Mao did gain the help from USSR to build up China's industry, but those strategic technologies such as nuke and space program, USSR didn't provide a lot of help since they didn't trust Mao.
But Mao and Zhou have recruited a lot Chinese graduate from the western countries.
Remember Qian Xuesen, the father of China's missile and space program, he was a top graduate from USA, and one of the most favorite students of Theodore von Karman.
He was also the first man who found Wernher von Braun and inspected him.
Without a genius and great scientist like Qian Xuesen, China's space program wouldn't go that far.
As matter of fact ...China did get all crucial technology before Sino-Soviet Split in 1960 .
Thereafter Chinese continued their own efforts ...but all the documents prove clearly
How Kruscheve gave warhead designs , plutonium processing plant , Uranium processing plant to Mao
Agreed after deportation from US during McCarthysm era Quain became father of china's missile programme
Also Russians gave R-2 rocket technology which was extremely helpful in initial designs and technology for both missiles and rockets ....
No doubt that afterwards Chinese own efforts helped to build upon initial help ...
But the momentum ...crucial head start ....in such coveted ...strategic technology which nations normally don't share .....
Soviets did share with China for their own compulsions ....
PRCwas crown jewel among all Soviet Block nations .....
Khruschev did not want to lose Ideological race with US , so was reluctantly forced to pay price of Nuclear weapons technology to PRC to keep Soviet block intact .....
These are undeniable facts of history ....