WASHINGTON - The European Space Agency (ESA), NASA and countless people who follow space missions are holding their breath for the biggest wake-up call in the solar system.
Monday morning at 5 a.m. EST, ESA's Rosetta spacecraft is scheduled to wake up after 957 days of hibernation.
The spacecraft will turn on heaters for its star trackers, fire thrusters, get aligned with the sun and call home.
Being 500 million miles away, this most anticipated signal to NASA's Deep Space Network (DSN) is expected between 12:30 and 1:30 p.m. EST. There will be a lot of people, including me, waiting for Rosetta's call home.
Because Rosetta is solar-powered, the spacecraft had to shut down everything but its computer and a couple of heaters, in order to conserve power. The spacecraft can now wake up because the solar panels are receiving enough energy from the sun to power up all systems.
Rosetta was launched in March 2004 and made three flybys of Earth and one of Mars to pick up enough speed to intercept periodic Comet 67P/Churyumov-Gerasimenko later this year.
Rosetta is designed to rendezvous and enter orbit around the comet for a survey in August. Once a suitable landing site is found, the Philae lander will detach and land on the surface of the comet, currently scheduled for November 2014.
Unlike last year's comet, ISON -- which originated from the Oort Cloud (the vast repository of a trillion-plus comets located a light year from the sun) and made its first-ever journey to the sun, only to be destroyed -- Comet 67P/Churyumov- Gerasimenko is a periodic comet. That means it orbits the sun regularly every six and a half years.
The comet has been observed seven times, dating back to 1969 when it was discovered.
Rosetta will give us our best view and data ever of a comet. Comets contain the original material of our solar system: the elements, molecules, gas, dust and ices that weren't used in making the planets or dwarf planets.
What sets Rosetta apart from previous cometary missions of the past is that for the first time, we will orbit a comet and land on it, instead of a one-and-done fly-by mission.
What is really thrilling is that we will have an up-close and personal view of Comet 67P/Churyumov-Gerasimenko, transforming from an inert icy dirt ball into a full-fledged active comet, spewing off gas and dust due to the intense heat of the sun.
With Rosetta and Philae, we will see how the comet changes as it approaches the sun, begins to heat up, passes closest to the sun, and then begins to shutdown as it zooms away.
An array of instruments are on the orbiter and lander, including three from NASA. These instruments will gather a treasure trove of never before acquired data and pictures during these critical stages in the life cycle of a comet's journey around the sun.
Philae will also drill into the nucleus -- the solid core of Comet 67P/Churyumov- Gerasimenko -- for a first-ever drill sampling of a cometary nucleus.
There are over a trillion comets and millions of asteroids in the solar system. The more we learn about them, the more we learn about our origins.
It is possible that comets and asteroids seeded the primitive Earth with the necessary precursors for life. We know that comets and asteroids have impacted the Earth in the past and will do so again in the future.
Therefore, anything and everything we can learn about them is beneficial, not only for science, but survival, as well.
Rosetta, if successful, will provide us with data and pictures that will go a long way in filling in the gaps of our knowledge about comets and our solar system's origins.
But it all hinges on Rosetta phoning home.
I'll let you know what happens because I will be listening in. You can follow Rosetta, too, on Twitter.
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