Help with Arduino Oxygen Sensing project

Hello Forum.  I am a novice when it comes to Arduino, but am helping a bunch of kids with a scientific project to put in their high power rocket that is part of a NASA project.

We need to measure the oxygen level in water, so we want to use the Gravity Analog Dissolved Oxygen Sensor.   We are going to have to take measurements over an extended period of time - weeks.  Since it is flying in a rocket, it will need to be battery powered (at least for the time that it is in the rocket).  It needs to datalog with time stamps.  Having temperature measurements at the same time as the oxygen measurements would also be useful.  Since this won't be connected to a computer, having a small LED display indicating the sensor readings would be a nice to have.

I want to make sure I get all of the components we need.  I am thinking the R3 board will work along with the I/O expansion shield (v7.1).  Does DF Robot have an integrated data logger with real time clock?

Thanks for your help and assistance.