By Steven Lee, PhD
Since the dawn of the Space Age, only Earth and its moon have been visited by more spacecraft than Mars. Beginning in 1960, about 40 missions (with about 60 spacecraft) have been launched toward the Red Planet. About 40 percent have succeeded, at least in part. Though the spectacular successes make it look easy, exploring Mars has proven to be one of the most difficult endeavors humans have ever attempted.
The wealth of data from these missions, and extensive observations from Earth, have given us a treasure trove of information about the present and past state of the Martian surface and atmosphere.
Despite all this discovery, details of the interior structure of the planet remain sketchy. How large is the core, and is it molten? What are the properties of the mantle? How thick is the crust? NASA’s latest mission to Mars, InSight (Interior Exploration Using Seismic Investigations, Geodesy, and Heat Transport), successfully landed on Nov. 26. It is designed to fill gaps in our knowledge through three primary experiments:
SEIS (Seismic Experiment for Interior Structure) features an ultra-sensitive seismometer deployed from the lander onto the surface using a robotic arm. Prelaunch testing of SEIS in Denver detected the signature of ocean waves crashing along the California coast! Detailed analysis of ground vibrations, caused by “Marsquakes,” meteoroid impacts, and even storms, will reveal much about the internal structure.
HP3 (Heat Flow and Physical Properties Probe) is an array of temperature sensors that use a self-hammering “mole” to burrow 10 to 16 feet into the surface. These observations will measure how the surface materials conduct heat and how much heat is flowing outward from the interior of the planet.
RISE (Rotation and Interior Structure Experiment) uses InSight’s radio connection with Earth to provide information about the Martian core through precise tracking of the location of the spacecraft on the surface as the planet rotates.
The InSight mission has Colorado connections. The spacecraft was designed, built, and tested right in our own backyard by Lockheed Martin Space in Littleton. InSight launched last May aboard an Atlas 5 vehicle provided by United Launch Alliance, based in Centennial. The Denver Museum of Nature & Science hosted a landing event on Nov. 26 for about 500 guests. An expert panel provided background on the mission, and guests gathered inside the Museum’s auditorium and by a giant screen in the atrium to witness history.
From the edge of our seats, we all watched live NASA TV coverage of the “6 Minutes of Terror” as InSight slammed into the Martian atmosphere at nearly 13,000 miles per hour, descended
under a supersonic parachute, then successfully performed a rocket-assisted soft landing on the surface. After a seven-month cruise (covering nearly 300 million miles), InSight received cheers in Denver and across the world as it arrived at its new home on Mars!
InSight is busily surveying its landing site and will soon use its robotic arm to deploy the instruments onto the surface. The two-year mission of data-gathering will add to the ongoing story of a place that continues to capture imaginations and inspire space explorers of today, and tomorrow. Visit the “Space Odyssey” exhibition at the Museum for the latest updates from this exciting mission. Go, InSight!
This is NASA InSight’s first full self-portrait on Mars. It displays the lander’s solar panels and deck. On top of the deck are its science instruments, weather sensor booms and UHF antenna. The selfie was taken on Dec. 6, 2018. Image credit: NASA/JPL-Caltech.
About the author: Dr. Steve Lee is a space scientist at the Denver Museum of Nature & Science. He is also a senior research scientist at the Space Science Institute in Boulder, and a co-investigator on two camera systems orbiting Mars aboard the Mars Reconnaissance Orbiter.