A powerful satellite will display changes on the Earth's surface in exquisite detail - up to a centimeter

But will the US-India mission be the last for NASA for a long time?

The amazingly high-resolution satellite launched today will soon display changes on the Earth's surface in unprecedented detail - tracking everything from sinking agricultural land to crumbling ice sheets and flood-devastated terrain. This is the largest collaboration in history between NASA and the Indian Space Research Organization (ISRO), which brings the dreams of scientists to study our dynamic planet.

In the coming days, the $1.2 billion NISAR satellite will deploy a round antenna 12 meters wide and start rebounding radar signals from Earth. Launched from Sriharikota, India, NISAR scans almost the entire planet twice every 12 days and measures vertical physical shifts on the ground measuring only one centimeter, even through the clouds and at night.

Watching the launch of NISAR is like being "a parent attending his son's graduation ceremony!" Speaks Deepak Putrevu, who is co-head of the scientific group of the mission for ISRO. "It's so exciting to watch."

But for NASA, this excitement is a concern, as U.S. President Donald Trump insists on reducing the agency's budget for the Earth science mission by more than 50% in fiscal year 2026. It is planned that NISAR itself will get the money to work as expected, but it may be one of the latest of its kind to be launched over the years: The White House wants to cancel most of NASA's upcoming flagship Earth observation missions "to achieve cost savings". And he wants to close several missions that are already working and collecting key information about changes on Earth.

"This is the size of the cut that will fundamentally destroy our ability" to improve the understanding of a changing planet, says Dylan Millet, an atmospheric chemist at the University of Minnesota at St. Paul, who chaired NASA's Earth Science Advisory Committee until March, when NASA dissolved it.

A push to respond to natural disasters

NISAR, which stands for NASA-ISRO Synthetic Aperture Radar, will use two radar devices operating at different wavelengths, one built by NASA and the other by ISRO, to map changing ice and the Earth's land surface. On a global scale, the satellite will be able to determine changes in soil moisture, forest biomass and glaciers, among others.

And it will help in responding to natural disasters such as floods, earthquakes and landslides, providing up-to-date information on how the Earth behaves. "You can begin to build up the ability to see disasters as they develop at a very fast pace, and this should help identify areas of concern to rescuers," says Paul Rosen, a researcher of the mission project at the NASA Jet Propulsion Laboratory in Pasadena, California.

NASA and ISRO began cooperating on NISAR in the early 2010s, when it became clear that both American and Indian scientists wanted to manage a large radar mission, Rosen says. If everything goes well with the deployment of the antenna and other tasks, NISAR should start providing scientific data within 90 days. It is planned that the mission will work for at least three years.

Uncertain future

What will happen after that is a more important question, at least for NASA. NISAR was to become a pioneer in a series of large Earth observation satellites aimed at measuring, among other things, the role of clouds and aerosols in climate change, as well as biological and geological interactions across the planet.

These missions were identified as top priorities for American Earth science researchers in two wish lists of "ten years of research" published in 2007 and 2018. NASA Director of Earth Sciences, Karen St. Germain told Nature that the decadal surveys confirm the importance of the information collected by NISAR and similar missions. "Our passion is to make the most advanced science we can do with the budget allocated to us," she said, highlighting two other NASA science launches over the past few years, satellites for measuring the height of the water and the color of the ocean. "We think that in fact we are entering a rather rich golden age of new types of data that can answer questions we have never been able to answer before," she added.

If the reductions proposed by Trump continue, some researchers say, NASA will lose the opportunity to engage in science, which will be the most important, as global warming increases the risks of extreme weather conditions and other dangers. "We must collect this data so that we can make informed decisions and plan for the future," says Millet, who, along with other members of the disbanded advisory group, published a letter to Science this month condemning potential cuts1.

According to many researchers, disabling long-term scientific tools, such as the carbon dioxide tracker on the International Space Station, which Trump's team is targeting, is also a mistake. "Sigious gaps in historical climate data will create an unprecedented problem," says Bernard Pinti, an atmospheric scientist who previously worked with the Climate Change Service in the European Commission's Copernicus Earth Observation Program. Germain said at a press briefing on July 29 that the cessation of long-term measurements is a natural consequence of missions approaching the end of their lives: "To a large extent, this is the case that some satellites retire as new ones appear."

The fate of NASA's Earth science missions is now in the hands of the U.S. Congress, which has the final authority to distribute federal money and during Trump's first presidency rejected almost all his proposals to reduce NASA research. For the next fiscal year, the Senate Appropriations Committee indicated that it would fully fund most of NASA's future Earth science missions, but the House of Representatives seems ready to accept most of the cuts proposed by Trump. Scientists will be looking forward to watching the two houses of Congress reconcile these disparate views and agree on the final budget in the coming months.