In just six weeks, NASA\u2019s next Mars rover will attempt an unprecedented landing on the Red Planet that will have mission engineers on the edge of their seats with excitement and worry.<\/p>\n
The 1-ton Curiosity rover \u2014 the centerpiece of NASA\u2019s $2.5 billion Mars Science Laboratory (MSL) mission \u2014 is due to touch down inside the Red Planet\u2019s Gale Crater on the night of Aug. 5. But it won\u2019t be easy.<\/p>\n
\u201cEntry, descent and landing, also known as EDL, is referred to as the \u2019seven minutes of terror,\u2019\u201d EDL engineer Tom Rivellini, of NASA\u2019s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., said in a recent JPL video.<\/p>\n
\u201cWe\u2019ve got literally seven minutes to go from the top of the atmosphere to the surface of Mars, going from 13,000 miles per hour to zero in perfect sequence, perfect choreography, perfect timing,\u201d Rivellini added. \u201cAnd the computer has to do it all by itself, with no help from the ground. If any one thing doesn\u2019t work just right, it\u2019s game over.\u201d<\/p>\n
Curiosity\u2019s landing will likely be more anxiety-inducing than most planetary touchdowns. The robot is too big to land cushioned by airbags like previous Red Planet rovers, so researchers had to come up with an entirely new method.<\/p>\n
They settled on a rocket-powered sky crane, which will lower Curiosity to the Martian surface on cables before flying off to crash-land on purpose a safe distance away.<\/p>\n
\u201cWhen people look at it, it looks crazy,\u201d EDL engineer Adam Steltzner, also of JPL, said in the video. \u201cThat\u2019s a very natural thing. Sometimes when we look at it, it looks crazy. It is the result of reasoned engineering thought, but it still looks crazy.\u201d<\/p>\n
On the night of Aug. 5, the MSL spacecraft will hit the Martian atmosphere going about 13,000 mph (21,000 kph). As it barrels through the Red Planet air, MSL\u2019s heat shield will literally glow, reaching temperatures of about 2,900 degrees Fahrenheit (1,600 degrees Celsius).<\/p>\n
The relatively thin Martian atmosphere will slow MSL down to only 1,000 mph (1,600 kph) or so, Rivellini said. So the spacecraft will also deploy a parachute, one that can withstand 65,000 pounds (29,500 kilograms) of force despite weighing just 100 pounds (45 kg) itself.<\/p>\n
But even the parachute won\u2019t be enough.<\/p>\n
\u201cThis big huge parachute that we\u2019ve got, it\u2019ll only slow us down to about 200 miles per hour,\u201d Rivellini said. \u201cAnd that\u2019s not slow enough to land. So we have no choice, but we\u2019ve got to cut it off and then come down on rockets.\u201d<\/p>\n
The rockets can\u2019t fire all the way to the ground, however, or they\u2019d raise a huge dust cloud that could damage the rover\u2019s instruments and mechanisms, researchers said. To avoid such a ruckus, Curiosity will be lowered to the Martian surface on 21-foot-long (6.4 meters) cables. When the rover is safely down, the cables will be released and the rocket-propelled sky crane will fly off so it doesn\u2019t crash into Curiosity.<\/p>\n
The 14-minute communications lag between Earth and Mars means that the MSL team won\u2019t be getting real-time updates about the rover\u2019s perilous journey.<\/p>\n
\u201cWhen we first get word that we\u2019ve touched the top of the atmosphere, the vehicle has been alive, or dead, on the surface for at least seven minutes,\u201d Steltzner said.<\/p>\n