Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v09_5/v9_507.txt

Internet Message Format | 1991-07-08 | 17KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from corsica.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/sYckq8y00UkV8I1E4u>;
          Sat, 24 Jun 89 00:26:49 -0400 (EDT)
Message-ID: <[e-mail]>
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Sat, 24 Jun 89 00:26:35 -0400 (EDT)
Subject: SPACE Digest V9 #507

SPACE Digest                                      Volume 9 : Issue 507

Today's Topics:
             Re: Orbital Queries
            * SpaceNews 19Jun89 *
              Re: Outer Space Committee
          Jonathan's Space Report, forwarded
           Computers for the space station
----------------------------------------------------------------------

Date: 18 Jun 89 20:08:02 GMT
From: att!tsdiag!ka2qhd![e-mail]  (John Magliacane Wall Township NJ)
Subject: Re: Orbital Queries


References: <[e-mail]>



Orbital inclination determines the apparent "direction" an earth satellite will
move when viewed on a map of the world. Orbital inclination is defined as the
angle between the orbital plane of a satellite and the equatorial plane of the
earth (the equator). The inclination can vary between 0 and 180 degrees.

A spacecraft will appear to move west-to-east if its orbital inclination is
between 0 and 90 degrees, while a spacecraft having an orbital inclination
between 90 and 180 degrees will appear to move east-to-west.

For example, the US Space Shuttles are usually launched into orbits having
inclinations between 28.5 and 57.0 degrees, and appear to move from west-to-
east, while OSCAR-11, an Amateur Radio communications satellite, appears to
move from east-to-west, since its orbital inclination is 98 degrees.

Another interesting point to note is that US Space Shuttles are ALWAYS launched
toward the East (over the Atlantic Ocean). This is the same direction as the
Earth's rotation. Therefore, the Earth gives the Shuttle an extra "push" into
orbit. Launching from the West coast would take a LOT more energy and fuel.

Also, the minimum orbital inclination of a Shuttle mission is 28.5 degrees --
the latitude of the Kennedy Space Center. This orbit is generated if the
orbiter is launched due East. If the Shuttle is launched either slightly North
OR South of due East, then the inclination is ALWAYS greater than 28.5 degrees.


-->> John A. Magliacane <<--


--
 UUCP   : ucbvax!rutgers!petsd!tsdiag!ka2qhd!kd2bd
 PACKET : KD2BD @ NN2Z (John)
          ..."There is no expedient to which a man will not resort to
          avoid the real labor of thinking." ....Sir Joshua Reynolds.

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

Date: 18 Jun 89 17:18:15 GMT
From: att!tsdiag!ka2qhd![e-mail]  (John Magliacane Wall Township NJ)
Subject: * SpaceNews 19Jun89 *


Bulletin ID: SPC90619

                              ---------
                              SpaceNews
                              ---------

                         MONDAY JUNE 19, 1989

SpaceNews originates at KD2BD in Wall Township, NJ, and is distributed weekly
around the world. It is available for UNLIMITED distribution.



* OSCAR-9 NEWS *
----------------
It looks like OSCAR-9 will NOT be taking any CCD pictures for some time.
A revised operating schedule was recently issued for OSCAR-9. Diary software
reloads will still take place on Tuesdays. Digitalker telemetry will follow.
The telemetry channels currently being downlinked via the Digitalker include:

08 : Battery Pack A Temperature (C)
18 : Battery Pack B Temperature (C)
22 : Battery Voltage +14V (Volts)
29 : Spacecraft -Y Facet Temperature (C)
35 : 145 MHz Beacon Output Power (UnCalibrateD)
39 : Spacecraft +Y Facet Temperature (C)
49 : Spacecraft +Z Facet Temperature (C)
59 : Spacecraft -Z Facet Temperature (C)

From Thursday at around 12:00 UTC, the spacecraft will transmit the following
sequence of data at 1200 bits/second:

Telemetry              :  60 seconds
News Bulletin          :  60 seconds
Whole Orbit Data (WOD) : 150 seconds

This will continue until 06:00 UTC on the following Tuesday when the beacon
will switch off to help facilitate a software reload.

The recent solar flare has greatly increased OSCAR-9's orbital decay rate.
This means OSCAR-9 will come into range a few minutes before your predicted
times of AOS. Here is element set 588 for UO-9 as issued by NASA on 13Jun89:

Epoch  : 89 161.08290495
Incli  : 97.5527
RAAN   : 214.2327
Eccen  : 3.717E-04
ArgPer : 153.8947
MeanAn : 206.2960
MeanMo : 15.59543431
Decay  : 8.6255E-04
RevNum : 42788


* UoSAT-D NEWS *
----------------
Harold Price, NK6K has been performing some performance tests on the UoSAT-D
PCE, the Microsat CPU, and other machines. The results are summarised below.

Using a dhryston C benchmark from Sept. '86 DDJ p.88, here are some
performance numbers (using a 6MHz AT as the index).    The same compiler and
options were used (/AS /Ze /Zp /Ot /Gs ).  /Gs (no stack checking) was used
because the S/C stack check is different than the dos version.  Normally /G1
(80186 instruction set) would be used for S/C programs.

The RIC is the PC card we're using for the simulator and for SW development.

Device       CPU       Clock       dhrystons/sec     index

Toshiba 3200 80286     12 MHz      3762              2.03
AT Clone     80286      8 MHz      2145              1.16
IBM AT       80286      6 MHz      1850              1.00
UoSAT PCE    80C186    7.3728 MHz  1398 +            0.75
RIC          80186     7.3728 MHz  1391 +            0.75
AMSAT proto  V40       7.372 MHz   861               0.47
AMSAT flight V40       4.608 MHz   538*              0.29*
IBM PC       8088      4.77 MHz    1531              0.29

+ The timer resolution of 10ms gives an uncertainty of +/-14 counts,
  these numbers are equivalent.

* calculated based on clock speed difference from wirewrap.

The RIC, Microsat Prototype, and UoSAT tests were done under the kernal, so
clock and scheduler overhead are included.  Zero wait states were used.

[Story via OSCAR-9]


* OSCAR-11 NEWS *
-----------------
A new binary dump format is now operating in the Forth Diary cycle.
The general format of the packet is as follows:

Sync 1 - 50H
Sync 2 - 41H
Frame Count MSW
Frame Count LSW

...64 bytes of data...

Checksum MSW
Checksum LSW - 16 bit addition of all bytes excluding syncs.

This data is transmitted for 15 seconds after the news bulletin, between the
Single Event Upset (SEU) dump and the Whole Orbit Data (WOD) dump in the
current schedule, and contains engineering data. It is anticipated that WOD
using this "packet" format will be introduced into the Diary schedule soon.


* OSCAR-13 SCHEDULE *
---------------------
Date    : 14Jun89 until 16Aug89 | 16Aug89 until 16Nov89
Attitude:           180/0       |           210/0
Mode-B  :     MA   0 to MA 110  |     MA   3 to MA 160
Mode-JL :     MA 110 to MA 145  |     MA 160 to MA 200
Mode-B  :     MA 145 to MA 255  |     MA 200 to MA 240
OFF     :             %         |     MA 240 to MA   3
Mode-S  :     MA 150 to MA 160  |     MA 210 to MA 222

Also, for a trial period the OMNI-directional 70cm antenna will be connected
to the Mode-B RCVR from MA 20 to MA 40. These changes have been introduced to
enable stations who have access around perigee to experiment with perigee
operation.  Mode S unchanged. 14May89: BLON/BLAT 212.0/+2.4 with a drift rate
of 0.016/-0.061 deg/day, respectively.

Transponders will be in operation during the whole orbit from June 14 until
Aug 16 due to excellent sunangle and power budget. No perigee operation
between August and November due to perigee solar eclipses!


* FEEDBACK WELCOMED *
---------------------
Feedback regarding SpaceNews can be directed to the author (John) via any
of the following paths:

UUCP   : ucbvax!rutgers!petsd!tsdiag!ka2qhd!kd2bd
PACKET : KD2BD @ NN2Z


* SOURCES *
-----------
Some of the news contained in this SpaceNews issue was obtained via
OSCAR-9, OSCAR-11 and the KA2QHD and NN2Z PBBSs.


* AMATEUR RADIO: A Natural Resource *


<eof>


--
 UUCP   : ucbvax!rutgers!petsd!tsdiag!ka2qhd!kd2bd
 PACKET : KD2BD @ NN2Z (John)
          ..."There is no expedient to which a man will not resort to
          avoid the real labor of thinking." ....Sir Joshua Reynolds.

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

Date: 19 Jun 89 14:59:36 GMT
From: bunny![e-mail]  (Horace Dediu)
Subject: Re: Outer Space Committee

In article <[e-mail]>, [e-mail] ("Keith F. Lynch") writes:
> > The Committee on the Peaceful Uses of Outer Space ...
>
> With China, the USSR Cuba, and other butchers as members.  Right.
And Romania too, holy cow!  The bandits of the world telling us how to
behave!
> I hope the US isn't involved.
>                                 ...Keith
Me too.
--
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: 15 Jun 89 18:10:31 GMT
From: usc!orion.cf.uci.edu!uci-ics!zardoz!tgate!ka3ovk!drilex!axiom!linus!alliant!merk!spdcc!ftp!poopsie![e-mail]  (Seth D. Hollub)
Subject: Jonathan's Space Report, forwarded

Jonathan's Space Report

Jun 15, 1989 (no. 18)

Hello again girls and boys, I'm semi-back! We still dont have the usenet
back after our system upgrade, so I'm asking a friend to post this.  I
wont see the net for another week or so, so email me questions rather
than post them.
---------------------------------------------------------------------

OV-102 Columbia due to be moved to the VAB on Jun 29

Launches: I'll be chronological for a change...

USA-37, launched May 10 by Titan 34D/Transtage, is a Vortex telemetry
intelligence satellite according to AvLeak, rather than a pair of
comsats as reported earlier.  It is now in geostationary orbit.

Kosmos-2020, launched May 17 by RN Soyuz from Baykonur, is a GRU recon
satellite expected to remain in orbit until mid-July.

Kosmos-2021, launched May 24 by RN Soyuz from Plesetsk, is another GRU
recon satellite, probably a Vostok-class payload, and probably landed
around Jun 7.  Meanwhile, Kosmos-2019 landed on May 18 after a 13 day
flight.

The first Resurs-F satellite, launched May 25 also by RN Soyuz from
Plesetsk, is another Vostok-class payload, this time for earth resources
photography.  The data is used by the 'Priroda' center.  Other
satellites in the same series have flown under the Kosmos name, like
Kosmos-2000 earlier this year; civilian applications are slowly being
declassified and removed from the Kosmos series.

Pravda reports that two separable 'Pion' air density research
subsatellites were carried into orbit with Resurs-F.  The satellites,
built by students at the Korolev Aviation Institute in Kubyshev, have
not yet been catalogued by NORAD.

Three GLONASS navigation satellites, Kosmos-2022,2023,2024, were
launched on May 31 by RN Proton from Baykonur into 19000 km orbits.

Yet another recon satellite, Kosmos-2025, orbited Jun 1 from Plesetsk;
no details yet on Kosmos-2026 launched Jun 7.

The first launch of the 44L version of Ariane 4 was successful on Jun 5.
The payloads were Superbird 1, a commercial Japanese comsat, and
Kopernikus/DFS, a West German TV (Deutsche FernSehen) satellite.

Jun 8 saw the launch of the 38th Molniya-3 satellite by RN Molniya
from Plesetsk, into a 12 hour elliptical orbit.

The second Delta II launch finally got off the ground on Jun 10,
from pad 17 at Cape Canaveral, placing a USAF Navstar navigation
satellite (USA-38) in orbit.

Finally, on Jun 14 the first Titan IV was launched from pad 41 at
Cape Canaveral, carrying the first of a new generation of early
warning satellites toward geostationary orbit.



 .----------------------------------------------------------------.
 |  Jonathan McDowell       |  phone : [phone]              |
 |  Center for Astrophysics | uucp: husc6!harvard!cfa200!mcdowell |
 |  60 Garden Street        | bitnet : [e-mail]        |
 |  Cambridge  MA 02138     |  inter : [e-mail]   |
 |  USA                     |   span : cfa::mcdowell              |
 |                          |  telex : 92148 SATELLITE CAM      |
 |                          |    FAX : [phone]              |
 '----------------------------------------------------------------'
--
     "Segments: Just Say No!", "Whadya mean there's no control key?"
[e-mail], ...ftp!poopsie!seth, 18 Rindge Av, Camb. Ma, 02140 USA Earth

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

Date: Mon, 19 Jun 89 15:06:47 EDT
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Computers for the space station


There is at least one reason to hope that the "PC compatible" machines
will not be the ones in charge of critical functions such as life support.
In the past, NASA has tended to use specialized custom computers in its
spacecraft, with one result being that they pretty much had control over
any software that the machines could use. In the PC world, there are hundreds
or thousands of people hard at work writing and spreading software to damage
or scramble PCs and their memory systems. In the scenario described earlier,
one of the astronauts smuggles aboard a copy of "Star Trek" downloaded from
a BBS, which contains a virus. Or someone gets the bright idea that the station
computers should be linked via radio to a terrestrial network, from which they
are attacked by a worm. The interconnectivity of the proposed computers implies
that a virus on one machine could propagate its effects to all the other
machines. Imagine the astronauts finding out that their system has crashed,
and having to wait several hours for a reboot before they can adjust their
atmosphere (though there are hopefully manual overrides for such situations).
Alternatively, suppose a robot arm holding a long, heavy rod goes berserk and
starts flailing it around until it punches a hole through a wall. Of course,
it may be possible to guard against such occurrences by stringent safeguards
to prevent the introduction of harmful software.

There have been several complaints about the choice of the Posix operating
system, on the grounds that it would be an exotic and expensive system, and
"plain old Unix" would be just as good. As I understand it, Posix is just
an attempt by the federal government, in light of the many operating systems
and many versions of Unix available, to come up with a standard which can be
specified in procurement orders, so the users will know what they are
getting. It is generally expected that within a few years, most or all
government computer orders for Unix-like operating systems will include
Posix specifications, so from this viewpoint it makes sense for the space
station computers to be expected to meet this standard.

In the debate on the choice of Ada for much of the software, I would like to
point out that saying "Ada is undesirable because not many programmers I know
program in Ada" is not entirely reasonable, because Ada is a young language,
and because not many programmers write software for the applications that are
the strong points of Ada. It has been claimed that a major purpose behind the
creation of Ada was to produce reliable software for real-time control in a
multiprocessor environment. If so, the space station should be a nearly ideal
environment for the use of Ada, assuming the computers are used largely to
control experimental processes. Though the speed and space efficiency of the
earliest compilers and compiled code were not impressive, they have continued
to improve, though it is not clear how far this improvement can go.

Dale Amon writes:
>...ADA is probably a mistake. ...Object oriented languages are the way the
>(non-government) world is going.
I have talked with several people who have studied Ada, and they claim that
object oriented programming is one of the major points of emphasis in the
design of the language.

There is a set of articles in the June 1 issue of Computer Design describing
changes in military procurement of mil-spec and off-the-shelf equipment and
relevant issues, plus the evolution and current status of Ada.

Incidentally, one application for which rapid response would be desirable is
maneuvers to avoid known large pieces of debris in orbit. Are there any
proposals on this subject? I presume the simplest approach would be to use
earth-based tracking and computers to decide when there might be a hazard.
Low earth orbits continually change due to atmospheric drag, so periodic
inspection will be necessary in any event.
                                    John Roberts
                                    [e-mail]

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

End of SPACE Digest V9 #507
*******************