Back in the 20th Century, going to Mars was considered to be an uphill task, let alone colonising it. Moreover, the interplanetary journey to Mars has a high failure rate. As per statistics, as much as 60% of all spacecraft destined for Mars failed before accomplishing its mission.
Going into the 21st Century, an ambitious business tycoon made a groundbreaking statement to colonise Mars. Above all, it was his goal of making life multiplanetary that compelled him to start a $20 billion company. Now he might be just years away from achieving his goal.
Elon Musk’s mission to make life multi-planetary
Back in 2002, Elon Musk was searching for cheap rockets for his “Mars Oasis” concept. Although a Russian company was ready to offer Musk his rockets, he was unhappy with the prices. After a session of brainstorming, he came to the conclusion that a rocket only cost 3% of the sales price for manufacturing. This insight was enough for him to start a company of his own – SpaceX. With a mantra of Mars Colonisation and multi-planetary life, Musk was certain that Reusable Launch Vehicles were crucial. Pertaining to his objectives, he began working on this rocket technology as early as 2005.
SpaceX’s Musk, along with his engineering team, believed in one thing. They were sure that it is economically feasible to upgrade an existing piece of technology rather than starting from scratch. Thus, the concept for Falcon 9 was born. The name Falcon 9 comes from its design. This rocket has 9 Merlin rocket engines, each of which producing 192,000 lbs of thrust. This rocket is capable of completing its mission even if 2 of its engines failed.
Adhering to Musk’s cost-effective plans for his space missions, Falcon 9 roughly costs $56 Million. Its first launch was in the year 2010. In 2017, Falcon 9 became the first rocket to relaunch and land a used orbital rocket stage. This was monumental for the rest of SpaceX’s Mars missions. Moreover, it gave people and the aerospace sector an assurance that RLV is the next big thing!
Code name: BFR
Even though the entire SpaceX team was in a state of euphoria following Falcon 9’s success, Musk knew it wasn’t enough for Mars. In 2012, he coined the term “Mars Colonial Transporter”. A vehicle big enough to put them on Mars. Subsequently, in 2014, he gave a tentative date of 2020 for this vehicle’s first launch. However, it was the name that was bothering Musk at that time. In 2016, he revised the name to “Interplanetary Transport System”. But the name didn’t last long. The very next month, he changed its name to “BFR”.
This name stood for a while. At the International Astronautical Congress, he said: “we are searching for the right name, but the code name, at least, is BFR.” While the rocket is called BFR, the booster first stage was termed “BFB” and the spacecraft as “BFS”. After 2 years, he finally came to a conclusion on the names. The spaceship was renamed Starship, and the first stage booster was named Super Heavy.
Super Heavy is a gigantic booster with a gross liftoff mass of 8,110,000 lb. Producing 16 million pounds-force during liftoff, the booster is powered using 24 to 37 Raptor engines. (We will get to Raptor Engines in a while). The final prototype would be 9 metres in diameter and 50 meters in height. The design is said to undergo various changes before its first flight.
As per the current design, the booster will have 31 engines and four diamond-shaped welded steel grid fins. These fins will aid in aerodynamically controlling the rocket. The booster uses sub-cooled liquid methane and liquid oxygen propellants. The RLV tech facilitates the booster to land at the launch site on its 6 legs.
Together with Super Heavy, Starship will represent a fully reusable transportation system. This system will eventually replace the Falcon 9 for interplanetary missions. Starship will house a 9-metre diameter forward payload compartment which would aid in a variety of missions including interplanetary transport. As far as the design is concerned, it would have 6 raptor engines. Three each optimised for sea-level and vacuum. The total thrust from these engines would be around 2,600,000 lbs.
As of now, SpaceX is working on various design variations. All of which has an end goal of rapid reusability and automated docking. Rapid reusability, in particular, would demand a design that could facilitate reentering from orbital velocities. This would help in landing the starship vertically. The tricky part of the design is the loading of propellants. The Mars trip is around 6 months. So, Musk came up with this concept of on-orbit propellant transfers. Similar to how an aircraft is refuelled during its flight. The Starship would reach Mars after this propellant loading.
Raptor Engine is the heart of this interplanetary transport system. With as much as 31 of them installed in Super Heavy and 6 in Starship, it is important to note why Raptors but not Merlins. Falcon 9 had Merlin Engines, but the shift to Raptor is because of the thrust demand. Raptor will produce nearly twice the thrust that Merlin produces. Above all, the major challenge is the use of Methane. There is not a single methane-powered rocket that has made it to orbit. If that’s not enough for history, Raptor will be the third full-flow staged combustion engine to be ever built. The attempts made by the Soviet Union and the US on this system was unsuccessful as it didn’t go beyond testing.
The difference between full-flow staged combustion and traditional engines lies in propellant expenditure. The Raptor engine burns the propellant in very high pressure. This high pressure would help to push these gases into the combustion chamber from the preburner. These burnt propellants are combusted again with the rest, thereby producing a huge thrust. This reduces propellant expenditure. Hence, Raptor has the best fuel efficiency amongst the class of all rocket engines.
Are we there yet?
Elon Musk’s mission for multi-planetary life does seem a bit of a long shot. But considering the advancements that he has made towards achieving the same, gives an optimistic impression. Moreover, Musk is currently planning on testing this vehicle this year.
According to the latest reports, SpaceX is planning to do an uncrewed test flight this year. This flight is expected to aim at an altitude of roughly 500 feet. In addition to that, Musk has already begun working on another variation. A variation in Starship’s design that would be slated to test an altitude of 12 miles. In “Elon Time” we can expect a Mars mission in 2022. But according to SpaceX president, Gwynne Shotwell, it would take a decade or less for this mission. She added that human transportation would begin by next decade.