<p>Apparently the orbital debris pattern might be quite bad, as a lot of staellites are in a similar height above the earth, especially as these fragments slowly de-orbit from drag. The iridium satellite which collided had a near circular orbit about 748-755 km high.</p><p>I went to my favorite satellite database and tallied up about 150 active satellites in nearly circular orbits which are from 550-750 km high. Here is a list (my list). Most of these satellites in this list are likely OK because I did not consider orbital intersection timings, and I was very relaxed in considering orbital inclinations. But some of them are definately at risk.</p><p>This list contains nearly every satellite the Chinese and German military has launched, 40 OrbComm machine-to-machine communication satellites which are moderately important , all of the Saudi and S. American comsats, and some key US defense satellites...and all the remaining Iridiums.</p><p>Falconsat</p><p>3 Fermi gamma ray scopes</p><p>3 Genesis</p><p>Hessi</p><p>4 IGS (1A, 3A, 3B, 4A)</p><p>71 remaining Iridiums</p><p>JeanBing</p><p><font color="#ff0000">4 Lacrosse sats</font> - I bet the US military is looking hard here</p><p><font color="#ff0000">2 Landsats</font></p><p>Lapan</p><p>4 Latin Sats</p><p>Nazing</p><p>NFire</p><p>NigeriaSat</p><p>OceanSat</p><p>Odin</p><p><font color="#ff0000">40 OrbComm</font> sats - significant communication satellites!</p><p>Sunsat</p><p>PcSat</p><p>pehuenSat</p><p>Posat</p><p>Tersona N-1</p><p>2 Quickbirds</p><p>2 RadarSat</p><p>5 Rabieye</p><p>reimiei</p><p>5 Sar-Lupe</p><p>11 SaudiComSat</p><p>10 Shijian, Shiyan</p><p>STPSat</p><p>Suzuki</p><p>Swift</p><p>tecSar</p><p>2 Theos</p><p>5 Yoagan</p><p>3 Zhanggoo</p><p>Rossi</p><p>UniSat</p><p>Vesat</p><p>UK-DMC</p><p> </p><p> </p><p> </p><p>from
http://news.yahoo.com/s/nm/20090212/ts_nm/us_space_collision_8</p><p>The collision between the Iridium Satellite LLC-operated satellite and the Russian Cosmos-2251 military satellite occurred at about 485 miles above the Russian Arctic.</p><p>That is an altitude used by satellites that monitor weather, relay communications and perform scientific observations.</p><p>"It's a very important orbit for a lot of satellites," said Air Force Colonel Les Kodlick from the U.S. Strategic Command. "We believe it's the first time that two satellites have collided in orbit."</p><p>The U.S. Joint Space Operations Center was tracking 500 to 600 new pieces of debris, some as small as 4 inches across, in addition to the 18,000 or so other man-made objects it previously catalogued in space, he said.</p><p>Russian Space Forces said it was monitoring debris that was spread over altitudes between 500 km (310 miles) and 1300 km (807 miles) above
<font class="klinkFont" color="#dc0000"><span style="font-weight:400;margin-bottom:-2pt;color:#000000!important;font-family:arial,helvetica,clean,sans-serif" class="kLink">earth</span></font>.</p><p>The priority is guarding the International Space Station, which orbits at 220 miles, substantially below the collision altitude. One Russian and two U.S. astronauts are currently aboard the station.</p><p>SPACE STATION</p><p>The orbit of the ISS can be changed by controllers from Earth but even a tiny piece of debris can cause significant damage to the space station as it travels at 8 km per second.</p><p>"If there is any threat to the ISS then there will be an announcement," one Russian space official said. Another said there was little immediate threat to the station.</p><p>The crash has underlined concerns about how crowded the orbit paths around the planet have become in recent decades.</p><p>But experts said the chances of such a collision are extremely low and added that leading space powers have been racing to develop new ways to destroy orbiting objects.</p><p>"The orbital altitude where the collision took place is among the most crowded in low Earth orbit," Texas-based security consultancy Stratfor said in a research note.</p><p>"But statistically speaking, the enormous scale of space makes the chance that this kind of direct collision would occur completely by accident infinitesimal," it said. </p><p>The collision occurred in a polar orbit not far from that of a defunct Chinese weather satellite shot apart by a ground-based ballistic missile in a Chinese weapons test in January 2007. </p><p>The United States used a missile to blow apart a tank of toxic fuel on a defective U.S. spy satellite last February. </p><p>There was no indication that Tuesday's collision was intentional on the part of anyone, said a U.S. government source who asked not to be named. </p><p>The European Union said on Thursday leading nations should adopt a code of conduct for civil and military activities in space. </p><p>(Additional reporting by Conor Sweeney, Tatiana Ustinova in Moscow, Tim Hepher in Paris and Jim Wolf in Washington; editing by Christian Lowe)</p><p><br /><br /> </p> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>