Falcon 9 second stage to be upgraded to ‘mini-BFR ship’
In the lead-up to the first flights of SpaceX’s Big Falcon Rocket, the current second stage of the Falcon 9 is to be modified to test some of its key design features, according to a tweet from company CEO Elon Musk.
SpaceX has previously stated it plans to start testing the second stage of the BFR, known as the Big Falcon Spaceship or BFS, as early as 2019 via short hops similar to the company’s Grasshopper program earlier in the decade. However, it appears an intermediate test phase is also in the works.
“Mod to SpaceX tech tree build: Falcon 9 second stage will be upgraded to be like mini-BFR Ship,” Musk tweeted on Nov. 7, 2018.
The exact details of this announcement are not yet known, however, in an answer to Twitter followers’ questions about when this might occur, Musk said the company is aiming for the first orbital flight of this modification by June 2019. What is also unclear is if this will be a one-off test or an upgrade to some or all second stages.
The BFS as currently designed looks similar in shape to the U.S. Space Shuttle. However, rather than wings, there are large control surfaces to help with drag and orientation during atmospheric entry and guide the vehicle to a predetermined spot, such as a landing zone.
Because the current Merlin Vacuum engine on the Falcon 9 second stage is not designed to operate in the atmosphere, actual propulsive landings with the stage is not expected to happen.
“Won’t land propulsively for those reasons,” Musk tweeted. “Ultra light heat shield [and] high Mach control surfaces are what we can’t test well without orbital entry. I think we have a handle on propulsive landings.”
As of September 2018, the fully-reuseable BFR system is expected to consist of a booster and spaceship totaling about 387 feet (118 meters) tall and 30 feet (9 meters) wide. The booster is designed to land propulsively back at its launch mount after the first phase of flight, while the spaceship would continue into orbit and perform its mission—deploy satellites, send cargo and people to Mars, or fly people to the Moon—before returning to Earth.
SpaceX and Musk have stated that the BFR could replace the company’s current fleet of rockets and spaceships once operational. One of its first missions is expected to be the recently announced “#dearMoon” project, which would involve sending Japanese billionaire Yusaku Maezawa and six to eight artists on a circumlunar flight no earlier than 2023.
An overview of the Big Falcon Spaceship. Video courtesy of SpaceX
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity.