  Parabolic flights provide cost-effective, time-limited access to "weightless"
or reduced gravity conditions experienced in space or on planetary surfaces,
e.g. the Moon or Mars. These flights facilitate fundamental research - from
materials science to space biology - and testing/validation activities that
support and complement infrequent and costly access to space. While parabolic
flights have been conducted for decades, reference acceleration profiles and
processing methods are not widely available - yet are critical for assessing
the results of these activities. Here we present a method for collecting,
analyzing, and classifying the altered gravity environments experienced during
a parabolic flight. We validated this method using a commercially available
accelerometer during a Boeing 727-200F flight with $20$ parabolas. All data and
analysis code are freely available. Our solution can be easily integrated with
a variety of experimental designs, does not depend upon accelerometer
orientation, and allows for unsupervised and repeatable classification of all
phases of flight, providing a consistent and open-source approach to
quantifying gravito-intertial accelerations (GIA), or $g$ levels. As academic,
governmental, and commercial use of space increases, data availability and
validated processing methods will enable better planning, execution, and
analysis of parabolic flight experiments, and thus, facilitate future space
activities.
