However, the development of ion thrusters requires a lot of money, and neither Caltech nor NASA can afford to do it alone. Caltech is a private university, and although it has been ranked first in the United States for nearly four consecutive years, it is impossible to make it spend billions or even billions of dollars in research and development funds to develop this ion thruster technology.

As for NASA, as a government department under the jurisdiction of the U.S. government, NASA's annual budget is extremely strict, and it is no exaggeration to say that in NASA, even a paper clip has a budget.

Therefore, it is obviously impossible to expect the direct leaders of these two jet propulsion laboratories to spend a huge amount of money to develop this most advanced engine technology.

However, as a semi-governmental, private laboratory, the Jet Propulsion Laboratory still has relatively independent power in some aspects. It is precisely because of this that Dr. Schmitz was able to make the cooperation between Star Exploration and Jet Propulsion Laboratory, which has the money and Jet Propulsion Laboratory has the technology, and the cooperation between the two is undoubtedly a win-win result.

With the support of Tang Feng, under the leadership of Dr. Schmitz and the support of the Jet Propulsion Laboratory technology, the deep-pocketed Star Exploration Company has successfully made a breakthrough in technology in just over half a year.

You know, the diameter of the ion thruster of Deep Space 1 was only 304 mm, and it was launched from the Kennedy Space Center in Florida on September 27, 2007, and it was planned to cost $357 million, the first human probe to explore the asteroid belt, and also the first human probe to orbit Ceres and Vesta, the two largest asteroids, the "Dawn" probe, and the diameter of the ion thruster applied on it was only 408 mm.

The working principle of the ion thruster is actually quite simple. This kind of engine converts electrical energy and xenon into a high-speed ion flow with a positive charge, and the metal high-voltage transmission network exerts electrostatic attraction on the ion flow, the ion flow accelerates, and the accelerated ions make the thruster propel the spacecraft forward.

Before mankind mastered the technology of controlled nuclear fusion, the power of spacecraft could only use oxidants and reducing agents as raw materials, because in space, spacecraft relied on the "principle of variable mass motion" to obtain power. i.e. the spacecraft as a closed system. There is a material ejection system (fuel combustion ejection) in which the ship's mass decreases in exchange for increased speed of "force". Attitude adjustment and orbit change all rely on such "force".

However, neither electricity nor heat can provide power for the spacecraft to move in space, so even if a nuclear reactor is put on the spacecraft, it can only allow the spacecraft to obtain enough power, but it cannot make the spacecraft gain the power to move forward.

However, once a breakthrough in ion thruster technology has been made, electric propulsion technology can successfully power the spacecraft. In contrast to conventional chemical propulsion, this type of engine requires only a strong current and a small amount of xenon to form thrust. It's undoubtedly much more advanced.

With this kind of engine, as long as there is enough electricity and xenon gas on the spacecraft, it can theoretically form a steady stream of propulsion to push the spacecraft forward.

However, before the technological breakthrough of ion thrusters, the shortcomings of the previously applied ion thrusters were too obvious, whether it was the ion thrusters used by Deep Space 1 or Dawn, the thrust was very small. On Earth, this ion propulsion system can only blow a piece of paper! Therefore. At present, this ion thruster cannot lift the spacecraft out of the earth's surface, and only in the weightlessness of outer space can this ion thruster be able to propel a spacecraft less than a thousand kilograms to accelerate, but it also takes a long time to accelerate.

But again, the advantages of ion thrusters are really beyond doubt. Conventional rockets are propelled forward by spewing high-speed gas from their tails, and ion thrusters use the same jet principle. But instead of burning fuel to emit a hot gas, it emits a beam of charged particles or ions. The propulsion it provides may be relatively weak, but the key point is that this ion thruster requires much less fuel than a normal rocket. As long as the ion thruster can maintain stable performance for a long time, it will eventually be able to accelerate spacecraft to higher speeds.

Most critically, the use of ion thrusters. Fuel consumption is reduced by at least 80% compared to conventional chemical propulsion. For example, there are now two 1,400-liter chemical storage tanks on the Dongfanghong 4 satellite platform in Huaxia, and the fuel in them is mainly used by the satellite to change orbits. The use of ion electric propulsion can save more than 80% of fuel, and at the same time, the weight of the satellite itself is also greatly reduced, now a communication satellite weighs about 4.8 tons, and the weight of the satellite itself is reduced to 1.8 tons with this technology. For example, there are only 56 transponders on the planet, and the space saved can be increased to 100, and the value of one transponder is about $1 million. In other words, a satellite with an ion-electric propulsion system will have twice as many scientific instruments on it as it does now.

In addition, for deep space exploration, spacecraft will have to travel a long distance, so if chemical fuel is used, most of the space on rockets and satellites will be occupied by fuel, and the corresponding scientific exploration instruments will be much reduced, and the cost of chemical fuel is also very high. After using the ion electric propulsion system, because its specific impulse is 10 times that of chemical fuels and requires less working medium, it can work in a gravity-free state in space for several years. NASA has calculated that it will take only three years for a probe using ionic electric thrust to reach Saturn, compared to seven years for a conventional spacecraft.

Therefore, no matter how you consider it, ion thrusters are an indispensable key technology for deep space exploration.

Now, thanks to the combined efforts of the Jet Propulsion Laboratory and Star Discovery, a breakthrough has been made in the diameter of the ion thruster. Despite the fact that the diameter of this new ion thruster has only increased by 500 millimeters, the thrust gained is seven times larger than that of the ion thruster on the upsurge of Dawn, so this new ion thruster is now ready for application in deep space exploration spacecraft. (To be continued.) )