and sat as a throw-away item.

			doug

                    I have talked to Ehud, and lived.
  -- >                  SYSMGR@CADLAB.ENG.UMD.EDU                        < --
From: roberts@cmr.ncsl.nist.gov (John Roberts)
Newsgroups: sci.space
Subject: Re: Titan
Date: 12 Dec 92 16:32:31 GMT
Article-I.D.: cs.Bz5nBG.Czw.1
Distribution: sci
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU


-From: gustav@arp.anu.edu.au (Zdzislaw Meglicki)
-Subject: Re: Cassini Undergoes Intensive Design Review
-Date: 12 Dec 92 04:28:51 GMT
-Organization: Centre for Information Science Research, ANU, Canberra, Australia

-Could anyone sum up at this stage what is known about Titan and especially
-about the question of a possible ocean there. I vaguely recall that some
-time ago radio-ranging of Titan returned somewhat mixed signals in this
-matter.

Recent radar mapping of Titan indicates that it does *not* have large oceans,
though there may be smaller bodies of liquid. I don't remember where I read
that - probably either Science News or sci.space.

-|> To
-|> further complicate the situation, the U.S. do not have any launch vehicles
-|> that are powerful enough to send Cassini on a direct trajectory to the
-|> outer planets.
-Right, can't the US build such a vehicle by then? Clearly, if any serious
-space exploration is to continue a powerful vehicle like that will be
-needed sooner or later anyway. What happened to the idea of nuclear 
-propulsion? 

It's the classic "big science" problem - it doesn't make sense to risk a
$4 billion mission on an unproven technology, when you can try it on a
~$100 million spacecraft going somewhere else. (Let's hope they try a small
nuclear spacecraft sometime soon - but even if they do, the technology is
unlikely to be ready in time for Titan, unless they delay it considerably.)

John Roberts
roberts@cmr.ncsl.nist.gov
From: matthew@phantom.gatech.edu (Matthew Thomas DeLuca)
Newsgroups: sci.space
Subject: Re: what the little bird told Henry
Date: 14 Dec 1992 07:59:45 -0500
Organization: The Dorsai Grey Captains
NNTP-Posting-Host: oit.gatech.edu

In article <1gasfqINNkpa@transfer.stratus.com> dswartz@redondo.sw.stratus.com (Dan Swartzendruber) writes:

>Look, it's pretty clear (at least to me, and going by some other recent
>postings, to other people as well) that Gary has some kind of axe to
>grind against the whole SSTO concept.

I don't agree with many of the statements that Gary has made about the SSTO
program, but it's refreshing to see someone who *doesn't* believe this will 
automatically be the salvation of the space program.  
-- 
Matthew Thomas DeLuca
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp:	  ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!matthew
Internet: matthew@prism.gatech.edu
From: anthony@csd4.csd.uwm.edu (Anthony J Stieber)
Newsgroups: sci.space
Subject: cryptocraft photography, Re: Aurora
Date: 16 Dec 92 20:18:07 GMT
Distribution: sci
Organization: Computing Services Division, University of Wisconsin - Milwaukee
NNTP-Posting-Host: 129.89.7.4

In article <1992Dec16.132541.18610@mnemosyne.cs.du.edu> dnadams@nyx.cs.du.edu (Dean Adams) writes:
>understandable.  Were there any photos of the F-117A prior to the
>official release?  I don't beleive so, even though it flew for almost
>a decade.

Yes, at least one in AW&ST, July 10, 1989, p22.  The picture clearly
shows the wings, double tail, and extended landing gear (gold colored
for some reason).  This is sometime after the first flights of the
craft in 1981, but of course all the early flights were done exclusivly
at night.  I don't remember when the offical pictures of the F-117A
were released.

I'm sure there will be pictures of whatever this/these craft are.  It
might be a couple years.  Someone with camera and a telescope lens
will catch it.
--
<-:(= Anthony Stieber	anthony@csd4.csd.uwm.edu   uwm!uwmcsd4!anthony
From: scott@psy.uwa.oz.au (Scott Fisher)
Newsgroups: sci.space
Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
Date: 18 Dec 1992 03:13:15 GMT
Organization: The University of Western Australia
NNTP-Posting-Host: wapsy.psy.uwa.oz.au


In article <1992Dec11.175719.24880@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>>on several grounds, the low chamber pressures lead to very high
>>loads on the turbopumps because so much more fuel per unit time
>>has to flow to achieve the high thrust required with low pressure
>>engines. Reducing stress in one area can lead to increased stress 

>I dont think that is an unsolvable problem.   THe Saturn F-1's sucked
>fuel like no tomorrow.   The soviet's haul fuel to feed those
>big protons and energiya engines.

>I suspect packaging and design are bigger problems  then just mass flow.

Q: What drives the turbo-pumps the rocket exhaust?

If this is so...why can't you bleed some pressure from the exhaust to pressurisethe tanks?  Is this done?

Regards Scott.
_______________________________________________________________________________
Scott Fisher [scott@psy.uwa.oz.au]  PH: Aus [61] Perth (09) Local (380 3272).                
                                                             _--_|\       N
Department of Psychology                                    /      \    W + E
University of Western Australia.      Perth [32S, 116E]-->  *_.--._/      S
Nedlands, 6009.  PERTH, W.A.                                      v       

Joy is a Jaguar XJ6 with a flat battery, a blown oil seal and an unsympathetic 
wife, 9km outside of a small remote town, 3:15am on a cold wet winters morning.
-------------------------------------------------------------------------------
From: BrianT@cup.portal.com (Brian Stuart Thorn)
Newsgroups: sci.space
Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
Date: Tue, 15 Dec 92 21:23:17 PST
Organization: The Portal System (TM)
  <1992Dec14.182820.9627@iti.org> <71695@cup.portal.com>
  <1992Dec15.134224.14502@iti.org>

>>In the history of spaceflight, that has seldom been the case.
>
>True, but that has far more to do with the design process we use for
>spacecraft. Shuttle is the most complex vehicle ever built according
>to NASA PR (I have no idea just why NASA thinks that is worth boasting
>about). There is no reason to think that building for simplicity won't
>work. That is why everybody who has studied the problem believes that
>a SSTO can be built either now or in the near future. Even NASA internal
>assessments say it can be done.
>
>  Allen

 That it can be done, I am more or less with you. (But I fully expect
 a design problem or two to slow things down...) That it can be done
 at the price you quote, that's another story. Say I'm from Missouri.
 Show me.
 
 -Brian
  
Newsgroups: sci.space
From: pgf@srl03.cacs.usl.edu ("Phil G. Fraering")
Subject: Second space hotel
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Sat, 19 Dec 1992 03:58:46 GMT

> More of interest, Pat is working on *Space Tourism* in Japan.
> 
> Guess who'll have the furst space hotel?

\It will be owned by Japanese corporations.
/
\But the staff will be British.

/(Hey, Dave, if jobs are tight in astronomy, you could get a job as
\concierge.  And do astronomy in your off hours, in the hotel's parking
/lot...)

Hmmph. The staff will be British. 

Hidden in this statement is the implied "the cooks will be
British" which means that whoever builds the second space 
hotel will have a good chance of putting the Japanese out
of business.

"Oh, you mean you're dehydrated from spacesickness? Well,
we have lukewarm tap water or lukewarm stout. Which'll
it be?"

"Ice? We're hoping we can get some up for the next time Halley
comes by..."

\Bill Higgins, Beam Jockey              | "Enough marshmallows
/Fermi National Accelerator Laboratory  | will kill you 
\Bitnet:           HIGGINS@FNAL.BITNET  | if properly placed."
/Internet:       HIGGINS@FNAL.FNAL.GOV  | --John Alexander, leader of
\SPAN/Hepnet:           43011::HIGGINS  | "disabling technologies"
/ [*Aviation Week*, 7 Dec 1992, p. 50]  | research, Los Alamos

Placed with what? A railgun?
-- 
Phil Fraering
"...drag them, kicking and screaming, into the Century of the Fruitbat."
<<- Terry Pratchett, _Reaper Man_
PGP key available if and when I ever get around to compiling PGP...
Newsgroups: sci.space
From: pyron@skndiv.dseg.ti.com (Dillon Pyron)
Subject: Re: Jet Lag
Reply-To: pyron@skndiv.dseg.ti.com
Organization: TI/DSEG VAX Support
Distribution: sci
Date: Tue, 15 Dec 1992 22:43:56 GMT


In article <Bz60zo.4t.1@cs.cmu.edu>, roberts@cmr.ncsl.nist.gov (John Roberts) writes:
># Henry's approach requires that you spend a day or more either before or after
>  the flight to adapt your schedule. In theory that makes sense, but in
>  practice it is likely to take considerable mental discipline (which Henry
>  has, no doubt, but I'm not so sure about the rest of the population). 
>  Before the trip, you're busy getting ready, taking care of last-minute
>  details, etc. And if you have limited vacation time, it might seem silly
>  to take an extra day of leave just to stay at home sleeping during the
>  day. Once you get to your destination, the natural incliniation is to
>  rush around doing things, rather than "waste" a day sleeping. A longer
>  travel time *forces* you to start adjusting (with various unpleasant side
>  effects, as Henry pointed out).

Light experiments have pointed at ways to trick the body into resynching using
bright lights and darkness.  But, again, this takes precious time.

>
># Many people tend to wake up at local dawn, regardless of how much sleep
>  they got. So it might be necessary to put black paper over the bedroom
>  window in order to adjust properly.

Experience agrees with this, see below.
>
># Humans are really only efficient at adjusting their sleep cycles forward -
>  it's much easier to stay up a little later and sleep a little later than to
>  go to bed earlier and get up earlier. So if the direction of travel is such
>  that backward adjustment is required, the fatigue brought about by sitting
>  for many hours in an uncomfortable seat might help you to sleep when you
>  ordinarily would not. But I wouldn't say that this is a real benefit of
>  prolonged travel time - it's more a *perceived* benefit.

My wife and I have found that, travelling to Europe, we typically feel shitty
for a day or so after getting there, but do quite well coming home (to Dallas),
while our travels to Hawai'i wind up with us doing very well when we get there
(up early in the morning, enjoying the day, etc) and not so hot when we return
home (admittedly, leaving vacation is a bummer).  I also felt much better after
a trip in first class (f-f miles) than any trip in catt- erh coach class.
>
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
(214)462-3556 (when I'm here)     |
(214)492-4656 (when I'm home)     |"Pacts with the devil are not legally
pyron@skndiv.dseg.ti.com          |binding!"
PADI DM-54909                     |-Friar Tuck   _Robin Hood:The Hooded Man_

Newsgroups: sci.space
From: strider@clotho.acm.rpi.edu (Greg Moore)
Subject: Re: fast-track failures
Organization: The Voice of Fate
Date: Thu, 17 Dec 1992 16:41:37 GMT

In article <1992Dec17.094818.7397@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>
>You wouldn't do a cheap and dirty Hoover Dam or Golden Gate bridge
>saying that if it failed you'd just shrug and go on to the next
>project. Aerospace has become like civil engineering. The costs
>of projects, and the effects of failure, have become high enough
>that you have to test extensively and have contingency options
>when subsystems don't meet their test requirements. You can't
>just say "oops" and drop the project if your cables are too thin
>to support the weight, or you get a galloping gertie in a breeze.
>
	A quote my dad learned in grad school comes to mind:
"Engineering is built upon the last failure."  Galloping Gertie
is an example of this.  Bridges built since have learned from that
failure.

>Gary


Newsgroups: sci.space
From: ewright@convex.com (Edward V. Wright)
Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
Date: Fri, 18 Dec 1992 17:12:44 GMT
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1992Dec17.102303.7906@ke4zv.uucp> gary@ke4zv.uucp (Gary Coffman) writes:

>According to Wales, the Shuttle proved in 1985 that it could fly for 
>$170 million with 9 flights a year.

Oh?  How did it "prove" that?

a) The total Space Shuttle operating and development budget for 1985
was cut back to $1.53 billion, and the Shuttle managed to fly nine
missions in that year, or

b) Wales did a *lot* of creative accounting?


>Lower flight rates mean higher per flight costs due to the high fixed
>cost, but $550 million would equate to four flights a year. Shuttle is
>doing better than that.

Or a lot worse.  The Shuttle program consumes much more than $2.2 billion
per year.
From: prb@access.digex.com (Pat)
Newsgroups: sci.space
Subject: Re: Soaring like and Eagle (was Re: Range Safety and DC-X)
Date: 15 Dec 1992 20:44:03 GMT
Organization: UDSI
NNTP-Posting-Host: access.digex.com

In article <1992Dec9.133140.6366@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>In article <1992Dec7.162938.1@fnalo.fnal.gov> higgins@fnalo.fnal.gov (Bill Higgins-- Beam Jockey) writes:
>>Oh, I don't know, Gary.  The thrust-to-weight ratio on DC-X probably
>>compares favorably with an F-15 Eagle...
>
>Yeah, but an Eagle has "wangs" (such as they are). :-)




Okay.

	How many F-15's  have succesfully been dead sticked in under 
operational conditions.  Not training,  but real life?  

	How many F-15's have been lost due to spin caused by 
single engine flame out?

	What is the incidence of total power loss per flying hour?

I would say they would be  a few, several and rare.  hence, what is the
big issue?  if something occurs  infrequently  and has at least as many
fatal modes as recoverable modes, i wouldn't consider it a win.

Newsgroups: sci.space
From: kentm@rebecca.its.rpi.edu (Michael V. Kent)
Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
Organization: Rensselaer Polytechnic Institute, Troy, NY
Date: Tue, 15 Dec 1992 03:57:59 GMT

>Now
>for the cost of a Shuttle flight, you could run a program to answer all the
>open technical questions and have enough left over to buy a Titan IV to
>launch the payload which would have gone up in the Shuttle.

>  Allen

That a DC-X and a Titan IV launch could be had for the cost of a Shuttle
mission I believe.  What I don't believe is that you'd get any knowldgeable
volunteers to fly a Spacelab mission on a Titan IV.

Mike

-- 
Michael Kent                                   kentm@rpi.edu
Flight Test Engineer                           Tute-Screwed Aero '92
McDonnell Douglas                              Rensselaer Polytechnic Institute
These views are solely those of the author.    Apple II Forever !!
Newsgroups: sci.space
From: aws@iti.org (Allen W. Sherzer)
Subject: Re: DoD launcher use
Organization: Evil Geniuses for a Better Tomorrow
Date: Sun, 13 Dec 1992 21:28:14 GMT

In article <1992Dec13.183545.9958@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:

>>for many applications satellite is better. Recon aircraft are too easy
>>to shoot down...

>We're talking about Iraq right? No air opposition right? Complete Coalition
>domination of the airspace right? 

I would hate to base all US defense donctrine on the assumption that ALL air
wars will be just like Iraq. BTW, despite our domination of the air, coalition
aircraft WHERE shot down.

For many applications satellites are more productive. They provide faster
responce and allow scarse aricraft to be better utilized.

>What can a satellite do for tactical recon that a SR71 can't?

Updates of the tactical situation with SR-71 would take about 6 to 8 hours
to get and would be several hours old by the time they get to the local
commanders. Satellite images take seconds to get and are fresh. In the Gulf
war, images just a few hours old would have been useless.

  Allen

-- 
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  aws@iti.org     |  nothing undone"                                       |
+----------------------132 DAYS TO FIRST FLIGHT OF DCX----------------------+
Newsgroups: sci.space,sci.astro,alt.sci.planetary
From: PHARABOD@FRCPN11.IN2P3.FR
Subject: Aurora
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Fri, 18 Dec 1992 09:24:20 GMT

Steinn Sigurdsson writes (16 Dec 92 15:21:32)

>Nah, not isolated enough, rumour seems to be that the forward
>base is a US NATO base in Scotland.

Could it be the Machrihanish (sp?) base?

J. Pharabod
Newsgroups: sci.space
From: rkornilo@nyx.cs.du.edu (Ryan Korniloff)
Subject: Re : Relay to Follow Galileo?
Organization: University of Denver, Dept. of Math & Comp. Sci.
Date: Wed, 16 Dec 92 01:44:12 GMT

>Path: mnemosyne.cs.du.edu!mercury.cair.du.edu!copper!vexcel!ncar!destroyer!caen!uunet!portal!cup.portal.com!BrianT
>From: BrianT@cup.portal.com (Brian Stuart Thorn)
>Newsgroups: sci.space
>Subject: Re: Relay to Follow Galileo?
>Message-ID: <71697@cup.portal.com>
>Date: 15 Dec 92 03:27:47 GMT
>References: <1992Dec14.034918.7060@mnemosyne.cs.du.edu>
>Organization: The Portal System (TM)
>Lines: 25
>
>>Well why did the HGA have to be cloed up in the first place? If it is too
>>big, then couldn't they have used a more powerful transmitter? I would
>>have rather tried to avoid such a chance for failure. If thay don't get
>>that HGA open then %30-%40 of the mission objectives will be lost. Or is
>>the radio frequncy have something to do with he size of the HGA???
>>
>>
>>        -- Ryan Korniloff
>>        -- rkornilo@nyx.cs.du.edu
>
>  Ryan...
>   
>  Galileo's umbrella-type High Gain Antenna was left in the folded
>  position because it was thought that the high temperatures it would
>  encounter during the Venus flyby portion of the mission could warp
>  the antenna. They attempted to open the antenna only after the Venus
>  flyby, when Galileo flew farther from the Sun. It was jammed.
>   
>  Cassini, I think, will have a standard hard HGA, similar to the
>  Voyager and Magellan antennae. I hope the Galileo problem does not
>  prevent future spacecraft from using the folding antenna design. It
>  worked quite well on the TDRS satellites.
>  
>  -Brian


But we're talking about a multi-Billion dollar program here. I just
wouldn't want to take that risk. That is a lot of money the throw away
because the "stupid" antanna won't open.. And this will further make the
image of NASA tarnish even more. Yet another American blunder.. we don't
need it. How are we going to argue that we need to go to this planet and
that planet if we can't build the hardware to do the job???


        -- Ryan Korniloff
        -- rkornilo@nyx.cs.du.edu
 

Newsgroups: sci.space