NASA has a billion-dollar mission to study oceans and climate – 02/20/2024 – Environment

After surviving four cancellation attempts, a new satellite designed by NASA to study in detail the only planet known to harbor life – ours – is now in space.

Pace (an acronym in English for plankton, aerosol, cloud and ocean ecosystem satellite) promises to revolutionize the understanding of the dynamics between the atmosphere and oceans, which involves processes essential to the evolution of the climate, responsible for the greatest uncertainties still remaining in the most modern climate models .

The satellite, weighing 1.7 tons and costing US$948 million (about R$4.67 billion), was launched from platform 40 of the Cape Canaveral Space Force Station, in Florida, with a Falcon 9 rocket from the company SpaceX, in the early hours of the 8th.

Placed in a sun-synchronous polar orbit, it will fly over all regions of the planet, always passing through each location at the same time. This is a useful procedure for comparing images taken on different days, but under the same lighting conditions — since the Sun is always in the same place in the sky during the passage.

The equipment flies at an altitude of around 675 km and has already established communication with the mission control center, located at NASA’s Goddard Space Flight Center, in Greenbelt (Maryland).

Over the next 40 days, it will commission all systems and instruments, and then begin its scientific mission – which will last at least three years, although researchers hope it could span a decade or more.

THREE INSTRUMENTS

The Pace only has three instruments on board. One of them is a hyperspectral camera designed to observe Earth’s oceans in detail, based on their color — not only what we can see with our own eyes, but also in ultraviolet and near infrared.

With this, the satellite will be able to track the distribution of phytoplankton — microscopic protist and bacterial organisms that live through photosynthesis, the process by which living creatures convert carbon dioxide and sunlight into oxygen and sugar. Most of the atmospheric oxygen that allows us to breathe, by the way, is the product of these microorganisms.

And the same applies to the oxygen consumed by other living beings in rivers and oceans. Finally, they are at the base of the marine food chain, which makes them very important for understanding the development of life as a whole on the planet.

The instrument will also allow us to identify which phytoplankton communities are present in which parts of the ocean, on a daily and global scale. The information collected will make it possible to predict the health of fish populations and monitor the emergence of harmful algae, in addition to identifying changes in the marine environment.

“This is not ‘scientific curiosity’. The oceans are important repositories of carbon dioxide and energy for the entire planet, and 75% of the Earth’s surface is covered by ocean water”, says Paulo Artaxo, researcher at the Institute of Physics from USP (University of São Paulo) and specialist in climate change. “They are fundamental for carbon cycling and energy balance.”

The two other instruments on board are polarimeters, which specifically measure sunlight that is reflected in the aerosols present in the atmosphere — microscopic particles of the most varied types, from dust to pollution — and becomes polarized (the electromagnetic waves start to travel only in a specific plane , rather than at all).

By mapping them and observing their dynamics in the atmosphere, Pace can make fundamental contributions to improving our climate modeling, essential for understanding and then mitigating and ultimately containing the current climate crisis driven by human activity, particularly with the burning of fossil fuels.

“These aerosols play a really important role, both in short-term weather — they seed clouds that grow to become storms and hurricanes — and in climate stability,” explains Karen St. Germain, director of NASA’s geosciences division.

“Aerosols reflect sunlight and [esses instrumentos] determine what their composition is, how big they are, what shape they are and where they are in the atmosphere, and this will determine what kind of clouds they seed. This relationship between aerosols and clouds, and their relationship with short-term weather and long-term climate, is the biggest source of uncertainty that we have, in particular, in climate modeling,” he says.

For her, “these new insights from Pace will help us answer the role of aerosols, how they create clouds and how this feeds climate feedback pressures.”

Artaxo, who has a large part of his work focused on studying the role of aerosols in the climate, highlights Pace as a major evolution.

“The new sensors are much more modern than those used on NASA’s Terra and Aqua satellites. Ten years of technological innovation have made a difference. The new sensors have better resolution and are more sensitive, in addition to having polarization, which greatly improves the detection of atmospheric aerosols and cloud properties.”

THE FIGHT TO GET TO SPACE

It’s customary to think of NASA as the space agency that explores space, more focused on other planets than ours. But in fact, the study of Earth itself, both as an end in itself and for comparison with its neighbors in the Solar System and beyond, is one of the agency’s core missions.

It currently operates 35 missions in Earth orbit, which also include instruments on NASA satellites (American Atmospheric and Oceanic Agency) and on board the International Space Station (ISS).

Pace joins the group at a cost of nearly $1 billion, but for some time the project’s fate was uncertain.

During Donald Trump’s administration, there was a determination to shift NASA’s focus away from missions aimed at studying the Earth, particularly in connection with climate change. For four years, between 2017 and 2020, the budget proposed by the White House provided for the cancellation of Pace. On each occasion, the US Congress repaid the funding and kept the mission on track.

The former administration’s obsession with taking down NASA’s climate study missions went so far as to try to cancel even the operations of instruments already launched, such as the Epic camera, aboard the NASA satellite Dscovr (an acronym in English for Climate Observatory). Deep Space), launched in 2015.

Now, Trump is fighting to return to the US Presidency. Could this mean a future abandonment of Pace or other NASA geoscience missions? Not for Artaxo. “It is not possible for a possible Trump administration to affect this data collection. The American Congress and the population would never allow such a debacle.”