Shadow on the ground, Curiosity on Mars – one of the first images to be sent to Earth from the newly arrived rover (credit: JPL)
At 06:14 BST (05:14 UTC), Curiosity, NASA’s latest and largest rover vehicle, officially arrived on the surface of Mars at the end of a 570-million-km journey, and the start of what promises to be a truly remarkable international mission (the science package that forms the heart of the mission – the Mars Science Laboratory itself – includes instruments from Canada, France, Spain, Russia, Germany, the UK and Finland as well as the United States, while scientists from around the world will be directly involved in analysing data and images returned by the rover).
The entire landing sequence – referred to as the EDL, for Entry, Descent and Landing – proceeded flawlessly, with telemetry confirmed the rover was on the surface of Mars arriving at mission control 06:32, after being relayed to Earth via an orbiting space craft above Mars and the Canberra Deep Space Communications Complex, Australia.
The landing was followed around the world, via NASA TV web feeds, Twitter and through the unique perspective of NASA’s Eyes on the Solar System, which presented a simulation of the entire EDL phase of the mission which could be played in real-time as events unfolded 246 million kilometres (154 million miles) away.
The descent stage simulated by Eyes on the Solar System (NASA)
The excitement of the event was genuinely palpable; not only was there the massive question as to whether the vehicle survive the “seven minutes of terror”, as the EDL had been dubbed by the mission team, there was concern whether NASA’s Mars Odyssey orbiter – the only vehicle in Mars orbit capable of relaying data received from Curiosity directly to Earth – would in fact be able to do so.
The 11-year-old orbiter has been struck by a series of problems over the last year, the most recent of which occurred immediately prior to an orbital manoeuvre designed to put the vehicle on the correct track in order to be overhead as Curiosity landed on Mars. While that problem have been successfully overcome, there was concern that the orbiter might fail to complete a final orientation manoeuvre designed to correctly align its antennae so it could act as a relay – and the manoeuvre itself could not be carried out until just 15 minutes prior to Curiosity arriving on Mars.
While NASA’s Mars Reconnaissance Orbiter (MRO) and Europe’s Mars Express were also on-hand to capture data transmissions from Curiosity, neither one has the ability to simultaneously receive data from the surface of Mars and transmit it directly back to Earth. Instead, telemetry from Curiosity would have to be recorded and then relayed to Earth many hours after then landing period. Thus, without Mars Odyssey, mission control – and the world at large – would have no idea as to Curiosity’s fate for a considerable period of time after the event.
As it was, everything worked flawlessly. Not only were the Odyssey team able to ensure the vehicle was on the right track ahead of EDL, the entire landing process ran to almost precisely to the projected schedule, key events occurring a matter of seconds behind the times being played-out on the Eyes on the Solar System EDL simulation.
For those used to the button-down shirt formality of NASA so beloved of Hollywood and familiar from achieve footage of the Apollo missions, the informality at JPL may have come as something of a surprise. As EDL progressed, team members passed jars of peanuts around, taking handfuls and munching on them in a long-standing tradition dating back to Ranger 7, the first US probe to successfully transmit close images of the lunar surface in 1964. Then, as Allen Chen, the EDL’s Flight Dynamics and Operations Lead announced, ”Touchdown confirmed, we’re safe on Mars!” the room erupted into scenes of heartfelt jubilation with shouts, cheers, hugs and even one or two little dances.
Adam Steltzner (right), the man who lead the team responsible for the Curiosity’s descent and landing systems, reaction to the first images received from Curiosity on Mars (credit: Brian van der Brug/Los Angeles Times-POOL)
Even with Odyssey on track and correctly oriented, there was still some doubt as to how much data would be relayed before Mars Odyssey dropped below the horizon relative to Curiosity and direct contact from the rover was lost. As well as transmitting confirmation it was down and relatively safe, the rover had been pre-programmed to record a number of rapid-fire images using the front and rear hazard avoidance cameras (Hazcams) in order to give some visual indication of the vehicle’s general condition / possible orientation. However, the window for data transmission was so tight, there was doubt that any of the images would be captured, compressed and transmitted prior to Odyssey moving out of range.
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