SpaceX aims to launch a new era in modern rocket science Tuesday by landing a key part of its Falcon 9 rocket on a barge in the Atlantic Ocean.
The California-based company headed by billionaire Internet entrepreneur Elon Musk has given itself just a 50-50 chance of success in the bid to guide the powerful first stage of the rocket to a floating platform about 200 miles (322 kilometers) off the coast of northern Florida after launching from Cape Canaveral at 6:20 am (1120 GMT).
But it hopes the effort, followed by more tries in the year ahead, will transform the rocket industry from one that creates parts worth millions of dollars that are left to fall into the ocean after blastoff, to one that reuses its assets much the way commercial airlines fly the same planes again and again.
"A fully and rapidly reusable rocket -- which has never been done before -- is the pivotal breakthrough needed to substantially reduce the cost of space access," said a SpaceX statement.
"The odds of success are not great -- perhaps 50 percent at best. However this test represents the first in a series of similar tests that will ultimately deliver a fully reusable Falcon 9 first stage."
- Guided rocket return -
The attempt will come after the Falcon 9 launches from NASA pad early Tuesday, carrying the unmanned Dragon cargo vessel which is packed with supplies and equipment for the six astronauts living at the International Space Station.
The rocket will separate, as it usually does, allowing the second stage to continue propelling the spaceship to orbit.
But this time, SpaceX will relight the engines on the 14-story tall Falcon 9 first stage.
Then, three separate engine burns should guide and slow the rocket down so it can land on the 300 by 100 foot (91 by 30 meter) platform, which SpaceX is calling an "autonomous spaceport drone ship."
The company has already shown in two tests that it could execute some control over the return the first stage of the Falcon 9, slowing it down to a hover before allowing it to splash into the ocean.
"During previous attempts, we could only expect a landing accuracy of within 10 kilometers," SpaceX said.
"For this attempt, we're targeting a landing accuracy of within 10 meters (yards)."
- Musk takes questions -
Musk said on Twitter Monday that he would answer questions about the launch on Reddit at 9 pm (0200 GMT).
The launch was initially supposed to take place last month, but SpaceX postponed it on Dec. 18 after unspecified "issues" arose during a launchpad test, it said.
If the company's fifth contracted launch with NASA to the ISS goes ahead as planned Tuesday -- and weather is 70 percent favorable for launch -- the Dragon cargo ship should arrive at the ISS on January 8.
SpaceX in 2012 became the first privately owned company to successfully send a cargo vessel to the ISS, restoring US access to the space station after the retirement of the space shuttle program in 2011.
The Dragon is the only cargo ship that can return to Earth intact, and SpaceX is working on a crew vehicle version that could carry people there in the next few years.
SpaceX has a $1.6 billion contract with NASA for 12 missions to supply the space station and return cargo to Earth.
Orbital Sciences also has a $1.9 billion contract with NASA to supply the space station.
However, an engine failure in its Antares rocket during an October launch attempt from Wallops Island, Virginia cost the company $200 million in lost parts and postponed its remaining launches until further notice.