Playing the claw game that sits in the entry area of your local Walmart store is a challenge to win. This is despite that fact that you are standing right in front of the glass case controlling the arm. If you had to play that claw game from another planet, the difficulty would be greatly compounded. This is essentially what NASA scientist will be doing when it comes to controlling the robotic arm used for the InSight mission.
While control of the arm will be difficult, another challenge is that the objects that NASA wants to pick up are much more fragile than the cheap toys you are trying to win from that claw machine. NASA’s Insight lander is set to arrive on Mars on November 26, 2018. This will be the first Mars mission to use a robotic arm to grasp instruments from a spacecraft and place them on the planet.
The goal of these instruments is to study the deep interior of Mars for the first time. The robotic arm on the lander is called the Instrument Deployment Arm and it is going to be picking up two sensitive science packages from the spacecraft deck and gently placing them on the surface of Mars. The two science packages are the Heat Flow and Physical Properties Package, to assess the interior of Mars, and the Seismic Experiment for Interior Structure, to study vibrations on the ground of the planet.
The latter science package is meant to study vibrations created by marsquakes and meteorite impacts. Insight’s robot arm also must pick up a Wind and Thermal Shield to place over the seismometer. All the components must be placed perfectly for the mission to be successful.
The team at JPL working on the robotic arm started with a leftover robotic arm from the Mars Surveyor 2001 lander that never launched. That arm was designed for lifting making it appropriate for the needs of InSight. The arm is also long at 5.9 feet, important because the seismometer and heat probe need to be a significant distance away for the instruments to function. The arm was completely refurbished for its new mission and will be put into use a few days after InSight lands.