Short answers, pulled from the story.
The U.S. Post Office dedicated a new stamp marking the 100th anniversary of Fort Bliss on the 5th of November 1948. This issue depicted a rocket designed after the German V-2 and over 64 million copies were printed by the Bureau of Engraving and Printing.
Echo 1 burned up upon reentry into the atmosphere on the 24th of May 1968. The U.S. Post Office issued a 4-cent stamp honoring this achievement on the 15th of December 1960 with more than 120 million copies produced using the rotary process.
Charles R. Chickering designed the Project Mercury commemorative stamp while working from his home under the guise of vacation. The Post Office Department released the 4-cent stamp at that exact hour when Colonel John Glenn returned safely to Earth after his historic orbital flight.
The U.S. Post Office issued a stamp commemorating Robert Hutchings Goddard on the 5th of October 1964 during a ceremony held in New Mexico. Esther Goddard attended the event and pressed the button launching two small rockets each carrying 1,000 first day covers for recovery.
Two 5-cent se-tenant stamps honoring Ed White went on sale the 29th of September 1967. Paul Calle designed the issue based on actual photos taken during the mission where he floated fifteen feet outside the Gemini IV capsule during June 1965.
A separate First Man on the Moon stamp appeared the 9th of September 1969 showing Neil Armstrong taking his first step. Paul Calle designed this image while the original master die for that stamp actually flew to the Moon and back.