Elon Musk led them to a staff dining area on the side of the factory.
It's a bit of a stretch to say "dining area" - several folding tables pushed together.
The table is covered with a disposable plastic tablecloth, and there is a refrigerator and a microwave in the corner.
A handwritten list taped to the refrigerator door reads "coffee, energy drinks, water, fancy yogurt."
The last few words were circled several times in red pen.
There is a huge Starship test flight schedule posted on the wall, with various test nodes marked on it with sticky notes of different colors.
Some of the notes have been peeled off and pasted so many times that they become curled.
Elon Musk took out a few bottles of water from the refrigerator and threw them on the table, and took out a large plate of cut sandwiches from the insulator--
The bread is sliced toast bought from the supermarket, sandwiched with ham, cheese and lettuce. There is no plate or any decoration.
He took a piece for himself first, took a big bite, and said vaguely while chewing, "You're welcome, this is the only one here."
Su Wantang put Zisha Pot on the corner of the table and went to boil hot water.
Shen Zhiyi took a piece of sandwich, and when he sat down, he was still looking at the Starship timetable on the wall.
Zhao Chen took the smallest piece and put it on the plate, opened the water and took a sip.
"You just said that SN8 will fly 60,000 feet by the end of the year."
Zhao Chen pushed the plate aside and tapped his fingers lightly on the table.
"If there is no problem with static ignition and three-engine integration, how do you internally estimate the success rate of the first high-altitude test flight?"
Elon Musk swallowed the sandwich, picked up a bottle of water from the table, unscrewed the cap, and took a sip.
"It won't work the first time."
He said it very calmly, as if he was stating a conclusion that had been written on the data sheet,
"SN8's belly-flop maneuver is to shut down the engine at an altitude of 60,000 feet.
Adjust the attitude so that the arrow body falls horizontally with its belly facing down, use the aerodynamic surface to control the attitude, and finally re-ignite and flip before landing.
This maneuver has never been performed on any aircraft.
We ran hundreds of simulations on the ground using pneumatic Model and propellant.
But the turbulence of the real atmospheric environment, the delay of the attitude Control System, and the time window for the three engines to re-ignite--
Every variable may cause the entire rocket body to disintegrate in the air.
My internal expectation for SN8 is that it can fly to 60,000 feet, do belly-flop, and re-ignite.
Landing - not expected. Landing is a matter for SN9 and SN10."
He placed the water bottle on the table and crossed his hands on the edge of the table.
"But after SN8 has finished flying, SN9 will be improved.
After SN9 has finished flying, SN10 will be improved again.
From the first failed landing to the first successful landing of Falcon 9, I don't know how many units were destroyed in the process. The same goes for Starship.
Every prototype is being welded and modified. If SN8 explodes, there will still be SN9, if SN9 explodes, there will still be SN10.
As long as the stainless steel is welded fast enough and the cost of failure is low enough, I can always find the right landing parameters."
"Where is Mars?"
Zhao Chen picked up the hot tea that Su Wantang just served,
"Your previous public timetable was that unmanned cargo would be launched in 2024 or 2026, and crewed cargo would be launched around 2028.
From SN8 to the real Mars mission, what is there in between?"
Elon Musk When he heard the words "Mars", his whole body relaxed obviously.
He pushed the sandwich aside, picked up a grease pen from the workbench, and
I drew a simple diagram on the repeatedly erased whiteboard beside the table--
The earth and Mars are two circles connected by an arc in the middle, with "Hohmann Transfer" and "26 months" marked on the arc.
"The first threshold is Orbital Refueling."
He pointed the tip of his pen on the arc between the earth and Mars,
"Starship has consumed more than half of its fuel after entering low-Earth orbit.
If you fly directly to Mars, the payload is only a few dozen tons, which cannot transport enough things.
Therefore, propellant must be added in low-Earth orbit first - several other Starships will serve as refueling ships to transport liquid oxygen and liquid methane up there.
Only after a Starship is filled up can it have enough thrust to fly to Mars.
This 'Orbital Refueling' technology has not yet been verified in orbit.
If successful, dozens or even hundreds of Starship can be launched in each Mars transfer window.
If it doesn't succeed, Project Mars will be just a concept."
He marked several numbers on the arc.
"The second threshold is the Mars transfer window. Earth and Mars come close to each other every twenty-six months, which is the optimal window for launch.
There was a window in 2022, but that time we were too late--
The verification of Starship and Orbital Refueling will take at least one year, and then unmanned round-trip testing will be required.
The 2024 window is more realistic.
The unmanned cargo ship Starship went over first and established preliminary propellant production facilities on the surface of Mars.
Mars There is carbon dioxide in the atmosphere and water ice on the surface. In theory, Sabatier Reaction can be used to synthesize methane and liquid oxygen on Mars.
If this works, the fuel for Starship's return trip can be produced locally on Mars, without the need to bring it back from Earth."
"There were no people in 2024, and there were people in 2026."
Zhao Chen repeated these two points in time.
"Yes. 2026 Manned Window.
There won't be many people going to Mars in the first batch, maybe just a few.
The first group of people to go will become permanent residents. They say that after the heroic death squads go, they can never return.
The real colonization will have to wait until the 2030s--
Only when the propellant production facilities, residential modules, and energy systems on board Mars are all in place can large-scale transportation of immigrants begin.
At this stage, hundreds of Starships are sent out at one window, each carrying dozens of people, plus thousands of tons of equipment and supplies.
It will take about ten years to build a self-sustaining base on Mars."
He changed a red pen from the whiteboard slot and wrote a number - "100" next to the Mars circle.
Then turned his head and looked at Zhao Chen.
"One million people. This is the long-term goal I have set for the Mars base.
It sounds crazy, but do the math - starting in the 2030s,
Each window sends hundreds of Starship, each ship carries dozens of people, and twenty-six windows equals several decades.
One million people were not sent there at once, but over several decades and thousands of Starships were sent there one after another.
The numbers sound huge, but when spread out over each year, they are no more exaggerated than the large-scale immigration in human history."
Su Wantang stood next to the whiteboard with a teacup in hand, looking at the number "100".
She is a philanthropist and has her own understanding of the number "one million people."
"If a million people want to survive on Mars, it's not just about the rocket.
Air, water, food, medical care, education, law - these things took decades or even centuries to build on Earth.
It's impossible to wait that long on Mars."
Elon Musk put the red pen in the whiteboard slot and turned around to look at Su Wantang.
"Yes. So Mars cannot be built by SpaceX alone.
More is needed - agriculture, construction, energy, healthcare.
Your Philanthropic Foundation is doing popular science on New Energy. Those children who touched the Solar Energy experimental device for the first time in rural primary schools,
If one day someone tells them that they need to build the first power station on Mars, will they want to go?
There will be people who want to go. There will always be people among a million who are willing to go.
Not everyone, but enough."
Zhao Chen Put the tea cup on the table, stand up and walk to the whiteboard.