Remember this picture? NASA is quietly planning to have an even better one of the Curiosity landing — perhaps even in colour — by Monday morning.
This snap, taken on 25 May 2008, is the parachute of the Mars Phoenix lander caught in the act 3 minutes before landing by the HiRISE camera on the Mars Reconnaissance Orbiter (MRO). Not only did the MRO give NASA a stunning image for the public, but it also provided crucial engineering information about one of the riskiest aspects of any Mars landing: whether the parachute opened completely.
And NASA is trying again. The MRO will slew into position and take a snap of Curiosity’s parachutes 60 seconds before landing, just before the rover is released from the back shell. It could even be possible to discern the heat shield on the ground. “We get one shot,” says Alfred McEwen, principal investigator of HiRISE (High Resolution Imaging Science Experiment) at the University of Arizona in Tucson.
This time, the chance of catching Curiosity on camera is only 60%, says McEwen. With Phoenix, there was about an 80% chance. The difference is because of the relative paths of the spacecraft. For the Phoenix landing, HiRISE’s long and narrow field of view was closely aligned with the path of the lander. For the Curiosity landing, the MRO will be much closer and looking almost directly down at Curiosity. But the paths are nearly perpendicular, which means that HiRISE’s field of view — a narrow north–south track about 6 kilometres wide on the ground — might not contain Curiosity, which will be barreling east along its 20-kilometre-long landing ellipse (see map after the jump).
There is a silver lining, however. Not only will the MRO be closer, but Curiosity’s parachute is about twice the size of Phoenix’s. In the Phoenix snap, the parachutes were just 10 pixels across. McEwen says that Curiosity’s parachutes could cover 50 pixels, making for a black-and-white image as detailed as 35 centimetres per pixel. And McEwen estimates that there’s a 20% chance Curiosity will fall along the central swath of HiRISE’s field of view, where there are colour detectors. “If we’re really, really lucky we’ll catch it in our colour strip,” he says.
McEwen expects to get the data back to Earth by 1 a.m. Pacific daylight time on 6 August. His team will spend a frantic few hours trying to spot Curiosity and process the image before delivering it to the Jet Propulsion Laboratory (JPL) in Pasadena, California, by 3 a.m. So forget the fish-eyed, fuzzy thumbnails that Curiosity’s hazcams are supposed to return first. By the time of the 9-a.m. press briefing on Monday morning, the JPL could have a beautiful surprise waiting for the public: a memento (hopefully not mori) of the most complicated landing ever attempted in the Solar System.