The NASA Distinguished Service Medal is the highest award that can be bestowed by the National Aeronautics and Space Administration of the United States. The medal may be presented to any member of the federal government, including both military astronauts and civilian employees.
The NASA Distinguished Service Medal is awarded to those who display distinguished service, ability, or courage, and have personally made a contribution representing substantial progress to the NASA mission. The contribution must be so extraordinary that other forms of recognition would be inadequate.
Typical presentations of the NASA Distinguished Service Medal included awards to senior NASA administrators, mission control leaders, and astronauts who have completed several successful space flights. Due to the prestige of the award, the decoration is authorized for wear on active uniforms of the United States military. Another such authorized decoration is the NASA Space Flight Medal.
Upon the recommendation of NASA, the president may award an even higher honor to astronauts, the Congressional Space Medal of Honor.
The medal was original awarded by the National Advisory Committee for Aeronautics and was inherited by NASA. The first NASA version (type I), featuring the NASA seal, was issued from 1959 until 1964, when it was replaced by the current type II medal (shown).
https://en.wikipedia.org/wiki/NASA_Distinguished_Service_Medal