Since the battery life was an issue, I would investigate the cause. Likely, the draw was too high for a 9 Volt Battery to power the circuits for much longer than an hour. It is also possible that the wiring and soldering didn't hold up to the stresses or there was a data limit on the SD card or the Arduino.
I would start by investigating data limits on the card or arduino as I would get a very quick answer. Next, I would find the equivalent draw of the circuitry and find out how long a new 9V should last under those conditions. Finally, I would investigate the wiring, plug the module back into a power source and see if any components had failed.
Solutions could include adding more battery power or a backup, decreasing the draw with resistors or removing sensors, improving soldering techniques (at this point I cold soldered a lot,) getting a better SD card or formatting the data stream better. Simply allowing for data collection at a 1 second interval instead of a 500 ms interval would save power and data space.
Additionally, If power and space allowed I would include an altitude sensor to be able to better plot variables against elevation in addition to time.