Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_6/V12_621.TXT

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Date: Tue,  4 Dec 1990 01:53:36 -0500 (EST)
Subject: SPACE Digest V12 #621

SPACE Digest                                     Volume 12 : Issue 621

Today's Topics:
               Columbia Liftoff
                 ASTRO update
           Re: living in the cradle forever
          Re: ELV Support to Space Station (1 of 2)
        Re: Re: Reusable Boosters & Insurance
             Re: * SpaceNews 03-Dec-90 *
          Latest post launched Keplerian data needed
          Re: Re: Reliability and Insurance (1 of 3)

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 2 Dec 90 07:20:26 GMT
From: uvaarpa!murdoch![e-mail]  (Greg Hennessy)
Subject: Columbia Liftoff


Columbia lifted off at 01:50 Eastern Standard time, in a beautiful
liftoff. The clouds cleared long enough for a launch.

Now to try to get some sleep before the  Scientific Observations and
Planning Group meeting in 7 and a half hours.

--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 2 Dec 90 07:15:14 GMT
From: uvaarpa!murdoch![e-mail]  (Greg Hennessy)
Subject: ASTRO update


The shuttle is currently in a hold at T minus nine minutes. The
hardware is fine, the only hold up is the weather. A helicopter is
trying to get more data. The last estimate I heard was a 50 percent
chance of launching tonight. The visibility is currently 7,000 ft, and
8,000 feet is needed. If the weather does not cooperate, there will be
two more attemts in the next 48 hours (plus a few). If a launch is not
sucessfull by approx 4 am Tuesday Dec 4th, the orbiter will be drained
and a another launch attempt will be seven days after the 4th.

If a launch is sucessful, here are some interesting info from the
early schedule, listed in Accumulated Mission Elapsed Time (AMET).

T-9 min GLS auto seq start
T-5 min orb apu start
T-3 min 30 sec MPS gimbal
T-2 min 55 sec LO2 prepressurazations
T-1 min 57 sec LH2 prepressurization
T-21 sec SRB gimbal profile
T-6.6 sec SSME 3 start
T-6.5 sec SSME2 start
T-6.4 sec SSME1 start
T-0 sec SRB iginition/Liftoff [NASA declares mission a sucess :^)]
T+29.7 sec SSME throttle down to 69%
T+50.1 sec MAX q start
T+1 min 6.2 sec ssme throttle up to 104
T+2 min 4.6 sec srb seperation
T+8 min 31.5 sec Main engine cutoff
T+8 min 57.5 sec ET separation [ET go home.]
T+22 min On station Debrief.
T+2 hour (hereafter written 0/02:00) BBXRT activation
0/03:10 Image pointing system activation
0/03:20 Payload activation
0/04:25 WUPPE activation
0/04:30 HUT activation
0/06:00 UIT activation
0/14:10 Joint Focus and alignment test
0/19:30 Focus test on Orion

First observatons are HUT observations of SS-CYG at 22.1 AMET,
adn BBXRT secondary observation of SSCYG also. WUPPE's first
observations as primary  instrument is HD37903 at 22.7 AMET. UIT's
first observation as primary is at 46.17 when it observes NGC 5139.



--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 2 Dec 90 18:43:18 GMT
From: [e-mail]  (Frank Lemoine)
Subject: Re: living in the cradle forever

Re the following citation:
    The earth is the cradle of humanity, but mankind will not
  live in the cradle forever  ....
  It is by Konstantin Tsiolokovsky, a Russian rocket scientist.
   (ie. not by Heinlein, the science fiction writer).

 This frequently cited quotation appears to be a bastardization
 of the following (translated from Russian)

     Mankind will not forever remain on the Earth, but will first
 timidly penetrate beyond the limits of the atmosphere and then
 acquire for himself all the in the near-Sun space.


---> Frank Lemoine
    Colorado Center for Astrodynamics Research
    University of Colorado, Boulder

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

Date: 30 Nov 90 20:15:53 GMT
From: edsews!teemc!fmeed1![e-mail]  (Russ Cage)
Subject: Re: ELV Support to Space Station (1 of 2)

In article <[e-mail]> [e-mail] (Charles Radley) writes:
>My original statement was correct as written, read it again.

But misleading.  It even misled you:

>Thank you for adding more numbers, I note that the big volume of a spinning
>station means it must accomodate a very substantial pressure load compared
>with a non-spinning station, another weight penalty.

To summarize my numbers:

Tension from pressurization:    190 klbs
Tension from rotation:         40 klbs

This is a very small increment, ~20%.  I've already shown
that the required mass of Kevlar to construct a 14.7 PSI
module is small, ~8000 lbs.   For a 7.5 PSI module, it
would be about half that, even with the extra axial
tension.  Circumferential stress would not change.

I am having serious doubts about your ability to impartially
analyze and critique concepts you don't like.  Part of being
scientific is checking your objections against reality and
'fessing up when they don't hold water.

>LLNL at a higher altitude will have a more severe radiation environment
>than Freedom.

It was my impression that LLNL specified a LOWER orbit.  My
archives are at home.  Allen?

>Also, the shielding capability of LLNL's non-metallic structure is much
>less than Freedoms aluminum modules.

1.)    Soft X rays are stopped by almost anything.  Fred offers
    little superiority of protection.
2.)    Charged particled are stopped by Earth's magnetic field.
    Orbiting lower would give superior protection against
    protons, which LLNL does if memory serves.  (Allen?)
3.)    Cosmic rays are less dangerous than their secondary
    particles.  Fred's aluminum structure would be MORE
    DANGEROUS than LLNL's lighter pressure hull.

PS:  Charles, your news-posting software is faulty; it does not
insert attributions or maintain the References: line properly.
Please have it fixed.  Also, if you could keep your line
length down to 70 characters, it would be appreciated.
--
Russ Cage    Ford Powertrain Engineering Development Department
Work:  itivax.iti.org!cfctech!fmeed1!cage   (CHATTY MAIL NOT ANSWERED HERE)
Home:  [e-mail]  (All non-business mail)
Member:  HASA, "S" division.

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

Date: 30 Nov 90 13:10:04 GMT
From: hpcc05!col!hpldola!hp-lsd!oldcolo![e-mail]  (Keith Hamburger)
Subject: Re: Re: Reusable Boosters & Insurance

Wales, the reliability estimates of SSX and all other SSTO, VTOL vehicles
is based on avoiding many of the problems you mentioned in other
messages.  VTOL vehicles can be incrementally tested by flying them at
low altitudes for long periods of time.  They can hover very nicely.  Our
own Hummingbird sounding rocket can hover for five minutes at one g.  If
there is a failure that would be catastrophic for a one-shot to orbit
vehicle (as all to date are) it would likely be minor if it occurs at
zero velocity within a few feet of the ground.  Following that type of
test flights can proceed to a few feet, a few miles, a few tens of miles,
a few hundreds of miles and on into the operational envelope.

In addition, VTOL vehicles are all designed with an intact abort feature.
 They can abort at any point in their flight envelope to virtually any
point on earth as they do not need a runway to land on.  In most failure
scenarios for VTOL vehicles the vehicle is recovered intact and the only
problem left to fix is the one that caused the failure.  All other
vehicle designs result in loss of the vehicle in most failure scenarios.

These features should eliminate the "infant mortality" rates that result
in the higher faailure rates of all other vehicles.

Keith L. Hamburger
Secretary, Hummingbird Launch Systems
VP, Pikes Peak L5 Chapter of the nss

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

Date: 2 Dec 90 19:00:51 GMT
From: envy![e-mail]  (Phil R. Karn)
Subject: Re: * SpaceNews 03-Dec-90 *

In article <[e-mail]> [e-mail] (John Magliacane) writes
an otherwise excellent tutorial on Keplerian orbital elements. However,
there are a few minor errors.
>ECCENTRICITY: (0..1)
>
>A dimensionless term used to describe the "flatness" of the elliptical orbit.
>A circle has an eccentricity of zero.  A line has an eccentricity of 1.
>The orbit of OSCAR-13 has an eccentricity of about 0.7.

Actually, a parabola has an eccentricity of 1. A line has an eccentricity
of infinity. Orbits with eccentricities between 1 and infinity are
hyperbolae. (The Voyager 1/2 and Pioneer 10/11 spacecraft are in hyperbolic
orbits with respect to the sun, i.e., they're on solar system escape
trajectories.)

>ARGUMENT OF PERIGEE: (XXX.XXXX degrees)
>
>The angle between the line from the Earth's center to the satellite's point
>of lowest altitude (perigee) and the line from the Earth's center to the
>point where the orbit crosses the equatorial plane, going north.

The angle should be measured the opposite way (i.e., from the ascending
node to the perigee point, not the other way around). Also, the angle
is measured in the orbit plane.

>MEAN ANOMALY: (XXX.XXXX degrees)
>
>The angle which specifies the position of a satellite in its orbit, measured
>from perigee.

No. This is "true anomaly". Mean anomaly is a somewhat artificial
value; it's actually a measure of TIME since perigee, with that time
value scaled so that 360 degrees represents one orbital period. Mean
and true anomaly coincide only at perigee (0) and apogee (180) except
in the case of a perfectly circular orbit, in which case they are
always the same.

>Some satellite tracking programs use SMA as a replacement for mean motion.
>The quantity (1440/MM) yields the anomalistic period of the satellite (in
>minutes between perigees).

Note that this is not recommended practice. Small errors in computed
SMA result in bounded errors in computed distance to the satellite (which
most hams don't care about, except for those doing ranging) while small
errors in computed mean motion can result in unbounded errors in
satellite position along the orbit as time increases. Therefore it's better
to use mean moton as input to the program and have it compute SMA
internally rather than the other way around.

>ORBIT NUMBER: (XXXXX)
>
>The number of perigees the satellite has experienced at the reference epoch.

This figure has probably caused more confusion in the amateur community
than any other, mainly because the figures included in the NORAD/NASA
bulletins are so often wrong. Some agencies count orbits as ascending
nodes (south-to-north equator crossings), others count them as perigee
passings, and because of continuous changes in the argument of perigee
caused by orbital perturbations (chiefly the earth's equatorial bulge)
these number diverge after some time in orbit.

Phil

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

Date: 3 Dec 90 05:53:47 GMT
From: deccrl!news.crl.dec.com!pa.dec.com!shodha.enet.dec.com!levers.enet.dec.com![e-mail]  (Bob Egan)
Subject: Latest post launched Keplerian data needed


Would someone post a post launch element set. I called the NASA BBS
and nothing is there. There is one news update of little value.

Thanks,
Bob

ps. If these are posted to an ftp site, I would appreciate a pointer
to them...




Bob Egan    [e-mail]
        --or-- ...!decwrl!levers.enet.dec.com!b_egan
        --or-- [e-mail]

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

Date: 30 Nov 90 13:10:04 GMT
From: hpcc05!col!hpldola!hp-lsd!oldcolo![e-mail]  (Keith Hamburger)
Subject: Re: Re: Reliability and Insurance (1 of 3)

Wales is right about how to insure sattelites into orbit.  As VP of Pikes
Peak L5 I (and others in our org.) have done some looking into such
issues.  If you build one sattelite it costs a given amount, just for
example we will use $1million.  Since that sattelite is one of a kind the
majority of that cost goes into development and design of new systems,
prototyping etc.  Say two-thirds.  That means that it will only cost 1.3
million to build two of the same bird as you only have to pay for
development once.

The next major cost, however, Wales did not address, that is launch cost.
 What we have advocated is a system whereby launchers can guarantee a
sattelite on orbit.  The launcher would take title of all sattelites
built (and would specify a certain number of backups) and would for a
fixed cost guarantee that one of them would be place functionally in
orbit, at which time title would revert to the owner.  That way the
launch company is taking all of the risk for launch failure, which is
much as it should be.

NEVER, NEVER, NEVER should a space organization consider commercial
insurance.  The insurance companies will never give you a reasonable rate
as they will claim there is not enough actuarial data to base a
determination.  The worst example of this is in liability insurance for
space launches.  The explosive capacity of a launch vehicle is less than
that of the fuel on board a large airliner.  Space launches are done at
remote locations as far from population centers as is reasonably
possible.  And launches are designed to fly over as few population
centers as possible.  In contrast, airlines fly in and out of the most
densely populated areas in the country and are directly over population
centers during the most dangerous times of their flights.  Therefore
launch insurance rates should be MUCH lower thatn flight insurance rates,
Right???  Wrong.  Usually greater by one or two orders of magnitude.

Keith L. Hamburger
VP Pikes Peak L5 Chapter of the national space society
Secretary, Hummingbird Launch Systems
627 Skyline Ave.
Colorado Springs, CO  80905
[phone] (home voice)

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

End of SPACE Digest V12 #621
*******************