The Californian SpaceX chief executive Elon Musk has warned Europe it must replace its Ariane 5 rocket if it wants to keep up with his company.
The low prices the US entrepreneur is quoting for his new Falcon 9 vehicle mean it is winning contracts that in the past would have gone to Ariane.
Mr Musk said that the cost of producing the current European rocket would kill it as a commercial entity.
"Ariane 5 has no chance," he told BBC News.
"I don't say that with a sense of bravado but there's really no way for that vehicle to compete with Falcon 9 and Falcon Heavy. If I were in the position of Ariane, I would really push for an Ariane 6."
Ariane's future will be a key topic this week for European Space Agency (Esa) member states.
They are meeting in Naples to determine the scope and funding of the organisation's projects in the next few years, and the status of their big rocket will be central to those discussions.
Video by: BBC News
