I ask you to build tractors, but you build rockets?

On December 10, the Aviation Development Commission officially determined the Tianwen series of detection missions for 2018:

The first is the launch vehicle, which is temporarily designated as Xinyuan-2B (three-stage configuration), with a Mars orbit carrying capacity of 10.4 tons.

A total of four Mars ground probes are planned to be launched, namely the Tianwen-1 to Tianwen-4 missions, all with the same functions.

The probes for the Tianwen 1 to 4 missions include a lander and a thruster. The latter is responsible for decelerating and sending the 6.5-ton lander into the Martian atmosphere.

The lander is divided into three parts: heat shield, patrol robot, and reducer.

The reducer is wrapped in a heat shield above the patrol robot. When it enters the atmosphere, it will first use a parachute for preliminary braking. After passing through the atmosphere, the heat shield will be thrown away, and then a rocket will be used to decelerate. It will be 4 to 5 meters above the ground. The patrol robot was suspended in the air at a certain distance and lowered with a cable, then broke away and crashed far away.

Compared with the lander mode on the moon, the purpose of this is to maximize the quality of the patrol robot and enhance its detection capabilities.

The patrol robot will adopt a traditional wheel-type design and is temporarily named the "Firefly" Mars rover, but it has a mass of up to 2.3 tons.

It will be equipped with a 650kg, 5.2KW high-power nuclear battery provided by Xinyuan, which can meet all the needs of the Firefly Mars rover.

"Yinghuo" is very powerful. In addition to carrying 16 types of analysis equipment, it will also be equipped with a multi-functional robotic arm. It will rely on its abundant power to be controlled by AI on Mars and explore a radius of about 200 kilometers in two years. area.

Four Mars rovers correspond to four locations where water is suspected to exist. It is enough to confirm that one location is available for synthetic fuel.

The Firefly Mars rover is the absolute main force in selecting Mars landing sites, and its core is a 5KW ultra-high-power nuclear battery.

The Aerospace Development Commission still has confidence in Xinyuan's nuclear technology, because the 50kg 280w RTG nuclear battery equipped for the Lunar Spider II: Explorer 2 launched this month has been delivered and has achieved the design goals.

The nuclear battery of the Mars rover is basically an additional battery pack, and Mars has an atmosphere that can dissipate heat and is much more comfortable than the moon. 5.2KW power is not difficult.

Curiosity, the first nuclear-powered Mars rover, weighs 900 kilograms and is equipped with a 45 kilogram 140w nuclear battery, which is far less powerful than Yinghuo.

However, Curiosity’s detection mission does not include frantically searching for water to prepare for manned landing, so the 140w nuclear battery is sufficient, so it is not a lack of technology.

In addition, a total of four resource exploration satellites in Mars orbit are planned to be launched. Each satellite weighs about 2 tons and will be hit by two Long March 7A rockets, which is enough to complete the resource exploration mission.

Of course, this is just the Tianwen plan, and Xinyuan is just an important contractor.

For Lin Ju himself, although the Advance is sufficient to complete the mission of landing on Mars, due to the uncertainty about the system, the Mars mission may be more complicated than he imagined.

The lunar plan's operations of synthesizing lunar surface fuel, repeatable unmanned spacecraft to deliver fuel to the lunar space station, and providing supplies to the spacecraft will also be moved to Mars.

And because Mars has higher gravity and atmospheric obstruction, the mass of the entire fuel supply system will inevitably double. Moreover, Mars is too far away and needs to wait for a window period. Every opportunity must be seized to dump as much mass as possible.

This makes the No. 4 rocket necessary. The Mars transportation capacity of 200 tons is four times that of the No. 3 rocket.

Moreover, the configuration of the No. 4 rocket has also been slightly adjusted by Serev. 39 hydrogen and oxygen engines will be placed side by side in the core stage at the same time. The solid propellers can be reused after splashing down at sea.

The hydrogen-oxygen engine combustion chamber used in the No. 4 rocket will be pressurized by more than 30%, and the sea-level thrust will increase to 280 tons while the volume remains unchanged, making the core-stage thrust alone more than 10,000 tons.

Serev liked the No. 4 rocket very much, mainly because the hydrogen-oxygen fuel was very clean, so he ignored the solid propeller.

The No. 4 rocket is now determined to have three configurations: basic type, type A, and type B.

The basic type will almost never be manufactured. It is a one-and-a-half-stage configuration with only the core stage and booster. The 39 engines in the core stage can flexibly adjust the working quantity and continue to work for 600 seconds, sending the load all the way into a low-Earth orbit of 300 kilometers. , with a transport capacity of 550 tons.

Type A is a second-level configuration, which means it would have 800 tons if used for low orbit, but its purpose is for the moon and can send a 360-ton payload to the lunar orbit.

Type B is a three-stage configuration specially designed for Mars, and it is also the configuration that Serev values ​​most. The Mars transport capacity is 200 tons, but the key point is that the third stage using liquid oxygen and liquid hydrogen fuel will go to Mars with the load and complete deceleration and braking. process.

Going to Mars will take 4 to 6 months faster, and the storage of liquid hydrogen and liquid oxygen fuel in space is a big problem.

Liquid hydrogen needs to be stored in an ultra-high pressure and ultra-low temperature environment, and it will continue to corrode the inner wall of the metal and cause catalysis. It is easy to leak when stored for a long time. There have been many examples in the history of aerospace.

Generally speaking, for this kind of large spacecraft to travel in deep space, it is appropriate for the thrusters to use storage-resistant normal-temperature fuel, which can be stored for a long time, even for several years.

But this fuel...it's extremely poisonous, and it only takes a little over 200 seconds to reach half of it.

Therefore, Serev decisively ruled out the possibility and decided to use zero evaporation storage technology on the third-stage fuel tank of the No. 4 rocket.

Existing liquid hydrogen storage methods require regular deflation to control the high pressure of liquid hydrogen volatilization inside the storage tank. The purpose of zero-evaporation storage technology is to store liquid hydrogen for an extremely long time without leaking at all.

Both the Alliance and NACA have done research in this area, but it was terminated without achieving much results. However, Serev plans to solve this problem in about a year.

For nothing else but high specific impulse and clean fuels, long live environmentalism!

The specific regulations of Xinyuan's Mars plan are still being slowly planned in Serev's mind, so Androv still doesn't know that he will continue to build such a big rocket in the next two years. He actually feels that the No. 3 rocket is enough. Used throughout the chemical energy era.

…

"Detach!"

500 seconds after the Artemis 1 mission took off, at an altitude of about 160 kilometers, the upper stage separated from the core stage with the spacecraft.

The antique-grade RL-10 engine starts and it will continue to accelerate, sending the Orion spacecraft to the moon within 48 hours.

The characteristics of the data returned were perfect, and Claire's heart was finally relieved.

The Orion spacecraft is very mature and requires little testing. Only the SLS rocket has been worrying. Fortunately, everything went normally during the 500-second flight. The wreckage of the booster has fallen into the ocean, which shows that the design is still successful. The first rocket cost more than 5 billion. The dollars are not wasted.

"Thank God, it seems that Xiao Hei can be a little happier when he leaves. Although he canceled the Constellation Project, restarting Artemis cannot do without his support."

Claire calmed her beating heart quietly, thinking that she had done a good job. If the three SLS and Falcon heavy rockets still cooperated to land on the moon, it could be implemented in March 2018.

Even without the Falcon Heavy, the two-shot SLS could complete the moon landing before August 2018 as originally promised.