Rosetta to sleep through loneliest leg of comet mission

Jun 06, 2011
Rosetta to sleep through loneliest leg of comet mission
Artist's impression of the Rosetta orbiter and lander. Credits: ESA

On 8 June, mission controllers will have the first opportunity to switch ESA's Rosetta comet-hunter into deep-space hibernation for 31 months. During this loneliest leg of its decade-long mission, Rosetta will loop ever closer toward comet 67-P, soaring to almost 1000 million km from Earth.

Marking one of the most dramatic and distant stages of the probe's 10-year journey to rendezvous with Comet 67-P/Churyumov-Gerasimenko, ground controllers at ESOC, ESA's European Space Operations Centre, plan to issue the final command next week to switch into hibernation mode.

This will trigger the last steps in the shut-down of the spacecraft, turning off almost all flight control systems including telecommunications and attitude control. Rosetta's were already individually powered down during the first four months of this year.  
 
"Rosetta is getting farther from the Sun, and soon there simply isn't going to be enough sunlight to power its systems," says Paolo Ferri, Head of ESOC's Solar and Planetary Mission Operations Division.

"We already achieved a record in July 2010 when we reached 400 million km from the Sun and became the most distant spacecraft ever to operate on solar power alone. Rosetta will double the record distance during the hibernation period."
 
Virtual shutdown of the entire spacecraft
 

The illuminated crescent of Earth showing part of South America and Antarctica. This OSIRIS image was acquired with the the narrow-angle camera from a distance of 350 000 km at 22:28 UTC last night. The resolution is 6.5 km/pixel. Credits: ESA 2009 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

The only devices left running will be the onboard computer and several heaters. These will be powered by the solar wings, and will be automatically switched on periodically to ensure that the entire satellite doesn't freeze up as its orbit takes it from 660 million km from the Sun out to 790 million km and back between now and January 2014.

Prior to entering hibernation, will be oriented so that its solar wings face the Sun and be placed into a slow spin, which will stabilise the satellite.

The window for issuing the hibernation command opens on 8 June, once the spacecraft status is confirmed. After the command is sent, there will be no signal sent to or from ground until 2014. A single computer timer will tick down the 136-week hibernation period.

Deep-space wake up call
 
At precisely 10:00 GMT on 20 January 2014, the timer will wake the spacecraft, which, seven hours later, will transmit a check signal to let mission controllers know that the spacecraft has woken.

"We've planned for for some time, and it's a complex phase of the mission," says Andrea Accomazzo, Spacecraft Operations Manager at ESOC.
 
"Still, for the flight control team, it's an emotional moment. We're essentially turning the spacecraft off. We're already looking forward to January 2014 when it wakes up and we get our back."

Explore further: Orion spacecraft transfers to Launch Abort System Facility

Related Stories

Rosetta's final Earth boost

Nov 04, 2009

ESA's comet chaser Rosetta will swing by Earth for the last time on 13 November to pick up energy and begin the final leg of its 10-year journey to comet 67P/Churyumov-Gerasimenko. ESA's European Space Operations ...

Boosting the accuracy of Rosetta's Earth approach

Oct 19, 2007

Yesterday, 18 October at 18:06 CEST, the thrusters of ESA’s comet chaser, Rosetta, were fired in a planned, 42-second trajectory correction manoeuvre designed to 'fine tune' the spacecraft's approach to ...

Rosetta correctly lined up for critical Mars swingby

Feb 15, 2007

ESA mission controllers have confirmed Rosetta is on track for a critical 250-km Mars swingby on 25 February. Engineers have started final preparations for the delicate operation, which includes an eclipse, ...

Rosetta closes in on Earth -- a second time

Nov 08, 2007

ESA’s comet chaser, Rosetta, is on its way to its second close encounter with Earth on 13 November. The spacecraft’s operators are leaving no stones unturned to make sure Earth’s gravity gives it the ...

Recommended for you

Student to live in simulated space habitat

2 hours ago

A Purdue University industrial engineering doctoral student is among six "crew members" spending the next eight months in a domed habitat on a volcanic landscape mimicking life on a Martian outpost.

The wake-up call that sent hearts racing

5 hours ago

"But as the minutes ticked by, the relaxed attitude of many of us began to dissolve into apprehension. Our levels of adrenaline and worry began to rise."

US-India to collaborate on Mars exploration

15 hours ago

The United States and India, fresh from sending their own respective spacecraft into Mars' orbit earlier this month, on Tuesday agreed to cooperate on future exploration of the Red Planet.

Swift mission observes mega flares from a mini star

15 hours ago

On April 23, NASA's Swift satellite detected the strongest, hottest, and longest-lasting sequence of stellar flares ever seen from a nearby red dwarf star. The initial blast from this record-setting series ...

Sandblasting winds shift Mars' landscape

20 hours ago

High winds are a near-daily force on the surface of Mars, carving out a landscape of shifting dunes and posing a challenge to exploration, scientists said Tuesday.

PanSTARRS K1, the comet that keeps going

22 hours ago

Thank you K1 PanSTARRS for hanging in there! Some comets crumble and fade away. Others linger a few months and move on. But after looping across the night sky for more than a year, this one is nowhere near ...

User comments : 0