The Curiosity rover is due to make a daring landing on the Red Planet at 10:31 p.m. Sunday, August 5 PDT (5:31 UTC August 6). That’s the time a signal confirming safe landing could reach Earth – give or take about a minute for the spacecraft’s adjustments to sense changeable atmospheric conditions.
According to NASA’s Jet Propulsion Laboratory in Pasadena, California – which is overseeing the mission – the Mars Science Laboratory spacecraft is healthy and on course for delivering the mission’s Curiosity rover to the Gale Crater on Mars. What will happen when it gets there?
The new Mars rover is larger than previous rovers, about the size of a sports utility vehicle, or SUV. It’s essentially a mobile geochemistry laboratory. But it was a formidable engineering challenge to soft land a rover this large on the Martian surface.
Curiosity was approaching Mars at about 8,000 mph (about 3,600 meters per second) Saturday morning. By the time the spacecraft hits the top of Mars’ atmosphere, about seven minutes before touchdown, gravity will accelerate it to about 13,200 mph (5,900 meters per second). During the seven minutes that the rover descends to the Martian surface, it will have to slow its speed from 13,200 mph to zero.
How will we know it has landed safely? The news will come via a relay by NASA’s Mars Odyssey orbiter. Curiosity will not be communicating directly with Earth as it lands, because Earth will set beneath the Martian horizon from Curiosity’s perspective about two minutes before the landing.
NASA plans to use Curiosity to investigate whether the study area has ever offered environmental conditions favorable for microbial life, including chemical ingredients for life. As for images from Mars’ surface, NASA says:
The first Mars pictures expected from Curiosity are reduced-resolution fisheye black-and-white images received either in the first few minutes after touchdown or more than two hours later. Higher resolution and color images from other cameras could come later in the first week. Plans call for Curiosity to deploy a directional antenna on the first day after landing and raise the camera mast on the second day.
The prime mission lasts a full Martian year, which is nearly two Earth years. During that period, researchers plan to drive Curiosity partway up a mountain informally called Mount Sharp. Observations from orbit have identified exposures there of clay and sulfate minerals that formed in wet environments.