Hermann Oberth's 1923 paper, Die Rakete zu den Planetenräumen ("The Rocket into Planetary Space"). And then in 1946 Lyman Spitzer wrote another paper "Astronomical advantages of an extraterrestrial observatory" describing advantages that a space-based telescope would have over ground-based ones. After he published his paper, Spitzer focused on trying to make his idea a reality. In 1962 the space program was tasked with creating such a telescope and in 1965 Spitzer was selected to lead a committee to flesh out the needs and requirements for such a telescope.
Orbiting Astronomical Observatory (OAO) mission from 1968 until 1972. Because of funding cuts, no further money was ear marked for a space telescope until 1978. From this money arose the idea for the Hubble, which was initially suppose to launch in 1983, but because of the Challenger disaster the Hubble had to remain grounded for many more years. Rather than being put on ice, the Hubble was put on liquid nitrogen, which cost $6 million per month. Scientists used this time to improve the Hubble. Because of huge advances in computer science during this time they were even able to create a whole new ground operating system and various other advancements that have allowed the Hubble to remain the coolest photographer in history. However, there have still been several trips to work on the Hubble. One such trip swapped out the tape storage device for a solid state storage device.
In addition to its pictures which have inspired many amateur star gazers, Hubble has helped solve many long-standing questions about outer space and has posed some new ones. We have a better idea about the age of the universe, but are less certain about the future. Hubble's unique vantage point far above the confines of our atmosphere has helped us to discover new galaxies.
You can go to the official HubbleSite web gallery to see some amazing pictures that it has taken.
If you want to, you can click on the highest resolution and take the pictures to kinkos or somewhere to get neat artwork. Or you can print from your printer for free. (Yeah, really kicking myself for those expensive prints I bought last year from the "space photographer" boo.).
Sources: from Wikipedia and the official HubbleSite. All pictures are from the official HubbleSite.