The Third part of my series one the Thor and Delta Rockets. At the start of the 1980's the Delta launch vehicle had managed to evolve from a small intermediate missile into a reliable launch vehicle that had carried hundreds of payloads over the last 2 decades. However, NASA was preparing to replace it with the Space Shuttle and it looked like it may be headed for retirement. But when the Space Shuttle was unable to deliver on its promises of reliable low cost launch services Delta was there to pick up the slack and continue its career up to the present day... or maybe 2018, depending on what you consider delta to be. A great deal of this research was compiled by Ed Kyle, thanks for his fantastic work. Follow me on Twitter for more updates: https://twitter.com/DJSnM I have a discord server where I regularly turn up: https://discord.gg/zStmKbM If you really like what I do you can support me directly through Patreon https://www.patreon.com/scottmanley