Spaceflight Insider

Rosetta mission celebrates one year anniversary of comet landing

Philae lander approaching the surface of comet Comet 67P/Churyumov–Gerasimenko image credit ESA posted on SpaceFlight Insider

Image Credit: ESA

Scientists with the European Space Agency (ESA) recently celebrated the one-year anniversary of the crowning achievement of the Rosetta mission – the landing of the Philae probe on Comet 67P/Churyumov–Gerasimenko. The tiny lander touched down on Nov. 12, 2014.

The Rosetta mission arrived at the comet on Aug. 6, 2014, after a two-year and seven-month-long hibernation as it traveled through space to match the solar orbit of the comet. Once Rosetta achieved orbit, the mission planners surveyed the comet, chose a landing site and launched the Philae lander to the Agilkia region of the comet.

That landing did not go as planned and the 220 pound (100 kg) probe bounced away from the comet’s surface when the anchoring pins on the craft failed to fire (they were designed to secure the tiny craft to the comet’s surface).

The lander repelled back and traveled across the comet bouncing twice before coming to a relatively undamaged rest in the Abydos region of the comet. The lander provided information during the 60 hours of life that the battery had – before shutting down due to a lack of power. The lander began rebroadcasting information on the comet when it was close enough to the Sun to allow Philae’s solar panels to recharge the batteries again. The probe sent information back to controllers on June 13, 2015. They had intermittent contact with the robotic explorer until July 9, 2015.

Rosetta_OSIRIS_Agilkia_LaForgia_Fig2_1000w ESA image posted on SpaceFlight Insider

The Agilkia area on comet 67P/Churyumov-Gerasimenko. The circle indicates where Philae touched down for the first time on 12 November 2014. The dashed line marks the comet’s equator. The large depression is the Hatmehit region. This image is a composite of five frames from the OSIRIS Narrow Angle Camera. Image & Caption Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

As the comet drew closer to the Sun, the Rosetta orbiter maneuvered to a higher orbit to avoid potential debris from the now outgassing comet. This orbital increase took Rosetta out of communication range of the Philae lander. As the comet recedes from the Sun, mission controllers will lower the spacecraft’s orbit and hopefully regain contact with Philae again. Rosetta is currently some 125 miles (200 km) above the surface of the cosmic dirty snowball – with controllers slowly guiding the spacecraft lower still.

Despite the setbacks that the lander has encountered, it was able to complete approximately 80 percent of its mission objectives. Meanwhile, the Rosetta spacecraft is still healthy and returning data.

“We recently celebrated our first year at the comet and we are looking forward to the scientific discoveries the next year will bring,” says Matt Taylor, ESA’s Rosetta project scientist.

Mission planners are looking at possible new targets of opportunity in terms of Rosetta.

“Next year, we plan to do another far excursion, this time through the comet’s tail and out to 2,000 kilometers (1,243 miles). To complement that, we hope to make some very close flybys towards the end of the mission, as we prepare to put the orbiter down on the comet,” Taylor added

As the comet and Rosetta move further away from the Sun, the solar panels on the spacecraft will provide lower and lower levels of power. Additionally, the comet will slowly appear to drift behind the Sun as it recedes, making communications difficult starting in September 2016. Program managers for Rosetta have decided that a controlled landing on the comet is the best course of action. To do this, they will have to adjust the spacecraft’s trajectory to ensure the landing is successful.

This is not as fantastic as it sounds, as NASA has already carried out a somewhat similar landing via the NEAR Shoemaker mission to the Eros asteroid.  NEAR Shoemaker carried out a slow descent to the surface of Eros which culminated in a landing just to the south of the saddle-shaped feature that had been dubbed “Himeros” on Feb. 12, 2001, at approximately 3:01 p.m. EST (19:01 GMT).

ESA does not know how the Rosetta mission will draw to a close. As is so often the case, mission managers work to get every bit of data possible from the spacecraft sent into the black.

“We are still discussing exactly what the final end of mission scenario will involve,” says Sylvain Lodiot, ESA’s Rosetta spacecraft operations manager. “It is very complex and challenging, even more so even than the lander delivery trajectory our flight dynamics teams had to plan for delivering Philae.

The team is hopeful that they can continue to receive data as Rosetta spirals to its landing. If so, the spacecraft could return valuable information about the comet before communications are eventually lost.

“We’ll control Rosetta all the way down to the end, but once on the surface it will be highly improbable that we’ll be able to ‘speak’ to it anymore,” Sylvain added.

For others involved with the highly successful mission, if things close out with a landing – that would just be icing on the cake.

“Landing Rosetta on a comet will be a fitting ending to this incredible mission,” says Patrick Martin, ESA’s Rosetta mission manager.

Video courtesy of ESA


Joe Latrell is a life-long avid space enthusiast having created his own rocket company in Roswell, NM in addition to other consumer space endeavors. He continues to design, build and launch his own rockets and has a passion to see the next generation excited about the opportunities of space exploration. Joe lends his experiences from the corporate and small business arenas to organizations such as Teachers In Space, Inc. He is also actively engaged in his church investing his many skills to assist this and other non-profit endeavors.

Reader Comments

Congratulations to ESA on a spectacular mission!

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