Reusable rockets promised to slash the cost of reaching orbit, but for decades the savings were largely theoretical. Recent flight data from SpaceX's Falcon 9 program have shown that previously flown booster stages perform comparably to new ones over multiple missions. The economic implications of this finding are still unfolding.
Which choice best describes the function of the second sentence in the text?
- A
It introduces a competing rocket program.
- B
It defines the term 'orbit'.
- C
It refutes the original promise of reusable rockets.
- Dcheck_circle
It provides empirical support that begins to make the theoretical savings concrete.
Explanation
Falcon 9 flight data turn the theoretical promise into something measurable. B captures this empirical-support function.