Pasadena: Scientists and engineers are anxiously waiting the descent of Mars rover `Curiosity` which is expected to land at 1:31 a.m. EDT (0531 GMT) on August 6 inside an 96-mile (155-km) wide impact basin.
The spacecraft is expected to hit the top of the Martian atmosphere at 1:24 a.m. EDT on August 6. If things go as planned, seven minutes later the rover will land inside Gale Crater, one of the lowest places on Mars.
The complicated touchdown that includes a 16 metre diameter supersonic parachute, a rocket-powered aerial platform and a so-called "sky crane" designed to lower the rover on a tether to the ground has been described as "seven minutes of terror" by NASA.
NASA last week successfully repositioned its Mars-orbiting Odyssey spacecraft so that it would be able to monitor Curiosity`s descent and landing and radio the information back to Earth.
Scientists will know only after 14 minutes whether Curiosity landed safely on the red planet.
The Mini Cooper-sized spacecraft has been careening toward Mars since its launch in November.
NASA`s most ambitious and expensive Mars mission, designed to last two years, aims to assess whether Gale Crater had all the ingredients at the right time and in the right places for microbial life to arise and be preserved.