Why was NASA's Scout launch vehicle phased out?

Question

I was asked this years ago (by a Boy Scout, no less!) and was unable to provide an answer, specially since Scout came to be one of the most dependable launch vehicles ever. It was also known as LTV Scout and was employed in several variants, including (for the military, I believe), the so-called Blue Scout.

Answer 1

2 reasone I can think of:

1. Very few satellite operators want to launch 400 pound satellites, anymore -- they want more and more (heavier) payloads.

2. Pegasus can carry about the same payload mass to the same orbits, and is *much* cheaper to launch than Scout.

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