The most important fact of this century is not that Earth is threatened in many ways, It is that for the first time in all of its history a decisive means of protecting the home planet exists. It is by using space.

No matter that astronauts and cosmonauts had perished in precisely designed and carefully tested machines. Solid engineering could always provide a safety margin, because the engineers believed, there was complete safety in numbers.

The question to ask is whether the risk of traveling to space is worth the benefit. The answer is an unequivocal yes, but not only for the reasons that are usually touted by the space community: the need to explore, the scientific return, and the possibility of commercial profit. The most compelling reason, a very long-term one, is the necessity of using space to protect Earth and guarantee the survival of humanity.

Challenger was lost because NASA came to believe its own propaganda. The agency's deeply impacted cultural hubris had it that technology-engineering-would always triumph over random disaster if certain rules were followed. The engineers-turned-technocrats could not bring themselves to accept the psychology of machines with abandoning the core principle of their own faith: equations, geometry, and repetition-physical law, precision design, and testing-must defy chaos.

The most important fact of this century is not that Earth is threatened in many ways, It is that for the first time in all of its history a decisive means of protecting the home planet exists. It is by using space.