The Indian Express (Delhi Edition)
A moment scientists are dreading: 3 Nasa satellites to die soon
SOMETIME IN the next few years — no one knows exactly when — three NASA satellites, each one as heavy as an elephant, will go dark.
Already they are drifting, losing height bit by bit. They have been gazing down at the planet for over two decades, far longer than anyone expected, helping us forecast the weather, manage wildfires, monitor oil spills and more. But age is catching up to them, and soon they will send their last transmissions and begin their slow, final fall to Earth.
It’s a moment scientists are dreading.
When the three orbiters — Terra, Aqua and Aura — are powered down, much of the data they’ve been collecting will end with them, and newer satellites won’t pick up all of the slack. Researchers will either have to rely on alternate sources that might not meet their exact needs or seek workarounds to allow their records to continue.
With some of the data these satellites gather, the situation is even worse: No other instruments will keep collecting it. In a few short years, the fine features they reveal about our world will become much fuzzier.
“Losing this irreplaceable data is simply tragic,” said Susan Solomon, an atmospheric chemist at the Massachusetts Institute of Technology. The main area we’re losing eyes on is the stratosphere, the all-important home of the ozone layer.
Recently, data from the microwave limb sounder on Aura has been proving its worth in unexpected ways, Salawitch said. It showed how much damage was done to ozone by the devastating wildfires in Australia in late 2019 and early 2020, and by the undersea volcanic eruption near
Tonga in 2022.
The end of Terra and Aqua will affect the way we monitor another important driver of our climate: how much solar radiation the planet receives, absorbs and bounces back to space. The balance between these amounts — or, really, the imbalance — determines how much Earth warms or cools. And to understand it, scientists rely on the instruments of NASA’S Clouds and the Earth’s Radiant Energy System, or CERES.
Right now, four satellites are flying with CERES instruments: Terra, Aqua, plus two newer ones that are also nearing their end.
Yet only one replacement is in the works. Its life expectancy? Five years.
These days, with the rise of the private space industry and the proliferation of satellites around Earth, NASA and other agencies are exploring a different approach to keeping eyes on our planet. The future may lie with smaller, lighter instruments, ones that could be put into orbit more cheaply and nimbly than Terra, Aqua and Aura were back in their day.
But for such technologies to be useful, they have to start flying before today’s orbiters go dark.