The Rosetta mission crew celebrate Philae successfully landing on comet 67P, at the European Operations Space Centre in Darmstadt, Germany
on 12 November 2014. Credit: ESA/J.Mai
By Amy Thompson
The European Space Agency
(ESA) led Rosetta mission, made history this past year, and, captured the
attention of people around the world
as it became the first to orbit and
land on a comet. The spacecraft
achieved its goal after deploying a
washing machine-sized lander onto
the surface of Comet 67P/Churyumov-Gerasimenko on Nov. 12. The
plucky little lander defied odds and
survived several bounces across the
comet’s surface to deliver its science
data before ulti mately entering into
an indeterminate hibernation period.
Rosetta embarked on a ten-year
journey across the solar system
to rendezvous with Comet 67P/
Churyumov-Gerasimenko, in hopes
of unlocking the secrets of the early
solar system. After launching from
French Guiana’s Kourou spaceport atop an Ariane 5 rocket on
March 2, 2004, Rosetta reached
its first major milestone a decade
later, by being the first spacecraft
to rendezvous with a comet.
The spacecraft is composed of
an orbiter –Rosetta—and a lander,
Philae. The pair was named for the
famed Rosetta stone and obelisk
that ultimately enabled us to decipher ancient Egyptian hieroglyphs.
Comets are essentially cosmic
time capsules, carrying with them
primordial components from the
beginning of the solar system. Just
as the Rosetta stone and Philae
obelisk helped unlock the secrets
of an ancient language, the Rosetta spacecraft and Philae lander
aim to help us understand how our
planet and solar system formed.
Rosetta’s journey to the comet
was not easy; in fact comet 67P
was not the original target. The mission was originally set to launch in
Jan. 2003 with an intended target
of comet 46P/Wirtanen in 2011. This
plan had to be revised following a
failure in the Ariane 5 rocket during a mission in 2002. After the issue
with the rocket had been resolved,
a new target, comet 67P/Churyumov-Gerasimenko, was selected.
A new launch date of Feb. 26 was
selected with a comet rendezvous
to occur in 2014. Finally, after two
launch scrubs, Rosetta blasted off
into space on March 2, 2004.
To achieve the velocity required to
rendezvous with 67P, Rosetta would
require more than just the boost an
Ariane 5 could provide. In order to
give her the boost she needed, Rosetta would complete three flybys of
Earth and one of Mars. In between
planetary flybys, Rosetta also took
advantage of the opportunity to
flyby and photograph two different asteroids -- 2867 Šteins and 21
Lutetia. Following the final flyby or
gravity assist from Earth, Rosetta now
had the momentum needed to propel itself out to meet comet 67P.
In order to save precious systems
on board, the Rosetta spacecraft
was placed in a 31-month hibernation period. On Jan. 20, 2014, following a very successful social media
campaign, people around the world
waited on the edge of their seats to
“wake-up Rosetta”. At this point in
its journey, the craft was far enough
from Earth that it took almost 30
minutes for the signal to travel each
way. Scientists had a window of time
where they hoped to see a spike on
their computer monitors; this would
signal that Rosetta had successfully
come out of hibernation. After an
agonizing wait, scientists in the operations center at ESA jumped for
joy when they saw it. Like a spike on
a heart monitor, the on-screen blip
announced Rosetta had awoken
and was ready to begin her work.
Over the next eight months, as
Rosetta closed the gap between
herself and the comet, scientists
began to see the first images of the
comet. As the images and data
came in, we learned more and
more about this enigmatic body.
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