How is NASA’s InSight Mars lander different from the Phoenix Mars lander?

This artist’s concept from August 2015 depicts NASA’s InSight Mars lander fully deployed for studying the deep interior of Mars. Image & Caption Credit: NASA /JPL-Caltech

In 2008, NASA’s Phoenix Mars lander touched down in the Red Planet’s polar region. Now InSight, which is based on the Phoenix lander, is being prepped for flight. The two probes are very similar in design, but what does InSight have that Phoenix didn’t?

If everything goes as planned, NASA’s Mars InSight lander, which was built by Lockheed Martin Space based out of Denver, Colorado, will be ferried to Vandenberg Air Force Base in California in prepar. When launched, it will become the first interplanetary mission launched from the U.S. West Coast.

When it comes to safely touching down on the surface of the Red Planet, NASA pretty much has the market cornered. Of the eight landing attempts since 1976 (half of which have included rovers), the U.S. space agency has only failed once, and that was nearly 20 years ago in 1999 (with the loss of the Mars Polar Lander which was similar in design to both the Mars Phoenix Lander and Mars InSight). As noted, InSight’s design is heavily based on the successful 2008 Phoenix lander, but what sets it apart from the other relatives in its technological family?

InSight undergoes a solar panel deployment test in early 2018. Photo Credit: NASA

For starters, Phoenix was sent to the Red Planet’s northern polar region to seek out water and for environments suitable for microbial life on Mars. If InSight (an acronym for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) touches down on the planet’s surface without a hitch, the probe should peer into Mars’ interior near the equator. Additionally, the spacecraft will collect data on Mars’ temperature, the planet’s seismology and other elements of Mars’ makeup.

It is hoped that InSight, by exploring the interior of a terrestrial world other than Earth, will provide more data about how rocky worlds formed. While all four terrestrial planets were formed around the same time, some 4.5 billion years ago, they each had very different fates and it is hoped InSight might be able to tell discover a reason for this.

If the Red Planet is still geologically active, InSight might detect “marsquakes,” something the U.S. space agency has not studied since the Viking missions of the 1970s and early 1980s. These landers came equipped with seismometers directly affixed to them. Because of this, NASA described the data that came from them as being “noisy.” InSight’s seismometers, on the other hand, will be placed directly on the Martian surface. It’s hoped this will provide much clearer data.

NASA noted via an agency-issued release that marsquakes differentiate from those on Earth in that quakes taking place on the Red Planet would use “other” forms of tectonic activity besides the motion of tectonic plates, which is the primary cause of earthquakes on Earth. Marsquakes, however, could be caused by cracks forming in the Martian crust or by volcanism.

If InSight experiences marsquakes, they would be like a “flashbulb” that would illuminate the interior of the world to the lander, according to NASA. Scientists could then review how the seismic waves pass through the flash-frozen world’s crust, mantle and core and therein potentially figure out the size of these layers and what they are comprised of. 

InSight also comes equipped with a self-hammering heat probe which should burrow down some 16 feet (5 meters) to measure Martian heat flow within the planet for the first time.

NASA said any marsquakes aren’t likely to be bigger than magnitude 6.0, but this could help reveal a few secrets about how Mars and other terrestrial worlds form. The processes that formed Earth and Venus have been eroded over the course of their existence, but Mars has maintained much of its history (for a period estimated at being some 3 billion years) and is, in some ways, a fossil of the Solar System’s formation, the space agency said.

Mars Cube One, or MarCO, will also help to differentiate InSight from previous, similar missions. These two tiny spacecraft (each is approximately the size of a briefcase) will separate from the main mission while in transit to the Red Planet and fly behind the lander. The duo will send back information about InSight’s flight down to the Martian surface and, if successful, will mark the first test of CubeSat technology at another planet. MarCO, NASA said, could mark a whole new means of interplanetary communications between Earth and spacecraft ranging deep into the Solar System.

NASA has tapped United Launch Alliance’s Atlas V rocket in its 401 configuration (meaning it will use a four-meter payload fairing and have a single engine in its Centaur upper stage), to send InSight on its way to Mars. Liftoff is currently scheduled for May 5, 2018, with a landing on the Red Planet’s just over six months later on Nov. 26, 2018.

InSight will land at Elysium Planitia, a flat-smooth plain just north of the equator and about 373 miles (600 kilometers) north of the Curiosity rover’s 2012 landing site. It is expected to operate for at least one Martian year, or about two Earth years.

Video courtesy of NASA JPL

Tagged: InSight Mars NASA Phoenix The Range

Jason Rhian

Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.