A number of mechanisms used on Odyssey are associated with its high-gain antenna. Three retention and release devises are used to lock the antenna down during launch, cruise, and aerobraking. Once the science orbit is attained at Mars, the antenna is released and deployed with a motor-driven hinge. The antenna's position is controlled with a two-axis gimbal assembly.

Four retention and release devices are used for the solar array. The three panels of the array are folded together and locked down for launch. After deployment, the solar array is also controlled using a two-axis gimbal assembly.

The last mechanism is a retention and release device for the deployable 6-meter (19.7-feet) boom for the gamma ray spectrometer.

All of the mechanisms combined weigh 24.2 kilograms (53.4 pounds).