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

Southern Nevada, Lincoln County.

In the desert of the great plains of central Aramco, a yellow building that blends in with the color of the sand stands alone.

This is the Jackass Flats (free translation: stupid apartment) testing site, and the team responsible for resuming the development of nuclear power engines is called the JF team, or JFT.

When Aramco carried out nuclear-powered rocket research, it included the "Kiwi" nuclear thermal rocket test engine in the ROVER program, the "Helios" nuclear thermal rocket engine, and the "Tit" nuclear thermal rocket engine; the NERVA NRX nuclear power in the NERVA program Rocket experimental engine, Experimental nuclear thermal rocket engine, SNTP plan, SEI plan, that is to say, there are at least 4 projects and 7 series.

In order to save time, the JFT team selected two models with suitable technical difficulty and performance for subsequent research.

The first is a high-thrust nuclear thermal rocket engine, which is expected to be used in the second and third stages of the rocket. The "Helios 2A" was chosen as the basic solution.

When the Helios 2A was tested in 1967, it ran at full power for 32 minutes at 4000MW (megawatt), with a peak power of 4082MW, a combustion chamber temperature of 2256K (1982 degrees Celsius), and a total flow rate of 118.8kg/s.

Helios 2A uses liquid hydrogen as fuel and has a specific impulse of 821 seconds, which means it can output 977KN, which is about 97.7 tons of thrust. It can be regarded as a high-thrust rocket engine.

The second is a space propulsion nuclear power device developed from the NERVA A6 engine developed in the NERVA (Nuclear Engine for Rocket Vehicle Application) program.

The maximum power of NERVA A6 can reach 1199MW. When working, the combustion chamber temperature is 2406K (2132 degrees Celsius), the specific impulse reaches 869 seconds, the flow rate is 32.7kg/s, the thrust is about 28.5 tons, and the maximum power can last for 60 minutes.

Both Helios 2A and NERVA A6 are actually in a relatively early stage. Due to the technical environment of the 1960s, the solutions were relatively conservative, and actual test indicators often exceeded the design.

In other words, both still have deep potential to be tapped.

But just the current indicators also beat all traditional rocket engines.

With the technical level of NERVA A6, just installing one on the space shuttle is enough to fly to and from the moon.

According to a rough calculation, if a space shuttle takes off from low-Earth orbit with a mass of 140 tons, then it only needs to consume about 45 tons of fuel to send a 20-ton payload to the moon, and it will consume another 20 tons of fuel on the return trip. As long as Just control the empty weight of the space shuttle to about 55 tons, which is not difficult with current technology.

Of course, the actual empty weight of 55 tons includes the mass of NERVA A6 and a more complex cooling system, but at least it shows that the theoretical prospects are quite good!

Freeman, the leader of the JFT team, was a senior engineer at DARPA (a nuclear propulsion research company with a military background). Now he is leading the team to develop a nuclear engine comparable to the A100 based on past data.

Freeman first ignored the outrageous indicator of 26,000 seconds specific impulse. He doubted whether it was an extra zero, because the second stage of traditional nuclear thermal engine technology has only developed to 2,000 to 3,000 specific impulses, and the number currently exceeds 10,000. It seems that only Hall thrusters can do it.

Other indicators of the A100 are pretty average. The thrust of 100KN is average. However, the total weight must be controlled well. This can be inferred from the aerodynamic layout of the H2 and the installation positions of the three engines at the rear.

Helios A2 and NERVA A6 are big guys, so reducing weight is not a small task.

The military requested that FATS plan to complete its first flight before July. Boeing said that the airframe refurbishment could make it in time, and then the military came to rush Freeman.

The military leader who contacted JET was a colonel. He looked young and gloomy, and he looked like he was supported by some big boss.

Freeman: "Colonel Anthony, you should know that anything related to nuclear power is dangerous and requires very careful verification before it can be put into practical use."

Anthony Potts did not refute, but shook a stack of photos in his hand, including satellite photos and spy photos.

The location of the Qingshan base is not considered hidden. Although the A100 engine was camouflaged when it was loaded onto a truck and shipped out, it was still captured by IAA informants, and the radiation source meter they carried with them confirmed that the shipped out should be a nuclear engine. .

The A100 itself is not a classified project, and all the major powers at the nuclear test site where it was tested have long been aware of it. Spy satellites did not spend much effort to confirm that A100 was being tested.

Although the specific results are unknown, this still greatly stimulated the Hexagon.

When Freeman saw these photos, he understood the military's urgency, but still wanted to try harder:

"Research on nuclear engines has been suspended for a long time, and the research plans at that time were all to replace the first-stage engine of the rocket. There was no consideration for use in space. You may not understand. Let me give you an example: This is like lifting a submarine from the sea. The difference between moving to land and still allowing it to travel is not an exaggeration in the technological span.

I guess the nuclear engine isn't the slowest part, why not wait? "

Anthony Potts: "That's the second thing, Dr. Freeman."

He once again took out a confidential document bag, unsealed it in person, and handed the information inside to Freeman.

The latter took the hand and turned it over, and found that what was recorded inside was the registration number of the NX-17 spacecraft - the Qianjunbang No. 1 disguised by Xinyuan in the Hexagon Building.

Anthony: "Look, XAP launched a space test nuclear reactor, and the power is not weak at all. We scanned it several times with several infrared satellites and found that its thermal power exceeded 4,000 kilowatts at its peak; the alliance's former Toba The power generation efficiency of the Si-1 nuclear thermal reactor is less than 5%, and the NX-17 seems to use the same thermionic power generation technology, so it can output at least 200 kilowatts of power.

200 kilowatts, doctor, this is not a small number. If they double this number, it can be installed on H2, which can provide 500 kilowatts of continuous power. With the addition of capacitors, it can reach more than 1 megawatt, no matter what kind of power it is. Can destroy any known satellite and spacecraft. "

Freeman carefully read the information collected by the Hexagon in various ways, and gradually understood the reason for the Air Force's anxiety.

The laser power envisaged in the first phase of the AAF's FATS plan is only in the megawatt range. Now the technology that can support such power has almost appeared, but the AAF has nothing yet.

However, he has some objections to the NX-17.

"NX-17 should not use thermionic power generation. The advantage of thermionic power generation is that it is small in size and light in weight, but the efficiency is very low. If you really need high-power power, you should use a closed Brayton cycle to generate electricity. The efficiency is six times that of the thermionic power generation. More than times, NX-17 weighs 22 tons. For such a large volume, the thermal exchange Brayton cycle must be used for power generation, and the power generation must have exceeded 1,500 kilowatts."

After speaking, Freeman took another look at the presumed structural diagram of NX-17 and said with certainty again:

"That's right, less than one-third of the volume is enough for thermion power generation. No matter how unprofessional they are, they still can't make the thermion power pile so big. You made a mistake here."

It's normal for non-professionals to make mistakes, and Freeman just reminded him, but Anthony Potts' eyebrows furrowed.

"Dr. Freeman, are you sure that thermionic power generation will only occupy less than one-third of the volume?"

Freeman nodded very firmly: "This is common sense that every middle school student knows. Your intelligence analysts may not be professional, but it doesn't matter.

Since you need it, I will try my best to improve on the NERVA A6..."

Before he finished speaking, Anthony interrupted Freeman and said seriously:

"Doctor, what I want to tell you is that there is indeed no nuclear expert in the intelligence analysis room, so we hired Professor Robert Pattinson of Pennsylvania State University. He analyzed the power, thermal power and power generation method of NX-17."

"Robert Pattinson?!" Freeman was a little unbelievable. This was his mentor, and there was no way he would make such a low-level mistake.