Colonel Gary Hobbes was the Mission Specialist for mission 'MME-877.' In an audio recording that he left behind, he mentions not being able to find a base camp or a rover and that the life support on his suit is almost gone. He also tells an unknown person named Jordan that he loves them. It is heavily implied that he was one of the original astronauts who first explored Mars and somehow got separated from the group, with 'MME' likely standing for "Manned Mars Exploration."
The winged insignia on his ID card does not belong to the Ultor Corporation or the Earth Defense Force, implying that the original manned Mars missions were conducted by another group prior to 2050, likely a government organization or space agency.
The insignia is an identical but mirrored image of that worn by present day United States Military Colonels, the same rank as was held by Gary Hobbes. This mirrored insignia is sometimes worn by members of the US Marine Corps, US Navy, US Coast Guard and also by members of the National Oceanic and Atmospheric Administration. Therefore it is implied that Col. Gary Hobbes was a member of one of these uniformed services.