Source: Starfinder Core Rulebook p.72
As a full action or as a move action by spending 1 Resolve Point, you can cause a powered weapon (either a ranged energy weapon or a melee weapon with the powered special property) in your possession to explode. You can use the weapon as if it were a grenade of the weapon's item level or lower dealing the weapon's normal damage type, except the weapon has a range increment of only 10 feet unless it is a thrown weapon. If someone tries to attack with the weapon, it explodes as a grenade would instead, centered on the user, and the user doesn't receive a Reflex save to negate the grenade's effect (if any). Once you've primed a weapon to explode in this way, it's difficult to reverse the effect, requiring 8 hours of work and a successful Engineering check (DC = 15 + your Engineering bonus); failing the check by 5 or more detonates the weapon. Once detonated, the weapon is destroyed, just like a grenade.