SpaceX Falcon 9 rocket took off successfully and deployed today 5 Iridium satellites and the two NASA satellites whose mission will be to measure, with unprecedented precision, changes in the water supply on Earth, over the next five years, as part of the NASA GRACE-FO mission.
Another successful launch for SpaceX
The reusable Falcon 9 rocket took off without problem from the Vandenberg military base in California, carrying the precious cargo of the two NASA satellites, the creations of a partnership between the German and the American space agencies.
Also, the Falcon 9 rocket carried 5 satellites of the Iridium communication network.
The rocket first placed the GRACE-FO satellites into orbit after eleven minutes of flight at an altitude of about 500 km. Then the Iridium satellites were dropped a little further away, after about an hour of flight.
The satellites will take over from those of the GRACE mission which, from 2002 to last year, flew over the Earth to produce a monthly map of water volume changes.
The two NASA satellites will use gravity to calculate the amount of water on Earth
The two satellites, each the size of a car, will fly 220 km apart.
The slightest variations in mass under them (a mountain, a lake, ice, aquifers) will cause a tiny change in gravity, temporarily changing the distance between the two satellites, measured to the nearest micron.
By continuously recording these variations in distance, the scientists will deduce the variations in mass of water on Earth, whether above or below the surface. Such variations from one month to the next may only be caused by water-related causes such as ice melting and passing through the oceans, water evaporating, rain replenishing groundwater, and so on.
This mission, called NASA GRACE-FO, will make it possible to monitor these trends over time.
On the other hand, for SpaceX, these satellite launches have become routine. This is the tenth successful deployment of the year, while the Falcon 9 rocket used on the launch of today had already been used once in January. This time, however, it won’t be recovered.