On Monday, September 17, 2018, during an evening press briefing, SpaceX announced their new 2018 BFR design along with the Japanese billionaire that is helping to fund the BFR development and purchasing the first human-crewed flight around the moon.
The BFR or Big "Falcon" Rocket is now in its third major design iteration, and could still change before being finalized. One of the most notable changes with this new design is that the new BFR design is 118 m tall vs. 106 m tall in the version announced in 2017. This would make the BFR taller than the Saturn V, and also taller than all configurations of the Space Launch System or SLS. Further, the space ship portion of the BFR is 7 m taller in the new design. The larger size allows the BFS, or Big Falcon Ship, to have a 1,000 cubic meter payload capacity versus an 825 cubic meter capacity in the old design. The tradeoff is less weight capacity, down to 100,000 kg from 130,000 kg.
The engine configuration of the ship portion of the BFR has also changed with seven sea level optimized raptor engines in the new design versus a combination of 4 vacuum optimized engines and two sea level optimized engine in the old design. That change will save cost and streamline development and production but does result in the ship portion being less efficient, and contributing to part of the loss of lift capacity.
There are still some unknowns like what type of abort system will be present for crew safety during launch. Since the crew cabin is attached to the upper stage to form the ship, it would be difficult to lift the ship off the booster fast enough to escape damage during a catastrophic failure of the booster. Likely there will be more announced on that as development progresses.
SpaceX still plans to begin hop tests with the ship portion of the BFR in 2019, with the human-crewed lunar flight optimistically scheduled for 2023. With the SLS also nearing its first launch and the big Blue Origin New Glenn rockets coming up in a few years as well, the early 2020s could prove to be a fascinating time for spaceflight!