Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V09_4/V9_476.TXT

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Subject: SPACE Digest V9 #476

SPACE Digest                                      Volume 9 : Issue 476

Today's Topics:
           Re: space news from May 1 AW&ST
 Tracking and Data Relay Satellite-4 declared operational (Forwarded)
            Re: How Hubble will get there
           Re: space news from May 1 AW&ST
            Re: Amazon Forest Destruction
     First Apollo lunar exploration crew interviewed (Forwarded)
          Re: Amazon Forest Destruction (was
          Re: Hang gliders and "bailing out"
          Re: Space Station computer system
               Re: SPACE Digest V9 #472
           Re: space news from May 1 AW&ST
            Space telescope optics
----------------------------------------------------------------------

Date: 5 Jun 89 14:27:12 GMT
From: att!cbnewsh![e-mail]  (maurice.r.baker)
Subject: Re: space news from May 1 AW&ST

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
> In article <[e-mail]> [e-mail] (Steve Hosgood) writes:
> >>NASA to test a parafoil system, developed by Pioneer Aerospace, for
> >>precision landings by parachute of launcher components...
> >
> >Wasn't this originally invented by Dr Francis Rogallo in about 1963? ...
>
> ......Deleted Henry's expalanation of Rogallowing vs. parafoil
>
> .....
> Gemini originally was going to use a
> Rogallo wing in hopes of developing pinpoint landing techniques.  The
> .....
> being able to make a pinpoint landing on land was clearly superior to splashing
> down in the ocean and having to be picked up.  The motive to change was
> --

Was there also some synergy here between the concept of "pin-point" landings
on terra firma, and the strong connection between Gemini and USAF ("Blue Ge-
mini"/MOL/etc.) ?  Particularly in light of Gemini capsule containing military
crews and/or classified documents, equip. etc. --- and landing in unfriendly
waters/territory.  I keep remembering space books from the eraly 1960s which
showed a Rogallo-wing equipped Gemini skidding to a stop on the land following
a visit to the MOL.  And the Gemini capsule had a USAF insignia painted on it.

Just a thought.....any other followups?

M. Baker
homxc!mrb1

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

Date: 5 Jun 89 21:46:19 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Tracking and Data Relay Satellite-4 declared operational (Forwarded)

Dwayne C. Brown
Headquarters, Washington, D.C.                      June 5, 1989

Jim Elliott
Goddard Space Flight Center, Greenbelt, Md.

RELEASE:  89-86

TRACKING AND DATA RELAY SATELLITE-4 DECLARED OPERATIONAL


     NASA's Tracking and Data Relay Satellite-4 (TDRS-4) became
operational Saturday, officials at NASA's Goddard Space Flight
Center (GSFC), Greenbelt, Md., announced today.

     The 5,000-pound communications satellite assumed satellite
communications responsibilities that were maintained by TDRS-1
since April 1983.

     TDRS-1 now is being moved to a new location, 79 degrees west
longitude, where it will serve as a backup to TDRS-4 and TDRS-3,
also known as TDRS-East and TDRS-West, respectively.  This move
began Sunday at 11:30 a.m. EDT.

     This switchover represents the completion of the three-
satellite TDRS constellation.  This new space-based system, used
for communications with the Space Shuttle and other spacecraft in
low-Earth orbit, offers great advantages over the worldwide
network of ground stations used since the inception of the U.S.
space program.

     NASA's ground station network could only provide support for
a small fraction -- typically 15 to 20 percent -- of each orbit
period of the user spacecraft.  The TDRS network covers at least
85 percent of each orbit period and facilitates a much higher
information flow rate between the spacecraft and the ground.

     "TDRS-4 will be located at 41 degrees west longitude just
off the coast of Brazil, and TDRS-3 is on station over the
Pacific south of Hawaii at 171 degrees west longitude," according
to Charles T. Force, acting associate administrator for Space
Operations, NASA Headquarters, Washington, D.C.

     "TDRS-4's position was 47 degrees west longitude when it
became operational.  The satellite is drifting at 1 degree a day
and is expected to reach its permanent location on June 10,"
according to Roger Flaherty, GSFC's TDRS network director.

     The TDRS system of satellite communications will support up
to 23 user spacecraft simultaneously and provide both multiple-
access service that relays data from as many as 19 low-data-rate
user spacecraft at the same time and a single-access service that
provides two high-data-rate communications relays from each
satellite.   The final testing required for "service acceptance"
of the total system is scheduled to be completed by the end of
August.

     The satellites are built by TRW, Redondo Beach, Calif., and
are operated and owned by Contel Federal Systems, Fairfax, Va.

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

Date: 5 Jun 89 14:08:41 GMT
From: stsci![e-mail]  (Jim Sims)
Subject: Re: How Hubble will get there

And the last unexplained TLA is

 GSE - Ground Support Equipment

(and yes, I promidse to be a good boy and _NOT_ post TLAs without translations
  from now on)



--
    Jim Sims      Space Telescope Science Institute      Baltimore, MD
             UUCP:  {arizona,decvax,hao,ihnp4}!noao!stsci!sims
    ARPA:  [e-mail]                           SPAM:  SCIVAX::SIMS

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

Date: 5 Jun 89 14:55:50 GMT
From: cs.utexas.edu!ut-emx!ut-emx.UUCP![e-mail]  (Clyde W. Hoover)
Subject: Re: space news from May 1 AW&ST

The very first model Revell model kit of the Gemini spacecraft I got
(circa 1964 or 5) had the parts to build it with landing skids.  There
was illustrated two landing methods - splashdown and parafoil.

Shouter-To-Dead-Parrots @ Univ. of Texas Computation Center; Austin, Texas
    [e-mail]; ...!cs.utexas.edu!ut-emx!clyde

Tip #268: Don't feel insecure or inferior! Remember, you're ORGANIC!!
      You could win an argument with almost any rock!

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

Date: 6 Jun 89 01:43:56 GMT
From: vsi1!v7fs1![e-mail]  (Mike Van Pelt)
Subject: Re: Amazon Forest Destruction

In article <[e-mail]> [e-mail] (Wayne D. T. Johnson) writes:
>Article in the local news last night:
>ozone was being destroyed by electrons coming from the magnetosphere
>this causing 14% of the ozone loss since 1975...

Oh NOOOOO!!!!!   We've got to BAN all ELECTRONS before we all DIE!!!!!!!

Either that, or outlaw the magnetosphere.

I suspected from the beginning that the so-called 'ozone hole' was just
part of a natural cycle that we would have been seeing all along if we
had had satellites for decades.  It makes no sense whatsoever that a
fluorocarbon-induced hole would first appear over the south pole.
--
Mike Van Pelt                          Here lies a Technophobe,
Headland Technology/Video 7               No whimper, no blast.
...ames!vsi1!v7fs1!mvp                 His life's goal accomplished,
                                          Zero risk at last.

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

Date: 5 Jun 89 15:47:16 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: First Apollo lunar exploration crew interviewed (Forwarded)

Kenneth C. Atchison
Headquarters, Washington, D.C.                       June 5, 1989

NTE:  N89-44  FIRST APOLLO LUNAR EXPLORATION CREW INTERVIEWED

     As a part of its activities supporting commemoration of the
first Apollo Program lunar landing and exploration mission, NASA
will uplink via its NASA Select televison system a question and
answer interview with the Apollo 11 Astronauts Neil Armstrong,
Buzz Aldrin and Mike Collins.

     Media representatives can downlink the interview at 1 p.m.
EDT, Friday, June 9, from NASA Select, Satcom F2R, transponder
13, C-bamd, located at 72 degrees W. longitude, frequency 3960.0
MHz, vertical polarization, audio monaural 6.8MHz.  Running time
is 32 minutes 38 seconds including 3 minutes of B-roll scenes at
the end.

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

Date: 4 Jun 89 20:15:00 GMT
From: m.cs.uiuc.edu![e-mail]
Subject: Re: Amazon Forest Destruction (was


  Money can't make the idiots in South America stop chopping down the
rain forests, but lack of money would do the job nicely. I suggest we
start out with economic sanctions, then send the Army down there and
blow up a few plantations if that doesn't work. It's time to get tough,
before the environment we live in up here in Babylon gets ruined!

-Johnny I-guess-this-nonsense-in-Beijing-is-getting-to-me
 University of Illinois at Urbana-Champaign
 Department of Computer Science
--------------------------------Disclaimer:------------------------------------
   Rule 1: Don't believe everything you read.
   Rule 2: Don't believe anything you read.
   Rule 3: There is no Rule 3.
-------------------------------------------------------------------------------

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

Date: 5 Jun 89 04:53:05 GMT
From: zephyr!tektronix!sequent![e-mail]  (Jeff Berkowitz)
Subject: Re: Hang gliders and "bailing out"

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Steve Hosgood) writes:
>>>NASA to test a parafoil system, developed by Pioneer Aerospace, for
>>>precision landings by parachute of launcher components...
>>
>>Wasn't this originally invented by Dr Francis Rogallo in about 1963? ...
>
>If I haven't got the terms mixed up, no, they are not the same thing.

Henry's analysis of the difference is (as usual :-) correct.  Parafoil-
like designs, however, are in use both as kites and as human-carrying
gliders; the latter are popular especially in Europe.  Their advantage
over hang gliders is that the lack of airframe makes them easy to fold
into a backpack and carry; they have a relatively poor glide, however,
and appear to be difficult for humans to flare (and therefore land) safely.

I'd like to advance the idea of Rogallo or parawing vehicles for crew
escape from low earth orbit.  There are several (unlikely) failure modes
which leave the shuttle "stuck" in orbit.  If you thought the Challenger
accident was tough to stomach, imagine the spectre of a shuttle crew
dying in orbit.

Could an escape vehicle consisting of a small solid fuel rocket (for
deceleration burn) and collapsible wing be used in this situation?
After the burn you would be "dropping like a stone" toward incineration
in the atmosphere.  The only solution would be "skipping" off the
atmosphere to lose velocity (an idea proposed as early as WWII).
With a small computerized guidance system, might it be possible to
do this safely?  My knowledge of mach 17 aerodynamics at the edge of
space is, mmm, not quite up to answering this (to say the least).

As people (of whatever nationality) make increasing use of L.E.O.,
seems to me a system for getting them back down in an emergency
will assume increasing importance.  (And guess what?  I didn't
even talk to a patent lawyer before I posted this! :-).

Another ex-hang glider pilot...
--
Jeff Berkowitz N6QOM            uunet!sequent!jjb
Sequent Computer Systems        Custom Systems Group

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

Date: 4 Jun 89 23:52:31 GMT
From: bunny![e-mail]  (Horace Dediu)
Subject: Re: Space Station computer system

In article <[e-mail]>, [e-mail] (Paul S. R. Chisholm) writes:
[stuff deleted]
> highlights:  they're talking about thirty to forty IBM PS/2 model 80's
> pointing devices, with 4 megabytes of RAM and running X-Windows,
> networked with Fiber Distributed Data Interface and perhaps IEEE 802
> (they didn't say if they meant Ethernet, Token Ring, or StarLAN).
> There's also an Earth-bound system, the Software Support Environment
> (SSE), for software development.  The whole deal will require 1,500,000
> lines of Ada code, including 900,000 for the SSE.

AAAAAAUUUUGGHHHH!!
That's it!  I've had it!  If this is true, then I'm going to lose all
compassion for NASA.  IBM PS/2(!), Ada(!!), 4megs(!), the next century(!).
Doomed to fail.  :-)  (Sorry about the religion, but this is ridiculous!)

--
Horace Dediu            Goodbye, cruel world.                 GTE Laboratories
[phone]          #cd /;rm -Rf * &                      40 Sylvan Road
UUCP:  ...!harvard!bunny!hhd0                                 Waltham, MA 02254
Internet: [e-mail] or [e-mail]

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

Date: Mon, 5 Jun 1989 15:19-EDT
From: [e-mail]
Subject: Re: SPACE Digest V9 #472

> rumors, facts, or in-between information on either Third Millenium
> (MMI) or External Tanks Corp. that is fairly recent (within the last

Both still exist. I spoke briefly with Dee Ann Divis of MMI last week.
They are alive and well and still not funded on their big projects.

AMROC will be launching a suborbital (150 up and about the same down
range) flight with paying customers, one of which is a fascinating
re-entry/recovery parasol product test. Flight due near end of July.
Rocket is same, with fewer engines, as will be used for an orbital
flight due early 1990.

SSIA, as you probably know, has already done a 150 mi commercial
sounding rocket flight with 5 minutes microgravity (Starfire 1).

Pacific American is under wraps but has bent metal. Gary is not talking
much.

OSC/Hercules will be testing orbital capability over the next year.

A "commercial" Delta launch was supposed to occur on 5/31, but I've not
heard if it went off or not. (Well, it is commercial, but not in the
same build-your-own-from-scratch-with-private-venture-capital class as
the other named above.)

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

Date: 5 Jun 89 17:18:08 GMT
From: ecsvax![e-mail]  (Charles J. Lord)
Subject: Re: space news from May 1 AW&ST

In article <[e-mail]>, [e-mail] (Steve Hosgood) writes:
> Wasn't this originally invented by Dr Francis Rogallo in about 1963? The
> project had been started in an attempt to come up with a method for dry-landing
> Apollo (and other) manned space capsules. It was scrapped because NASA found
> that the wet-landing system developed over many years worked OK and there
> was no real need to change.

Yes, but it was the Gemini that was outfitted at least on paper
for the Rogallo wing and skids (looked like water skis to me).
I seem to remember a 1:1 mockup in a drop test in Missles and
Rockets back in '63-64 or so...

BTW, wasn't the airfoil really invented by him earlier, like in the
mid-1950's?
--
 *  Charles Lord               ..!decvax!mcnc!ecsvax!cjl  Usenet (old) *
 *  Cary, NC                   [e-mail]            Usenet (new) *
 *  #include <std.disclamers>  [e-mail]          Bitnet       *
 *  #include <cutsey.quote>    [e-mail]      Internet     *

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

Date: Mon, 5 Jun 89 16:56:05 EDT
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Space telescope optics


Several people have posted to the net stating that the Hubble Space Telescope
could not focus on an object as close as the earth. I tend to be somewhat
skeptical of this claim, because of the phenomenon known as depth of field.
In photography, it has been noted that objects slightly in front of or behind
the plane of optimum focus often come out in reasonable focus, because the
spread of light from these points is smaller than the effective "grain size"
of the film. Other things being equal, the higher the f-ratio of the system,
the greater the depth of field. In cameras, the depth of field is also
determined by focal length, the quality of the optics, and the maximum
acceptable degree of blurring (circle of confusion).

Of particular interest in this case is the hyperfocal distance of the system.
A camera which is focused at the hyperfocal distance is considered to have
acceptable focus out to infinity. It is generally also true that a system
focused at infinity will produce acceptable images of objects as close as the
hyperfocal distance. I have taken several pictures using a non-SLR camera
on a sunny day (aperture set very small => high f-ratio) of objects at a
great distance, which came out OK, even though I had carelessly left the
focus at 8 feet (!)

I believe the HST has a primary mirror 94 inches across, which is a tiny
fraction the distance from its projected orbit to the earth. I don't have
much information on the other parameters of the HST (primary focal length,
effective f-ratio, dimensions of optical sensors, etc.), but a few guesses
and application of the formulas used for cameras suggest that the
hyperfocal distance may be only a few miles. Does anyone have any better
numbers?
                          John Roberts
                          [e-mail] (new address)

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

End of SPACE Digest V9 #476
*******************