It is still unclear whether a 1,000 pounds of toxic hydrazine fuel onboard the satellite were destroyed. The U.S. Department of Defense (DoD) said it will take 24 hours to ascertain whether the fuel tank was indeed destroyed by the impact.
U.S. Navy officials were closely monitoring the weather conditions throughout the day. Sources at the Pentagon said these had to be ‘perfect’, and due to the high swells in the Pacific Ocean west of Hawaii, they were only confident about the missile launch just a few hours before it took place.
The Pentagon said there were a limited number of ‘windows of opportunity’ during which the missile could be fired. The first of these opened at approximately the same time the space shuttle Atlantis was preparing to land in Florida, making it too dangerous for fear that some of the destroyed satellite’s debris would strike the shuttle. –In addition to the time frame that was used to down the satellite today, the U.S. Navy had a number of 10-second windows of opportunity over the next tens days.
The 5,000-pound satellite was shot down from a height of about 247 kilometers above sea level shortly before it was about to enter the Earth’s atmosphere. The U.S. devoted $60 million for this mission, in order to prevent the unlikely scenario that the faltered satellite would have survived the re-entrance to the atmosphere possibly releasing toxic gases over a populated area. The satellite failed very close to the time it was launched and therefore, carried an almost full tank (1,000 pounds) of frozen, toxic hydrazine propellant. If this gas would have been released, it would have covered an area the size of two football fields. “The regret factor of not acting clearly outweighed the regret factor of acting.” – said James Jeffrey, Deputy National Security Adviser.
Shortly after the satellite malfunctioned in December 2007, a team of over 200 scientists started working on designing a special air-defense missile system for the shoot-down mission. The Pentagon reported that the strike was timed to minimize the possible impact of the larger debris that fell through the atmosphere, saying that “the U.S. is prepared to offer assistance to governments to mitigate the consequences of any satellite debris impacts on their territory”.
NASA has warned the population not to collect or approach any of the satellite debris that might fall to the ground, stating that only the local authorities are able to take care of the matter safely. “The satellite that is degrading from orbit has hazardous materials on board that could pose immediate hazards to people if they come in contact with the material” – they said.
Video of the intercept can be found here (scroll down).
Top image: SM3 launch on June 22, 2006 from the Aegis cruiser USS Shiloh (Credit: DoD).