All Images Source: SpaceX
Elon Musk, the founder and CEO of SpaceX, answered several questions via Twitter this week. He provided some interesting details about Starship, the future stainless steel rocket-spacecraft duo that will replace all the company's launch vehicles. The first flight prototypes of Starship are currently under development at their South Texas facility located in Brownsville's Boca Chica Beach.
Image: Starship Mk1 at Boca Chica, Texas Source: SpaceX
Musk talked about how the spacecraft will need to work in order to achieve his goal of making humans a multi-planet species. He stated that the reason he is accumulating assets on Earth, is to further fund the Mars colonization mission.
"Helping to pay for this is why I’m accumulating assets on Earth."
The final version of Starship will need to be capable of being reused several times per day, as well as take megatons of cargo per year to Mars in order to establish and maintain a permanent human settlement. In a series of Tweets he explained:
"Megatons per year to orbit are needed for life to become multiplanetary.
Building 100 Starships/year gets to 1000 in 10 years or 100 megatons/year or maybe around 100k people per Earth-Mars orbital sync. Starship design goal is 3 flights/day avg rate, so ~1000 flights/year at >100 tons/flight, so every 10 ships yield 1 megaton per year to orbit."
Building 100 Starships/year gets to 1000 in 10 years or 100 megatons/year or maybe around 100k people per Earth-Mars orbital sync— Elon Musk (@elonmusk) January 17, 2020
SpaceX aims to make a craft that will eventually be as reusable as an airplane or a car, with a lifespan of around 20 to 30 years like the commercial aircraft we use today.
The Starship spacecraft is being designed with the plan of launching it for an average of 3 flights per day, that is an average of 1,000 flights per year for one particular Starship.
Per year, SpaceX plans to build 100 Starships each carrying over 100 tons per flight. So, the goal is to build 100 Starships every year that could perform 1,000 flights each per year -that will transport as much as 100 megatons of cargo, or 100,000 people to Mars over the course of the next decade.
"Loading the Mars fleet into Earth orbit, then 1000 ships depart over ~30 days every 26 months. Battlestar Galactica …"
Helping to pay for this is why I’m accumulating assets on Earth.— Elon Musk (@elonmusk) January 17, 2020
Each passenger trip would be done "per Earth-Mars orbital sync" that is when Mars' orbit is closer to Earth which occurs roughly once every 2 years, an approximate time of 26 months. Once every 2 years, 1,000 ships will all depart Earth over the course of 30 days during the close Mars transit.
Musk also detailed that Starship will require to be refueled in space prior to the Starship fleet departure towards Mars. The in-orbit refuel to make the trip to Mars is needed because more power is utilized to exit Earth’s atmosphere, which leaves the craft with insufficient propellant to reach Mars soon. He further explained that refueling in orbit during a reverse trip from Mars towards Earth is not needed because Mars gravity is only about ~38% of the surface gravity on Earth. For perspective, if you weigh 100 pounds on Earth, you would weigh only 38 pounds on Mars. Musk explained:
"Densification isn’t needed to return the ship & limited cargo from Mars, but it’s an option for increasing cargo return capability if needed. What’s amazing is how non-linear the effect of gravity is. Starship can travel by itself from surface of Mars to surface of Earth, but requires massive booster on Earth with orbital refilling to get to Mars, which is ~38% of Earth gravity."
What’s amazing is how non-linear the effect of gravity is. Starship can travel by itself from surface of Mars to surface of Earth, but requires massive booster on Earth with orbital refilling to get to Mars, which is ~38% of Earth gravity.— Elon Musk (@elonmusk) January 16, 2020
SpaceX wants to send one million people to Mars by 2050. Musk aims to make flights affordable enough so that the average citizen can move to Mars if they would like, "anyone can go if they want, with loans available for those who don’t have money." There "will be lots of jobs on Mars" especially jobs involving building a propellant plant on the Red Planet.
Needs to be such that anyone can go if they want, with loans available for those who don’t have money— Elon Musk (@elonmusk) January 17, 2020
Starship's Raptor engines were especially developed to work via In-Situ Resource Utilization (ISRU), which is a term used to describe using what is available on the astronomical body. This includes, developing technology or survival mechanisms using what is available on Mars' surface. Starship's Raptor engines are powered by cryogenic methane and liquid oxygen which can be made on Mars upon arrival. By taking carbon dioxide from the Red Planet's atmosphere and sub-surface ice water to synthesize methane and liquid oxygen. This could be achieved through electrolysis and the Sabatier process to create fuel for Starship, in order to come back to Earth. Building a propellant plant will be one of the most important tasks future Martians will work in, to transform humans into a successful spacefaring civilization.
This week, during an event Musk said he believes the first human to send a Tweet text message from Mars will happen "five years from now... probably not more than nine years from now." Ambitious timeline! We could see the first human set foot on Mars soon!