At 1:31 AM on Monday, August 6, after nearly nine months of travel,NASA's Mars Science Laboratory mission (with a rover named Curiosity) will arrive on Mars.
In what is being called the "7 minutes of terror," the spacecraft's entry, descent and landing sequence will require a lot of things to go perfect in order for the mission to be a success.
It takes 14 minutes at light speed for the signal to get from Mars to the mission-control scientists at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
The project cost $2.5 billion and will begin a two-year quest to explore the interior of Mars' Gale Crater and hunt for evidence of an ancient ocean there.
Here's the timeline of what will (hopefully) happen:
- Ten minutes before the spacecraft arrives, it will fire thrusters to swing the probe's heat shield into a forward position. As the probe streaks through the sky, the heat shield will reach more than 2,000 degrees C (3,632 degrees F).
- Guided only by an onboard computer, small thrusters will steer the spacecraft through the Martian sky, and pull a series of "S" turns to line it up with its landing spot in the Gale crater. After more tungsten weights are shed, the probe deploys a parachute and blasts the heat shield free, revealing a video camera to record the landing.
- One mile above the ground, the spacecraft cuts the parachute loose, and begins to fall, until eight retrorockets fire up to control its descent
- As it nears the surface, the probe begins what NASA calls a Sky Crane maneuver that lowers the Curiosity rover down on nylon ropes. When the rover hits the Mars surface, the spacecraft flies to one side and crash lands a short distance away.
Through the entire descent, there is nothing the mission scientists can do from their offices at Nasa's Jet Propulsion Laboratory in California, but wait for the rover to call home.