China has declassified some of its top-secret military operations via a five-episode documentary that began broadcasting on Friday, which marked the 98th anniversary of the founding of the People's Liberation Army.

In the TV series, Gong Jian, or Forging Ahead, clips are shown of officers and technicians of the PLA Rocket Force taking part in a full-range test launch of a nuclear-capable intercontinental ballistic missile, or ICBM, on Sept 25, with the video coverage having been made public for the first time, unveiling some details of the historical moment in the history of the PLA and maneuvers of one of the military's most sensitive strategic forces.

The clips show that the missile launch test was conducted in accordance with its original schedule despite the location of the operation having just been hit by a strong storm.

An officer appearing in the documentary said that he "had waited for the order (to fire an ICBM) for many years", and that the weather conditions before the scheduled launch date "were more complex than those in previous exercises and rehearsals".

He stressed that the test "was closely related to the honor of the Rocket Force, and was also linked with the motherland's dignity and prowess".

The documentary includes scenes of Rocket Force soldiers operating and maintaining huge missile launch vehicles, and multiple short-range ballistic missiles being fired one by one.

It shows the last minutes of the Sept 25 test, with officers starting to conduct firing sequence and leaving the launch vehicle. Then a large missile is seen soaring skyward.

These scenes are followed by a clip of Senior Colonel Zhang Xiaogang, a spokesman for the Ministry of National Defense, declaring on Sept 25 that the Rocket Force launched on that morning an ICBM, carrying dummy warheads, into open waters in the Pacific Ocean.

The launch was the first time in more than four decades that China made public its flight test of an ICBM.

The last time the nation made such a flight test public was in May 1980, when the baseline model of the DF-5 was fired from the Jiuquan Satellite Launch Center in Northwest China and hit a preset area in the South Pacific after flying more than 9,000 kilometers. That was the first time a DF-5 missile carried out a full-range test flight.

In another part of the documentary, scenes of sailors operating one of the PLA Navy's Type 09IV-A nuclear-powered ballistic missile submarines are shown.

Sailors performed damage-control and underwater infiltration drills in a clip, displaying high morale as they were fully aware that the vessel is part of the pillar of China's sea-based nuclear deterrence system.

Wu Peixin, a military affairs observer, said the inclusion of the scenes of top-secret missile tests and nuclear submarine operations represents the unprecedented level of confidence and transparency in the Chinese armed forces.

"They will act as a gentle but powerful reminder to the world that though the Chinese people and the PLA love and cherish peace and stability, we will never hesitate to smash any attempt to jeopardize our sovereignty, territorial integrity, security and interests, and we are definitely able to do that," Wu said.