In just over
50 years of space exploration humanity has landed spacecraft on Venus,
the moon, Mars, Saturn's moon, Titan, and two asteroids. Now a new
object can be added to that list: a comet.
(continued)
But
Esa scientists are concerned about the future of the Philae probe after
yesterday's less than perfect landing, which saw it bounce two times
before settling on the surface.
The
probe has returned the first ever image from the surface of the comet
but it apparently shows a 'worrying amount of shadow' that may mean the
spacecraft is either on its side or stuck in a hole.
'Welcome to a comet!' Esa tweeted this
remarkable picture from comet 67P confirming that Philae is
successfully on the surface - but the amount of shadow in the picture is
quite worrying and may confirm the probe is on its side or in a hole.
At the lower middle can be seen one of the three legs of the lander,
each of which contains an ice screw to keep Philae anchored to the
surface
The
probe landed on the comet at around 3.30pm GMT yesterday but then
bounced twice, first to a height of 0.62 miles (1km) and then to a much
lower height before coming to rest. It is also thought to be about 0.62
miles (1km) from its intended landing site.
According to Emily Lakdawalla of
the Planetary Society, the first image of the surface of the comet
returned by Philae shows a 'worrying amount of shadow' that may suggest
it is on its side.
She
continued: 'Why I don't like shadow: bad for recharging solar panels,
also may mean low operating temperatures. I'll ask about these things
later.'
Earlier
data had also suggested that only some of the solar panels on Philae
were getting sunlight, which seems to have been confirmed by the amount
of shadow in the picture. The reason for the shadow could be that Philae
is not upright or that it is in a hole.
And
speaking to MailOnline Mark Bentley, the Principal Investigator on
Rosetta's Midas instrument, said: ‘There is a chance it is on its side,
but a good radio link suggests it is the right way up
He continued: 'From what we’ve heard overnight it seems there is a suspicion yesterday that there was some bouncing involved.
‘Two instruments have confirmed Philae appears to have touched down followed by two subsequent touchdowns effectively.
‘So the fact we’re now getting data back from the orbiter looks good, it suggests the lander is stable on the surface.
‘But
we don’t know what the state is yet, how it’s sitting, what its
orientation is. These are important things that need to be figured out
today.'
The latest news is a worrying state of affairs for the remarkable landing yesterday.
At
the European Space Agency’s mission control, a faint radio signal came
back from the Philae lander at 4pm - proof that it had finally reached
the surface of the comet 67P/Churyumov-Gerasimenko after a decade-long
chase through space.
But when it first made contact with the surface it failed to fire harpoons that would have kept it attached to the comet.
This
resulted in it bouncing to a huge height of 0.62 miles (1km) above the
comet before again coming into the contact with the surface. This time
it bounced again but to a much smaller altitude.
'Drifting
into space is still a major worry,' continued Mr Bentley. 'At the
moment the comet is still inactive. Philae is sitting on the surface and
operations can all go ahead.'
'If
it’s not anchored there’s a problem with what to do when drilling for
example and several instruments designed to sample the environment.'
'If
you try to push down with the drill it could lift the lander off the
surface. So those operations will be suspended until the Esa team knows
how stable it is.'
He
also confirmed that it was not clear why the harpoons didn't fire and
attempts to fire them again to keep Philae attached to the surface could
be problematic. Firing them could push the spacecraft off the surface
as its thruster on top to hold it down is not working.
The final approach: This image shows
comet 67P/CG from a distance of approximately 1.8 miles (3km) from the
surface. Philae is now thought to be on the surface but its exact
orientation is unknown. It bounced twice before coming to rest
What's next for Philae: the sensors that will reveal what life on a comet is like
Dr
Stephan Ulamec, who ran the audacious landing, said it was not yet
clear if its three ice screws had deployed either. These are a passive
device used to keep Philae attached to the surface but without the use
of the harpoons they could be important in keeping it anchored.
‘Did
we just land in a soft-sand box and everything is fine? Or is there
something else happening? We still do not fully understand what has
happened,' he said.
Despite
the unknowns, the team were treating the landing as a success last
night. Further data will be forthcoming later today that will confirm
the state of Philae on the surface.
Yesterday
British scientist Dr Matt Taylor, who played a key role in the mission,
said: ‘To see this mountaineering effort, that we’ve descended a lander
to the surface of a comet, I can’t put words to it. It’s beautiful.’
And the expert was so confident of success that he had even had an image of the space probe tattooed on his right leg.
Before
the attempt yesterday, there was also a good luck message from a man
who had once boasted of boldly going into space himself.
Star Trek actor William Shatner sent the team a video in which the 83-year-old said: ‘Good luck Rosetta, Philae’s gonna land.’
One
scientist then described the seven hours of ‘terror’ they went through
to drop the Philae lander 13.6 miles (21.9km) above the comet from its
mothership, Rosetta.
Dr
Matthew Genge, of Imperial College London, said during the wait: ‘This
is the most difficult landing in space history – like landing a balloon
in a city centre on a windy day with your eyes closed.’
Much of the equipment aboard the lander was switched on for the first time after lying dormant during the ten-year journey.
Klim
Churyumov, one of the Ukrainians who discovered the comet 45 years ago
and named it, said from mission control in Darmstadt, Germany: ‘We saw
the first light from this comet in 1969, now we are landing on it. It is
a fantastic, outstanding event, the first like it in human
civilization.’
The probe is equipped with cameras, a suite of ten instruments, and a drill that can bore out samples to a depth of nine inches.
Although no official images from the
surface have been released, this shot spotted by twitter user
@coreyspowell appears to show a shot from the surface of the comet. ESA
is expected to release the first official shots tomorrow.
Almost there! An image from the lander as it approached the surface was briefly shown yesterday
Rosetta's probe, Philae, has
successfully landed on its comet 67P/Churyumov-Gerasimenko. Pictured is
the mission control team in Darmstadt, Germany celebrating immediately
after the announcement
The lander announced its arrival with this historic tweet for its ten year mission
Ptolemy,
a British-built laboratory the size of a shoebox, will be used to
analyse the composition of samples from the 4.5billion-year-old comet.
Scientists
hope the £1billion project will solve some of the greatest puzzles in
science – including the origins of life on Earth.
Open
University Professor Ian Wright, who helped create Ptolemy, said: ‘The
idea that comets may have brought the building blocks of life to Earth
is one of the reasons why we want to study them.’
Professor
Stanley Cowley, planetary scientist at the University of Leicester,
added: ‘It is an interesting relic from that otherwise inaccessible
epoch.’
However,
controllers have revealed that because harpoons supposed to tether it
to the surface had not fired, the lander may have actually bounced,
effectively landing twice - and leaving it attached only by screws on
its legs.
'It's
complicated to land on a comet, and complicated to understand what has
happened during this landing,' said Dr Stefan Ulamec, Philae Lander
Manager.
'The good news is we touched down, we had a clear signal and recieved data.
'The
not so good news is that the anchoring harpoons did not fire. We looked
into the data, and we don't fully understand what has happened.
We had fluctuations in the radio link, but it always came back again.
'Some of the details indicate the lander may have lifted off again, it is bouncing.
'Two hours later, this stopped. We may have landed not once, but twice.'
In an emotional speech, Esa director general Jean-Jacques Dordain said: 'It's a big step for human civilisation.'
Scientists hope data from the probe will help reveal how the solar system was first created 4.5 billion years ago.
The
confirmation of the landing was relayed via Rosetta to Earth and picked
up simultaneously by a ground station in Malargüe, Argentina and
Madrid, Spain, before being confirmed in Darmstadt.
Ahead of the landing, Rosetta took a
number of images of Philae during its daring descent. This view shows
the lander's consert antennae deployed. It also shows three lander feet
and the Rolis descent camera boom
Overjoyed: The Ukrainian astronomer
Klim Tchurjumov (right), one of the discoverers of the comet
67P/Tchurjumov-Gerassimenko, and ESA General Director Jean-Jacques
Dordain (left) hug each other at the satellite control center of the
European Space Agency (ESA) in Darmstadt, Germany
'Esa and its Rosetta mission partners achieved something extraordinary today,' said Dordain.
'Our
ambitious Rosetta mission has secured another place in the history
books: not only is it the first to rendezvous with and orbit a comet,
but it is now also the first to deliver a probe to a comet's surface.'
'After
more than 10 years travelling through space, we're now making the best
ever scientific analysis of one of the oldest remnants of our solar
system,' added Alvaro Giménez, Esa's director of Science and Robotic
Exploration.
'Decades
of preparation have paved the way for today's success, ensuring that
Rosetta continues to be a game-changer in cometary science and space
exploration.'
'Hollywood is good, but Rosetta is better' - said the UK Space Agency CEO Dr David Parker.
At mission control the news was greeted with jubilation and high emotion by staff on the project
Applause: Media and dignitaries from around the world erupt in applause as they hear of Philae's success
However,
while the lander has touched down on the comet using its harpoons,
scientists said that it had not yet deployed its anchors which meant
that it was not completely attached to the surface.
The
surface was much softer than they expected, so there were some concerns
that it was not securely fixed on the comet – although from a software
point of view things seemed to be fine.
Engineers will attempt to fire the anchors again soon in order to keep Philae attached to the surface of the comet.
Esa director general Jean-Jacques Dordain (pictured) said: 'This is a big step for human civilisation'
Rosetta has chased comet
67P/Churyumov–Gerasimenko through space for more than ten years in what
has been described as 'the sexiest, most fantastic mission ever'
Rosetta
has chased comet 67P/Churyumov–Gerasimenko through space for more than
ten years in what has been described as 'the sexiest, most fantastic
mission ever'.
Speaking live on TV, Matt Taylor, project scientist of Rosetta, talked about the complexities of the mission.
'I
said she was sexy but I never said she was easy,' he said, describing
the thruster issue that worried scientists earlier today.
Despite
this, after a four billion mile (6.5 billion km) journey, the probe
successfully released Philae from its grip to land on the comet,
travelling at 1 metre (40 inches) per second.
At 08.35 GMT yesterday, mission
control in Darmstadt, Germany, sent a command to release the Philae
probe from Rosetta's grip. This picture shows the neck region of Comet
67P/Churyumov-Gerasimenko. It was captured around 4.8 miles (7.7km) from
the surface of the comet
Ecstatic: Mission scientists have undergone an agonising seven-hour wait today, as Philae fell to its comet
Success! Scientists were shown looking emotional as they realised they had made space history
'We
are extremely relieved to be safely on the surface of the comet,
especially given the extra challenge of the comet's unusual shape and
unexpectedly hazardous surface,' said Stephan Ulamec, Philae Lander
Manager at the DLR German Aerospace Center.
'In
the next hours we'll learn exactly where and how we've landed, and
we'll start getting as much science as we can from the surface of this
fascinating world.'
Engineers were forced to endure a tense wait to discover whether the lander successfully grabbed onto the comet at 3.30pm GMT.
Ahead of the landing, Rosetta captured several images of Philae during its daring mission using its Osiris camera.
One
stunning shot showed the lander's antennae deployed, along with all
three lander feet and the Rolis descent camera boom that took the
photograph of Rosetta.
A view further away taken by Rosetta's Osiris camera. 'It's me… landing on a comet and feeling good!', Philae tweeted
Reflection: Astronomer Klim Ivanovych
Churyumov, who discovered the comet 67P/ Churyumov-Gerasimenko in 1969,
reacts after the successful landing of the Philae lander on the comet
Immediately after the image was released, Philae tweeted: 'It's me…landing on a comet and feeling good!'.
The
separation of Philae from Rosetta was confirmed at 9.03am GMT today,
and just after 11am GMT mission control in Darmstadt, Germany received a
signal confirming the lander was working.
Throughout the day, the lander has transmitted data and images back to Earth.
'Everything looks really, really good,' said Philae lander manager Stephan Ulamec.
However,
the success of the mission hung in the balance because Philae has a
faulty thruster, which means it may have had to rely solely on harpoons
to attach itself to the surface.
Whether or not it was able to make the thruster work in time has yet to be revealed by Esa.
Tense: Mission director, Paolo Ferri,
in the moment he realised the probe had landed on the comet. 'For me
this is a dream come true', he told MailOnline
The cold thruster would have been used to push Philae closer to the comet.
Without
it, Philae would have been forced to rely on its three landing screws
and two harpoons to successfully attach itself to the surface.
However,
if the thruster was reactivated and all went to plan, at touchdown a
landing gear would have absorbed the force of the landing.
Ice
screws in the feet and a harpoon system locked to the comet's surface
and the thruster would have pushed it down into the surface to
counteract the impact of the harpoon.
Before Philae's release, Esa said there was 'no going back'.
'This
is the most difficult landing in space history, like landing a balloon
in a city centre on a windy day with your eyes closed,' said Matthew
Genge, a senior lecturer in Earth and planetary science at Imperial
College London.
At 08.35am GMT the mission control team in Darmstadt, Germany, sent a command to release the Philae probe from Rosetta's grip.
The
probe was in free fall for during 'seven hours of terror', before
attempting to land on the icy surface of comet 67P/Churyumov-Gerasimenko
at a site called Agilkia.
'We'll
need some luck not to land on a boulder or a steep slope,' said Stephan
Ulamec, Philae Lander Manager at the DLR German Aerospace Center, ahead
of the landing.
Speaking
to Astronomy Now, Head of Mission Operations Paolo Ferri said they had
received both positive and negative readings from the thruster.
'We don't know whether the motor is working or not. We have inconsistent readings,' he said at the time.
This picture from mission control
shows the team preparing to receive confirmation from the Philae lander
that it had separated from Rosetta earlier this morning
This graphic details how the Philae
lander will touchdown on the surface of comet 67P. Without its cold
thruster on top, however, the landing was due to be even more risky than
thought
The team in Darmstadt, Germany, are
pictured here celebrating as news of Philae's separation from Rosetta
was received earlier this morning. Since then, the probe has landed and
scientists around the world celebrate
Philae's
cold thruster is nitrogen-powered and is designed to fire on landing in
order to prevent the probe from flying off into space due to the
comet's weak gravity.
In order to prepare cold-gas jets, scientists use one of two pins to puncture a wax seal on the thruster's gas tank.
Experts detect success by the change in pressure in the piping system.
However, this morning mission controllers did not see pressure increases after two attempts with each of the two pins.
But
according to the industry provider, there may still be a chance that
retrying the puncture of the wax seal would succeed, even after four
failed attempts.
The
comet is currently 300 million miles away (480 million km), and is
travelling through space at about 34,000 mph (55,000 km/h).
Yesterday
flight managers gave their 'OK' to the first of four checks that must
be carried out before the probe Philae can descend from its orbiter
craft onto a comet in deep space this afternoon.
Esa also revealed this new image showing how the comet would dwarf London
This is an artist's impression Philae, showing how it made its way to the surface of the comet today
Pictured is a separate Esa Rosetta control team in Toulouse, France awaiting news of the separation
Anxious: Scientists (mission
controller Paolo Ferri pictured in foreground) faced a gruelling
seven-hour wait to discover if the Philae probe had managed to safely
land on the comet it has chased for 10 years
Esa has now successfully made contact
with the Philae lander after it separated from the Rosetta spacecraft
this morning at 08.35am GMT. It is now heading towards the comet and is
expected to attempt to land on the surface at 4pm GMT. Pictured right is
Paolo Ferri, Head of Mission Operations, celebrating making contact
The
checklist was preceded by a brief moment of worry when Philae 'took a
bit longer than expected' to be activated, said Paolo Ferri, mission
leader at Darmstadt.
'We
were a bit worried at first that the temperature would be wrong (for
the descent) but it all worked out. We didn't lose any time,' Ferri
said.
No
one has ever attempted such a daring feat, and even Esa engineers admit
they initially thought it sounded more like science fiction.
Scientists hope that Rosetta and Philae could help unravel secrets of how the solar system formed 4.5 billion years ago.
Rosetta has also been aiming to work out the plasma characteristics of the comet (illustrated)
At 0835am GMT the team in Darmstadt,
Germany (picture from mission control shown) sent a command to release
the Philae probe from Rosetta's grip
Engineers at Rosetta mission control
have made history by landing the Philae probe on comet 67P. Pictured is
an artist's impression
Emotions
at mission control were running high ahead of the landing. 'This, for
me, is a wonderful dream come true,' Paolo Ferri, mission director told
MailOnline. 'Just thinking about it…I have tears in my eyes.
'You
spend a lot of your time in very odd situations with [Rosetta], working
weekends, and getting calls in the middle of the night. It's not fair
to compare it to a relationship with a human, but it's very close.'
When
it was launched in 2004, Rosetta was so far from 67P that it had to
pass Earth three times and Mars once, so that it could use the planets'
gravity to slingshot its way deep into the solar system.
The
spacecraft will spend more than a year studying the comet, which is
made up of material left over from when our solar system was first
created 4.5 billion years ago.
Ahead
of the landing, Esa has published a series 'beauty shots', taken by
Rosetta's navigation camera, revealing the varied and dramatic terrain
of the mysterious rock.
Rosetta's target comet,
67P/Churyumov–Gerasimenko, is about 2.48 miles (4km) wide. Here it is
shown alongside some of Earth's landmark
Illustrated here are the various
scientific instruments on the Philae lander that will be used to study
the comet when it is attached to the surface
Rosetta has chased comet
67P/Churyumov–Gerasimenko through space for more than ten years in what
has been described as 'the sexiest, most fantastic mission ever'
(illustration of solar system shown)
The images shows a raised plateau on
the larger lobe of Comet 67P/Churyumov-Gerasimenko. It was captured from
a distance of 6 miles (9.8 km) from the center of the comet
The mission began as a concept about
three decades ago and was the brainchild of Gerhard Schwehm, former
Rosetta Project Scientist (pictured in the 1980s)
Incredibly,
many of the images were taken at less than six miles (10km) from the
comet's surface, and highlight what a challenging task Philae engineers
have ahead of them.
The
Philae probe aims to analyse the comet in more detail than Rosetta ever
could. The results, Esa claims, could completely rewrite the history of
how the Earth formed.
As
Philae descends, it will be travelling at walking speed of 3ft (one
metre) per second relative to 67P while the duck-shaped rock is rotating
constantly.
Philae
will need to be released with pinpoint accuracy as its landing site
contains a mix of sheer cliffs and deep craters – any of which could
scupper its chances.
Scientists
are aiming to land on a spot named 'Agilkia' on the smaller 'head' lobe
of 67P after Philae is released from a distance of 14 miles (22.5km)
from the centre of 67P.
Rosetta has been taking scientific
readings of the comet since it arrived, including measurements of the
magnesium on the surface (shown)
The daring descent Philae (artist's
impression shown) will take seven hours from separation. It will be
exactly nine years that a similar landing attempt on an asteroid by
Japan's Hayabusa failed in 2005
This image shows the Agilkia landing
site on Comet 67P/ChuryumovGerasimenko, taken with Rosetta's navigation
camera on 6 November. It was captured at a distance of 22 miles
(35.5km)
Jose
Pellon-Bailon, one of eight flight engineers responsible for Rosetta,
told MailOnline there are a number of things that could go wrong during
the descent.
For instance, Rosetta might not release Philae at the right spot if the thrusters are activated at the wrong time.
Jets of gas spewing from the comet could also cause problems during, moving Philae off course.
Another concern is the strange duck-shape of the comet, which means Philae could crash land, damaging its instruments.
And even if Philae lands safely, it will need to attach itself to the comet using harpoons.
Philae
is able to withstand temperatures of 150°C (300°F), but it could
become too hot to operate as the comet travels towards the sun.
But if it all goes to plan, it could trigger more mission to comets in the future.
'The
other scientific instruments are collecting a huge amount of data and
I'm sure they'll provide to the scientific community a humongous
richness,' Pellon-Bailon said.
At
the moment, communication between Rosetta and mission control take 28
minutes and 20 seconds each way – the time it takes for a signal to
travel 315 million miles (510 million km) to Earth.
'It's
difficult, in the sense that you are commanding something and you are
seeing the effects almost one hour later,' says Pellon-Bailon. 'If we
land on the comet, it will be very emotional.'
Ferri's biggest fear isn't that Philae will be damaged during the descent, but that it could fail to send a signal back at all.
'This
would be a huge disappointment,' he says. 'Of course, the landing
mission would be off, but also we wouldn't have learned why.'
The landing has been described by Esa as 'ridiculously difficult'.
'Imagine the comet as Mont Blanc,' says Ferri.
'You fly with an aircraft at 13.6 miles (22km) in altitude - so twice the altitude of a normal airline.
'At a certain point you have to drop a box and hope that it lands on the mountain within a square km.'
Pellon-Bailon says his team are fully prepared, even down to what they will eat on the day.
Scientists describe it as a 'Jupiter class' comet which takes 6.45 years to complete one full circuit of the sun
The icy core, or nucleus, is about 2.4 miles (4km) across and the comet takes around 12.4 hours to rotate fully.
The comet has now been observed from Earth on seven approaches to the Sun: in 1969, 1976, 1982, 1989, 1996, 2002 and 2009.
Over
an entire year, as it approaches the sun, Rosetta will orbit the comet,
mapping its surface and studying changes in its activity.
As
its ices evaporate, instruments on board the orbiter will study the
dust and gas particles that surround the comet and trail behind it
Peanuts
are crucial. 'We found out that people at Nasa eat peanuts on the day
of the special activity. In a mission that is problematic, they will
always have peanuts on the table.'
Esa
has inherited the superstition, and Ferri confirms that it's vital to
the success of the mission. 'I'll also be wearing the same tie I wore
when Rosetta launched ten years ago,' he says.
The bizarre rituals at mission control are hoped to steady nerves as engineers perform complex manoeuvres around the comet.
Pellon-Bailon
says when he first got involved in the mission in the early 1990s, it
sounded to him like science fiction. Even now, he can't quite believe
they've reached the comet.
'It
sounds crazy when you say it out loud,' says Ferri. 'Sometimes I sit
back and think, there's a two cubic metre box flying half a billion
kilometres away, that is now sending a very faint signal.
'That signal is picked up in Australia, and now I'm looking at it. Then I think, how is it possible?'
But it has been possible, and even if Philae doesn't make it on tomorrow, the mission has already achieved its main objective.
'You
have to remember, and we have to remember, this landing is spectacular,
but it is only one part of the mission,' says Ferri.
'Whatever happens, data from Rosetta has already rewritten the history of our solar system.'
from Dailymail
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