One of the world’s most venerable radio telescopes is on the brink of catastrophe, triggering a frantic race by engineers at the Arecibo Observatory in Puerto Rico to save it after two critical cables supporting a 900-ton equipment platform broke.

The platform, held aloft over a massive dish by cables strung to towers, must be quickly stabilized, or it could crash to the ground and destroy the telescope. With the loss of these two cables, the remaining cables are under increased strain, and it’s uncertain whether rescue efforts will be successful.

“For me, it’s probably fifty-fifty,” says former observatory director Michael Nolan, now at the University of Arizona. “They are doing what can be done. I’m still really worried that they