PARIS — The French space agency, CNES, on Dec. 11 said it is partnering with Google on the Google X Project Loon to deploy more than 100,000 balloons in the stratosphere to provide high-speed Internet to regions without it.

CNES officials said early tests of the Loon project with balloons launched from New Zealand convinced the agency that the Google idea, while “appearing crazy,” was feasible and merited a closer look.

CNES has maintained an active balloon launch program for studies of upper-atmospheric air currents, the chemical composition of the atmosphere at specific altitudes and other purposes, launching as many as 20 balloons a month.

Internet search giant Google earlier this year announced the Loon project as a way of delivering Internet to regions whose terrestrial infrastructure is not up to the task.

In a Dec. 11 statement, Google Vice President Mike Cassidy, in charge of the Loon project, said the company is evaluating multiple designs for Loon, with CNES and others.

“No single solution can solve such a big, complex problem,” Cassidy said. “That’s why we’re working with experts from all over the world, such as CNES, to invest in new technologies like Project Loon that can use the winds to provide Internet to rural and remote areas.”

Deploying Loon would require substantial regulatory and diplomatic effort to win the regulatory approval for every nation whose territory is overflown by one of the balloons, a challenge that CNES faced about three years ago as it planned an equatorial balloon campaign.

“We needed authorizations from 78 nations in the latitudes we wanted to use,” said Philippe Cocquerez, CNES project head for balloons. “It’s a lot of diplomatic work.”

At the outset, CNES will advise Google on balloon design, with the two sides pooling research resources. CNES will perform flight analysis and Google will provide the French agency with help in long-duration balloon campaigns.

Vincent Dubourg, deputy director for balloons, said the Loon project was an easy sell for CNES given the Loon project’s ambition.

“To get a constellation of more than 100,000 balloons to operate for months at a time — it’s an impressive project,” Dubourg said in a statement. “We put up a maximum of 20 or so balloons a month, which fly for maybe three months. So the scale [of Loon] is impressive.”

Early Loon designs show a pumpkin-shaped structure about 15 meters in diameter — larger than the 10-meter balloons often used by CNES. The CNES stratospheric balloons are carried by winds alone and their trajectory is not managed from the ground.

One design being considered involves housing an air-filled balloon inside a larger helium-filled balloon, Cocquerez said. The air has the effect of lowering the balloon’s altitude by as much as a couple of kilometers. When the air is released, the balloon rises to its previous altitude of around 20 kilometers — above most weather and commercial air traffic.

“This kind of initiative does appear crazy,” Dubourg said. “But there is always something to learn for the rational Cartesians like us at CNES.”

Marc Pircher, director of CNES’s Toulouse Space Center in Toulouse, France, said CNES had been working with Google for about a year but had refrained from announcing it until the two sides were sure there was productive work they could do together.

In a Dec. 12 interview, Pircher said Google is paying CNES “a very small sum” related to intellectual property related to balloon design developed over the years of CNES experiments with stratospheric balloons.

“When they approached us I have to admit that given our experience in stratospheric balloons – their cost of development, of maintenance, the need to recover them after the mission, the regulatory issues with civil-aviation authorities – I really didn’t think it was realistic,” Pircher said.

“And of course it may never be developed. But what our team saw in working with the Google team in New Zealand was instructive for us. They have ideas that will reduce the cost of the balloons by 10 times or so. This is something that will be useful to use for our science missions, regardless of what happens with Loon.”