Don Kessler and Burt Cour-Palais submitted the paper "Collision frequency of artificial satellites" on 7th November 1977, more than 43 years ago & just 20 years after the launch of the first artificial satellite. The predictions were striking. The warnings were clear #SpaceDebris

Phillip Anz-Meador joined Don for their paper "Critical number of spacecraft in low Earth orbit" which Phillip presented at the 3rd European Conference on #SpaceDebris in 2001, nearly 20 years ago. The paper included one of the first attempts at identifying a "carrying capacity"

I presented my first #SpaceDebris paper at the 3rd European Conference and Phillip was one of the chairs of the session. At the start of my talk I apologised to the attendees for being tired: my daughter was just a few months old and we were enduring sleepless nights...

This weekend my daughter and I enjoyed an evening walk around our neighbourhood, looking up at the starlit sky as we made our way. It struck me how little progress we have made to tackle #SpaceDebris, how warnings nearly half-a-century old have made such little difference.

How the night sky we take so much for granted could be irrevocably changed in just a few years, thanks to satellites speeding by. How frustrated Don Kessler must feel at seeing the same stories appearing in the media year after year. How we seem to repeat the same mistakes.

We already know many answers, but each generation wants to make them their own. We reinvent the wheel. Reimagine the same problem in new ways, but ultimately arrive at the same thinking and the same warnings.

Isn't it time to change our approach? To heed the warnings we have been given? To use our understanding & make a difference? To imagine how our children's children will want, and need, space and the night sky, and to deliver that for them. Isn't that what #SpaceSustainability is?