Challenges Made, Challenges Met

They said these could never be done:

Sailing across the Atlantic Ocean – until Columbus sailed it

Building the transcontinental railroad – until the golden spike finished it

Creating the Panama Canal – until the first ship crossed it

Flying a heavier-than-air vehicle – until the Wright Brothers flew it

Sinking the unsinkable ship – until an iceberg sank it

Breaking the sound barrier – until Chuck Yeager broke it

Eliminating smallpox – until a vaccine was discovered for it

Traveling into space – until Yuri Gagarin traveled into it

Walking on the moon – until Neil Armstrong walked on it

When will the next great impossibility become possible?