Washington, Aug 6 (IANS): US space agency's nuclear-powered one tonne rover Curiosity, packed with sophisticated instruments, touched down on Mars Sunday on a quest for signs of whether the Earth's neighbour has evidence of past and present habitable environments.
It was a tense and daring scientific mission to land the rover on the surface of Mars. And it succeeded.
"Touchdown confirmed for @MarsCuriosity," said a NASA tweet as ecstatic scientists celebrated.
Its mission: to see if Mars ever could have supported small life forms like microbes...and if humans could survive there someday.
The six-wheeled rover, weighing about one tonne, dwarfs all previous robots sent to the surface of Mars.
It is about twice as long and more than five times as heavy as any previous Mars rover, Xinhua reported.
It has been equipped with 10 scientific instruments, including two for ingesting and analysing samples of powdered rock delivered by the rover's robotic arm.
The rover was on a precise course for a landing beside a Martian mountain to begin two years of unprecedented scientific detective work, according to NASA.
During a prime mission lasting one Martian year - nearly two Earth years - researchers will use the rover's tools to study whether the landing region has had environmental conditions favourable for supporting microbial life and favorable for preserving clues about whether life existed.
The $2.5 billion Mars Science Laboratory, the formal name of the mission deploying the Curiosity rover, was launched from Cape Canaveral in Florida, Nov 26, 2011.
BBC reported that a staggering two-thirds of all missions sent to Mars have failed while entering the thin but unforgiving Martian atmosphere.
NASA's strategy was to use a sequence of fully automated manoeuvres to slow the entry from an initial 20,000km/h at the top of the atmosphere to less than 1m/s at touch-down.
The last stage in the sequence will see a hovering, rocket-powered crane lower the rover to the ground on nylon cords, the media report explained.
Tense scientists waited for news as the 250 million km between Mars and Earth means there is a 13-minute lag in communications.
"I'm safely on the surface of Mars. GALE CRATER I AM IN YOU!!!," said a tweet after the rover landed safely on Mars.
Moments earlier, another tweet said: "Backshell separation. It's just you & me now, descent stage. Engage all retrorockets!"
The critical tweets began with the one saying: "Guided entry is begun. Here I go!".
Less than a minute later, another said: "Parachute deployed! Velocity 900 mph. Altitude 7 miles. 4 minutes to Mars!".
Soon after landing on Mars, the rover beamed its first photograph which showed a shadow of the rover on the red planet.
"It once was one small step... now it's six big wheels. Here's a look at one of them on the soil of Mars," added a tweet that referred to astronaut Neil Armstrong's famous words "one small step for man, one giant leap for mankind" after he set foot on moon.
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