Environmental Sample Processor (ESP)

How does the 2G ESP work?

In short, the 2G ESP robotically performs three actions:

  1. Filter seawater
  2. Create a “lysate” by applying a lytic agent and heat to break open filtered material (i.e., cells)
  3. Move lysate to the array, develop the array, photograph, and send data to shore

These procedures take place in small reaction chambers called “pucks”.  A puck may hold a probe array (for analytical purposes) or serve some other function (e.g., filter water). There are several types for different purposes, but all have the same external shape and size for handling by ESP mechanics.


A single puck for the 2G. Note all pucks have this same external form, regardless of their function.


The ESP uses several puck-types, depending on the type of analysis desired. Here the pucks are disassembled, showing puck bottoms (first row) and puck tops (second row).

Pucks are stored in a circular array of seven tubes called a carousel.  For a deployment, six tubes are filled.  As the instrument goes through a sequence of operations and analyses, used pucks are dropped into the empty tube.  Each tube holds 22 pucks, so a 2G ESP holds a full complement of 132 pucks. The following silent movie takes you inside a deployed ESP, and shows how a robotic hand moves pucks from the carousel into clamps for filtering seawater, creates a lysate from what was filtered, passes lysate over an array, develops the array, and transmits data back to shore.