Short story ID: Shuttle, Omni magazine

There was a short story published in Omni back in the '80s. It was about a guilt-ridden engineer who worked on the shuttle Challenger, who takes a bomb aboard an aircraft. I think the title of the story was Two-Minutes, Thirty-[something] Seconds, which was the length of time it took Challenger’s crew compartment to fall into the sea. (That might not have been the title at all, but it’s what I remember.)

Can someone tell me the correct title and the name of the author?

Thanks.

“Two Minutes Forty-Five Seconds” by Dan Simmons. First published in OMNI Magazine, April, 1988.

Grazie!