Conference 7.286::space

    Jul 21 88  - The Globe and Mail
    
    "SOVIET SATELLITE GOES OUT OF CONTROL"
    
    "3% chance of hitting CANADA..."
     
    Question is  'How can one come up with 3%, 30 days in advance ???'
    		 I knoe there are computers out there (in here too),
    but I would like to learn more about it.
    
    Anyone interested in providing some light???
    
    
    Jean-Rene (S/W spec III, Winnipeg, Canada)

    One quick guess, maybe the satelite spends upon average 3% of its
    on orbit time over Canada, thus equating time over the country to
    the chance of hitting the country.  I think this is a good first
    approximation and is very likely what they did.
    
    Tony

    .2 is what I thought when I read first note. If it is in a polar
    orbit (I don't know what they use for these), then Canada probably
    constitutes 3% of the earth's land area.
    
    Is this the new international measure of satellite hazard, i.e.
    the probably of hitting Canada?   :-)))
    
    gary

    re .3: well, it's extremely important if you live there...  |^)
    
    In my simple mind, I thought that I was about to learn something
    new and exciting about satellites and their tracking and trajectory
    forecast. How stupid of me... 8*)
    
    Thanks for the response in .2 ( well, AND .3); I think you're right
    about 3% of orbiting time spent over CANADA.
    
    tnxs
    
    Jean-Rene

    c1900 has some automatic equipment that may or may not
    work, there are explosives charges that are supose to go off 
    automaticly if it gets out of control.
                   
    Get out of control I think means if the nuck core did not
    seperate (which so for it has not) in a given period of
    time if it starts decaying. There was also talk about a secondary system
    but again very little detail.  ( all this from Tass )
    
    As for why 3%, no idea except they got it last time, however
    and if you know the mass etc of a bird and it is not
    under control you can predict where it will fall.  NASA
    had predicted two birds over South America about two months 
    back and they were very close, within mins on one of them.
                                                                
    If you do see it , watch the color it burns at, now
    does anyone what color different metal and U235 burns at?
    
    
    
    

    I was being facetious about their comment about Canada. You can make
    the same comment (different % of course) about any area that is under
    the satellite's orbit. If that comment came from Tass then I guess
    their journalist are subject to the same strange mentality that western
    journalists are. 
    
    I vaguely remember the same thing thing happening in Australia after
    Skylab ('the mumble-x satellite is expected to reenter over the
    norther hemisphere today.. the chance of it hitting Australia was
    described as "extremely small"'). Very much like the Monty Python
    'news for parrots'. Anyway...
    
    They ought to be able predict the reentry point fairly accurately
    as the orbit begins to decay. 'They' being either the Soviets or Spacom
    in Cheyenne Mountain.
    
    If I remember correctly, the preferred method of retiring these is
    the seperate the reactor and boost it into a very high orbit so
    that the radioactive elements have decayed long before the orbit
    does. The backup is to power it into a very steep reentry and hope
    that everything burns up above the tropopause (I assume that is
    the goal). Apparently both of these failed?
    
    I think the core is plutonium. Since power/mass is the reason to
    use nuclear power, it makes sense to use a more efficient source.
    Unfortunately, its much nastier if it gets into the biosphere.
    
    gary

    They now have a third 'safty' backup
    
    1st   seperate the core and put it into the higher orbit
    2nd   seperate the core at reentry time so it can burn up
    3rd   if all seperation efforts fails then the steep orbit
          but the core is hightly protected but TASS says it will
          burn up
    4th   if no earth control it will decay naturaly and the
          chance for a large section to hit the earth is high
    
    No mention as to what will happen but the 1st did not happen
    they were trying the 2nd and no results were publish if that
    was successful, 
    
    as for the 3rd of 4th if someone has a recent element set
    make a visual observation an see if it is blinking
    ie tumbling in orbit, this would give and indication of 
    the stability of the orbit.   More then likly it will
    not be a naked eye object as there are no solar panels.
    
    john
    

I heard something to the contrary on All Things Considered (radio news 
"magazine" program on NPR) last week.  Apparently, the design goal is to
have the core _protected_ in case of reentry so that it lands in _one_
recoverable piece (or non-recoverable deep in the ocean).  Plutonium vapor
and/or particulates in the atmosphere are apparently a no-no, as is
scattering in chunks over the north country.

>"magazine" program on NPR) last week.  Apparently, the design goal is to
>have the core _protected_ in case of reentry so that it lands in _one_

On re-reading, this statement is partially misleading.  This is the
second-best alternative for reentry, after ejection of the core into a
higher orbit.

    the NY Times had the following article about the deorbiting
    of Kosmos 1900
    
    The Federal Emergency Management Agency was form after
    the Three-Mile Island accident out of the old Federal Radiological
    Emercency Responce plan has been put on aleart for a possible
    clean up on Kosmos 1900.  No new indication as to when or where
    just a repeated of a TASS statement that said Soviets controllers had
    lost radio contract with the stellite in April and that it is expected
    to fall to Earth in Aug or Sept.
    
    The European Space Agency last week predicted that it would
    plunge to Earth in mid-September.
    
    K-1900 must be  very dense to stay so long in low Earth orbit.
                                                 
    I have notice that the KVANT propulsion unit is also in very low
    Earth orbit and should also decay within the next few months.
    The KVANT unit however has no radioactive elements it was a simple
    space tug use to dock the KVANT astrophysical lab to the MIR sapce
    complex.
    
                                                 

Newsgroups: sci.space
Path: decwrl!labrea!bloom-beacon!athena.mit.edu!snowdog
Subject: COSMOS 1900
Posted: 17 Sep 88 05:50:43 GMT
Organization: Massachusetts Institute of Technology
  
    Our group of satellite observers (based in Toronto) has been
attempting to track COSMOS 1900.  It is indeed decaying fast now and
should decay on the order of days from now.  I'll give more information 
as it becomes available; in the meanwhile, here is a recent element set: 
  
Norad # 18665
Epoch  88257.87186801
n dot over 2  .00244519
n dot^2 over 6  .35493E-04
B star        .83369E-04
Bultin #   471
inclination  64.9552
RA of A node  262.4211
eccentricity  .0015167
arg. of peri  282.9835
mean anom   76.9422
mean motion  16.250448637
rev #    4449
 
    Rich
 
    "Cruising under your radar
     Watching from the satellites
     Take a page from the red book
     And keep them in your sights."

    
  
    a slightly newer set for all the chicken little fans,
    still doing a good job not deorbiting so I would assume
    the mass to perimenter is large, maybe an Oct deorbit but
    I am not sure do to the M/P ratio and the solar conditons.
    
    
Cosmos 1900
1 18665U          88258.73335818 0.00209600  35792-4  69546-4 0   ???
2 18665  64.9567 259.1711 0015159 282.8266 077.0874 16.25406409 44633
    
    
    john
    

    ESA predict that C1900 will deorbit +- two weeks around the center
    date of the 9th of Oct, if it starts tumbling it could be as early
    as the 20th of Sept
    
    A second safety safeguard was discribe by the soviets, when the
    spacecraft altitude is less the 100km the Rorsat and reactor fuel
    core will automatically separate increasing the likeihod that it
    would burn up. Last week the bird was at 200km when it reaches the
    altitude of 120km friction heating shoud begin triggering the sepertion
    at about 100km.   If it does this the Soviets say the the incress
    in cancer deaths will be in the order of several hundred.  The US
    report on what the incress will be is classified.
    
    jb
    

    TASS:
    The backup radiation safty system automaticalled operated an on
    the 1st of Oct 1988 at 00 hrs 08 min Moscow Time seperated the nuclear
    power unit into a 'safe' orbit of approximatly 720Km.  The rest
    of the satellite then deorbited and ceased to exist before it hit
    the Earth.
    

Newsgroups: sci.physics
Path: decwrl!labrea!rutgers!iuvax!pur-ee!pur-phy!piner
Subject: "What's New"  01/19/89
Posted: 22 Jan 89 11:50:32 GMT
Organization: Purdue Univ. Phys Dept, W.Lafayette, IN
  
Posted: Thu  Jan 19, 1989   4:01 PM EST              Msg: AGIJ-3356-2300
From:   RPARK
To:     WHATSNEW
 
    WHAT'S NEW, Friday, 20 January 1989                Washington, DC
 
    2. THE INCREASED USE OF NUCLEAR POWER SOURCES IN EARTH ORBIT, by
both the US and the Soviet Union, was the subject of a sharp division
of opinion at an arms control session at the joint APS/AAPT/AAAS
meeting in San Francisco this week.  Attention has been focused on the
dangers of such devices by the recent troubles of COSMOS 1900, a
Soviet nuclear-powered radar reconnaissance satellite, but 10-20% of
all missions involving nuclear power sources, both Soviet and
American, have experienced some sort of accident.  In the case of
isotope sources the launch is perhaps the most critical phase, but for
reactors, which are launched cold, the hazard comes later after
buildup of fission products.  The 1987 APS study on directed energy
weapons called attention to the requirements of SDI for nuclear
powered satellites, but in Congressional testimony Lowell Wood of
Livermore Labs denied any intention of SDI to use such satellites.  At
Wednesday's session, however, Col. Hess of SDIO defended the need for
up to a hundred satellites powered by the 100kW SP-100 being developed
by DOE and contended that such power sources would be needed for civil
applications such as satellite control.  He acknowledged the need for
a new "Multimegawatt" burst power supply.  A new Academy study, headed
by Gen. Gavin of Grumman, supports the SP-100 development. 
 
    Robert L. Park  (202) 232-0189      The American Physical Society 
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