NASA has confirmed that InSight is go for launch at 4:05 am PDT (7:05 am EDT) on Saturday. The historic mission will mark the first time that a deep space probe has lifted off from the US Air Force's Vandenberg base in California, and will place an unmanned lander on the surface of Mars to learn more about the interior and dynamics of the Red Planet.

According to NASA, the InSight mission will lift off from Vandenberg Air Force Base Space Launch Complex 3E. There is a two-hour window, so minor delays can be accommodated. Countdown begins today at 10:14 pm PDT (Saturday, May 5, 1:14 am EDT) after which the 260-ft-tall (80-m) Mobile Service Tower will roll back to reveal the United Launch Alliance (ULA) Atlas V rocket that will fire the spacecraft into a polar orbit. After lift-off, InSight is expected to head south over the Channel Islands and will reach orbit 13 minutes into the flight as it passes about 1,200 mi (1,900 km) northwest of Isabella Island, Ecuador.

NASA says that if the May 5 launch is aborted, there are more launch windows available until June 8. Even if there is a delay, the probe is expected to reach Mars on November 26, 2018 at about noon PST (3:00 pm EST). The mission was originally scheduled to launch in March 2016, but was postponed due to an instrument malfunction in one of the onboard experiments.

"For those Southern Californians who are interested in rockets or space exploration, or have insomnia, we hope to put on a great show this Saturday," says Tom Hoffman, InSight project manager. "But for those who want to sleep in on Saturday, there will be another opportunity to engage with this historic mission. We will be landing on Mars in the western Elysium Planitia region on Monday, November 26, around noon Pacific time. You will be able to watch a live stream of this landing while working on your holiday shopping."

Source: NASA