News that an unmanned failed Russian space probe — the Phobos-Grunt, or Phobos-Ground in English — was about to smack into Earth shot like wildfire through the airwaves last week as the truth emerged that the Russians had little idea of where it was going to land. Now that it has most definitely crashed somewhere on the planet, they are saying they have no idea where it actually did land or whether the toxic heap of metal sufficiently burned up in the atmosphere. Though the trajectory of spacecraft falling to Earth has always been a difficult thing to predict, the missing Phobos-Grunt is especially worrisome as it is the largest and most toxic piece of space junk to ever plummet to land.
The Phobos-Grunt was built to complete a mission to the strangely shaped Phobos (shown above), the largest of Mars’ moons, take soil samples and return to Earth in 2014. The $170 million spacecraft was holding 12 tons of highly toxic rocket fuel that was to be the propellant for the very long mission. When the craft took off on November 9th something went awry, and the Phobos-Grunt became stuck in Earth’s atmosphere and repeated tries to bring it back to life failed. The wait then started to see when it would succumb to gravity and tumble back into Earth’s atmosphere. Though the Russian space agency, Roscosmos, said that all of the fuel and most of the pieces of Phobos-Grunt should have burned up in the atmosphere, they have no idea if that is actually the case.
An estimated 17,000 pieces of space junk measuring 10 centimeters or more are currently stuck in the orbit around Earth and pose a huge danger to satellites attempting to navigate around the planet. When one falls to Earth, as the Phobos-Grunt did, those on the ground attempt to plot its course but variables like atmospheric winds and unexpected solar winds can seriously impede the ability to plot a probable course. In cases like this one, space officials are not able to retrieve the huge hunk of metal (like the 14.9 ton Phobos-Grunt) to ensure that it doesn’t pollute the environment. This whole situation makes us wonder why we’re still using toxic rocket fuel at all when research into lightweight, efficient propellants like solar sails could provide a safer more efficient alternative.