We landed twice: Philae comet probe may have bounced after harpoon failure

By Dave Gilbert, CNN
Updated 4:22 PM EST, Wed November 12, 2014
02:58 - Source: CNN
Comet landing an 'engineering miracle'

Story highlights

NEW: Mission controllers say probe's anchoring harpoons failed and craft may have bounced

NASA scientist calls the comet the most "bizarre, wonderful thing I have ever seen"

The probe tweets: "Touchdown! My new address: 67P!"

Philae is equipped with nine experiments, including drill to sample surface and test in an on-board oven

(CNN) —  

The comet probe Philae may have bounced when it landed, the European Space Agency said Wednesday.

It is the first time a soft landing has been achieved on a comet – but there was a hitch.

Comet 67P has a very weak gravity, so anchoring harpoons were designed to shoot into the comet to fix the spacecraft to the surface. They failed to fire and Philae is not firmly secure, ESA says.

Philae lander manager Stephan Ulamec said the probe may have lifted off again and turned.

“So maybe we didn’t land once – we landed twice,” he told a news conference.

“Did we land in a soft sandbox or is there something else happening? We don’t fully understand what happened,” he said.

Ulamec said scientists remain upbeat as they are still receiving data from the spacecraft and they hope to learn more Thursday.

Shortly after landing was confirmed, the probe tweeted: “Touchdown! My new address: 67P!” Later, it tweeted again: “I’m on the surface but my harpoons did not fire.”

What can we learn from comet landing?

Led by ESA with a consortium of partners including NASA, scientists on the Rosetta comet-chasing mission hope to learn more about the composition of comets and how they interact with the solar wind – high energy particles blasted into space by the sun.

Speaking to CNN shortly after the landing, ESA lander system engineer Laurence O’Rourke said they were trying to check the orientation of the craft, to see “how we landed and where we landed.”

“We are extremely happy,” he said. “To get the signal it had touched the surface was a major achievement – it was quite extraordinary. Philae is already taking measurements, sniffing the comet.”

He also said the probe could start drilling into the surface and analyzing the material as soon as Thursday.

The comet is currently 500 million kilometers (310 million miles) from Earth and pictures from the Rosetta mission to track it on its orbit around the sun have amazed scientists.

We can land on a comet, but we can’t …

NASA’s chief scientist, Ellen Stofan, told CNN: “That comet is the most bizarre, wonderful thing I have ever seen. Those images have just blown me away. Philae was such a huge success before it even did anything, so kudos to ESA and the scientific community.

“No one has ever gotten data like Rosetta has gotten. No one has ever been able to land on a comet the way Philae just did.”

The Rosetta probe sent an unexpected final image back to Earth shortly before it made a controlled impact onto the surface of Comet 67P last September.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team
The Rosetta probe sent an unexpected final image back to Earth shortly before it made a controlled impact onto the surface of Comet 67P last September.
The Rosetta spacecraft's high-resolution camera took this image of the Philae lander on September 2, 2016. The lander is wedged into a dark crack on a comet, named 67P/Churyumov--Gerasimenko, hurtling through space. The discovery comes less than a month before the Rosetta mission's end.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team
Philae has been found! —
The Rosetta spacecraft's high-resolution camera took this image of the Philae lander on September 2, 2016. The lander is wedged into a dark crack on a comet, named 67P/Churyumov--Gerasimenko, hurtling through space. The discovery comes less than a month before the Rosetta mission's end.
"We are so happy to have finally imaged Philae, and to see it in such amazing detail," says Cecilia Tubiana of the OSIRIS camera team. She was the first person to see the images when they were downlinked from the Rosetta probe, according to the European Space Agency.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team
Philae is wedged in a dark corner of Rosetta —
"We are so happy to have finally imaged Philae, and to see it in such amazing detail," says Cecilia Tubiana of the OSIRIS camera team. She was the first person to see the images when they were downlinked from the Rosetta probe, according to the European Space Agency.
The image is detailed enough that viewers can pick out features of Philae's 3-foot-wide (1 meter) body. Even two of its three legs can be seen.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team
Philae found using images from Rosetta —
The image is detailed enough that viewers can pick out features of Philae's 3-foot-wide (1 meter) body. Even two of its three legs can be seen.
One of the primary objectives of the Rosetta mission was to drop the Philae lander onto the comet. The probe was successfully deployed in November 2014, becoming the first probe to land on a comet. But Philae failed to grab onto the comet and bounced around. It fell silent a few days later. Then on June 13, 2015, Philae came out of hibernation and "spoke" to mission managers at the European Space Agency for 85 seconds. This photo above was taken by the lander's mothership, the Rosetta orbiter, after the lander started its descent to the comet.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team
One of the primary objectives of the Rosetta mission was to drop the Philae lander onto the comet. The probe was successfully deployed in November 2014, becoming the first probe to land on a comet. But Philae failed to grab onto the comet and bounced around. It fell silent a few days later. Then on June 13, 2015, Philae came out of hibernation and "spoke" to mission managers at the European Space Agency for 85 seconds. This photo above was taken by the lander's mothership, the Rosetta orbiter, after the lander started its descent to the comet.
The Rosetta spacecraft captured this image of a jet of white debris spraying from Comet 67P/Churyumov--Gerasimenko on July 29, 2015. Mission scientists said this was the brightest jet seen to date in the mission. The debris is mostly of ice coated with dark organic material.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The Rosetta spacecraft captured this image of a jet of white debris spraying from Comet 67P/Churyumov--Gerasimenko on July 29, 2015. Mission scientists said this was the brightest jet seen to date in the mission. The debris is mostly of ice coated with dark organic material.
This image of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta on July 8, 2015 as the spacecraft and comet headed toward their closest approach to the sun. Rosetta was about 125 miles (201 kilometers) from the comet when it took this image.
Photos: Rosetta: The comet chaser
PHOTO: Rosetta/Navcam/ESA
This image of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta on July 8, 2015 as the spacecraft and comet headed toward their closest approach to the sun. Rosetta was about 125 miles (201 kilometers) from the comet when it took this image.
Philae wakes up! Mission managers posted this cartoon of the lander yawning after it came out of hibernation on June 13, 2015. They also sent a series of tweets between the lander and its mothership, Rosetta.
Photos: Rosetta: The comet chaser
PHOTO: ESA
Philae wakes up! Mission managers posted this cartoon of the lander yawning after it came out of hibernation on June 13, 2015. They also sent a series of tweets between the lander and its mothership, Rosetta.
Comet 67P/Churyumov-Gerasimenko is a Jupiter-family comet. Its 6.5 year journey around the Sun takes it from just beyond the orbit of Jupiter at its most distant, to between the orbits of Earth and Mars at its closest. The comet hails from the Kuiper Belt, but gravitational perturbations knocked it towards the Sun where interactions with Jupiter's gravity set it on its present-day orbit.
Photos: Rosetta: The comet chaser
PHOTO: Courtesy ESA
Comet 67P/Churyumov-Gerasimenko is a Jupiter-family comet. Its 6.5 year journey around the Sun takes it from just beyond the orbit of Jupiter at its most distant, to between the orbits of Earth and Mars at its closest. The comet hails from the Kuiper Belt, but gravitational perturbations knocked it towards the Sun where interactions with Jupiter's gravity set it on its present-day orbit.
This image of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta on June 5, 2015, while the spacecraft was about 129 miles (208 kilometers) from the comet's center.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/NavCam
This image of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta on June 5, 2015, while the spacecraft was about 129 miles (208 kilometers) from the comet's center.
Rosetta's navigation camera took this image of the comet on June 1, 2015.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/NavCam
Rosetta's navigation camera took this image of the comet on June 1, 2015.
The Rosetta Mission is tracking Comet 67P/Churyumov-Gerasimenko on its orbit around the sun. This image was taken on May 3, 2015 at a distance of about 84 miles (135 km) from the comet's center.
Photos: Rosetta: The comet chaser
PHOTO: Courtesy ESA/Rosetta/NavCam -- CC BY-SA IGO 3.0
The Rosetta Mission is tracking Comet 67P/Churyumov-Gerasimenko on its orbit around the sun. This image was taken on May 3, 2015 at a distance of about 84 miles (135 km) from the comet's center.
This image of Comet 67P/Churyumov-Gerasimenko was taken on April 15, 2015.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/NavCam -- CC BY-SA IGO 3.0
This image of Comet 67P/Churyumov-Gerasimenko was taken on April 15, 2015.
Rosetta snapped this wide-angle view of Comet 67P/Churyumov-Gerasimenko in September 2014. Rosetta was about 107 million miles (172 million kilometers) from Earth and about 92 million miles (148 million kilometers) from the sun when the photo was released.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta
Rosetta snapped this wide-angle view of Comet 67P/Churyumov-Gerasimenko in September 2014. Rosetta was about 107 million miles (172 million kilometers) from Earth and about 92 million miles (148 million kilometers) from the sun when the photo was released.
A camera on Rosetta took this picture of Comet 67P/Churyumov-Gerasimenko on November 22, 2014, from a distance of about 19 miles (31 kilometers). The nucleus is deliberately overexposed to reveal jets of material spewing from the comet. The 2.5-mile-wide (4-kilometer) comet has shown a big increase in the amount of water its releasing, according to NASA. The space agency says about 40 ounces (1.2 liters) of water was being sprayed into space every second at the end of August 2014.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta
A camera on Rosetta took this picture of Comet 67P/Churyumov-Gerasimenko on November 22, 2014, from a distance of about 19 miles (31 kilometers). The nucleus is deliberately overexposed to reveal jets of material spewing from the comet. The 2.5-mile-wide (4-kilometer) comet has shown a big increase in the amount of water its releasing, according to NASA. The space agency says about 40 ounces (1.2 liters) of water was being sprayed into space every second at the end of August 2014.
Rosetta took this picture of a section of the comet's two lobes from a distance of about 5 miles (8 kilometers) on October 14, 2014.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta
Rosetta took this picture of a section of the comet's two lobes from a distance of about 5 miles (8 kilometers) on October 14, 2014.
The Rosetta spacecraft's Philae lander is shown sitting on Comet 67P/Churyumov-Gerasimenko after becoming the first space probe to land on a comet on November 12, 2014. The probe's harpoons failed to fire, and Philae bounced a few times. The lander was able to send back images and data for 57 hours before losing power.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta
The Rosetta spacecraft's Philae lander is shown sitting on Comet 67P/Churyumov-Gerasimenko after becoming the first space probe to land on a comet on November 12, 2014. The probe's harpoons failed to fire, and Philae bounced a few times. The lander was able to send back images and data for 57 hours before losing power.
Rosetta's lander, Philae, wasn't able to get a good grip on the comet after it touched down. This mosaic shows Philae's movements as it bounced across the comet.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta
Rosetta's lander, Philae, wasn't able to get a good grip on the comet after it touched down. This mosaic shows Philae's movements as it bounced across the comet.
Philae snapped these images after landing, and mission scientists used them to create a panoramic view of the landing site. A graphic shows where the probe would be sitting in the photograph.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta
Philae snapped these images after landing, and mission scientists used them to create a panoramic view of the landing site. A graphic shows where the probe would be sitting in the photograph.
The image of Comet 67P/Churyumov-Gerasimenko was taken by a camera on the Philae lander during its descent to the comet on November 12, 2014. The lander was about 1.9 miles (3 kilometers) from the surface at the time. Philae touched down on the comet about seven hours later.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/Philae/
The image of Comet 67P/Churyumov-Gerasimenko was taken by a camera on the Philae lander during its descent to the comet on November 12, 2014. The lander was about 1.9 miles (3 kilometers) from the surface at the time. Philae touched down on the comet about seven hours later.
Rosetta's OSIRIS camera captured this parting shot of the Philae lander after separation.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team
Rosetta's OSIRIS camera captured this parting shot of the Philae lander after separation.
Rosetta's lander Philae took this parting shot of its mother ship shortly after separation on November 12, 2014, as Philae headed for a landing on Comet 67P. While Philae is the first probe to land on a comet, Rosetta is the first to rendezvous with a comet and follow it around the sun.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/Philae/CIVA
Rosetta's lander Philae took this parting shot of its mother ship shortly after separation on November 12, 2014, as Philae headed for a landing on Comet 67P. While Philae is the first probe to land on a comet, Rosetta is the first to rendezvous with a comet and follow it around the sun.
This mosaic is made of four individual images taken about 20 miles (31.8 kilometers ) from the center of the comet on November 4, 2014.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/NAVCAM
This mosaic is made of four individual images taken about 20 miles (31.8 kilometers ) from the center of the comet on November 4, 2014.
Rosetta took this image of comet 67P/Churyumov-Gerasimenko on September 15, 2014. The box on the right shows where the lander was expected to touch down.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta
Rosetta took this image of comet 67P/Churyumov-Gerasimenko on September 15, 2014. The box on the right shows where the lander was expected to touch down.
The spacecraft sent this image as it approached the comet on August 6, 2014. From a distance of nearly 81 miles (130 kilometers), it reveals detail of the smooth region on the comet's "body" section.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The spacecraft sent this image as it approached the comet on August 6, 2014. From a distance of nearly 81 miles (130 kilometers), it reveals detail of the smooth region on the comet's "body" section.
This image, captured August 7, 2014, shows the diversity of surface structures on the comet's nucleus.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/NAVCAM
This image, captured August 7, 2014, shows the diversity of surface structures on the comet's nucleus.
The comet's "head" can be seen in the left of the frame as it casts a shadow over the "body" in this image released August 6, 2014.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The comet's "head" can be seen in the left of the frame as it casts a shadow over the "body" in this image released August 6, 2014.
This image of the comet was taken on August 1, 2014, as Rosetta closed in its target.
Photos: Rosetta: The comet chaser
PHOTO: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
This image of the comet was taken on August 1, 2014, as Rosetta closed in its target.
Rosetta's mission started on March 2, 2004, when it was launched on a European Ariane 5 rocket from Kourou, French Guiana.
Photos: Rosetta: The comet chaser
PHOTO: ESA/CNES/ARIANESPACE
Rosetta's mission started on March 2, 2004, when it was launched on a European Ariane 5 rocket from Kourou, French Guiana.
Rosetta is named after the Rosetta Stone, the black basalt that provided the key to deciphering Egyptian hieroglyphs. Scientists think the mission will give them new clues about the origins of the solar system and life on Earth. The mission is spearheaded by the European Space Agency with key support from NASA.
Photos: Rosetta: The comet chaser
Rosetta is named after the Rosetta Stone, the black basalt that provided the key to deciphering Egyptian hieroglyphs. Scientists think the mission will give them new clues about the origins of the solar system and life on Earth. The mission is spearheaded by the European Space Agency with key support from NASA.
This photo shows Rosetta being tested before it was wrapped in insulating blankets and loaded on a rocket for launch.
Photos: Rosetta: The comet chaser
PHOTO: ESA/A.Van Der Geest
This photo shows Rosetta being tested before it was wrapped in insulating blankets and loaded on a rocket for launch.
Rosetta has massive solar wings to power the spacecraft. They were unfurled and checked out at the European Space Agency's test facilities before being packed up for liftoff.
Photos: Rosetta: The comet chaser
PHOTO: ESA
Rosetta has massive solar wings to power the spacecraft. They were unfurled and checked out at the European Space Agency's test facilities before being packed up for liftoff.
After its closest approach to Earth in November 2007, Rosetta captured this image of the planet.
Photos: Rosetta: The comet chaser
PHOTO: ESA
After its closest approach to Earth in November 2007, Rosetta captured this image of the planet.
Rosetta snapped this image of Earth in November 2009. The spacecraft was 393,328 miles from Earth.
Photos: Rosetta: The comet chaser
PHOTO: ESA
Rosetta snapped this image of Earth in November 2009. The spacecraft was 393,328 miles from Earth.
Rosetta passed asteroid Steins in September 2008, giving scientists amazing close-ups of the asteroid's huge crater. The asteroid is about 3 miles in diameter.
Photos: Rosetta: The comet chaser
PHOTO: ESA
Rosetta passed asteroid Steins in September 2008, giving scientists amazing close-ups of the asteroid's huge crater. The asteroid is about 3 miles in diameter.
Rosetta took this image of Mars as it looped through the solar system.
Photos: Rosetta: The comet chaser
PHOTO: ESA © 2007 MPS for OSIRIS Team MPS/UPD/ LAM/IAA/ RSSD/ INTA/ UPM/ DASP/ IDA
Rosetta took this image of Mars as it looped through the solar system.
This image was taken by an instrument on Rosetta's Philae lander just minutes before the spacecraft made its closest approach to Mars. Part of Rosetta and its solar arrays are visible.
Photos: Rosetta: The comet chaser
PHOTO: ESA
This image was taken by an instrument on Rosetta's Philae lander just minutes before the spacecraft made its closest approach to Mars. Part of Rosetta and its solar arrays are visible.
On July 10, 2010, Rosetta flew about 1,864 miles from asteroid Lutetia, which is 10 times larger than asteroid Steins.
Photos: Rosetta: The comet chaser
PHOTO: ESA
On July 10, 2010, Rosetta flew about 1,864 miles from asteroid Lutetia, which is 10 times larger than asteroid Steins.
Look closely at the top of this picture. See that dot? That's Saturn. Rosetta snapped the picture of asteroid Lutetia and captured Saturn in the background.
Photos: Rosetta: The comet chaser
PHOTO: ESA
Look closely at the top of this picture. See that dot? That's Saturn. Rosetta snapped the picture of asteroid Lutetia and captured Saturn in the background.
After taking pictures of Earth, Mars and asteroids, Rosetta was put into hibernation in May 2011 after it reached the outer part of the solar system. Mission managers woke it January 20, 2014.
Photos: Rosetta: The comet chaser
PHOTO: ESA
After taking pictures of Earth, Mars and asteroids, Rosetta was put into hibernation in May 2011 after it reached the outer part of the solar system. Mission managers woke it January 20, 2014.

Astronomer Robert Massey also called the landing a tremendous achievement.

“A comet is a bit like a time capsule, which is why it’s s