Science

– 10 years of uninterrupted cellular measurement knowledge from Mars

November 25, 2022

NASA’s Mars Science Laboratory (MSL) rover Curiosity first landed on Mars in August 2012. Since then, the rover has collected steady environmental measurements which have stunned and delighted mission scientists.

Over the previous 10 years, Curiosity has traveled practically 29 km and climbed 625 meters, exploring Gale Crater and the bottom of Mount Sharp earlier than its touchdown web site.

To at the present time, dramatically exceeding the mission’s preliminary two-year aim, the rover’s devices stay absolutely operational. A number of the mechanical components present indicators of damage, however the sensors are nonetheless going sturdy, transmitting distinctive knowledge from the purple planet.

Right here, Harri Heinonen, lead engineer of Vaisala’s sensor growth crew, and Professor Ari-Matti Harri, head of area observations and analysis on the Finnish Meteorological Institute (FMI), focus on why the info from MSL Curiosity is so necessary.

Background

Vaisala has a protracted historical past in area exploration, courting again to the Nineteen Fifties, when Vaisala transformed the frequency of a radio theodolite to assist monitor the world’s first synthetic satellite tv for pc, Sputnik I.

Since 1992, Vaisala’s carbon dioxide, humidity and temperature sensors have been utilized in bioscientific experiments each on board area shuttles and on the Worldwide House Station.

FMI was chargeable for constructing the humidity and stress measurement devices utilized in MSL’s Curiosity Rover Environmental Measurement System (REMS). These probes used Vaisala sensor heads, however the relationship between FMI and Vaisala goes again additional than the Curiosity mission – Vaisala was based in 1936 by Professor Vilho Väisälä, who additionally retained FMI management positions till 1948.

Vaisala and FMI have since labored collectively on many different initiatives, together with interplanetary exploration missions such because the Cassini Huygens probe, which landed on Saturn’s largest moon Titan in 2005, and the Phoenix lander, which efficiently landed on Mars in 2008.

Why Mars?

Mars is dusty and chilly with a really skinny ambiance. The typical temperature on Mars is about -60°C. Nevertheless, daytime air temperatures have been recorded at +35°C and floor temperatures usually rise to +20°C at noon on the equator, with a low of round -153°C on the poles.

Generally known as the Pink Planet, its floor accommodates massive quantities of iron oxide, however the formation of this materials continues to be a matter of debate. Mars has the tallest mountain in our photo voltaic system (17 miles excessive – 3 times the peak of Mount Everest) and the deepest and longest valley.

There’s sturdy proof from quite a few research that billions of years in the past Mars was wetter and hotter with a thicker ambiance. On the time, it resembled Earth in lots of respects, and the 2 are sometimes called sister planets.

A roughly comparable measurement and orbiting planet with an analogous inclination has comparable seasons, with day and night time on Mars lasting about 24 and a half hours on Earth. Nevertheless, the Martian 12 months is nearly twice as lengthy (687 Earth days) as a result of it’s farther from the Solar, so its orbit is longer and it strikes a bit of slower.

From a analysis perspective, Mars affords a chance to higher perceive how Earth has developed and the way it’s prone to change sooner or later. For instance, if Mars and Earth had been moist and heat just a few billion years in the past, we have to perceive why they selected completely different paths later.

After Earth, Mars is probably the most noticed planet, and given the similarities between the 2 planets, the info collected to date has allowed scientists to use present terrestrial meteorological fashions to the Martian setting.

Steady monitoring of Mars permits these fashions to be additional refined to make Martian local weather predictions extra correct.

A curious approach

The MSL Curiosity mission was initially meant to take environmental measurements throughout one Martian 12 months. The aim of this research was to find out whether or not Mars might have supported microscopic life sooner or later in its previous. The conclusion was a powerful “YES!”.

MSL Curiosity has carried out so effectively that NASA just lately introduced a three-year extension of its mission. Within the coming interval, MSL Curiosity will climb to increased altitudes, learning crucial sulfate-bearing layers that present distinctive perception into the historical past of Martian water.

Along with cameras and radiation detectors, MSL Curiosity additionally has devices that enable it to carry out chemical evaluation on Mars. An X-ray alpha particle spectrometer measures the quantity and sorts of chemical components when close to the rock or soil floor.

The “ChemCam” laser, digital camera and spectrograph work collectively to establish the chemical and mineral composition of rocks and soil. The Chemistry and Mineralogy Instrument performs chemical evaluation of powdered rock samples, and the Pattern Evaluation Device accommodates three completely different devices that seek for and measure natural chemical substances and light-weight components probably related to life.

Chemical evaluation of rocks and dirt helps scientists higher perceive the historical past of Mars. Nevertheless, environmental measurements inform us in regards to the present situations of the planet.

The MSL Curiosity REMS is positioned within the “neck” of the rover, about 1.5 m above the bottom, and accommodates Vaisala/FMI stress and humidity sensors, in addition to sensors to measure temperature, wind and UV radiation.

REMS was designed to function at extraordinarily low energy and function in a temperature vary of -130 °C to +70 °C. Measurements are taken for at the very least 5 minutes each hour, each Martian day or ‘sol’. This knowledge permits Earth mission scientists to supply every day and seasonal stories on the meteorological situations surrounding the rover.

House-proof sensors

It is onerous to think about more difficult situations than these skilled by sensors aboard NASA’s rovers each in flight and when exploring the planet’s floor. Along with big temperature and stress adjustments, the sensors should additionally face up to very excessive vibrations.

The Vaisala sensor heads put in on the Curiosity rover are primarily the identical ones used each day by virtually each trade on Earth, though Vaisala modified the stress sensor barely to match the very low ranges skilled on Mars. .

Each stress and humidity sensor applied sciences had been game-changing after they had been first launched, providing a brand new degree of accuracy and long-term reliability. That is clearly helpful for mundane customers, however when the closest service engineer might be 400 million kilometers away, it’s important!

At FMI, the instrumentation growth course of concerned designing the electronics, Faraday cage, encapsulation, housings and connectors, and dirt safety. Naturally, the sensors had been examined in each potential approach earlier than the ultimate design was accepted and the sensors had been rigorously despatched to the REMS Principal Investigator on the Heart for Astrobiology in Spain.

The humidity sensors characteristic Vaisala’s HUMICAP expertise, a capacitive skinny movie polymer sensor consisting of a substrate onto which a polymer movie is deposited between two electrodes.

The polymer both absorbs or emits water vapor when the humidity of the setting rises or falls, which adjustments its dielectric properties and thus the capacitance of the sensor, which is measured and transformed right into a humidity studying.

Vaisala’s BAROCAP is a micromechanical stress sensor that makes use of single crystal silicon materials to measure dimensional adjustments in a silicon membrane. As the encompassing stress will increase or decreases, the membrane flexes, thereby rising or reducing the peak of the vacuum hole contained in the sensor.

Reverse sides of the hole act as electrodes, and because the distance between them adjustments, the capacitance of the sensor adjustments, which is measured and transformed into stress readings.

The important thing options of each sensors are their long-term stability and their capacity to face up to mud, chemical substances and harsh situations. The ten-year lifespan of the sensors on board MSL Curiosity isn’t any shock to Vaisala’s sensor growth crew, who consider that because the rover’s REMS ages, the related electronics usually tend to fail than the sensor heads themselves.

Discovering solutions to fundamental questions

The advantages of area exploration imply various things to completely different individuals. For instance, on a purely scientific foundation, we people are naturally curious and wish to know extra about our world and past.

Nevertheless, this data serves a higher goal than merely satisfying curiosity; it helps defend humanity and the setting we rely on.

If we are able to perceive how planets type and evolve, we are able to higher predict and mitigate cosmic phenomena resembling planetary destruction, asteroid collisions, mass extinctions, or situations that make Earth uninhabitable.

House exploration helps us higher perceive these points, and for some, Mars exploration could ultimately allow interplanetary human switch—if vital.

In accordance with NASA, area exploration helps reply basic questions on our place within the universe and the historical past of our photo voltaic system. By fixing the challenges of human area exploration, we broaden expertise, create new industries, and assist promote peaceable communication with different nations.

Mars is probably the most noticed planet – as Earth’s sister, it supplies a chance for comparative planetology. A whole lot of scientific papers have been revealed worldwide on this analysis, and given the numerous traits the 2 planets have in frequent, many take into account Mars a kind of scientific sandbox. For instance, if scientists can uncover why Mars and Earth developed in such other ways, it’s hoped that this can assist to higher perceive the way forward for Earth.

After discovering that situations on Mars could have been favorable for all times previously, scientists at the moment are investigating whether or not microscopic life existed at the moment, which can assist to higher perceive the primary existence of dwelling organisms on Earth.

Since 1960, there have been 49 missions to Mars, about half of which have failed. Many of the failures occurred in earlier years, however these experiences have knowledgeable subsequent missions as scientists all over the world have realized extra about area journey, expertise and the problems of touring to, orbiting, and touchdown on Mars.

Ready

Environmental monitoring knowledge is critical to know the planet’s local weather, so the longevity of MSL Curiosity’s efficiency has been a giant bonus, and the reliability of the devices on board the rover has allowed it to considerably broaden its mission.

You will need to perceive that the MSL Curiosity mission is a crucial step in NASA’s Mars exploration program. The Perseverance Rover, incorporating next-generation Vaisala expertise in FMI-developed gear, landed on Mars in February 2021; searching for indicators of historical life and accumulating rock and soil samples for potential return to Earth.

Furthermore, the 2 rovers, working about 2,000 km aside, will lay the muse for an atmospheric commentary community wanted to higher perceive and predict Martian climate.

Our complete understanding of the Martian local weather and its historical past requires a greater spatial distribution of measurements. Subsequently, will probably be necessary sooner or later to have the ability to observe concurrently in a number of locations on the planet.

Knowledge from devices aboard the MSL Curiosity and Perseverance rovers could in the future enable individuals to go to Mars.

However maybe the best worth of measurement knowledge is in serving to to search out solutions to humanity’s massive questions: How did life start? Are we alone? and what’s the universe made from?


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