Curiosity, NASA’s Mars rover, preps for difficult landing (VIDEO)

Curiosity, the most complex and expensive robot ever sent to Mars, is expected to touch down on the red planet on Sunday — but not before it puts NASA scientists through what they're calling the "seven minutes of terror." 

The rover, which is being sent to investigate whether or not Mars can support life, is expected to break to a stop from a speed of 13,000 miles per hour in just seven minutes, the Associated Press reported. 

"The degree of difficulty is above a 10," Adam Steltzner, an engineer at NASA's Jet Propulsion Laboratory, which manages the mission. 

Curiosity is a nuclear powered machine roughly the size of a car, too big to land using the usual technique of bouncing rovers off the planet's surface wrapped in air bags, CBS News reported. Instead, the one-ton rover will be lowered onto Mars from a rocket propelled platform by cables, a new strategy that has yet to be tested.

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As the Obama administration slashes its funding for NASA's Mars mission from $587 million in 2012 to $360 million in 2013, and down to $189 million by 2015, the mission to land Curiosity has taken on an even greater importance, Space.com reported.

"What a tremendous opportunity it is for us," Jim Green, head of NASA's planetary science division, said at a conference in March of the rover. "I believe [Curiosity] will open up that new era of discovery that will compel this nation to invest more in planetary science."

Doug McCuistion, the director of NASA's Mars Exploration Program, called Curiosity's landing "arguably the most important event" in the history of planetary exploration, according to Space.com. 

Meanwhile, NASA has enlisted William Shatner, who played Captain James T. Kirk in "Star Trek," to explain the significance of Curiosity's landing to the general public in videos being circulated online, Fox News reported.