ViaSat-2, which is to be stationed above the Americas, has a total throughput capacity of about 300 gigabits per second.
The spacecraft was part of a dual payload on the Ariane flight.
It was joined by Eutelsat 172B, a UK/French-built platform to go over the Pacific.
Both satellites will be chasing the rampant market for wi-fi on aeroplanes.
Airlines are currently in a headlong rush to equip their fleets with connections that will allow passengers to use their mobile devices in mid-air.
More than 6,000 commercial aircraft worldwide were offering an onboard wi-fi service in 2016; it is expected more than 17,000 will be doing so by 2021.
In-flight internet has traditionally had a terrible reputation, but there is a feeling now that the latest technology really can give passengers a meaningful slice of bandwidth and at a competitive price.