By 2035, the report said, China could have roughly 1,500 nuclear warheads -- an "accelerated expansion" of its stockpile, a senior defense official told CNN.While Friday marked the "first time the world's first sixth-generation aircraft (was) seen by the public," Northrop Grumman said, airmen and aircraft enthusiasts alike will have to wait until next year to actually see one in the air.The first B-21 flight is expected to happen in 2023, Air Force spokeswoman Ann Stefanek said, though she emphasized that the timing of the first flight "will be data and event, not date, driven."The Air Force previously said that the new nuclear-capable stealth bomber, which has the ability to carry both nuclear and conventional weapons and which will fall under the Air Force's Global Strike Command, will be "the backbone of the future Air Force bomber force," designed in a way that is ripe for future modernization efforts."We wanted [to] ensure the aircraft had a strong name airmen could take pride in, especially those who will have the opportunity to fly and maintain the B-21," Lt. Col. Jaime Hernandez, commander of the 337th, said in 2016."