Excess Baggage
At some point aboard the Tempest, you'll talk to Suvi and she'll note that she's discovered an extra 70 kilos of mass aboard. It might be having an effect.
You can look for it by scanning the rooms aboard ship. Each one has a pipelike structure that reveals the presence or absence of excess mass, and prompts a wry comment from Ryder.
Some of these are amusing enough, but when you're ready to tie this one up, head to the Storage Room where Vetra likes to hang out. You'll find the excess mass behind the bulkhead.
Talk to Kallo on the bridge for the history of this anomaly. You have two almost identical choices, but both lead to a smattering of AVP and the resolution of this quest.