One of Google's so-called moonshots is trying to get its high-flying internet balloons off the ground in Kenya, where the tech giant hopes to deliver 4G cell phone services in its first commercial test ever.
Born in 2011, Loon is now collaborating with Telkom Kenya to bring services to remote mountain villagers in the coming months.
But Reuters tech reporter Paresh Dave says there are lingering doubts about the viability of the balloon technology.
SOUNDBITE: PARESH DAVE, REUTERS CORRESPONDENT, saying: "Some of the wireless carriers wonder if Loon can overcome some of the reliability and technical challenges that still exist.//In other cases it's related to the financial viability of these balloons.
Does it actually cover enough people to make sense economically for these companies.
In other cases there's regulatory questions around sort of safety and will governments allow these balloons be floating high above people." The giant helium balloons - which fly twice as high as airplanes - have already shown they are useful.
Loon provided free services to wireless carriers in Peru and Puerto Rico after cell phone towers were knocked out by an earthquake and hurricane.
But the balloons face some practical issues.
Namely, wind- which moves the balloons out of range - and the sun.
UV rays mean the balloons have to replaced every six months as the plastic deteriorates.
The project has to deal with a few issues on the ground, too.
Loon faces a lawsuit by rival Space Data, which alleges Google stole its ideas in 2008.
And then there's the issue of competition.
SOUNDBITE: PARESH DAVE, REUTERS CORRESPONDENT, saying: "Things like lasers, blimps, drones, a lot of companies a lot of startups looking at a lot of different technologies.
And of course even satellites.
Several billionaires with companies looking at satellites like Elon Musk and Richard Branson and Jeff Bezos." But none of that is holding back the balloons from flying.
Kenya's government just gave final regulatory approval for Loon to move ahead, and Indonesia issued preliminary approval for Loon to fly on over.