The Solar System Exploration Centre was the organisation responsible for coordinating the various Zero X expeditions to Mars during either the 2060s (PROSE: Ambush!) or the 2080s.
The first mission was scrubbed due to sabotage while the second mission reached Mars but crashed back on Earth. The next two expeditions were led by Captain Black and Paul Travers, (PROSE: 'Jinx Ship' Blasts Off For Mars) though they occurred in a disputed order. (PROSE: Mars Ship Hi-Jacked, Capt. Black Mars Expedition Lost!)
Black led an SSEC team to Mars with the aim of hunting the source of the "strange" radio signals coming from the planet. Although the mission was ostensibly a success, Black inadvertently started the Mysteron War while in command. (PROSE: 'Jinx Ship' Blasts Off For Mars) When Zero X returned to Earth, Black was the only person on board. (COMIC: SPECTRUM)
In an account dated to 25 February 2067, officials from the Solar System Exploration Centre revealed nothing more to TV 21 than that Travers had been instructed to pick up sealed orders. Rumours suggested that his new mission had something to do with revolutionary new rocket engines too dangerous to be tested on Earth. (PROSE: Ambush!)