Of course, in addition to the large thrust rocket engine technology of one or two thousand tons, Wang Bin and Tiangong technology also need a small thrust rocket engine technology of one or two hundred tons, or even a small thrust engine technology with a thrust of only a few cattle and dozens of cattle, if they want to develop aerospace technology.


    In addition, there are steering propulsion devices and measuring wheels of space vehicles.


    These technologies need energy coins to buy. Thinking of these, Wang Bin began to worry about the energy coins in his hands again, because according to the technologies that need to be purchased, it is really not enough to buy just by relying on the energy coins in his hands.


    After all, a thousand tons of high thrust rocket engine technology, coupled with technologies in other parts of the rocket, such as rocket body technology and fuel tank technology, will require nearly two million energy coins, while a hundred or two tons of low thrust rocket engine technology will require at least hundreds of thousands of energy coins.


    If you add a few cattle, dozens of cattle and various steering thrusters, the energy coins required will definitely exceed the energy coins Wang Bin now has.


    In addition, if you want to manufacture launch rockets, these rocket engine technologies alone are not enough. You also need multi-stage rocket technology, bundled rocket technology, etc. according to Wang Bin''s estimation, no one has two million energy coins.


    He can''t buy a complete set of high thrust rocket technology at all. If he adds rocket recovery technology, Wang Bin needs at least 8 million energy coins.


    This made Wang Bin a little stunned for a moment. After all, in his original plan, Wang Bin thought that as long as the price of three or four million energy coins, he could buy the whole fourth generation rocket technology. However, after calculation, the price of four million could only buy the engine technology, which made him a little overwhelmed.


    But then Wang Bin thought that he didn''t need to buy a complete set of fourth generation rocket technology. In fact, many technologies. With the strength of Tiangong technology, as long as there are corresponding talents, it''s not difficult to develop technologies that are not different.


    Moreover, even if Wang Bin and Tiangong technology can''t develop corresponding technologies for a while, he can turn to the official for help, and the strength of Huaxia Aerospace absolutely has relevant technologies.


    Thinking of this, Wang Bin loosened his frown, so he now used the price of one million energy coins to buy the fourth generation rocket engine technology of 1000 tons, and then spent the price of 55 energy coins to buy the fourth generation engine technology of 100 tons and 200 tons.


    As for the micro rocket propulsion technology with smaller thrust, Wang Bin did not buy it, because he knew that such propulsion technology could definitely be developed with the ability of Tiangong technology. Even if they could not, he could also turn to the official space agency for help.


    In terms of various space steering thrusters, Wang Bin did not buy them in the system. As before, thrusters like this are definitely not a problem for their Tiangong technology. He doesn''t have to worry at all. Moreover, as long as he has high thrust rocket engine technology, the official is absolutely happy to help.


    Finally, the rocket control system, the rocket fuel tank and the recovery system. For the rocket fuel tank technology, Wang Bin thought about it. He still spent 300000 energy coins to buy five diameters, namely 1m, 1.5m, 2.5m, 3.5m and 5m, 15 fuel tank modules and separators, and larger diameter fuel tanks and separators, Wang Bin didn''t buy it.


    Because he knew that even if he bought the larger diameter rocket fuel tank module technology now, he could not use it for the time being. Most importantly, among these engine technologies he purchased, the diameter of the largest engine, that is, the 1000 ton rocket engine technology, was only 2.5 meters. Therefore, Wang Bin did not need the larger diameter fuel tank technology for the time being.


    Of course, with these fuel tank technologies, Wang Bin believes that it is not difficult for them to develop larger diameter rocket fuel tank technology.


    In fact, Wang Bin knows that the fuel tank technology of the rocket is not difficult, and the reason why Wang Bin buys these technologies is that the price is so high is entirely because these technologies also include the production equipment technology of these technologies.


    When Wang Bin bought all these technologies, the more than 1.5 million energy coins he had just obtained had been completely painted, and even the nearly 55 energy coins left in his hands had been almost consumed.


    Of course, Wang Bin felt a little sad about spending so many energy coins at one time, but he thought that their Tiangong technology was different from the past, and the speed of making energy coins was not comparable when he just got the technology mall system.


    You know, in the past, if he wanted to save 50 omnipotent coins, it would take nearly a month to save them, but now! As long as he sells a Tiangong 001 UAV, it is enough for him to buy a lot of technology.


    Most importantly, judging from his sale of UAVs this time, as long as the price of UAVs he will sell in the science and technology mall in the future is not too high, its buyers will not feel less.


    Thinking of these, Wang Bin''s heart suddenly felt much better.


    After buying the technology, Wang Bin immediately withdrew from the system, returned to reality and prepared to rest. As for the technologies just purchased, in addition to the technologies in his mind, physical objects such as design drawings, technical parameters, processing technology and material formulas were put in the store for the time being. After all, compared with reality, the security in the mall is higher, He doesn''t want the technology he bought at such a high price to make it cheaper for others.


    ........


    Early the next morning, after breakfast, Wang Bin immediately came to the company and rechecked the Tiangong 001 UAV that flew yesterday with Professor Zhang and others, and reassembled the UAV.


    When Wang Bin assembled the UAV again and moved it to the runway, chief engineer Lin and general Qiu also came to their Tiangong technology.


    "Mr. Wang! I have two good news to tell you that the engine production certificate submitted by Tiangong technology has been recognized by our military and our opinions have been submitted to relevant departments. If there is no accident, your production license should be passed these days!" when general Qiu came to the runway, Immediately smiled and told Wang Bin about the engine production license passed at yesterday''s meeting.


    "Really? General Qiu, that''s great. In this way, as long as the whole life test run of this engine can exceed 2000 hours, we can carry out small batch production of this engine, and we can also start to establish a production line with him." after listening to general Qiu''s words, Wang bin immediately said happily.