Contributed by Brendt C. Hyde and Ian Nicklin.
The Russian space probe Phobos-Grunt was all set to journey to a moon of Mars called Phobos. It was going to collect samples from the moon and return them to Earth. Unfortunately, the mission ended before it could even begin. The probe was launched in November 2011 and safely made it off of the ground, however, the probe failed to transfer to its interplanetary trajectory. Instead it stalled near the Earth and has slowly been falling back to the Earth ever since. It is estimated that the probe will fall through the Earth’s atmosphere in mid-January.
The probe is carrying tons of a toxic rocket fuel, which will likely burn up in the atmosphere. However, some of the solid material will likely make it to the Earth’s surface. Because of its orbit, the probe will come down within about 50° of the equator (north or south) and latest predictions suggest that it will crash into the Indian Ocean.
Initial uncertainty in the crash location caused a lot of people to worry (and a lot of scary articles to be written) about the possibility of people being hurt by falling debris. Hopefully this blog will make things a little less scary. Many articles written on this topic fail to mention that the Earth is about 70% covered by ocean and that there are vast uninhabited areas such as deserts. The percentage of the Earth populated by major cities is actually quite small when you look at the big picture. It is not impossible that pieces of Phobos-Grunt will fall in your backyard, but the odds are insanely low, so relax.
So, now the question becomes “why did Phobos-Grunt fail”. The answer to this is likely quite simple – underfunding. Mars is very hard to get to and Russia has had a lot of bad luck trying to accomplish the task. About 50% of all Mars missions fail to meet their goals. The Phobos-Grunt mission had a cost of about 163 million dollars (USD) and NASA has also had failures with missions of similar cost. This may seem like a large price tag, but let’s try to put things in to perspective. The current NASA lead mars mission, the Mars Science Lab, had a cost of about 2.5 billion dollars (USD).
Simply put, going to Mars isn’t cheap. This is one reason why many of the future missions to Mars are going to be international efforts. This spreads the cost around and takes advantage of the expertise available around the globe. Hopefully, this technique leads to more successful Mars missions and less ‘space junk’ plummeting to Earth!