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The CZ-10 team now, apart from being busy, hasn't actually encountered any major issues, given that the 5-meter rocket body technology of the CZ-5 isn't complicated and has been successful for so many years.
The connectors between the four boosters and the core stage had also withstood simulated tests, with thousands of tons of thrust acting on structures that still had to separate, which was unprecedented in China's aerospace history.
Busy but orderly, moving ahead steadily and quickly - that was the real picture of the space agency at the moment, but NACA, on the other hand, had run into trouble.
The trouble was the SLS rocket.
The SLS rocket originated from the STS, the Space Shuttle program.
How does the Space Shuttle reach space? Its main propulsion comes from three RS-25 hydrogen-oxygen engines at the tail of the Shuttle, while it rests on an orange fuel tank with a solid rocket booster on each side.