Rosetta Closing in on Comet 67P/Churyumov-Gerasimenko after Decade Long Chase

ESA’s Rosetta Spacecraft nears final approach to Comet 67P/Churyumov-Gerasimenko in late July 2014. This collage of imagery from Rosetta combines Navcam camera images at right taken nearing final approach from July 25 to July 31, 2014, with OSIRIS wide angle camera image at left of comet’s coma on July 25 from a distance of around 3000 km. On July 31 Rosetta had approached to within 1327 km. Images to scale and contrast enhanced to show further detail. Credit: ESA/Rosetta/NAVCAM/OSIRIS/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Collage/Processing: Marco Di Lorenzo/Ken Kremer – kenkremer.com
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The European Space Agency’s (ESA) Rosetta spacecraft is at last rapidly closing in on its target destination, Comet 67P/Churyumov-Gerasimenko, after a decade long chase of 6.4 billion kilometers through interplanetary space. See imagery above and below.

As of today, Friday, August 1, ESA reports that Rosetta has approached the ‘rubber ducky looking’ comet to within a distance of less than 1153 kilometers. That distance narrows with each passing moment as the speeding robotic probe moves closer and closer to the comet while looping around the sun at about 55,000 kilometers per hour (kph).

Rosetta is now just 5 days away from becoming Earth’s first probe ever to rendezvous and enter orbit around a comet.

See above our image collage of Rosetta nearing final approach with the spacecrafts most recent daily Navcam camera images, all taken within the past week starting on July 25 and including up to the most recently release image snapped on July 31. The navcam images are all to scale to give the sense of the spacecraft approaching the comet and revealing ever greater detail as it grows in apparent size in the cameras field of view. The navcam images were also taken at about the same time of day each day.

The highest resolution navcam image yet of the two lobed comet – merged at a bright band – was taken on July 31 from a distance of 1327 kilometers and published within the past few hours by ESA today, Aug 1. It shows the best view yet of the surface features of the mysterious bright necked wanderer composed of primordial ice, rock, dust and more.

The Navcam collage is combined with an OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) wide angle camera view of the comet and its asymmetric coma of ice and dust snapped on July 25 from a distance of around 3000 km, and with an exposure time of 300 seconds. The OSIRIS image covers an area of about 150 x 150 km (90 mi x 90 mi). The images have been contrast enhanced to bring out more detail.

Scientists speculate that the comets bright neck region could be caused by differences in material or grain size or topological effects.

Rosetta’s history making orbital feat is slated for Aug. 6 following the final short duration orbit insertion burns on Aug. 3 and Aug. 6 to place Rosetta into orbit at an altitude of about 100 kilometers (62 miles) where it will study and map the 4 kilometer wide comet for some 17 months.

The comet rotates around once every 12.4 hours.

Crop from the 31 July processed image of comet 67P/Churyumov-Gerasimenko, to focus on the comet nucleus. Credits: ESA/Rosetta/NAVCAM
Crop from the 31 July processed image of comet 67P/Churyumov-Gerasimenko, to focus on the comet nucleus. Credits: ESA/Rosetta/NAVCAM

“If any glitches in space or on ground had delayed the most recent burns, orbital mechanics dictate that we’d only have had a matter of a few days to fix the problem, re-plan the burn and carry it out, otherwise we run the risk of missing the comet,” says Trevor Morley, a flight dynamics specialist at ESOC.

In November 2014 the Rosetta mothership will deploy the Philae science lander for the first ever attempt to land on a comet’s nucleus using harpoons to anchor itself to the surface while the comet is rotating.

As Rosetta edges closer on its final lap, engineers at mission control at the European Space Operations Centre (ESOC), in Darmstadt, Germany have commanded the probes navigation camera (navcam) to capture daily images while the other science instruments also collect measurements analyzing the comets physical characteristics and chemical composition in detail.

ESA’s Rosetta Spacecraft nears final approach to Comet 67P/Churyumov-Gerasimenko in late July 2014. This image collage from Rosetta combines Navcam camera images taken nearing final approach from July 25 (3000 km distant) to July 31, 2014 (1327 km distant).  Top row shows images as seen by spacecraft. Bottom row shows images rotated to same orientation.  Images to scale and contrast enhanced to show further detail. Credit: ESA/Rosetta/NAVCAM. Collage/Processing: Marco Di Lorenzo/Ken Kremer
ESA’s Rosetta Spacecraft nears final approach to Comet 67P/Churyumov-Gerasimenko in late July 2014. This image collage from Rosetta combines Navcam camera images taken nearing final approach from July 25 (3000 km distant) to July 31, 2014 (1327 km distant). Top row shows images as seen by spacecraft. Bottom row shows images rotated to same orientation. Images to scale and contrast enhanced to show further detail. Credit: ESA/Rosetta/NAVCAM. Collage/Processing: Marco Di Lorenzo/Ken Kremer

The probe has already discovered that the comet’s surface temperature is surprisingly warm at –70ºC, which is some 20–30ºC warmer than predicted. This indicates the surface is too hot to be covered in ice and must instead have a dark, dusty crust, says ESA.

Comet 67P/Churyumov-Gerasimenko is a short period comet some 555 million kilometres from the Sun at this time, about three times further away than Earth and located between the orbits of Jupiter and Mars.

You can watch the Aug. 6 orbital arrival live via a livestream transmission from ESA’s spacecraft operations centre in Darmstadt, Germany.

While you were reading this the gap between the comet and Rosetta closed to less than 1000 kilometers!

The coma of Rosetta's target comet as seen with the OSIRIS wide-angle camera. The image spans 150 km and was taken on 25 July 2014 with an exposure time of 330 seconds. The greyscale relates to the particle density in the coma, with highest density close to the nucleus, becoming more diffuse further away. The hazy circular structure on the right is an artefact. The nucleus is also overexposured. The specks and the streaks in the background are attributed to background stars and cosmic rays.  Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The coma of Rosetta’s target comet as seen with the OSIRIS wide-angle camera. The image spans 150 km and was taken on 25 July 2014 with an exposure time of 330 seconds. The greyscale relates to the particle density in the coma, with highest density close to the nucleus, becoming more diffuse further away. The hazy circular structure on the right is an artefact. The nucleus is also overexposured. The specks and the streaks in the background are attributed to background stars and cosmic rays. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, commercial space, MAVEN, MOM, Mars and more Earth and Planetary science and human spaceflight news.

Ken Kremer

ESA’s Rosetta Spacecraft nears final approach to Comet 67P/Churyumov-Gerasimenko in late July 2014. This collage of imagery from Rosetta combines Navcam camera images at right taken nearing final approach from July 25 (3000 km distant) to July 31, 2014 (1327 km distant), with negative OSIRIS wide angle camera image at left of comet’s expanding coma cloud on July 25. Images to scale and contrast enhanced to show further detail. Credit: ESA/Rosetta/NAVCAM/OSIRIS/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA    Collage/Processing: Marco Di Lorenzo/Ken Kremer
ESA’s Rosetta Spacecraft nears final approach to Comet 67P/Churyumov-Gerasimenko in late July 2014. This collage of imagery from Rosetta combines Navcam camera images at right taken nearing final approach from July 25 (3000 km distant) to July 31, 2014 (1327 km distant), with negative OSIRIS wide angle camera image at left of comet’s expanding coma cloud on July 25. Images to scale and contrast enhanced to show further detail. Credit: ESA/Rosetta/NAVCAM/OSIRIS/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Collage/Processing: Marco Di Lorenzo/Ken Kremer
Birthday cakes at @ESA_Rosetta Flight Dynamics are taking strange binary shapes these days... #ESOC. Credit:  ESA
Birthday cakes at @ESA_Rosetta Flight Dynamics are taking strange binary shapes these days… #ESOC. Credit: ESA

Space Science Stories to Watch in 2014

There’s an old Chinese proverb that says, “May you live in interesting times,” and 2013 certainly fit the bill in the world of spaceflight and space science. The past year saw spacecraft depart for Mars, China land a rover on the Moon, and drama in low Earth orbit to repair the International Space Station. And all of this occurred against a landscape of dwindling budgets, government shutdowns that threatened launches and scientific research, and ongoing sequestration.

But it’s a brave new world out there. Here are just a few space-related stories that we’ll watching in 2014:

An artist's conception of ESA's Rosetta and Philae spacecraft approaching comet 67P/Churyumov-Gerasimenko. (Credit: ESA-J. Huart, 2013)
An artist’s conception of ESA’s Rosetta and Philae spacecraft approaching comet 67P/Churyumov-Gerasimenko. (Credit: ESA-J. Huart, 2013)

Rosetta to Explore a Comet: On January 20, 2014, the European Space Agency will hail its Rosetta spacecraft and awaken it for its historic encounter with comet 67P/Churyumov-Gerasimenko later this year in August. After examining the comet in detail, Rosetta will then dispatch its Philae lander, equipped complete with harpoons and ice screws to make the first ever landing on a comet. Launched way back in 2004, Rosetta promises to provide the cosmic encounter of the year.

The October 19th, 2014 passage of comet C/2013 A1 Siding Springs past Mars. (Credit: NASA/JPL-Caltech)
The October 19th, 2014 passage of comet C/2013 A1 Siding Springs past Mars. (Credit: NASA/JPL-Caltech)

A1 Siding Springs vs. Mars: A comet discovery back in 2013 created a brief stir when researchers noted that comet C/2013 A1 Siding Springs would make a very close passage of the planet Mars on October 19th, 2014. Though refinements from subsequent observations have effectively ruled out the chance of impact, the comet will still pass 41,300 kilometres from the Red Planet, just outside the orbit of its outer moon Deimos. Ground-based observers will get to watch the +7th magnitude comet close in on Mars through October, as will a fleet of spacecraft both on and above the Martian surface.

A recent tweet from @NewHorizons_2015, a spacecraft that launched just weeks before Twitter in 2006.
A recent tweet from @NewHorizons_2015, a spacecraft that, ironically, launched just weeks before Twitter in 2006.

Spacecraft En Route to Destinations: Though no new interplanetary missions are set to depart the Earth in 2014, there are lots of exciting missions currently underway and headed for worlds yet to be explored. NASA’s Dawn spacecraft is headed towards its encounter with 1 Ceres in February 2015. Juno is fresh off its 2013 flyby of the Earth and headed for orbital insertion around Jupiter in August 2016. And in November of this year, New Horizons will switch on permanently for its historic encounter with Pluto and its retinue of moons in July 2015.    

LUX & the Hunt for Dark Matter: It’s all around us, makes up the bulk of the mass budget of the universe, and its detection is THE name of the game in modern astrophysics. But just what is dark matter? Some tantalizing– and hotly contested –data came out late last year from of an unusual detector deep underground near Lead, South Dakota. The Large Underground Xenon experiment (LUX) looks for Weakly Interacting Massive Particles (WIMPs) interacting with 370 kilograms of super-cooled liquid Xenon. LUX requires its unique locale to block out interference from incoming cosmic rays. LUX is due to start another 300 day test run in 2014, and the experiment will add another piece to the puzzle posed by dark matter to modern cosmology, whether or not detections by LUX prove to be conclusive.   

The LIGO Livingston Observatory. (Photos by Author)
The LIGO Livingston Observatory. (Photos by Author)

 The Hunt for Gravity Waves: Another story to watch may come out of Caltech’s twin gravity wave observatories when its Advanced LIGO system goes online later this year. Established in 2002, the Laser Interferometer Gravitational-Wave Observatory (LIGO) is comprised of two detectors: one in Hanford Washington and one outside of Livingston, Louisiana. The detectors look for gravity waves generated by merging binary pulsars and black holes. Though no positive detections have yet been made, Advanced LIGO with boast ten times the sensitivity and may pave the way for a new era of gravitational wave astronomy.

An artist concept of MAVEN in orbit around Mars. (Credit: NASA's Goddard Spaceflight Center).
An artist concept of MAVEN in orbit around Mars. (Credit: NASA’s Goddard Spaceflight Center).

 Spacecraft reach Mars: 2014 is an opposition year for the Red Planet, and with it, two new missions are slated to begin operations around Mars: India’s Mars Orbiter Mission (MOM) also known as Mangalyaan-1 is slated to enter orbit on September 24th, and NASA’s MAVEN or Mars Atmosphere and Volatile Evolution Mission is set to arrive just 2 days earlier on September 22nd. MOM and MAVEN will join the Curiosity and Opportunity rovers, ESA’s Mars Express,  NASA’s Odyssey spacecraft and  the Mars Reconnaissance Orbiter in the quest to unlock the secrets of the Red Planet.

Space Tourism Takes Off: Virgin Galactic’s SpaceShipTwo passed a key milestone test flight in late 2013. Early 2014 may see the first inaugural flights by Virgin Galactic out of the Mohave Spaceport and the start of sub-orbital space tourism. SpaceShipTwo will carry two pilots and six passengers, with seats going for $250,000 a pop. Hey, room for any space journalists in there? On standby, maybe?

The First Flight of Orion: No, it’s not the first flight of the proposed sub-light interplanetary spacecraft that was to be propelled by atomic bombs… but the September launch of the Orion Multi-Purpose Crew Vehicle is the first step in replacing NASA’s capability to launch crews into space. Exploration Flight Test 1 (EFT-1) will be a  short uncrewed flight and test the capsule during reentry after two orbits. It’s to be seen if the first lunar orbital mission using an Orion MPCV will occur by the end of the decade.

Launch of the SpaceX CRS-2 mission to the ISS in early 2013. (Photo by author).
Launch of the SpaceX CRS-2 mission to the ISS in early 2013. (Photo by author)

 The First Flight of the Falcon Heavy: 2014 will be a busy year for SpaceX, starting with the launch of Thaicom-6 out of Cape Canaveral this Friday on January 3rd. SpaceX is now “open for business,” and expect to see them conducting more satellite deployments for customers and resupply missions to the International Space Station in the coming year. They’ll also be moving ahead with tests of their crew-rated version of the Dragon capsule in 2014. But one of the most interesting missions to watch for is the demo flight of the Falcon 9 Heavy slated to launch out of Vandenberg Air Force Base by the end of 2014.… more to come!

The Sunjammer Space Sail: An interesting mission moves in 2014 towards a January 2015 launch: LGarde’s Sunjammer solar sail. Sunjammer will test key solar sail technologies as well as deliver the Solar Wind Analyzer (SWAN) and the MAGIC Magnetometer to the L1 Earth-Sun Lagrange point. Sunjammer will launch on a Falcon-9 rocket and deploy a 1200 square metre solar sail weighing only 32 kilograms. This will be a great one for ground satellite-spotters to track as well as it heads out!

Gaia Opens for Business: Launched on a brilliant night-shot out of the Kourou Space Center in French Guiana on December 19th of last year, the European Space Agency’s Gaia space observatory will begin its astrometry mission in 2014, creating most accurate map yet constructed of our Milky Way Galaxy. But we also anticipate exciting new discoveries due to spin-offs from this mission, to include the discovery of new exoplanets, asteroids, comets and much more.

And as in years previous, the quest to explore brave new worlds will be done against the backdrop of tightening budgets. Just like in household budgets, modern spaceflight is a continual conflict between what we would wish and what we can afford. In recent years, no mission seems to be safe, and there have even been occasional congressional rumblings to pull the plug on missions already underway. Interesting times, indeed… 2014 promises to be an extraordinary time in spaceflight and space science, both on Earth and beyond.