SpaceX hopes to recover engines

SpaceX is planning to launch a rocket early today that could be most notable for what happens as it returns to Earth.

The rocket, scheduled for liftoff at 6:20 a.m. EST from Cape Canaveral, Florida, will carry cargo to the International Space Station. It’s the first such mission since Oct. 28, when a supply ship that another company, Orbital Sciences, was operating for NASA exploded seconds after leaving the launchpad.

Besides delivering food, equipment and experiments, SpaceX engineers plan to attempt what has never been done. Instead of letting the rocket’s towering first stage disintegrate upon re-entry to the atmosphere, they plan to land it on a barge floating in the ocean.

Typically, the rocket’s first stage, which includes the engines needed to blast it to space, is allowed to fall back to Earth after separating from its payload. After burning up in the atmosphere, it lands in pieces in the ocean or remote places.

But Musk wants to land the 14-story first stage, which includes nine engines, and reuse it on a future flight.

The feat could transform space travel by sharply lowering the cost.

“To say it would be revolutionary is absolutely true,” said Charles Lurio, a Boston-based space analyst who publishes the Lurio Report. “It could be a race toward the bottom in terms of cost.”

The space shuttle was reusable, Lurio said, but it was extraordinarily expensive to rebuild and refurbish once it was back on Earth.

Already, SpaceX has shaken up the satellite-launching business by having some of the lowest launch costs in the world.

“Reusability is really, I think, the critical breakthrough needed in rocketry to take things to the next level,” founder Elon Musk explained this fall at a public event at MIT.

But the landing won’t be easy. The Hawthorne, California-based company compares it to “trying to balance a rubber broomstick on your hand in the middle of a windstorm.”

To start, engineers must slow the rocket, traveling at nearly 3,600 miles per hour, to zero. They already proved they could do that in two previous launches, when they slowed the first stage so that it briefly hovered over the water before toppling over.

With this launch, the rocket will be equipped with landing legs and deployable steering fins that will help engineers guide it to the barge, which will be floating in the Atlantic some 200 miles east of Jacksonville, Florida.

Musk calls the football-field-size barge the “autonomous spaceport drone ship.” It is not anchored, but equipped with thrusters that help it stay in place.

The company said last month the chance of success are “50 percent at best.”