SpaceX is analyzing the use of single-stage Starship spacecraft as a potential rapid Earth-to-Earth transport system, meant to realize hypersonic mass-transit at “business-class” prices.
The gist is fairly simple: by cutting down on the complexity of the hardware and infrastructure involved, Earth-based transport via reusable rockets immediately becomes a far more plausible proposition. Huge challenges remain, but many of those challenges could potentially become identical to those that Starship must already face to achieve SpaceX’s ultimate goal of Mars colonization.
The single most important aspect of any high-volume form of mass transit is passenger safety.
From a statistical standpoint, rockets are thousands of times less safe than passenger aircraft, in large part due to their complexity and cost. As it turns out, an almost invariably foolproof method of improving the safety of a given thing is reducing its complexity (within moderation, of course). The fewer the parts there are, the fewer the parts that can fail and the easier (and cheaper) gathering data and evidence will be.
Originally, SpaceX’s 2017 Earth-to-Earth concept relied on a full two-stage BFR rocket (now Starship/Super Heavy) that could transport passengers anywhere on Earth in 30-60 minutes. Expected to launch off of giant, floating platforms, boosters would launch and land on the same platform while sending Starships on there way around the world. Starships would head to identical platforms at their destination and land directly beside that platform’s booster.
Much like BFR itself has radically changed in the last 18 or so months, it appears that SpaceX’s concept of Starship-based Earth transportation services has also continued to evolve. According to Musk’s May 30th tweets on the subject, one obvious method of improving the viability of the concept involves entirely removing the booster.
SpaceX could transport passengers up to ~10,000 km at speeds as high as “Mach 20” (6.9 km/s, 15,500 mph).
Company could offer ~20-minute trips from New York City to London or ~40-minute trips from Los Angeles to Tokyo as just two examples. Transportation could become far similar to airliner-style travel.
Add 2 to 4 more Raptors for Starship point to point on Earth. You can go surprisingly far, even with low lift/drag. This was an unexpected result (Elon Musk, May 30, 2019).
The SpaceX dream of global, hypersonic mass-transit is clearly still alive and well. According to President and COO Gwynne Shotwell, SpaceX could begin offering Earth-to-Earth transport services as early as 2025, if not earlier with Musk’s proposed Starship-only variant.