A Spark of Hope
Complete the mission "Risk/Reward" in the EDZ.
The node for this mission can be found in the EDZ section of the Director.
Devrim has pinpointed the likely location of Cayde's stash in the Cosmodrome. Find it and the weapon frame it hides, and you can use the superconductor to complete the weapon.
"This seems like an awful lot of trouble to go through to hide some loot. This weapon must be something special." —Ghost