On Tuesday evening, SpaceX revealed that it has performed a critical static firing of one of its boosters. Not just any booster though; this exact same booster launched a cargo spacecraft to the International Space Station last April. This is the Falcon 9 rocket the company plans to use for its first-ever re-flight of an orbital rocket stage.

SpaceX has previously disclosed that its customer for the launch will be Luxembourg-based satellite operator SES, which wants to launch its geostationary satellite SES-10. Although no launch date has been set for the flight, the successful firing of the used first stage, which occurred last week at the company's facilities in McGregor, Texas, lends credence to a potential March liftoff from Kennedy Space Center in Florida.

The innovative rocket company has now returned seven boosters to Earth, by land and sea, during the last 13 months. However, the promise of reusable rockets won't be fulfilled until launch vehicles can be swiftly refurbished and launched again. After all, the space shuttle was almost fully reusable, but the cost of restoring a flown shuttle to flight-ready status tallied in the hundreds of millions of dollars and took months, even under the best of circumstances.

A March launch would mean an 11-month turnaround, which is far from optimal, but understandable for the first time. SpaceX's founder and chief executive, Elon Musk, has acknowledged the company must do better in the future if resuable flight is to become economically viable. He says the next—and likely final—iteration of the Falcon 9 rocket will be optimized for reuse. "Block 5 is the final upgrade of the Falcon architecture," he tweeted earlier this year. "Significantly improves performance & ease of reusability. Flies end of year."

It now seems likely that SpaceX will fly the landed boosters it currently has, at most once or twice, before retiring them, instead of multiple times. Although the company hasn't elaborated on the problems with the engines, booster structure, or composite materials that have shown wear and tear after their orbital launches and returns, Musk is confident that changes to the Block 5 version of the rocket will solve the problem. "I think the F9 boosters could be used almost indefinitely, so long as there is scheduled maintenance and careful inspections," he has said.