April 6, 1973

NASA launches Pioneer 11, the second of two probes along with Pioneer 10 sent out to explore the outer solar system. Pioneer 11 became famous for being the first man-made object to fly by Saturn and also for making the closest flyby of Jupiter. After passing Saturn, Pioneer 11 continued on a trajectory towards the center of the Milky Way and will pass the star Lambda Aquila in 4 million years. The last contact with Pioneer 11 was in November of 1995. Both Pioneer spacecraft carry a plaque with a message from humanity in the chance that it is ever intercepted by intelligent life.

April 6, 1965

Intelsat I, the world’s first commercial communication satellite was launched into geosynchronous orbit above Earth. Built by the Hughes Aircraft Company, launched by NASA, and run by the Communications Satellite Corporation (COMSAT), Intelsat I was was nicknamed “Early Bird” and would go on to handle the first nearly instantaneous communications between Europe and North America. When activated in June of that year, Early Bird proved the feasibility of using synchronous satellites for commercial communications and handled telephone traffic, TV signals, telegraph, and faxes.