Comet Probe Rosetta Rises And Shines Right On Time

Artist’s impression of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko (not to scale). After extensive mapping by the orbiter in August–September 2014, a landing site will be selected for Philae to conduct in situ measurements in November 2014. Credit: ESA–C. Carreau/ATG medialab

Like some space age Rip Van Winkel, the Rosetta probe finally woke up early today after 2 1/2 years of sleepy hibernation. Launched in March 2004 by the European Space Agency (ESA), the comet chasing space probe has made numerous orbits around the sun, picking up speed through gravitational boosts from close flybys of Earth and Mars. It’s now 500 million miles from Earth – almost to Jupiter’s orbit – and headed for the 2.4 mile diameter comet 67P/Churyumov-Gerasimenko.

Due to reach the comet in May, the Rosetta mission is unlike any previous comet encounter. Instead of a quick flyby, the probe will place itself in orbit around 67P and study it up close for more than a year.

Most exciting, Rosetta carries a 220-lb. lander named Philae (FYE-lee) to the comet’s surface to photograph its surroundings and analyse samples drilled from its crust. Scientists are hoping to find organic compounds there that may have acted as seeds to spur the origin of life of Earth. It’s widely believed that icy comets, laden with water and organics, regularly pummeled the planet during its youth.

Artist’s impression of Rosetta orbiting the icy nucleus of Comet Churyumov-Gerasimenko. Expect the probe to arrive in less than 4 months. Credit: ESA

European Space Agency scientists woke up Rosetta this morning around 4 a.m. CST. Like my daughters when they were teenagers, it will take some time for Rosetta to “get out of bed”. Over the next seven hours engineers will warm up its star tracking cameras – crucial to helping the craft to point itself in the right direction using familiar constellations – ignite the rocket thrusters to slow its spin, turn on its radio transmitter, point it toward Earth and finally beam a message back to Earth with the good news that everything’s A-OK.

Rosetta is so far away that it will take the message, traveling at the speed of light, 45 minutes to arrive at Earth. In May the probe will enter into orbit around the comet and gradually slow down and move in closer to map its surface. Come November it will release the lander which will descend to 67P’s surface and fire two harpoons to anchor itself in the comet’s low gravity. The last thing scientists want is to see their precious machine bounce off Churyumov-Gerasimenko and fly off into space.

Here’s the mission timeline:

* May 22 – comet rendezvous
* August – start of global mapping
* November 11 – Philae lands on the comet
* Aug. 13, 2015 – Rosetta and comet reach perihelion (closest to the sun at 116 million miles).
* End of mission: Dec. 2015

Video showing how Philae will land on the comet. Very exciting!

While Rosetta has made two important flyby studies of asteroids prior to sleep-mode, its prime goal is to determine the origin of comets. Rosetta is packed with instruments that will create a portrait of the 67P’s icy nucleus, determine what it’s made of and watch the coma (comet atmosphere) and jets of dust and ice evolve as the comet approaches and then recedes from the sun. Rosetta’s name comes from the famous Rosetta stone, the key to translating Egyptian hieroglyphics. Scientists hope the spacecraft will perform a similar role in helping us understand comets.

Mission control, with the signal spike from Rosetta on the display screen early this afternoon CST. Credit: @DavidRowlandson

This just in: “The signal is here. It is unmistakable. Rosetta is awake,” writes ESA’s live blogger Stuart Clark.

“Now it is up to us to drive it to the comet,” said Andrea Accomazzo, Spacecraft Operations Manager. Congratulations Rosetta crew, now the fun begins!

3 Responses

  1. Troy

    Maybe because it is ESA I didn’t hear much about this mission, enough so that I was confusing it with Ulysses (mission to the poles of the sun). I’d be interesting to see close up of the comet surface and dynamic changes like outbursts. I don’t think we even know if (or how) human visitors could visit a comet.
    I haven’t really heard why the probe was put into sleep. I’m guessing they don’t want to tax the deep space network as there is a lot of probes out there. Since it is solar powered I don’t see much use of actual shut down of everything except some sort of timer.

    1. astrobob

      Hi Troy,
      It was put to sleep to conserve power. Even though the solar panels are huge, they don’t produce enough power at such great distances (~5 AUs) to maintain the probe’s power needs. It now moves back toward the sun as it chases the comet. Encounter occurs when the comet is ~4 AUs from the sun.

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