Normally one of the rookie astronauts takes responsibility for designing the crew logo and Laurel Clark did it for STS-107. Terry Johnson at NASA was the graphic artist who worked with Clark and created the final design that the crew approved.
A variety of concepts were presented to Clark and she chose the ones she liked, offering input into what should be changed or added. The earliest logos just have placeholders for the names of the pilots because they were designed before they were assigned to the crew.
The final design for the STS-107 logo is one of the better shuttle crew logos. It's simple and tells the mission's story. It’s the first shuttle patch in the shape of the space shuttle.
Many people were confused by the “µg" on the logo. It's actually the Greek letter "mu" which is used in scientific circles as an abbreviation for "micro", indicating a millionth. “µg" is actually "microgravity", the theme for many of the mission's objectives.
The official announcement read – “This is the insignia for STS-107, which is a multi-discipline microgravity and Earth science research mission with a multitude of international scientific investigations conducted continuously during the planned 16 days on orbit. The central element of the patch is the microgravity symbol, µg, flowing into the rays of the astronaut symbol. The mission inclination is portrayed by the 39 degree angle of the astronaut symbol to the Earth's horizon. The sunrise is representative of the numerous experiments that are the dawn of a new era for continued microgravity research on the International Space Station and beyond. The breadth of science conducted on this mission will have widespread benefits to life on Earth and our continued exploration of space illustrated by the Earth and stars. The constellation Columba (the dove) was chosen to symbolize peace on Earth and the Space Shuttle Columbia. The seven stars also represent the mission crewmembers and honor the original astronauts who paved the way to make research in space possible. The Israeli flag is adjacent to the name of the payload specialist who is the first person from that country to fly on the Space Shuttle.”