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Date: Sat,  6 Apr 91 02:15:07 -0500 (EST)
Subject: SPACE Digest V13 #369

SPACE Digest                                     Volume 13 : Issue 369

Today's Topics:
			 Re: Space technology
		 Re: NY Times Article: Nuclear rocket
			 Re: Space technology
		       Re:  Launch Technology:
		Re: comsat cancellations and lawsuits
	     NASA Headline News for 04/05/91 (Forwarded)
			    Re: "Follies"

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

Date: 5 Apr 91 20:21:39 GMT
From: usc!rpi!news-server.csri.toronto.edu!utzoo!henry@apple.com  (Henry Spencer)
Subject: Re: Space technology

In article <5612@media-lab.MEDIA.MIT.EDU> minsky@media-lab.media.mit.edu (Marvin Minsky) writes:
>I take it from this that Maynard is hinting that microcomputers are a
>NASA spin-off.  What is the history of this often-repeated claim?  

Integrated circuits were, to some degree, spinoff from ICBM projects,
which may be the source of this.  NASA has done a lot for things like
instrumentation and telemetry but has never been on the leading edge
of computing to any great extent.
-- 
"The stories one hears about putting up | Henry Spencer @ U of Toronto Zoology
SunOS 4.1.1 are all true."  -D. Harrison|  henry@zoo.toronto.edu  utzoo!henry

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

Date: 5 Apr 91 20:49:07 GMT
From: orca!bambam!bpendlet@uunet.uu.net  (Bob Pendleton)
Subject: Re: NY Times Article: Nuclear rocket

In article <11094@exodus.Eng.Sun.COM>, jmck@norge.Eng.Sun.COM (John McKernan) writes:
> bpendlet@bambam.dsd.es.com (Bob Pendleton) writes:
> >Personally I'm glad to hear that they are developing the pellet bed
> >reactor for propulsion applications. BUT, I'm very distressed to hear
> >that they were looking at using it inside the atmosphere.
> 
> Why assume, a priori, that testing anything nuclear in the atmosphere
> would be a bad thing. 

I'm assuming, a priori, that you read the rest of my posting to get to
the last paragraph. I pointed out that pellet bed/particle bed
reactors are about the safest way to go for nuclear rockets.

> This is new technology, so we really have no idea
> how much radioactivity a nuclear rocket of this design would give off.

You just answered your own question. Until the technology for making
the pellets is proven you can't be sure that they will not fail and
release very hot nuclear products into the atmosphere.

If, after testing, the failure rate is low enough I have no real
problem with operating nuclear rockets in the atmosphere. But during
testing you can't be sure. So lets test it outside the atmosphere.  I
DO have problems with operating them in trajectories that intersect
the surface of the earth.

> If the amount of radiation released is low and both the thrust and the
> ISP are high, such a nuclear rocket might be a very good replacement
> for or supplement to chemical rockets. 

Absolutely right. But, do you know the difference between "radiation"
and "radioactive materials?" The radiation release will be very high
no matter what. But, a few more gammas in the upper atmosphere is a
"who cares."  It's the release of radioactive elements that I worry
about.

> Although the the impression I
> get is that they are many many dollars away from a flyable system, so
> the whole "nukes in the atmosphere" flap is probably moot anyway.

Probably moot. I agree. But I grew up in Salt Lake City. I've seen the
feds dump fallout on a city and then deny it. I don't trust the feds
with nuclear anythings. Especially secret ones.


> John L. McKernan.                                                  jmck@sun.com
> Disclaimer: These are my opinions but, shockingly enough, not necessarily Sun's
> -------------------------------------------------------------------------------
>    "It's kind of a macho thing,
>     programmers are always trying to be weirder than their machines."

-- 
              Bob Pendleton, speaking only for myself.
   bpendlet@dsd.es.com or decwrl!esunix!bpendlet or utah-cs!esunix!bpendlet

                         Tools, not rules.

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

Date: 5 Apr 91 19:17:37 GMT
From: media-lab!minsky@eddie.mit.edu  (Marvin Minsky)
Subject: Re: Space technology

In article <4923@lib.tmc.edu> jmaynard@thesis1.med.uth.tmc.edu (Jay Maynard) writes:
>} . . .   Carl Sagan is fond of
>}saying that in matters of applied research, if the object is a no-stick
>}frying pan, you're almost always better off backing research into no-
>}stick frying pans rather than laser-guided tennis balls.

>...he says, as he types on his microcomputer-based terminal...

I take it from this that Maynard is hinting that microcomputers are a
NASA spin-off.  What is the history of this often-repeated claim?  

Why am I skeptical?  Because (1) I recall the push toward
microcomputers being a very broad goal of many companies, large and
small and (2) the sense that NASA was never directly concerned with
the latest forms of the technology, for valid reliability reasons.  So
it is true that the space program provided an incentive for integrated
computers -- or could it have even diverted energy away from that goal
by emphasizing the inproved reliability of earlier discretely
assembled systems?

Just wondering.

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

Date: 5 Apr 91 19:51:01 GMT
From: snorkelwacker.mit.edu!spool.mu.edu!samsung!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo!henry@apple.com  (Henry Spencer)
Subject: Re:  Launch Technology:

In article <9104051927.AA22572@ucbvax.Berkeley.EDU> space+%ANDREW.CMU.EDU@msu.edu writes:
>I can imagine you back in the 1900's  arguing that since cars are so slow and
>noisy, pollution-ridden, and unrealiable that we should move on to the
>hovecraft or the monorail...

The most amusing part, actually, is the juxtaposition of Nick's "I know 
what has potential and what doesn't, and chemical rockets don't, so no
further work should be done on them" with his J. Paul Getty signature
quote:  "If you want oil, drill lots of wells".
-- 
"The stories one hears about putting up | Henry Spencer @ U of Toronto Zoology
SunOS 4.1.1 are all true."  -D. Harrison|  henry@zoo.toronto.edu  utzoo!henry

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

Date: 5 Apr 91 23:03:02 GMT
From: usc!samsung!rex!rouge!dlbres10@ucsd.edu  (Fraering Philip)
Subject: Re: comsat cancellations and lawsuits

In article <1991Apr5.160636.12262@pbs.org> pstinson@pbs.org writes:

>By the way, just what financial losses are we talking about?  Sure it cost more
>to launch aboard the Arianes than Hughes had been promised for the shuttle, but 
>if Hughes did not have customers lined up, it wouldn't have launched the birds
>period.  I suspect they have made up any "losses" by passing them on to the end
>users.

Well, building the however-many-hundreds of million dollars 'birds'
only to have them have to sit in a clean room (costs a lot of money in
itself) for several years (have you ever heard of time-value of money?
Oh, you're from PBS, I shouldn't have expected you to have heard of
such bourgeois concepts). And your final argument ("So what if they
have such trememdous cost increaces? Can't they just pass it on to the
consumer?") shows a lot of ignorance. The consumers would just buy the
services from someone cheaper because they weren't so stupid as to
trust the U.S. government's word. And that reflects very strongly on
us, because we the people elected said government which by its breach
of contract and the ensuring delays in launch of many sattelites has
caused one company, Geostar (with no connection to the
Military-Industrial complex you are so ready to totally condemn
without trial) to have to go into reorganization. We don't have the
Soviet excuse that we're not in control.

I myself am very unenthusiastic about my alleged representative to the
world (the government) practicing such questionable business ethics
(among other things, such as... well, that strays from the scope of
sci.space). 

Phil Fraering
dlbres10@pc.usl.edu
Disclaimer: Appropriate disclaimers, whatever they are, apply.

P.S.: If all you are going to do is sprout the "conventional" "wisdom"
of the more obnoxious "conservatives" or "liberals" then please go
somewhere else to do so so that those of us looking for real solutions
instead of the "two sizes fits all" ideological straightjackets will
have _some_ place to discuss things? We put up with that sort of stuff
enough from the mainstream press like CNN and PBS.

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

Date: 6 Apr 91 00:31:09 GMT
From: usenet@ames.arc.nasa.gov  (Peter E. Yee)
Subject: NASA Headline News for 04/05/91 (Forwarded)


             Headline News
Internal Communications Branch (P-2) NASA Headquarters

  Friday, April 5, 1991	Audio Service: 202 / 755-1788

This is NASA Headline News for Friday, April 5, 1991 . . .

Atlantis lifted off this morning at 9:22 am on the STS-37 Gamma 
Ray Observatory deployment mission.  The countdown process was 
uneventful.  Launch was delayed slightly, less than five minutes, while 
weather aircraft surveyed a low-cloud-ceiling situation.  Ascent 
performance of Atlantis' solid rocket boosters and three main 
engines was absolutely nominal.  The orbiter is now in a 281-mile-
high circular orbit.

On-orbit activity today for Commander Steve Nagel and his crew 
includes activation of the robot arm which will be used to deploy the 
Gamma Ray Observatory and activation of the cabin-mounted 
experiments.  Scheduled activity tomorrow, Saturday, includes 
inspection and preparation\ of the GRO spacecraft for its planned 
deployment on Sunday.  Monday's activity includes the spacewalk 
experiments aimed at developing space station assembly techniques.

                   * * * * * * * * * * * * * * * *

The Jet Propulsion Laboratory's Magellan Project Office announced it 
has accomplished one of the mission goals a month early.  The 
project said the spacecraft has mapped more than 70 percent of the 
planet nearly 30 days sooner than the 243-day goal.  By the end of the 
first 243-day mapping cycle, on May 15, Magellan will have mapped 
more than 84 percent of Venus.  Owing to the exceptional quality of the 
returned data and nominal performance of the spacecraft, NASA has 
approved a second 243-day mapping cycle.  The first objective of 
this extended period will be to collect the remaining 16 percent of 
surface radar images, including the never-seen south pole.  Additional 
objectives include acquiring surface radar imagery from different view 
angles to yield new perspectives and allow for image comparisons from 
one mapping cycle to the next.

                   * * * * * * * * * * * * * * * *

The rollout of the newest orbiter, OV-105, the Endeavour, is set 
for April 25 at Rockwell International's Space Division facility at 
Palmdale, Calif.  The rollout will be the centerpiece of a ceremony set 
to be held at 2:00 pm EDT.  NASA Administrator Richard Truly and 
members of Endeavour's first mission flight team will participate in 
the rollout ceremony.  Endeavour is then scheduled to be mated to 
NASA's new 747 Shuttle Carrier Aircraft and flown to Kennedy, 
staying overnight at Ellington Field, near Johnson Space Center, 
Houston, enroute.

                   * * * * * * * * * * * * * * * *

Congress reconvenes Monday, April 8.  House appropriation 
hearings are currently scheduled for April 9 through 11.

                   * * * * * * * * * * * * * * * *

NASA will provide a special television service during the STS-37 
mission to improve the coverage of NASA Select in the Western U.S. 
and in Alaska and Hawaii.  Each day NASA will transmit a two-hour 
edited version of that day's NASA Select events on the Spacenet 1 
satellite.  The transmissions will be made between midnight and 
2:00 am Eastern time on Spacenet 1, transponder 17L.  Normal, 
continuous coverage of the mission will be on NASA Select on F2R, 
transponder 13.
	
Here's the broadcast schedule for Public Affairs events on NASA Select 
TV.  All times are Eastern.  NASA Select TV is carried on GE Satcom 
F2R, transponder 13, C-Band, 72 degrees W Long., Audio 6.8, 
Frequency 3960 MHz.

Friday, 4/5/91
	12:36 pm	From Atlantis, live payload bay views.
	12:45 pm	From Johnson Space Center, live flight director change-
			of-shift briefing.
	2:38 pm		From Atlantis, live payload bay views and robot-arm
			system checkout.
	3:48 pm		From Atlantis, live checkout of Gamma Ray Observatory
			in the payload bay.
	4:20 pm		From Kennedy Space Center, playback of STS-37 launch 
			video, all camera locations included.
	7:00 pm		From Johnson Space Center, playback of STS-37 flight-
			day-one flight crew activities and payload bay views.
	7:30 pm		From Kennedy Space Center, playback of STS-37 launch 
			film footage - slow motion photography.
	8:45 pm		From Johnson Space Center, live flight director
			change-of-shift briefing.
Saturday, 4/6/91
	4:45 am		From Johnson Space Center, live flight director
			change-of- shift briefing.
	4:45 am		From Atlantis, live amateur radio operations.
	11:18 am	From Atlantis, live crew checkout of spacesuits.
	12:45 pm	From Johnson Space Center, live flight director change-
			of-shift briefing.
	1:55 pm		From Atlantis, playback of views of Central and South 
			America.
Sunday, 4/7/91
	6:45 am		From Johnson Space Center, live flight director
			change-of-shift briefing.
	6:48 am		From Atlantis, live deployment of Gamma Ray 
			Observatory (process begins at 7:20 am and continues
			through 1:00 pm).
Monday, 4/8/91
	8:28 am		From Atlantis, live extravehicular development
			experiment coverage of spacewalking astronauts.
	
All events and times may change without notice.  This report is filed 
daily, Monday through Friday, by 12:00 pm, Eastern.  It is a service of 
NASA Headquarters Office of Public Affairs.  Contact:  CREDMOND 
on NASAmail or at 202/453-8425.

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

Date: 3 Apr 91 07:10:21 GMT
From: unisoft!fai!sequent!crg5!szabo@ucbvax.Berkeley.EDU  (Nick Szabo)
Subject: Re: "Follies"

In article <1991Apr2.165653.15383@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:

>...technology development, which is exactly what a cheap-launcher project
>*doesn't* need:  a bunch of wonderful new ideas that don't quite work. 

Judging from this, it seems that chemical rockets are at the point where 
technological tweaks will serve only to drive cost/lb. back up.  Another 
sign of a stagnant technology: technical improvements are forbidden!  Or, 
more to the point, the improvements are so small as to not be worth the 
cost.

I may actually be more optimistic about chem rocket technology than Henry
seems to be.  There is still room for what I call "paradigm improvment"
by private enterprise.  An example of paradigm improvement is working
the technology on variables to which less attention has been paid,  such as 
reliability or response time.  However, it seems clear that major cost/lb. 
advances will not be forthcoming from technology improvements inside the 
limited domain of chemical rockets.


>ALS's biggest problem, though, is the same one that bedevils any big-launcher
>project right now:  where's the market? 

I find myself quite in agreement with Henry here (surprise! :-).   
The commercial market is mostly mid-range (satcoms and remote sensing) 
with a growing entry level (AMSAT, phone cell sats).  NASA and DoD 
insist on going high end, for reasons of history (Apollo) and popularity, 
not economy.  There is no ALS market outside these entities, and depending 
on politics (NASA tied to Shuttle, USAF to Titan IV) there may not be 
inside them either.

It goes back to the first point, though.  If chem rockets are incapable
of tech progress for current markets, but instead must be targeted 
at a much larger speculative market for improvements to seem viable, 
then the technology is pretty much dead in the water. Real tech progress 
can address current markets with a significant improvement, or create a 
dramatically new level of affordability and thus start a new market, for 
example the Apple II and Pegasus.

I tend to think there is some room for paradigm improvment left, a task 
well suited to private enterprise.  Look at Pegasus, which 
recognizes there are many other important variables to a transportation 
system besides cost/lb.  OSC and Hercules chose to work on response 
time and entry-level costs, improving the former by over an 
order of magnitude and the latter by a factor of 5, while only raising 
cost/lb. to $8,000 (at current volumes).   Incidentally, they also
introduced some untried launching technology, air launch and winged
flight, and still spent only $50 million: clear evidence that it is
scale, not new technology, that inflates the cost of a project.
This kind of paradigm improvement is not readily acheivable in the 
government monopoly, rule-by-popularity sphere (outside of defense, 
where getting killed in this war provides incentive to advance beyond 
fighting the last war).  Private enterprise still has room to greatly 
improve chemical rockets, but it is time for government R&D to move on 
to the next generation.


-- 
Nick Szabo			szabo@sequent.com
"If you want oil, drill lots of wells" -- J. Paul Getty
The above opinions are my own and not related to those of any
organization I may be affiliated with.

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

End of SPACE Digest V13 #369
*******************