Repurposed technology used to probe new regions of Mars’ atmosphere

Utilizing the repurposed gear, a staff together with Imperial Faculty London researchers have measured components of the Martian environment that have been beforehand unimaginable to probe. This consists of areas that may block radio alerts if not correctly accounted for—essential for future Mars habitation missions.

The outcomes of the primary 83 measurements, analyzed by Imperial researchers and European House Company (ESA) colleagues throughout Europe, are published at the moment within the journal Radio Science.

To realize this, ExoMars’ Hint Fuel Orbiter (TGO) teamed up with one other ESA spacecraft orbiting the pink planet: Mars Categorical (MEX). The 2 craft preserve a radio hyperlink, in order that as one passes behind the planet, radio waves minimize by way of the deeper layers of the Martian environment.

Modifications within the environment’s refractivity—the way it bends the radio waves—trigger tiny however detectable shifts within the radio frequencies obtained by the spacecraft. By analyzing this shift, scientists can decide the density of the decrease environment and the electron density within the ionosphere—a charged higher layer of the environment. The method is known as mutual radio occultation.

Lead creator of the examine Jacob Parrott, a Ph.D. pupil from the Division of Physics at Imperial, mentioned, “The techniques on MEX and TGO weren’t initially designed to do that—the radio antennas we used have been made for communication between orbiters and rovers on the planet’s floor. We needed to reprogram them whereas inflight to hold out this new science.

“This modern method is prone to be a game-changer for future missions, proving that mutual radio occultation between two orbiting spacecraft is a cost-effective technique to extract extra scientific worth from current gear.”

Dream teamwork

Beforehand, radio occultation was performed utilizing the radio hyperlink from a Mars orbiter to massive floor stations on Earth. The radio sign from the orbiter could be monitored because the spacecraft “set” (was occulted) behind Mars, that means the sign handed by way of the layers of the planet’s environment.

Utilizing two orbiting craft to take this measurement is already a typical technique to examine the Earth’s environment: 1000’s of such measurements happen between international navigation satellites, the place the information they supply are used for atmospheric monitoring and climate prediction.

Nonetheless, this technique had solely been used on Mars 3 times earlier than; by NASA in 2007 as a {hardware} demonstration. The brand new use by the 2 ESA spacecraft marks the primary time this method has been routinely utilized to a different planet.

Now its viability has been confirmed, the scientists and engineers behind the work are trying into tips on how to increase the usage of this method in future Mars missions.

Research co-author Dr. Colin Wilson, Mission Scientist for the ExoMars Hint Fuel Orbiter and Mars Categorical at ESA, mentioned, “ESA has now demonstrated the viability of this method, which may very well be transformational for Mars science sooner or later.

“There are at the moment seven spacecraft orbiting Mars; because the variety of spacecraft will increase, as it should in coming many years, the variety of radio occultation alternatives will increase quickly. Due to this fact, this method might be an more and more essential device for learning Mars.”

Extra measurements, extra insights

Spacecraft-to-spacecraft occultation permits extra measurements to be taken and permits new areas of the environment to be probed.

As a result of typical radio occultation measurements on Mars contain a radio hyperlink to a floor station on Earth, the measurement location is fastened relative to Earth’s gradual motion. This makes it laborious to seize international adjustments on Mars, as researchers are sometimes trying on the similar spots.

Moreover, this technique can solely pattern close to sundown and dawn due to Earth’s proximity to the sun, limiting our view of Mars’ atmosphere.

Furthermore, conventional radio occultation suffers from “occultation seasons,” the place measurements are solely doable for a couple of months annually because of the spacecraft’s orbit. For instance, Mars Categorical may solely carry out radio occultation for 2 months in 2022.

Mutual radio occultation overcomes these issues, permitting researchers for the primary time to discover all the depth of Mars’ ionosphere round midday and midnight.