Chapter 281 Heavenly Questions

On December 10, the Aerospace Development Commission officially confirmed the Tianwen series of exploration missions in 2018:

First, the launch vehicle, temporarily designated as the New Yuan-2B (three-stage configuration), with a Mars orbital capacity of 10.4 tons.

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

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

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

The reducer is wrapped in the heat shield above the patrol robot. When entering the atmosphere, a parachute will be used for preliminary braking, and the heat shield will be discarded after passing through the atmosphere. Then, a rocket will be used to decelerate, and the patrol robot will be lowered with a cable at a distance of 4 to 5 meters from the ground, and then it will be detached and crashed.

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

The patrol robot will adopt the traditional wheel design and is temporarily named "Firefly" Mars rover, but its mass is as high as 2.3 tons.

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

"Firefly" is very powerful. In addition to the 16 analytical equipment it carries, it will also be equipped with a multi-functional robotic arm. It will rely on its own abundant power to be controlled by AI on Mars and explore an area with a radius of about 200 kilometers within two years.

Four Mars rovers correspond to four suspected water sites. As long as one place can be confirmed for synthetic fuel, it will be enough.

Firefly Mars rover is the absolute main force in the selection of Mars landing sites, and the core is the 5KW ultra-high-power nuclear battery.

The Aerospace Development Commission still trusts Xinyuan's nuclear technology, because the 50 kg 280w RTG nuclear battery equipped for the second generation of lunar spiders: Explorer II launched this month has been delivered, reaching the design goal.

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

The first nuclear-powered Mars rover, Curiosity, weighs 900 kg and carries a 45 kg 140w nuclear battery, which is far less powerful than Firefly.

However, Curiosity's exploration mission does not include frantically looking for water to prepare for manned landing, so the 140w nuclear battery is enough, so it is not a lack of technology.

In addition, there are four resource exploration satellites to be launched in the orbit of Mars, each weighing about 2 tons, which will be launched 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 Qianjin is enough to complete the mission of landing on Mars, due to the uncertainty of the system, the Mars mission may be more complicated than he imagined.

The operation of synthesizing fuel on the lunar surface, reusable unmanned spacecraft to send fuel to the lunar space station, and providing supplies for the spacecraft in the lunar plan must also be moved to Mars.

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

In this way, the No. 4 rocket is necessary. The 200-ton Mars transport capacity is four times that of the No. 3 rocket.

In addition, Shelev has made some adjustments to the configuration of the No. 4 rocket. The core stage will have 39 hydrogen-oxygen engines placed in parallel at the same time, and the solid propellant can be recycled and reused after splashing down at sea.

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

Shelev likes the No. 4 rocket very much, mainly because the hydrogen-oxygen fuel is very clean, and the solid propellant is ignored by him.

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

The basic type is almost never manufactured. It is a one-and-a-half-stage configuration with only the core stage and booster. The 39 engines of the core stage can flexibly adjust the number of working hours and work continuously for 600 seconds, sending the payload into a 300-kilometer low-Earth orbit all the way, with a transport capacity of 550 tons.

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

Type B is a three-stage configuration designed specifically for Mars, and it is also the configuration that Shelev values ​​the most. It has a Mars transport capacity of 200 tons, but the key point is that the three-stage using liquid oxygen and liquid hydrogen fuel will go to Mars with the payload and complete the deceleration and braking process.

Going to Mars, it will take 4 to 6 months at a faster speed, 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 to cause catalysis. Long-term storage is very likely to leak, and there have been many examples in the history of aerospace.

Generally speaking, for such large spacecraft deep space navigation, it is advisable for the thruster to use storage-resistant room temperature fuel, which can be stored for a long time, and several years is not a problem.

But this fuel... It is highly toxic, and it only takes a little over 200 seconds to charge halfway.

So Shelev decisively ruled it out and decided to use zero evaporation storage technology on the third-stage fuel tank of the No. 4 rocket.

Existing liquid hydrogen storage methods all require timed deflation to control the high pressure of liquid hydrogen volatilization inside the storage tank, while the purpose of zero evaporation storage technology is to store liquid hydrogen for a very long time without leaking out at all.

Both the Alliance and NACA have done research in this area, but they were terminated without much success. However, Shelev plans to solve this problem in about a year.

If nothing else, it is for high specific impulse and clean fuel, long live environmentalism!

The specific charter of Xinyuan's Mars plan is still being slowly planned in Shelev's mind, so Androv doesn't know that he will continue to work on this big rocket in the next two years. He actually thinks that the No. 3 rocket is enough for the entire chemical energy era.

…

"Detach!"

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

The antique-level RL-10 engine started, and it will continue to accelerate to send the Orion spacecraft to the moon within 48 hours.

The data characteristics sent back are very perfect, and Claire's heart, which has been hanging, is finally put down.

The Orion spacecraft is very mature and almost does not need any testing. Only the SLS rocket has been worrying. Fortunately, everything was normal during the 500-second flight. The wreckage of the booster has fallen into the ocean, which shows that the design is still successful. The more than 5 billion US dollars spent on the first rocket was not wasted.

"Thank God, it seems that Xiao Hei can be happier when he leaves. Although he canceled the Constellation plan, restarting Artemis cannot be separated from his support."

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

Even without the heavy Falcon, two SLSs could complete the moon landing before August 2018 as originally guaranteed.