Definition: Compose a new way to ask the same question. The new question must be asking the exact same thing as the original question does. Without any other information, you should be able to tell that the original question and the new question are the same. Preserve bracketed phrases in your new question. You can change the rest of the question provided the above requirements are satisfied. The new question must have a natural, fluent formulation, as if it were composed by a native English speaker. You will be given three pieces of information to help you create better questions. Those are: "Answer": the answer to the question, e.g., "Honolulu". "Answer Type": the type of the answer, e.g., "Location". "Auxiliary Information" is a detailed description of some concepts mentioned in the question, if any.
Input: original question: What is the development status of the [Space Shuttle main engine]?
answer: flown
answer type: Rocket engine development status.
auxiliary information: The Aerojet Rocketdyne RS-25, otherwise known as the Space Shuttle Main Engine, is a liquid-fuel cryogenic rocket engine that was used on NASA's Space Shuttle and is planned to be used on its successor, the Space Launch System. Built in the United States by Rocketdyne, the RS-25 burns cryogenic liquid hydrogen & liquid oxygen propellants, with each engine producing 1,859 kN of thrust at liftoff. Although the RS-25 can trace its heritage back to the 1960s, concerted development of the engine began in the 1970s, with the first flight, STS-1, occurring on April 12, 1981. The RS-25 has undergone several upgrades over its operational history to improve the engine's reliability, safety and maintenance load. The engine produces a specific impulse of 452 seconds in a vacuum, or 366 seconds at sea level, has a mass of approximately 3.5 tonnes, and is capable of throttling between 67% and 109% of its rated power level in one-percent increments. The RS-25 operates under temperatures ranging from ‚àí253 ¬∞C to 3,315 ¬∞C. On the Space Shuttle, the RS-25 was used in clusters of three engines mounted in the aft structure of the Orbiter, with fuel being drawn from the external tank.

The [Space Shuttle main engine] has what type of development status?