Editor's Note (Nov. 26): The Mars InSight landing today! Read more about the scheduled landing and keep checking Space.com for updates on this exciting mission. NASA's InSight Mars Lander: Full Coverage

NASA's InSight Mars lander is a stationary probe designed to study the interior of the Red Planet. It will be a stationary mission, not like NASA's famous Opportunity, Spirit and Curiosity rovers,. Staying in place is necessary for its major science goals, which include learning more about the Martian composition, and how tectonically active Mars is. The mission will also be notable for its CubeSats, which will be the first time such tiny spacecraft fly beyond Earth.

InSight launched toward Mars on May 5, 2018, from Vandenberg Air Force Base in California, on an Atlas V vehicle from United Launch Alliance. If successful, the mission will land on Nov. 26, 2018, at the Martian Elysium Planitia, an equatorial zone just south of an ancient volcanic area. InSight will send back data about the Red Planet's interior for about 1 Mars year, or 728 Earth-days (a little more than two Earth years). You can see launch photos here.

This artist's concept from August 2015 depicts NASA's InSight Mars lander fully deployed for studying the deep interior of Mars. (Image credit: NASA/JPL-Caltech)

InSight is short for a rather lengthy name: Interior Exploration using Seismic Investigations, Geodesy and Heat Transport. The mission has a total cost of $814 million, NASA officials have said.

Brief development history

InSight was one of 28 submissions for NASA's next Discovery-class mission in 2010. This type of mission is a lower-cost explorer of the solar system. During InSight's selection round, individual proposals weren't allowed to exceed $425 million, excluding the cost of the launch vehicle.

InSight – then known as the Geophysical Monitoring Station (GEMS) – and two other finalists (Titan Mare Explorer and Comet Hopper) each received $3 million in May 2011 to perform a concept study. InSight was tapped in August 2012 for the next launch. Construction began on InSight in May 2014. Its manufacturer is Lockheed Martin Space Systems.

NASA's InSight Mars Lander: 10 Surprising Facts

In December 2015, NASA announced it could not launch as planned in March 2016 because of a leak in one of the craft's instruments, the Seismic Experiment for Interior Structure (SEIS). At the time, agency officials said the mission might be removed entirely from the launch manifest. One limitation the agency cited was concern about exceeding the $675 million cost of the mission that included launch, data analyses and scientific operations. (At the time, they had spent $525 million.)

By the following fall, in September 2016, NASA announced a revised launch date for InSight. The announced delay to spring 2018 was no large surprise to the community, because the orbits of Mars and Earth only align favorably for a spacecraft flight every 26 months; outside of that window, it takes too much fuel to easily get to the Red Planet.

"The instrument redesign and two-year delay add $153.8 million" to the $675 million mission cost, NASA said in a statement. "The additional cost will not delay or cancel any current missions, though there may be fewer opportunities for new missions in future years, from fiscal years 2017-2020," it added.

InSight's landing zone is a flat stretch of the western Elysium Planitia, near the Martian equator. (Image credit: NASA/JPL-Caltech)

Science goals and instruments

InSight has two major science goals, according to NASA. The first is to examine the interior — what it is made of, and what processes occur. The lander will provide information on the size and composition of the Martian core, crust and mantle. It also will show "how warm the interior is and how much heat is still flowing through," NASA said. The second goal is to learn if Mars is tectonically active (including where seismic activity is located), and how frequently meteorites slam into its surface.

InSight in Pictures: NASA's Mission to Probe Mars's Core

"Previous missions to the Red Planet have investigated its surface by studying its canyons, volcanoes, rocks and soil. But the signatures of the planet's formation can only be found by sensing and studying its vital signs far below the surface," NASA said.

InSight has three instruments that are designed to look at the deep interior of Mars and learn about the planet's geological activity, warmth and elements of its evolution, according to NASA.

The Seismic Experiment for Interior Structure (SEIS) will detect seismic waves from meteorite impacts, magma movements inside the planet, or marsquakes.

The Heat Flow and Physical Properties Probe, or HP 3 , will burrow about 5 meters (16 feet) into the surface. Its main job is to sense heat underground.

, will burrow about 5 meters (16 feet) into the surface. Its main job is to sense heat underground. The Rotation and Interior Structure Experiment, or RISE, will aim to provide more information about the composition of the Martian core. It will keep careful track of where the lander is located, and from that information, discern any wobbles in the orbit of Mars as the planet orbits the sun. The composition of the core will influence the degree and type of oscillation Mars experiences.

InSight has a robotic arm that is more than 7 feet (2.4 m) long. This arm will place the seismometer and heat-flow probe on the surface for their measurements. The arm also features a camera that will take "color 3D views of the landing site, instrument placement, and activities," according to NASA. In addition, InSight has sensors to provide information on the weather, and any changes in the local magnetic field nearby the lander.

Riding along with InSight will be the first cubesats to fly beyond Earth. The experiment, which encompasses two spacecraft, is called Mars Cube One. The cubesats will fly behind InSight during its journey to Mars. NASA has named the cubesats "Wall-E" and "Eva" because they use fire extinguisher fluid as thruster propellant, just like the animated robot in Disney's "Wall-E" movie.

If successful, once InSight begins its entry into the Martian atmosphere, the cubesats will send information back to Earth about the spacecraft's last few minutes flying to the Red Planet's surface.

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