2022 Neff Public Lecture

65 years after Sputnik: A critical juncture in humanity’s use of space

Near-Earth space has become increasingly valuable and its use for civil (e.g., scientific), commercial, and military purposes has grown enormously in recent years. This growth has been driven in part by a rapid decrease in space-launch costs, which have declined by a factor of 30 over the past decade and are expected to decrease further during the next few years. It has also been driven by a vast expansion in the use of commercial satellites to support a wide variety of activities, including communications and Earth observations. The growing use of space is having a dramatic impact on human activities but also on the space environment. This environment is very vulnerable and can easily be ruined by irresponsible behavior or a small number of destructive actions or events. Low-Earth and geosynchronous orbits are becoming crowded. Missile defense systems threaten satellites in these orbits. Destruction of satellites by anti-satellite weapons has increased dangerous space debris in low-Earth orbits. Collisions between satellites or attacks on them could have catastrophic consequences for our ability to use space. Unless we manage the threats posed by crowding, orbiting debris, and deliberate destructive actions, humanity will lose the use of space. I discuss approaches that would preserve our ability to use it.