Early versions of the StarCraft manual state that the Apollo Reactor and Cloak upgrade for the wraith were to be researched at the physics lab rather than the control tower. This has been changed for later releases of the manual.
Remastered building wireframe
Underwood, Peter, Bill Roper, Chris Metzen and Jeffrey Vaughn. StarCraft (Manual). Irvine, Calif.: Blizzard Entertainment, 1998.