A Swiss firm says it intends to construct a robotic rocket plane that will launch satellites into orbit off the back of a modified jetliner.

Swiss Space Systems -- S3 -- says its unmanned suborbital shuttle could be traveling to launch height atop an Airbus A300 jetliner by 2017.

"S3 aims to develop, build, certify and operate suborbital space shuttles dedicated to launching small satellites, enabling space access to be made more democratic thanks to an original system with launching costs up to four times less than at present," the company, which has headquarters in Payerne, said in a statement.

While it will concentrate on launching unmanned satellites at first, it has plans beyond that, a company spokesman said.

"Our first priority is the launch of small satellites until 2018," Gregoire Loretan, S3's head of communications, told SPACE.com. "And the goal for S3 is to establish certification process and standards to help the development of manned flight afterwards."

The carrier aircraft would lift the robot rocket plane to a lunch altitude of about 33,000 feet, S3 said, at which point the rocket plane will utilize a liquid oxygen and kerosene rocket engine to reach an altitude of around 50 miles, high enough to put a satellite equipped with its own small rocket into orbit about 434 miles above Earth.

After deploying the satellite the robotic space plane would glide to Earth and land at a spaceport S3 said it will build in Payerne.