In September of 2019, SpaceX unveiled the first Starship prototype, the first of several test vehicles that would validate the design of the next-generation spacecraft that would fulfill Musk’s promise of making commercial flights to the Moon and Mars. And while there was a bit of a setback in November of 2019 after the Mk. 1 suffered a structural failure, Musk indicated that the company would be moving forward with other prototypes.
As Musk explained at the time, this would consist of the Mk. 3 prototype conducting an orbital test flight to an altitude of 100 km (62 mi) sometime in 2020. According to recent filings made with the FCC, this test could be happening as early as mid-March and will involve the vehicle launching from the company’s test facility in Boca Chica, Texas, and flying to an altitude of 20 km (12.6 mi) before landing.
As per the filings, SpaceX is requesting access to radio frequencies for the sake of a “[e]xperimental launch, landing, and recovery of the Starship suborbital test vehicle” so that ground controllers can communicate with the vehicle during flight and monitor its trajectory. This data will be directly shared with the National Telecommunications and Information Administration (NTIA), the US Air Force, and NASA.
This test will be another major step in the development of the Starship and Super Heavy launch system, which Musk claims will be capable of transporting payloads of up to 100 metric tons (Us tons) and crews of up to 100 to deep space. This would include sending cargo and crews to the Moon by 2022 and 2024 (respectively) with the long-term aim of conducting regular missions to Mars.
A test flight to an altitude of 20 km (12.6 mi) is in keeping with what the Mk. 1 was originally scheduled to do. Unfortunately, this prototype suffered an explosion on November 20th during a loading test, where the vehicle’s oxygen and methane tanks were filled with cryogenic liquid to see how they held up when fully-pressurized.
In response, the company decided to scrap the prototype and carry on with fully-assembled Mk. 2 and the improved Mk. 3 design (which is being built at their facility in Boca Chica, Texas). In contrast to the Mk. 1 and Mk. 2, this hull of the Mk. 3 prototype would be made up of single-piece rings of welded steel and would have an engine configuration that is optimized for orbital flight.
Whereas the Mk. 1 and Mk. 2 had six Raptor engines optimized for sea-level, the Mk. 3 would have three sea-level optimized engines and three vacuum-optimized Raptor engines. This is identical to what the final design of the Starship calls for while the Super Heavy launch vehicle will have 37 Raptor engines – 30 of which will be sea-level-optimized and 7 vacuum-optimized Raptor engines.
While a 20 km flight is short of the 100 km (62 mi) orbital test that SpaceX hopes to accomplish, it is a major stepping stone for both the Starship and the Raptor engine that powers it. In addition to success ground-tests involving the Raptor engine, SpaceX flight tested the engine using the Starship Hopper to an altitude of 150 meters (500 ft) last summer.
However, an orbital test flight is still a long way away and much needs to happen before that can be accomplished. In the meantime, SpaceX’s FCC filing has requested permission to fly as early as March 16th, though it would give them until September 16th to perform this test flight. While Musk tends to be optimistic with his timelines, his company has a reputation for delivering eventually!
Further Reading: The Verge