Edwin Hubble, a renowned astronomer, revolutionized our understanding of the universe. He proved the existence of galaxies beyond the Milky Way and discovered that the universe is expanding. His ...

Astronomer Dr. Edwin Powell Hubble (1889 - 1953) sitting in a chair at a desk reading a journal. Image: New York Times Co./Getty Images This article was originally featured on The Conversation.

Hubble launched on April 24, 1990, stowed inside the cargo bay of space shuttle Discovery. STS-31 was Discovery's 10th launch, and it was the 35th space shuttle mission overall.