The first version of the Falcon 9 flew in 2010 as part of a NASA program designed to create a commercial cargo service to the space station, after the space shuttle program was cancelled for being too costly, complex and ultimately risky.
The Falcon Heavy is 230 feet tall and consists of three Falcon 9 first-stage cores.
What's essentially different with the upgraded Block 5 first stages, however, is that they are deliberately created to fly 10 times with just brief inspections between landing and lift-off, and up to 100 times with some refurbishment involved. The US Air Force is targeting October for its Space Test Program 2 mission, known as STP-2, a spokeswoman for the Air Force Space Command said in an email. Since then, SpaceX has flown used boosters eleven times.
Among the reusability upgrades are an improved heat shield, extra thermal protection coating to limit re-entry heating damage and a set of retractable landing legs for rapid recovery and shipping, which will help cut the turnaround time for launches.
The highlight of this flight is the debut of the Block 5 version of the Falcon 9 rocket (which Ars previewed thoroughly last week).
The Falcon 9's most important and controversial upgrades concern the engines and the plumbing that fuels them.
The first crew-carrying flights using this system could come as early as this year, SpaceX representatives have said. In 2014, both SpaceX and British aerospace company Boeing were awarded a shared $6.8 billion contract by NASA to ferry astronauts to the International Space Station.