After 10 years and 7 billion kilometres, the first spacecraft to try to land on a comet is close to its target – provided the scientists can wake up the probe. If they succeed, the mission could provide vital clues soon to the origins of our own solar system, as
It has been slumbering for almost three years. But later today a signal from Earth will awaken the spacecraft
The target is a four kilometre-wide comet heading towards the Sun. After its midday alarm call,
The task has been compared with the film Armageddon, which featured
The path of comet Churyumov-Gerasimenko – named after the Russian scientist who discovered it in 1969 – is considerably less dramatic, with nothing worse than a close encounter with Jupiter.
But the prospect of a successful landing on a comet is generating just as much excitement as the plot of a science fiction film, at least among the world's scientific community.
Launched by the
Hence the decision to hunt down comet Churyumov-Gerasimenko, also known as comet 67P. Like all such bodies, it is a collection of dirt and ice that is thought to be a remnant of the birth of the solar system.
Since its launch,
That begins today, by what the ESA calls "the most important alarm clock in the solar system", a computer on the spaceship.
At the mission control in Darmstadt,
Before that, the spaceship will switch on its "star trackers", taking it out of its hibernation spin, checking its position and beginning the process of warming up other systems.
After firing thrusters the craft will have its solar arrays directly aligned with the Sun. It will next turn its antenna towards Earth to send a signal home. In all, it will take about six hours before scientists know all is well.
Because the distance is so enormous, the message will take nearly 45 minutes to reach Earth, with ESA relying on
In the next stage of the €1.3 billion (Dh7.8bn) mission,
This will include putting into place procedures to correct two small glitches that have occurred during the 10-year mission. One involves two of four "reaction wheels" that turn the ship, with the other a leak of helium for the thrusters.
All being well,
At present, scientists are divided over whether to pick one of three "live" sides, where material is being released into space, or another location less likely to damage the lander's instruments.
Finally, in November,
Once on the surface, Philae will start conducting a series of nine experiments, including a drill to extract material from the comet's interior.
While this stage of the mission is scheduled to last a week, there are hopes it will last much longer, with the rest of the mission scheduled to end in December next year.
For comet 67P, though, time is also running out. It is thought to have originated in the Kulper Belt, a reservoir of icy objects beyond Neptune. Collisions eventually eject some of these towards the Sun.
Comet 67P's trajectory will have taken it towards Jupiter, altering its orbit. Such bodies are known as short-period comets, as the heat of the Sun causes them to melt.
After so many billions of years, 67P will be lucky to survive another 20.
Most Popular Stories
- Major Phone Makers Sign Anti-Phone-Theft Pledge
- College Board Offers a Sneak Peak at New SAT
- 'Beige Book' Federal Reserve Survey, April 2014: Full Text
- Salsa Legend Cheo Feliciano Killed in Car Crash
- Miss. Gov. Signs Bills to Curb Unions
- Google Q1 Earnings Dip as Ad Prices Slip
- Hiring and Weekly Jobless Claims Both Edge Up
- PepsiCo Q1 Profits Rise on Snack Sales, Cost Cuts
- Snowden Questions Putin on TV Call-in Show
- Poor Barbie Sales Drag on Mattel