Posted on 02/12/2009 5:40:00 AM PST by Freeport
WASHINGTON - Iridium Satellite LLC confirmed today that one of its satellites was destroyed Tuesday in an unprecedented collision with a spent Russian satellite and that the incident could result in limited disruptions of service.
According to an e-mail alert issued by NASA today, Russia's Cosmos 2251 satellite slammed into the Iridium craft at 11:55 a.m. EST (0455 GMT) over Siberia at an altitude of 490 miles (790 km). The incident was observed by the U.S. Defense Department's Space Surveillance Network, which later was tracking two large clouds of debris.
"This is the first time we've ever had two intact spacecraft accidentally run into each other," said Nicholas Johnson, chief scientist of NASA's Orbital Debris Program Office at the Johnson Space Center in Houston. "It was a bad day for both of them."
The collision appears to be the worst space debris event since China intentionally destroyed one of its aging weather satellites during a 2007 anti-satellite test, Johnson told SPACE.com. That 2007 event has since left about 2,500 pieces of debris in Earth orbit, but more time is needed to pin down the extent of Tuesday's satellite collision, he added.
(Excerpt) Read more at space.com ...
ROFL! Good one ;o)
No, because if you produced an infinite number of objects, they would fill an infinite amount of space. They wouldn't be able to move. :-) ...that is, unless your infinite space is a larger infinity.
Mental exercises dealing with infinity have no bearing on reality.
“Given the Russian bird had been orbiting for some 15.6 years, that’s impressive durability for those thrusters and their control system.”
After actually looking at the nearly perpendicular orbits of the two satellites, I don’t really think this was intentional. It would be extremely difficult to pull that off.
Having fuel available after 15 years isn’t too likely either, even if the control system was still working.
Wow! That’s nearly a 90 degree angle between the two orbits. How many times per second did each satellite get out of its own way? How high was each orbit, measured in satellite diameters? How many times a day did each satellite pass through the point of intersection?
“How high was each orbit”
They each orbited in a range (apogee and perigee).
IRIDIUM 33:
Epoch (UTC): 03:48:05, Thursday, February 12, 2009
Eccentricity: 0.0010587
Inclination: 86.391°
Perigee height: 776 km [465 miles]
Apogee height: 791 km [474 miles]
Right Ascension of ascending node: 120.6806°
Argument of perigee: 81.0572°
Revolutions per day: 14.32479644
Mean anomaly at epoch: 279.1894°
Orbit number at epoch: 59767
http://heavens-above.com/orbit.aspx?satid=24946&lat=0&lng=0&loc=Unspecified&alt=0&tz=CET
______________________________________________
COSMOS 2215:
Epoch (UTC): 02:00:40, Thursday, February 12, 2009
Eccentricity: 0.0024852
Inclination: 74.0399°
Perigee height: 767 km [460 miles]
Apogee height: 803 km [482 miles]
Right Ascension of ascending node: 14.7272°
Argument of perigee: 157.0294°
Revolutions per day: 14.32047327
Mean anomaly at epoch: 203.2039°
Orbit number at epoch: 81778
http://heavens-above.com/orbit.aspx?lat=0&lng=0&alt=0&loc=Unspecified&TZ=CET&satid=22675
They couldn't move because they would be running into each other :-)
Box battery flak like the Germans used in WWII was also relatively ineffective but tell that to the unlucky ones.
You can rotate, pick any satellite, zoom in, etc. It is a NASA site.
Space Command publishes all known close approaches of unclassified payloads of any kind by any user and all known unclassified objects about a week in advance. (Debris/debris close approaches are ignored.) This gives operators of payloads an opportunity to maneuver to a safer orbit. These predictions are predicated on the assumption that the cataloged objects do not maneuver.
Iridium is a marginally economical operation, living off a Pentagon subsidy in exchange for affording the U.S. military additional capacity. Since Iridium can maneuver, it's failure to do so indicates that the operators did not anticipate any hazard.
Given that the Iridium had a small, but not zero value, to the U.S. military and the “defunct” satellite was Russian, the circumstances are suspect. It should be possible to scrub observations of both vehicles to see if they are even remotely consistent with the hypothesis of an accidental collision. I'll take a wait and see attitude on that.
One cannot completely dismiss the possibility that the defunct Russian vehicle impacted a cataloged or uncataloged debris sometime after the last published predictions and was nudged into the Iridium, but I, for one, see this as very, very unlikely. In the “OJ was framed by racist cops” level of plausibility.
There were two known previous collisions of tracked objects. This was the first collision of a tracked object with another tracked object that had an active payload.
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