OKAY–first off, InSight is a LANDER. Meaning when it lands on Mars, it stays put and will not move around like the rovers do (i.e. Curiosity and Opportunity). The InSight mission is focused on analyzing the interior of Mars. The name InSight is actually an acronym for Interior Exploration using Seismic Investigations, meaning it’ll be measuring Mars quakes. InSight will have a five meter probe that will go into the surface of Mars to take multiple measurements of its interior. InSight will be the first mission to peer deep into Mars interior.
It’ll be analyzing geophysical data, and scientists hope that data will answer questions about the formation, the evolution and the composition of Mars and other rocky bodies in our solar system. Insight will be landing at Elysium Planitia, a low-lying plain just north of the equator on Mars. This is the perfect area for InSight because it is solar powered! This area offers maximum Sun exposure and has a smooth penetrable surface. Once it has landed, scientists here on Earth will peer through InSight’s cameras to observe the surroundings of where the lander landed. And once all is clear and ready to go, InSight will begin to settle into its new home. It will deploy its hardware, extend its twins solar arrays, and prepare itself for a two-year job.
Before I get into the details of InSight, I want to compare it to Curiosity’s location. Curiosity is at the Gale Crater, which has a mountain of layered materials in the center, which if it were on Earth, would be a mountain five kilometers (3 miles) high! Curiosity has been analyzing the layers because it’s been telling us a bit about what Mars was like in the past. Thera are layers of clay materials near the bottom of the mound, and just above that are layers with sulfur and oxygen-bearing minerals. There are also channels that appear to have been carved out by water at one time.
InSight has a robotic arm with a five finger grapple that will be controlled by engineers here on Earth, and will be used to deploy its equipment. Payload systems engineer Farrah Alibay said: “Have you ever played the claw game at arcades? That is essentially what we’re doing but million miles away.” There is actually a simulation lab for the engineers to practice controlling the robotic arms located at JPL’s In-Situ instrument lab in Pasadena, California. Once the InSight team successfully operates the arm to deploy InSight’s instruments, it will be known as the first time that a robotic arm has been used to set down hardware on another planet!
They will also be facing extreme temperature changes on Mars because of its location near the equator, where summer sun causes temperature swings from 21°C (70°F) to as low as -73°C (-100°F) at night! Thankfully the InSight engineers were able to make it survivable under many layers of protection. There are two main instruments on InSight. The first is called Seismic Experiment for Interior Structure, also known as SEIS, which contains an array of seismometers used for measuring the size, speed and frequency of Seismic waves produced by the shifting and cracking of the Martian interior, also known as Mars quakes! SEIS can measure ground movement smaller than the width of a hydrogen atom! That’s really really tiny!!
Tom Hoffman says, “ If there happened to be a butterfly on Mars and it landed very lightly on the Seismometer, we’d actually be able to detect that.”
Seismometers are also used on Earth to detect earthquakes, but they are handled much more delicately, put in place and never touched again. The seismometers on Mars are a lot stronger, able to handle the rumble from the rocket launch, the atmospheric entry, descent and landing.
This seismometer can also can detect liquid water, meteorite impacts and plumes from active volcanoes. It will do this by using temperature sensors moving along with the probe, and InSight will be able to gather the temperature readings and conductivity measurements and tell scientists just how much heat is emitting from the inside of Mars. Or, rather, how much heat as lacking. This data will lead researchers to deriving ideas of what exactly the planet is made of, and how its composition compares to Earth’s.
The second instrument that InSight will have is the heat flow and physical properties probe, also known as HP3. It’s a 18-inch probe that will dig about 16 feet into the Mars soil. The reason it’s digging this deep? Because at that depth it will be unaffected by the temperature changes on the martian surface! By the way, all of this digging will take weeks with frequent pauses to measure how effectively the surroundings conduct heat.
Comparing this equipment to Opportunity, Curiosity and Spirit rovers, none of Insight’s predecessors had a seismometer onboard. They had the usual tools, like spectrometers to measure different elements, the Pancam to see what’s around them, the X-ray spectrometer, a microscopic imager, and a calibration target and sundial to adjust the lighting for the cameras for the variation in lighting from dust and wind storms! Also onboard the rovers is a RAT, aka Rock Abrasion Tool. It’s attached to the Instrument Deployment Device, or IDD, and it has two diamond-tipped grinders that dig holes in the surface of Mars about 45 mm (about two inches) in diameter and 5 mm (1/5 inch) deep. It gets to the fresh rock that has been untouched to analyze and figure out more about Mars’ history.