For the first time in over six years, a spacecraft has landed on Mars. At about 11:54 am PST (2:54 pm EST) this Monday, the unmanned NASA InSight lander touched down on the Red Planet at the Elysium Planitia in the northern hemisphere. The culmination of over a decade of planning, years of delay, and seven months of travel over a distance of 301,223,981 mi (484,773,006 km), the 1,340-lb (608-kg) laboratory is reported to be in good condition as NASA engineers await the first images from the Martian surface.

Today's landing came at the end of what NASA likes to call the "seven minutes of terror" – the sequence of events in the last moments of a Martian landing when everything must come off exactly as planned, as the spacecraft rides the knife's edge between success and disaster. Because mission control back on Earth is over 90 million mi (145 million km) away, it takes eight minutes and seven seconds for any radio signals to reach InSight, so the craft's onboard computers must handle any landing emergencies by themselves.

Based on NASA's previous Phoenix Mars polar lander, Insight uses the same entry, descent and landing system, though with a number of technical improvements that allow for a larger lander and the ability to set down at a higher elevation on the planet. On the way to Mars, the lander rested inside of a protective aeroshell attached to a cruise module ever since its launch from Vandenberg Air Force Base in California atop a United Launch Alliance Atlas V rocket on May 5, 2018.

The landing was observed not only by NASA's Mars Reconnaissance Orbiter and Mars Odyssey, but also by an experimental Mars Cube One (MarCO) spacecraft that was launched with InSight and has trailed it ever since. The goal was that MarCO could provide faster confirmation of the landing before it flew by Mars and into deep space.

The entry phase began at 11:40 am PST (2:40 pm EST) when the aeroshell separated from the cruise stage. One minute later, the spacecraft turned to present its heat shield to the approaching atmosphere, which it struck at 11:47 am PDT (2:47 pm EST) at about 12,300 mph (19,800 km/h).

Within two minutes, the heat shield reached a temperature of about 2,700° F (1,500° C) as the atmosphere generated eight gees of force and engulfed the protective shell in a ball of ionized plasma, cutting off radio communications.

At 11:51 am PST (2:51 pm EST), the spacecraft had slowed down enough for its supersonic parachute to deploy. Fifteen seconds after that, the heat shield jettisoned and the lander legs extended 10 seconds later. Guided by radar to the landing zone, the parachute and back shield were cut loose at 11:53 am PST (2:53 pm EST), and a half a second later the 12 landing rockets fired.

In less than 30 seconds, the craft was slowed to a descent speed of 5 mph (8 km/h) for a soft landing on the Martian plains. At 12:01 pm PST (3:01 pm EST), the first telemetry beeps were transmitted over the X-band radio back to mission control at the Jet Propulsion Laboratory in Pasadena, California.

NASA is currently awaiting the first data from InSight and after 5:35 pm PST (8:35 pm EST), it's expected that the Mars Odyssey orbiter will confirm that the lander has deployed its solar panels.

The space agency says that because the goal of the InSight mission is to study the structure and dynamics of the deep interior of Mars, there is no need for it to be mobile like the previous Curiosity lander, and it doesn't matter where it set down. This is why Elysium Planitia was chosen. Though it's at a higher elevation, making it more difficult for the spacecraft to decelerate, it's flat and largely free of gullies or debris. In addition, its location near the equator makes it warmer, placing less strain on the craft's heating systems.

Now that InSight is down, engineers will spend the next two or three months testing its systems (especially its robotic arm) before beginning the main task of boring into the Martian surface to begin geological experiments.

"We've studied Mars from orbit and from the surface since 1965, learning about its weather, atmosphere, geology and surface chemistry," says Lori Glaze, acting director of the Planetary Science Division in NASA's Science Mission Directorate. "Now we finally will explore inside Mars and deepen our understanding of our terrestrial neighbor as NASA prepares to send human explorers deeper into the solar system."

UPDATE November 26, 4pm EST: The Insight Mars lander has sent its first image -

The spotty first image shows the area in front of the lander. It was taken using the Lander's Instrument Context Camera (ICC) and transmitted via the MarCO CubeSat mission. (NASA/JPL-Caltech)

Source: NASA

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