Night Owls

NASA's Mars Climate Orbiter has been lost as it arrived at Mars. Investigators later found that one piece of ground software gave thruster data in imperial units (pound-force seconds) while the navigation software expected metric units (newton-seconds), so the spacecraft flew far too close to the planet. Later in 1999 the Mars Polar Lander was also lost during its landing attempt. Source

NASA has picked Gale Crater, just south of the Martian equator, as the landing site for the Mars Science Laboratory rover. Orbiters have seen signs of past water there, including clay minerals and sulfates, which can help preserve evidence of past environments. In the middle of the crater rises Mount Sharp (Aeolis Mons), a mound of layered rock about 5.5 km high. Source

Russia's Phobos-Grunt spacecraft, meant to bring back soil from the Martian moon Phobos, separated from its rocket correctly but its own engines did not fire to send it towards Mars. It also carries China's first Mars probe, Yinghuo 1. Russia's previous Mars attempts, Phobos 1 and 2 (1988) and Mars 96, also failed, and about half of all missions sent to Mars have failed. Source

NASA's Curiosity rover lifted off on an Atlas V rocket from Cape Canaveral at 10:02 a.m. EST (15:02 UTC) for an 8.5-month trip to Mars. The car-size rover weighs about 900 kg and is about 2.9 m long. The mission, officially called Mars Science Laboratory, was planned since 2003 and slipped two years from its original 2009 launch, which raised its total cost by 56 percent to about $2.5 billion. Source

JPL has released a video in which the engineers who designed Curiosity's landing system describe the last minutes before touchdown. In seven minutes the spacecraft must slow from about 13,000 mph (21,000 km/h) to zero, completely on its own, using a heat shield, a huge parachute, rockets and a 'sky crane' that lowers the rover on cables. Engineer Adam Steltzner admits it looks crazy, but says it is the result of reasoned engineering. Source

Landing on Mars has a long record of drama. The Soviet Mars 3 made the first soft landing in 1971 but fell silent after about 20 seconds. NASA's Viking 1 and 2 landed in 1976, Pathfinder and its small Sojourner rover in 1997, the Spirit and Opportunity rovers in January 2004, and the Phoenix lander, which found water ice, in 2008. Failures include NASA's Mars Polar Lander, which crashed in 1999, and Britain's Beagle 2, lost on Christmas Day 2003. Source

President Obama's proposed 2013 budget cuts NASA's planetary science funding by about 20 percent, much of it from the Mars programme. NASA has pulled out of the European-led ExoMars missions planned for 2016 and 2018, and its Mars chief Doug McCuistion says the next US Mars mission, in 2018 or 2020, may have about $800 million, far less than Curiosity's $2.5 billion. Source

Mount Sharp rises about 5 km from the centre of the 154-km-wide Gale Crater, higher than any peak in the continental United States. Its layers may record a billion years or more of Martian history. Orbiters have seen clays and sulfates near its base, minerals that form in water. Curiosity's chief scientist John Grotzinger says nothing like its 5 km of flat-lying layers exists on Earth. Source

Curiosity weighs about a tonne, too heavy for the airbags that cushioned Spirit and Opportunity. Instead a rocket-powered descent stage will hover and lower the rover on nylon tethers, wheels down, then fly away and crash at a safe distance. Former NASA chief technologist Bobby Braun says the plan looks scary but is technically sound and the right way to land a rover this size. Source

NASA's 11-year-old Mars Odyssey orbiter fired its thrusters for six seconds on 24 July, moving six minutes ahead in its orbit so it will be overhead during Curiosity's landing. Odyssey had a reaction wheel problem in June and went into safe mode on 11 July. Earth will set below the Martian horizon before touchdown, so Odyssey is the only way to hear about the landing in real time. NASA's Mars Reconnaissance Orbiter and Europe's Mars Express will also record signals, but send them on hours later. Source

Curiosity is due to land at about 10:30 p.m. PDT on 5 August (about 05:30 UTC on 6 August). Its job is to find out whether the Gale Crater area ever had conditions that could support microbial life. It is not designed to detect life itself. Its ten instruments can take pictures, analyse soil and rock, and fire a laser at rocks to measure their chemistry. NASA's science chief John Grunsfeld calls the landing the hardest robotic mission NASA has ever attempted at Mars. Source

NASA will show its live landing coverage on the giant Toshiba Vision screen in New York's Times Square, below the New Year's Eve ball. The broadcast runs from 11:30 p.m. EDT on Sunday 5 August to 4 a.m. EDT on Monday (03:30-08:00 UTC). No real video of the landing is possible; viewers will see mission control waiting for signals. Source