Destiny Wiki

A Ghost telemetry link that speeds the development of your upgradeable Rocket Launchers. Lasts 30 minutes.
― In-game description

Rocket Launcher Telemetry is a consumable that increases the experience gained towards rocket launchers for 30 minutes.

Prior to Destiny: The Taken King, they could be purchased from Xûr or from dismantling upgraded legendary rocket launchers. After The Taken King, they were replaced by Heavy Telemetry.