The concept for Tomatosphere originated in late 1999 and the project held its first formal meeting on February 7, 2000. The project was formally activated when 200,000 Heinz tomato seeds went into space on November 30, 2000, with Canadian astronaut, Dr. Marc Garneau. The seeds were part of an experiment designed to test the effects of short- term space travel on seed germination and interaction with new techniques designed to enhance germination rates. An equal number of seeds stayed behind on Earth and the two lots, space-flown and Earth-bound, were further sub-divided into two treatments using new Infra Red and Red light technology developed at the University of Guelph. The resulting four treatments were packaged and sent to almost 2700 classrooms across Canada, along with posters and a teacher's guide matched to the Pan-Canadian Protocol for Collaboration on School Curriculum, a framework of Science Learning Outcomes developed by the Council of Ministers of Education, Canada. The emphasis for the curriculum connections was from grade 3 (plants and soil) to grade six (space).
The project met with an overwhelming response from educators and students. As such, in 2003, the project expanded to involve more than 5 000 classrooms across Canada; the scope of the project was also expanded from the original grade 3 - 6 focus to include grades 8 - 10. The scope of the curriculum in grades 8 - 10 allows for the incorporation of several objectives relative to the ISS mission objectives, the overall concept of humans in space, and the application of knowledge from space programs to the well-being of humankind on Earth.