Having successfully launched a used first booster in a mission for the first time, Space Exploration Technologies Corp. (SpaceX) is considering trying to land an upper stage from a Falcon Heavy demo flight for full reusability, according to company founder and CEO Elon Musk.

Musk said Friday on Twitter that the odds of successfully returning a Falcon Heavy upper stage are low, but that it might be worth trying. Falcon Heavy has not flown yet.

Musk said, in another tweet, that a Falcon Heavy test flight is currently scheduled for late summer. Falcon Heavy is the heavy lift variant of the Falcon 9, which successfully flew a used first booster Thursday as part of a mission for Luxembourg-based communications satellite owner and operator SES. The satellite successfully reached its destination geostationary transfer orbit. The company also successfully landed the rocket on its floating drone ship off the Florida coast.

SpaceX successfully launches a used first stage booster for the first time March 29 on the SES-10 mission. Photo: SpaceX.
SpaceX successfully launches a used first stage booster for the first time March 29 on the SES-10 mission. Photo: SpaceX.

One space expert believes the Falcon 9 design has become stable, meaning it hasn’t changed recently. Space consultant and shuttle veteran Rand Simberg said Friday the company had made changes to Falcon 9 over the years, including lengthening the fuel tank to add capacity and allow the rocket to have enough propellant to fly back. He said SpaceX also went to a densified propellant so it could get more propellant to a given volume.

SpaceX, Simberg said, also went from a square 9 configuration with three engines in three rows, to an octagon of eight engines with a center engine. This was in addition to a whole redesign of the thrust structure and engine upgrades. SpaceX didn’t respond to requests for comment Friday.

“I think they’re to the point where they are happy with the configuration and they’re going to use it for both the Heavy and Falcon 9,” Simberg said. “Now that the design is stable, they can focus on just flying and getting experience on it.”

Jim Ball, principal at Spaceport Strategies LLC, said Friday the next step for SpaceX will likely be determining how many times this used booster, now launched twice, can be flown and when does constant reflight require a more extensive refurbishment system. The first stage for SES-10 was previously used on the successful NASA Commercial Resupply Services-8 mission in April 2016.