June 25, 2020

Rover

The Mars 2020 rover analysing rocks with its robotic arm. Credits: NASA/JPL-Caltech

Perseverance, the Mars 2020 rover, is based on the Mars Science Laboratory’s Curiosity rover configuration. It is 3 metres long, 2.7 metres wide and 2.2 metres tall, and tips the scales at 1,050 kilograms.

The rover’s body—called the warm electronics box or WEB for short—protects its computers and electronics, and maintains a constant temperature. The upper deck of the rover provides a platform for its mast, which can take pictures as it scouts the Martian terrain.

The rover has two identical computers that can back each other up. They communicate with the rover’s functional units through two networks designed to aviation reliability standards. The computers also talk directly to the rover’s instruments to send commands and retrieve their data.

The rover has many complementary cameras. Four will be used during the descent phase and will each have a microphone:

  • A camera on the back shell will look upward to capture the parachute opening.
  • A camera on the descent stage will look down at the rover and surface below.
  • A camera on the rover will look up at the descent stage to film sky crane operations during descent.
  • Another camera on the rover will look down at the Martian surface.

Besides supporting engineering operations, these cameras will bring live pictures for the public of the mission’s descent towards the surface of Mars.

9 engineering cameras:

  • 6 Hazcams, 4 at the front and 2 at the rear, will detect obstacles—rocks, ruts and dunes—that could obstruct the rover’s progress, enabling it to navigate autonomously. The front cameras will also be used to watch the robotic arm’s movements. They are 60 to 70 cm above the ground.
  • 2 Navcams at the front and rear of the rover, and 2 Mastcams.
  • CacheCam will watch as rock samples are deposited into the rover's body before the tubes are sealed.

In addition to the microphone that will listen for sounds during the landing phase, a special microphone on the SuperCam instrument will help scientists to study rocks by recording the sounds from plasma flashes produced by the laser, as well as the sounds of the rover itself.

The rover’s 2-metre robotic arm is extremely mobile. It is topped by a turret with a suite of instruments capable of taking pictures, analysing elemental compositions and collecting small samples.

The rover has 6 wheels, each with its own individual electric motor. The two front and two rear wheels also have individual steering motors, allowing the rover to turn in place a full 360 degrees.

The rover needs power to drive, conduct science operations and communicate. Electricity is produced by an MMRTG (Multi-Mission Radioisotope Thermoelectric Generator), which converts heat from the natural radioactive decay of plutonium into a steady flow of electricity. The MMRTG also charges two primary storage batteries. Excess heat from it also keeps the rover’s body and instruments at their correct operating temperatures.

The rover has 3 antennas for sending back data and receiving commands. The UHF antenna communicates with satellites in Mars orbit. The 2 VHF antennas communicate directly with a network of antennas on Earth. These have less bandwidth and are only used if the link with Mars satellites is lost.

Instruments

Where the science instruments are on the rover. Credits: JPL/NASA

  • Mastcam-Z: An advanced camera system with panoramic and stereoscopic imaging and zoom capability. The instrument also will determine mineralogy of the Martian surface and assist with rover operations. The Principal Investigator is James Bell from Arizona State University in Phoenix.

  • SuperCam: An instrument that can provide imaging, chemical composition analysis and mineralogy. It will also be able to remotely detect the presence of organic compounds in rocks and regolith. It also has a special microphone. The Principal Investigator is Roger Wiens, Los Alamos National Laboratory (LANL), New Mexico. This instrument also has a significant French contribution from CNES and the IRAP astrophysics and planetology research institute and a French Co-Principal Investigator, Sylvestre Maurice.

  • PIXL (Planetary Instrument for X-ray Lithochemistry): An X-ray fluorescence spectrometer that will also incorporate a high-resolution imager to determine the fine-scale elemental composition of Martian surface materials. PIXL will also provide capabilities for more detailed detection and analysis of chemical elements than ever before. The Principal Investigator is Abigail Allwood from NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

  • SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals): A spectrometer that will provide fine-scale imaging and uses an ultraviolet (UV) laser to determine fine-scale mineralogy and detect organic compounds. SHERLOC will be the first UV Raman spectrometer to fly to the surface of Mars and will provide complementary measurements with other instruments in the payload. The Principal Investigator is Luther Beegle from JPL.

  • MOXIE (Mars Oxygen ISRU Experiment): An exploration technology investigation that will produce oxygen from carbon dioxide in Mars’ atmosphere. The Principal Investigator is Michael Hecht from Massachusetts Institute of Technology, Cambridge, Massachusetts.

  • MEDA (Mars Environmental Dynamics Analyzer): A set of sensors that will provide measurements of temperature, wind speed and direction, pressure, relative humidity and dust size and shape. The Principal Investigator is Jose Rodriguez-Manfredi from the Centro de Astrobiologia, Instituto Nacional de Tecnica Aeroespacial, Spain.

  • RIMFAX (Radar Imager for Mars' Subsurface Exploration): A ground-penetrating radar that will provide centimetre-scale resolution of the subsurface geologic structure. The Principal Investigator is Svein-Erik Hamran from the Forsvarets Forskningsinstitutt, Norway.