On July 23rd, 2007, the crew of the International Space Station did some orbital fly-tipping. They dumped a double refrigerator-sized piece of equipment overboard and sent it toward Earth. Mission control at the time assured the public that it would orbit for about 300 days and most of it would burn up. The first issue is that, a year on, it is still orbiting and it is expected to do so until the end of 2008 at the earliest. Second issue is that a large portion of the kit will survive re-entry. Uncontrolled re-entry like this is by nature hard to predict where it will impact. Although the ISS had little option but to dump the used Early Ammonia Servicer (EAS), was there a better, safer alternative?
We all know that with manned exploration of space comes consequences, and space debris is one of the most significant. Low Earth orbit is becoming more and more cluttered, causing concern for future access to space. Today, I wrote about a huge chunk of space junk that had been dropped by the ISS last year. Before it succumbs to gravity, the EAS will provide amateur astronomers and naked-eye observers with a superb light show in the form of a mag. +2.0 speeding point of light seen in the night skies of Europe and North America. Once the enthusiasm for spotting the space station’s largest dumping effort begins to pass, the inevitable question will surface: Where will it hit Earth?
Unfortunately, NASA doesn’t seem to have an answer. Alas, that decision appears to be down to gravity (with a bit of atmospheric physics thrown in). I wouldn’t be overly concerned if this object was small, but it has a mass of 635 kg and it appears to be passing over huge swathes of populated continents.
NASA and the ISS had little option but to jettison the EAS, but there appears to be little consideration of the outcome when a significant amount of the EAS will certainly survive the high temperatures of re-entry. Plus it doesn’t instil much confidence when the original timeline of orbit (300 days) is grossly underestimated. Perhaps efforts should have been made to dismantle the EAS whilst in orbit? Perhaps NASA calculated a large portion of the mass will burn up, leaving a non-hazardous piece to drop to the ground? I’ll be interested if more news about the EAS surfaces over the coming weeks.
Coming to a back yard near you…