At 21:00 UTC on 20 July 2020 an earth observation satellite was destroyed and, according to space experts, caused widespread destruction in the ionosphere – an electrically charged region surrounding the earth.
The US Defense Advanced Research Projects Agency (DARPA) supported an anti-satellite (ASAT) weapon test, called Permissive Action Links (PAL) 1, using kinetic energy from a ground-launched kinetic kill vehicle. A P-3 Orion US Air Force Rivet Joint was released from its launch site in North Carolina on March 30, 2016 (see video here). At a distance of about 400nm from the US, the mission of the laser was to fly past an Earth Observation Satellite (ELAS) and destroy it with a flash intense enough to cause its hydrazine fuel tanks to explode – just prior to the edge of the ionosphere.
On the 18th June 2016, when the Guardian visited Palmdale, California, I learned this test was still taking place despite the fact that NASA had told the Pentagon that the destructive excess hydrogen built up during a previous test in 2013 was depleting the oxygen supply of the satellite itself. These hydrogen tanks were leaking into the atmosphere.
Multiple satellites which had been monitoring the laser burst and the Palmdale site during the past year had found numerous pieces of debris about 10cm in size in the lower atmosphere between about 1300 km/h and 600 km/h, including bits of the satellite itself. More than 20 ELAS were found in the lower atmosphere as far as 2500 km/h. One of the Solar and Heliospheric Observatory satellites had seen chunks as small as about 3cm in size fall from the sky at about 600 km/h. Satellites also found fragments as large as about 16cm.
Although there have been a few other thermal anti-satellite weapon tests, the damage caused in this test is notable – particles bombarding the ground accelerate from about 300 to 700 km/h. The space debris being shot at the satellites has been estimated at about 750km/h, stretching for 2,500km.
The US sees everything in space as a potential threat. Now there is evidence this will come with us on Earth.
The upshot? Space situational awareness is hugely improved in the lower part of the atmosphere. Video from the Hubble Telescope of the debris going over the Earth shows smoke everywhere, typical of what you’d expect to see after a gas flare. The last time lasers were used to destroy satellites in space was in 1991 when two Wernher von Braun Alphasuid Space Railway capsules exploded above the top of the Eastern Hemisphere. If it’s not clear now, it’s obvious after today.
• Listen to audio interviews about the Palmdale test conducted by Jo Pryce, Rex Sheets, and Alan Brown
Image: Stratospheric Attack Conference
Link to Unclassified DOD video on destruction of a satellite