More audacious than Rosetta

More audacious than Rosetta

Philae’s landing on 67P is a remarkable feat, but its real success will be when it inspires more ambitious missions.

Comets are believed to have transported molecules responsible for the origin of life on Earth.
Comets are believed to have transported molecules responsible for the origin of life on Earth.

Humans have a tendency to create and break boundaries with equal exertion. But the last 50-odd years have verified that the struggle over these boundaries exists only on and around Earth, and the vast inhospitable expanses of outer space provide abundant prospects and challenges to prompt united exploration and expansion of the human footprint. One such bold initiative is the cornerstone mission of the international European Space Agency — Rosetta.

The November 12 touchdown of Rosetta’s Philae Lander on the surface of the comet 67P/ Churyumov-Gerasimenko has become a frontier feat at par with the Apollo 11 mission and the Voyager Interstellar Mission in terms of science, technology and civilisational implications.

Rosetta has reached the comet after facing copious challenges, making it a marvel among space missions. The first critical challenge was its nearly 11-year, arduous flight to a fast-rotating comet no wider than five kilometres. Rosetta had to perform several slingshots using the gravities of the Earth, Mars and Earth again before it could reach 67P.

While performing these difficult slingshots, it successfully managed to take scientific measurements and images of Earth, Mars and the two main-belt asteroids it flew past — the 2867 Šteins and 21 Lutetia.


The second major challenge for Rosetta was the deep space communications capability it demanded for more than a decade, especially when its complete system, except a few communication systems that had been shut down, was reactivated following a 31-month long hibernation-cum-travelling period. The third major challenge was to orbit and land on a surface potentially prone to quakes and ultra-cold geysers.

Of the three main phases of Philae’s scientific mission, the ESA has successfully undertaken the first two — separation, descent and landing (SDL) and first science sequence (FSS). Philae’s landing was always a huge confrontation for the mission managers and scientists.

On November 12, as Philae was about to touchdown, it failed to deploy the harpoon and anchor its grip on the surface. This led to an unforeseen consequence, where the lander bounced twice after the first touchdown (on its proposed site, Agilkia) to finally land on a harsh, non-desired location hundreds of metres from Agilkia. Despite these chance events, Philae has etched its name in human history for being the first-ever human-made probe to land on the surface of a comet and commence the ultimate objective of the mission, which is to characterise the comet. As planned, Philae has utilised its battery-packs that were supposed to power it during SDL and FSS. It now anticipates recharging of its solar panels to conduct its last long-term science (LTS) phase, as the comet continues to move closer to the sun.

Rosetta’s objectives are even more ambitious than the mission itself. The comet 67P belongs to a group of celestial bodies previously residing in the outer regions of our solar system, but at a certain point of time were pulled into their current orbits by the huge gravity of Jupiter. Hence, having spent billions of years in the frigid peripheries, comets are widely known to have preserved the signatures of astrochemical processes that occurred in interstellar and protostellar (period of the sun’s infancy) environments. The exploration of comets is, therefore, akin to travelling via a time machine and arriving in an era when the Earth did not even exist.

Comets are believed to have transported molecules responsible for the origin of life on Earth. Exploring them is thus a significant step towards the age-old quest for the origins of humanity. Also, since comets are abundant with organic material that has been processed for billions of years in space, there is a stark possibility of finding, if not by Rosetta but on subsequent missions, metamaterials that can potentially possess superlative properties compared to Earth-based counterparts. So, comet exploration has huge potential to satiate both material and philosophical desires.

There are two kinds of space missions — one driven by the need to demonstrate superiority, the other by the need to explore. Rosetta is of the second kind. It has been a collective effort of several thousand scientists spanning across three generations. The investment of several million man-hours, the training of three generations banishing social, cultural and national boundaries, and the sentience of the early mission designers to proceed with the mission, despite knowing that they might probably not see and experience its final glory, make Rosetta one of the most inspiring projects ever undertaken.

Despite the numerous conflicts on Earth, the vastness of space gives humans a common sense of heritage and purpose. In the 21st century, when the world looks forward to an advancing Asia, it looks at it not only as a potential market for commodities but also as a huge pool of human resource that can be trained and nurtured for global projects more ambitious than the Rosetta. The landing of Philae on 67P is surely a remarkable feat, but its real success lies in the fact that it is going to inspire more audacious space missions that will travel to and explore other enigmatic celestial objects. Humanity has achieved something extraordinary this month; it has set a footprint on a time-travelled comet. Rosetta is now signalling the need for even greater audacity.

The writer is a member of the COSAC instrument team at the Max Planck Institute for Solar System Research, Germany. COSAC is one of the scientific instruments on board the ESA Philae Lander. Views are personal.