In a recent report, the National Research Council (NRC) recommended that NASA should continue to fly flagship missions as a major component of its exploration program. Flagship missions are large, complex, and expensive missions that are designed to address major scientific questions and advance our understanding of the universe. They are typically carried out by teams of scientists and engineers working together with NASA.

The NRC report found that flagship missions have been highly successful in achieving their scientific goals and in inspiring the public about space exploration. For example, the Hubble Space Telescope has revolutionized our understanding of the universe, and the Cassini-Huygens mission has provided stunning images and data from Saturn and its moons. Flagship missions have also helped to attract and retain top talent in the space sector.

However, the NRC report also found that flagship missions are becoming increasingly expensive and complex. As a result, NASA is under pressure to scale back its flagship program in order to make room for other priorities, such as robotic exploration of the solar system and human missions to Mars.

The NRC report concluded that NASA should continue to fly flagship missions, but that it should make changes to the program in order to address the challenges of cost and complexity. These changes include:

* Focusing on missions that are aligned with NASA's strategic goals.

* Reducing the cost of flagship missions by using new technologies and partnerships.

* Increasing the efficiency of flagship missions by streamlining management and oversight.

* Improving the public engagement and outreach of flagship missions.

The NRC report's recommendations provide NASA with a roadmap for continuing to fly flagship missions in the face of challenges. By making these changes, NASA can ensure that flagship missions continue to be a major force in space exploration for years to come.

Here are some specific examples of how flagship missions have advanced our understanding of the universe:

* The Hubble Space Telescope has revealed the existence of dark energy, which is causing the expansion of the universe to accelerate.

* The Cassini-Huygens mission has discovered oceans of liquid hydrocarbons on Saturn's moon Titan and a possible underground ocean on Jupiter's moon Europa.

* The Mars Curiosity Rover has found evidence that Mars could have once been habitable for microbial life.

These are just a few examples of the many discoveries that have been made by flagship missions. By continuing to fly flagship missions, NASA can continue to make progress in our understanding of the universe and our place in it.