Earlier this month, SpaceX successfully launched a round of financing, the company’s largest to date,media reported. The company has since begun to reveal more details about its Starship launch vehicle platform plans. Unlike the company’s current Falcon rocket boosters and Dragon spacecraft, the Starship is SpaceX’s platform for deep space exploration, especially for missions the company hopes will make life on Mars.
In this regard, SpaceX founder, chief engineer and CEO Elon Musk provided more details about the spacecraft’s overweight boosters at the Humans to Mars 2020 Virtual Summit yesterday. The booster is said to be one of two parts of the platform that SpaceX plans to use to support manned and non-manned missions — also known as starships.
Musk also told the conference that SpaceX will begin building boosters this week. It comes after he revealed over the weekend that he hopes his company will make Super Heavy’s first prototype flight in October. Musk said on Friday that the prototype would use two Raptor engines, with a total thrust of 16.5 million pounds.
Earlier this month, Musk also revealed an important development in spaceX’s Raptor engine. This engine was the first in the engine to use a mixture of propellant for combustion. Typically, rocket engines come in two types, depending on whether fuel is injected into their combustion chambers using pumps that drive the engine with certain propellants. Engines that use propellant to drive pumps are called “open cycle” engines, and they are less efficient than those that use all fuel to burn to generate thrust. The latter is known as the full-flow phased combustion engine, and raptor is the first of its kind — it was tested last year on the Starhopper test aircraft. Musk also revealed earlier this month that the engine also achieved a record for propellant pressure in the combustion chamber of a 330bar rocket engine, and yesterday’s disclosure added more detail to that record.
At the summit, the executive revealed that when Raptor’s cabin pressure reached 330 bar, its upstream pressure was 1070 bar. Upstream pressure refers to the pressure of the propellant when it enters the combustion chamber of the engine, which must be higher than the combustion chamber pressure according to the propulsion principle. The downstream pressure is the pressure when the final reaction product escapes from the combustion chamber, which is lower than the upstream pressure.
Musk speculated that Raptor could achieve a push-to-weight ratio of 200, more than SpaceX’s Merlin engine currently has. Raptor’s oxygen fuel ratio is currently 78:22.
Musk also reiterated at the summit that building a production system for starship launch systems is the most difficult part of the project. He will also use super Heavy boosters to reduce the number of engines from 31 originally planned by SpaceX to 28. In addition, in delving into more details, the supervisor said that 20 of the 28 engines on the booster would not be able to control the rocket, but would only be used solely to generate thrust.
While talking about the promise that starships will also become a potential lunar landing system, Musk said life support systems for lunar missions would be relatively easy, but they would create more complex Mars spacecraft.
Finally, before the first manned flight, the design of the starship will be validated by launching dozens of satellites.