Europe rocket crisis looms amid Ariane 5's final flight

Europe's space program headed into uncharted territory this week, after an Ariane 5 rocket blasted off for the final time, and with no firm date set for the arrival of its replacement.

The European Space Agency's 53-meter-tall, three-stage, heavy-lift launcher set off from the Kourou spaceport in French Guiana on Wednesday to deliver two military communications satellites into orbit.

During its 30-year tenure, the workhorse Ariane 5 undertook 117 missions and only failed twice, earning it a reputation as the European Space Agency's reliable alternative to launchers operated by NASA and Russia's Soyuz program, and putting Europe firmly on the space-race map.

During its long, reliable run, Ariane 5 rockets, which are expendable and built anew for each mission, delivered over 230 satellites into orbit.

However, its replacement, Ariane 6, is not expected to be ready until at least next year and, with Europe no longer able to commission space on Russian launchers, the continent is likely to rely more heavily than ever on United States launchers.

Josef Aschbacher, the ESA's director general, told the BBC: "Europe finds itself … in an acute launcher crisis."

He said the ESA had to retire the Ariane 5 because the cost of building new versions for each mission had become unsustainable compared to the cost of cheaper competitors. Chief among them, Reuters reported, was the reusable Falcon launcher produced by Elon Musk's SpaceX company, which was significantly cheaper to commission than the Ariane 5.