Sylvester's Frontier

Sylvester’s Frontier

The Spacecraft That Couldn’t Enter Safe Mode

How a rare software interaction blocked Proba-3’s recovery path, and six tests for resilient autonomy.

Oct 27, 2026

On 14–15 February 2026, ESA’s Proba-3 Coronagraph spacecraft encountered an unusual software fault during an ordinary attitude-control operation. A routine recovery action failed, the spacecraft drifted away from its intended orientation, and its solar panel stopped facing the Sun. Battery power dwindled. Contact with the ground was lost.

Engineers event…

Subscribe for free to continue reading

Enter your email and get every post from Sylvester's Frontier.
Already have an account? Sign in
© 2026 Sylvester Kaczmarek · Privacy ∙ Terms ∙ Collection notice
Start your SubstackGet the app
Substack is the home for great culture