A huge piece of space debris, weighing 1400 lb (635 kg) and the size of two refrigerators, is gradually falling to Earth, giving observers on the ground a great opportunity to see it. The junk was jettisoned from the International Space Station (ISS) in 2007 and it is expected to re-enter the atmosphere later this year or early 2009. The Early Ammonia Servicer (EAS) was dropped from the ISS after a seven hour spacewalk and pushed in the opposite direction of the space station’s orbit shortly before a re-boost by a Soyuz resupply vehicle. This ensured the EAS would pose no danger to the ISS or crew on future orbits. Now the container is beginning its final few months in space and the bets are on as to where it will crash to Earth…
When the EAS, filled with ammonia coolant, had served its purpose the ISS crew had little choice but to throw it overboard. Astronaut Clay Anderson led the July 23rd 2007 operation with the assistance of cosmonauts Fyodor Yurchikhin and robotic arm operator Oleg Kotov as they shoved the EAS Earth-ward along with a 212 lb (96 kg) stanchion used to attach a camera to the station. The whole EVA lasted 7 hours and 41 minutes and the EAS was noted as the largest single piece of junk dropped from the ISS. At the time, mission control estimated that the EAS would orbit the Earth for 300 days; obviously this was a huge underestimate as it continues to spiral closer to the atmosphere one year after the mission.
The EAS is a huge piece of debris and easily tracked from the ground and poses no threat to missions, but it may be a hazard if, as expected, a large portion of the equipment survives re-entry. Dangers aside for now, the EAS is providing amateur astronomers with a new target to point their telescopes at. When the EAS was jettisoned, it was barely visible to the naked eye as it sped overhead with a magnitude of +4 to +4.5. Two days ago on July 20th, veteran satellite observer Marco Langbroek of Leiden, the Netherlands reported observing the EAS at an observable magnitude of +2.0. But it is moving very fast due to its decreased altitude.
Currently, the EAS can be seen over Europe, and next week North America will be able to spot it. For information on where and when to look for a chance to observe this huge lump of waste from the ISS, check out SpaceWeather.com’s Simple Satellite Tracker before it starts to flirt with our upper atmosphere in the next few months.