InSight Instrument

InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) is a robotic NASA spacecraft designed to study the deep interior structure of Mars. InSight, the first rover specifically equipped to “look beneath” Mars’ surface, aimed to measure the planet’s vital signs—its pulse (seismology), temperature (heat flow), and reflexes (geodesy). Launched on 5 May 2018, the spacecraft successfully landed on Mars on 26 November 2018 and concluded its mission in December 2022.

InSight (TRT News)

Scientific Objectives

InSight’s primary goal was to answer fundamental questions about how terrestrial planets like Earth formed 4.5 billion years ago. To achieve this, it focused on Mars’ internal structure:

• Core: Determine the size, composition and physical state (liquid or solid) of Mars’ core.
• Crust: Understand the thickness and structure of the planet’s crust.
• Mantle: Reveal the structure and composition of the mantle.
• Internal Heat: Measure the rate of heat flow from within the planet.
• Seismic Activity: Determine how frequent and how strong “Mars quakes” are.

Design and Scientific Instruments

Overall Structure InSight’s design was based on the successful Phoenix lander, which landed on Mars in 2008. The spacecraft was equipped with two circular solar panels and featured a robotic arm (Instrument Deployment Arm) to place its scientific instruments onto the surface.

Main Scientific Instruments InSight carried three primary scientific instruments to achieve its objectives:

• SEIS (Seismic Experiment for Interior Structure): This seismometer, the mission’s most critical instrument, was designed to detect even the smallest seismic vibrations by being placed directly on the Martian surface. It collected data on the planet’s interior by measuring seismic waves generated by Mars quakes or meteorite impacts.
• HP³ (Heat Flow and Physical Properties Package): Also known as “the mole,” this heat probe was intended to burrow up to five meters below the Martian surface to measure heat flowing from within the planet. However, the unexpected and loose structure of Mars’ soil (regolith) prevented the mole from gaining sufficient friction to progress. Despite over two years of troubleshooting efforts by the team, the instrument failed to reach its target depth, rendering this aspect of the mission unsuccessful.
• RISE (Rotation and Interior Structure Experiment): This geodesy experiment used radio signals between InSight and NASA’s Deep Space Network (DSN) on Earth. By precisely measuring Doppler shifts in these signals, it tracked Mars’ wobble as it rotated on its axis. These wobble measurements provided crucial information about the size and density of the planet’s core.

InSight (Anadolu Agency)

Mission Timeline

Launch and Landing InSight was launched on 5 May 2018 from Vandenberg Air Force Base in California. This marked the first interplanetary launch from the west coast of the United States. After a seven-month journey, it successfully landed on 26 November 2018 on Elysium Planitia, a flat and expansive plain on Mars.

Surface Operations and Mission End Following landing, InSight carefully deployed its SEIS and HP³ instruments onto the Martian surface using its robotic arm. While the SEIS seismometer became operational, the HP³ probe’s failure to penetrate the soil triggered an extended troubleshooting effort. Over the course of its four-year mission, InSight collected valuable scientific data. However, over time, dust accumulating on its solar panels significantly reduced the spacecraft’s power generation capacity. As InSight’s power dwindled, communication was lost in December 2022, and NASA officially declared the mission concluded.

Key Discoveries and Legacy

Despite the failure of its heat probe, the InSight mission made revolutionary contributions to Martian science:

• Mars Seismology: InSight detected over 1,300 Mars quakes, definitively proving that Mars is seismically active and creating the first seismic catalog of any planet other than Earth.
• Mars’ Internal Structure: Using seismic data, scientists produced the first detailed map of Mars’ interior. They determined that the planet has a larger and liquid core than expected, as well as the thickness of its crust and the structure of its mantle.
• Soil Properties: The challenges encountered by the HP³ mole provided vital new insights into the physical properties of Martian soil, informing future drilling and excavation missions.

InSight transformed Mars from a world known only by its surface features into a planet whose internal dynamics and structure are now characterized.