The Electron rocket, which belongs to the category of micro-launchers and is only 18 meters high, took off at 13:00 local time (01:00 GMT) from Mahia, in northern New Zealand, according to Rocket Lab.
The two satellites, Cubesats, weigh only about five kilograms and will evolve at an altitude of about 550 kilometers. A second rocket is to be launched in about two weeks, again by Rocket Lab, which will carry two other satellites to complete this small constellation.
It will then have the ability to pass every hour over hurricanes (or typhoons on the Pacific), against every six hours currently. The mission was named TROPICS.
These satellites will allow scientists to "not only see what is happening at a given moment (...) but to really see how things evolve hour by hour," NASA scientist Will McCarty told a news conference.
"We will always need the big satellites," he added. "But what we can learn from this mission is additional information to the flagship satellites we already have."
This information collected on rainfall, temperature and humidity can be used to improve weather predictions, including where the hurricane will make landfall and at what intensity, and thus better prepare for possible evacuations of populations living on the coasts.
"Many organizations, such as the U.S. National Hurricane Center and the Joint Typhoon Warning Center, are ready to receive our images, to help them keep their meteorologists informed," said Ben Kim, also a NASA official.
In the longer term, a better understanding of the formation and evolution of these storms will improve climate models.
The constellation was originally supposed to have six satellites instead of four, but the first two were lost due to a malfunction of a rocket from the US company Astra shortly after liftoff last year.
As the ocean surface warms, hurricanes (or typhoons) become more powerful, according to scientists.
The Hurricane Ian that devastated Florida in 2022 claimed dozens of lives and caused more than $100 billion in damage, by far the world's costliest weather disaster last year.
© 2023 AFP