At 10:31 p.m. PDT on Aug. 5, after nearly nine months of travel, NASA’s Mars Science Laboratory mission (with a rover named Curiosity) will arrive at the Red Planet. The $2.5 billion rover will begin a two-year quest to explore the interior of Mars’ Gale Crater and hunt for evidence of an ancient ocean there. But before this hunt can begin, Curiosity has to land.

The Mars Science Laboratory landing sequence has been the topic of much discussion even before the mission launched on Nov. 26, 2011. Nicknamed “seven minutes of terror,” the spacecraft’s entry, descent and landing sequence will require a lot of things to go perfectly right — all before anyone on Earth receives even a single signal, due to the length of time it takes for information to travel from Mars to Earth.