"Explosive bolts" refers to special fasteners that are designed to separate or disconnect something quickly and forcefully through controlled explosions. Full definition
They tried to land near the beach but missed, finally landing just off the shore, but explosive bolts used to open the hatch failed to work. (inc.com)
These include: concerns about tiny cracks found in fuel lines (which grounded the shuttle fleet during the year before Columbia's last flight), other leaks, faulty sensors and hinges, and problems with explosive bolts that separate the booster rockets from the orbiter. (newscientist.com)
On Christmas Day of last year, a set of explosive bolts fired, three compressed springs separated probe from orbiter, and Huygens began its approach to Titan. (discovermagazine.com)