The MARSIS instrument on ESA’s Mars Express spacecraft, famous for its role in detecting signs of liquid water on the Red Planet, is getting a major software upgrade that will allow it to see in greater detail beneath the surfaces of Mars and its moon Phobos than ever before.
Mars Express was ESA’s first mission to the Red Planet. Launched 19 years ago, on June 2, 2003, the orbiter has spent nearly two decades studying Earth’s neighbor and revolutionizing our understanding of Mars’ history, present and future.
MARSIS – water on the red planet
The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument on Mars Express was instrumental in looking for and discovering signs of liquid water on Mars, including a suspected 20 by 30 km lake with salt water buried under 1.5 km of ice in the southern polar region.
Operated by the Istituto Nazionale di Astrofisica (INAF), Italy, MARSIS is fully funded by the Italian Space Agency (ASI), sending low-frequency radio waves to the planet using its 40-meter antenna.
Most of these waves are reflected from the planet’s surface, but significant amounts travel through the crust and are reflected at boundaries between layers of various materials below the surface, including ice, soil, rock and water.
By examining the reflected signals, scientists can map the structure beneath the Red Planet’s surface to a depth of several kilometers and study features such as the thickness and composition of the polar caps and the properties of volcanic and sedimentary rocks.
From Windows 98 to Mars 2022
“After decades of fruitful science and an understanding of Mars, we wanted to push the instrument’s performance beyond some of the limitations required when the mission began,” said Andrea Cicchetti, MARSIS Deputy PI and Operation Manager at INAF, who led the development of the upgrade.
“We faced a number of challenges to improve the performance of MARSIS,” said Carlo Nenna, MARSIS on-board software engineer at Enginium, who is implementing the upgrade. “Not least because the MARSIS software was originally designed more than 20 years ago in a development environment based on Microsoft Windows 98!”
The new software was designed together with the INAF team and Carlo and is now being implemented by ESA on Mars Express. It includes a series of upgrades that improve onboard signal reception and data processing to increase the amount and quality of scientific data sent to Earth.
“Previously, to study key features on Mars, and to study its moon Phobos at all, we relied on a complex technique that stored a lot of high-resolution data and filled the instrument’s internal memory very quickly,” says Andreas.
“By throwing away data we don’t need, the new MARSIS software allows us to turn on MARSIS five times as long and explore a much larger area with each pass.”
“There are many regions near the south pole on Mars where we may have already seen signals pointing to liquid water in lower-resolution data,” adds ESA Mars Express scientist Colin Wilson.
“The new software will help us study these regions more quickly and comprehensively in high resolution and confirm whether they harbor new water sources on Mars. It really is like having a brand new instrument aboard Mars Express nearly 20 years after launch. ”
The workhorse of Mars
Old enough to vote in many places on Earth, Mars Express continues to deliver amazing science and remains one of ESA’s cheapest missions to fly.
“Mars Express and MARSIS are still very busy,” said James Godfrey, Mars Express spacecraft operations manager at ESA’s ESOC mission center in Darmstadt, Germany. “The team has done a great job designing the new software, maximizing impact and minimizing patches, allowing us to continue to get the most out of this accomplished spacecraft.”
Learn about the other new scientific and operational activities that Mars Express has recently made possible on the Mars Express blog.
MARSIS was developed by the University of Rome, Italy, in collaboration with NASA’s Jet Propulsion Laboratory in Pasadena, California.
The INAF team acknowledges support from the Italian Space Agency (ASI) through contract ASI-INAF 2019–21-HH.0.