UPDATED: 12:04 p.m. ET
In one of the biggest space successes in years, a spacecraft named Rosetta landed a refrigerator-sized robot onto a comet.
Operated by the European Space Agency, the mission had a 70% chance of success. If Rosetta was just millimeters off on the drop, it could have resulted in total failure.
This landing is the main reason Rosetta made the 10-year journey to comet 67P/Churyumov-Gerasimenko, which is currently orbiting between Mars and Jupiter.
Rosetta deployed Philae early on Wednesday from about 14 miles away from the center of the comet. Philae is now on its own. The descent took about seven hours. The Rosetta team received the signal from Philae around 11 a.m. ET.
How it all went down
If you're just tuning in, however, here are the highlights:
2:57 a.m ET:
Rosetta and Philae were cleared for separation despite some issues with the active descent system. Its cold gas thruster, which was designed to push the spacecraft onto the comet as harpoons and ice screws lock it to the surface, wasn't working.
Final Go/NOGO complete! I We're GO for separation!!! — ESA Rosetta Mission (@ESA_Rosetta) November 12, 2014
4:07 a.m. ET:
Separation was confirmed. It takes the radio signals on Rosetta 28 minutes and 20 seconds to reach Earth, which means separation actually occurred at 3:35 a.m. ET.
SEPARATION CONFIRMED! Safe journey @Philae2014! — ESA Rosetta Mission (@ESA_Rosetta) November 12, 2014
6:09 a.m. ET:
Contact was made with Philae around 6 a.m. ET. ESA confirmed that: "Mission control have regained contact as expected after separation."
Finally! I’m stretching my legs after more than 10 years. Landing gear deployed! #CometLanding — Philae Lander (@Philae2014) November 12, 2014
9:20 a.m. ET
Philae sent back its first photo from its landing attempt. The image shows Rosetta's solar panels.
Hey @ESA_Rosetta, did you get my first postcard? CIVA took the image. Guess who’s in it? #CometLanding— Philae Lander (@Philae2014) November 12, 2014
.@philae2014’s first postcard just after separation – it’s of me! #CometLanding Credit: ESA/Rosetta/Philae/CIVA pic.twitter.com/OXJwGunL3V— ESA Rosetta Mission (@ESA_Rosetta) November 12, 2014
Nice one! I’ve never seen you from this angle before, @ESA_Rosetta! #CometLanding— Philae Lander (@Philae2014) November 12, 2014
10:11 a.m. ET
About one hour until landing, Rosetta snapped this photo of Philae as it headed toward the comet.
It’s me… landing on a comet & feeling good! MT @ESA_Rosetta: I see you too! #CometLanding pic.twitter.com/DjU0J1Ey4H— Philae Lander (@Philae2014) November 12, 2014
11:04 a.m. ET
The ESA Rosetta team received a signal from Philae. The landing was a success.
RECEIPT OF SIGNAL FROM SURFACE European Space Agency receiving signals from @Philae2014 on surface of comet #67P/CG #cometlanding— ESA Operations (@esaoperations) November 12, 2014
The team behind @Philae2014 tweeted the landing in several languages.
#COMETLANDING A SUCCESS. We've just made space history http://t.co/d4ljbx7UqF pic.twitter.com/MaVdlRoqab— Mashable (@mashable) November 12, 2014
Minutes later, the team confirmed that Philae successfully deployed its harpoons, attaching itself to the comet. (
MT @esaoperations: Harpoons confirmed fired & reeled in. Flywheeel now be switched off. @Philae2014 is on the surface of #67P #CometLanding— ESA Rosetta Mission (@ESA_Rosetta) November 12, 2014
11:55 a.m. ET
Initially, the Rosetta team thought the harpoon deployment was a success. However, on further analysis they learned that it didn't work the first time, so they tried once again.
More analysis of @Philae2014 telemetry indicates harpoons did not fire as 1st thought. Lander in gr8 shape. Team looking at refire options— ESA Operations (@esaoperations) November 12, 2014
I’m on the surface but my harpoons did not fire. My team is hard at work now trying to determine why. #CometLanding— Philae Lander (@Philae2014) November 12, 2014