Introduction  The goal of this project was to design a release mechanism for two spherical satellites. The mechanism  was to fly on a risk reduction mission to verify the design and operation of the system for a future, more ambitious mission. Because of the n eed to maintain a constant drag coefficient under any orientation, the  satellites had no external appendages or hard points for contact. The spheres and their release systems  had to be enclosed within the Canister for All Payload Ejections (CAPE). CAPE is an aluminum cylinder 0.56 m ID x 1.3 m long. The Space Test Progr am-H2-Atmospheric Neutral Density Experiment Risk  Reduction Mission (STP-H2-ANDE RR) flew aboard Space Shuttle mission STS-116.   The Naval Research Laboratory designed satellites were Mock ANDE Active (MAA) and Fence  Calibration (FCal). MAA was 0.48 m in diameter and 52 kg. FCal was 0.44 m in diameter and 63 kg. MAA  was desired to have a spin rate of 1-10 rpm upon orbit insertion. Each satellite was enclosed in its own  cylinder. The cylinders were joined together by two Motorized Lightband separation systems (MLBs).  When the MLBs separated, the satellites were simultaneously pushed out of the cylinders by compression springs. The name given to everything contained within the CAPE that separated from the  Shuttle was the Internal Cargo Unit (ICU).  At the end of one of the cylinders was a larger Lightband,  CAPE Separation System (CSS) (see Figures 1-5).  The ICU was ejected from the CAPE by means of the CSS, a 0.59-m diameter NEA-actuated Lightband  separation system. Approximately 40 seconds later, two diameter 0.50-m MLBs, ICU Separation Systems (ISS), were to simultaneously separate at the center of the ICU. The lower haves of each Lightband with  the motor mechanism were attached to the central Av ionics Deck. The upper half of each Lightband was  attached to the open end of each cylinder. Upon separation, each satellite ejected from the cylinders through the center of the upper ring.  ICU Design  The ICU consisted of five separ able elements, the FC al Cylinder/ICU Lid, FCal, Avionics Deck, MAA and  MAA Cylinder. The structural components had the following masses, FCal Cylinder 38.1 kg, Avionics  Deck 18.5 kg, MAA Cylinder 13.4 kg resulting in a combined ICU mass of 185 kg. Roller Guides on the  outside of the cylinders ensured proper ejection from  the CAPE. Conical pedestals held Viton o-rings.  These o-rings compressed the satellites at + and – 45 deg latitude. The o-rings preloaded the satellites to  minimize vibration during the launch environment. 6 Delrin sleeves ran axially along the inside of each  cylinder to prevent marring of the satellites. Compression springs with Delrin guides were placed at   + & - 36-40 deg latitude to aide in ejecting the satellites from the cylinders and overcoming any possible  o-ring to satellite stiction. The upper portion of the spring guide held a radial ball bearing that contacted  the satellite. Each satellite had two 10-mm diameter countersin ks at 15 deg latitude nearest the Avionics  Deck. The Avionics Deck Pedestals held accepting 90° conical tipped snubbers meant to engage the  satellite countersinks. One snubber contained a magnet to activate an inhibit keeping the satellites turned  off until ejection. The second snubber on each satellite acted as a back-up to prevent rotation of the  satellite during launch incase the o-ring compression was insufficient. MAA contained a third snubber at  its Delrin equator. This served as a temporary hinge point to impart rotation on MAA during its ejection  from the cylinder. The entire structure of the ICU was 6061-T6 aluminum alloy. MAA had 6061-T6  hemispheres with a Delrin equator. Its surface comprised of alternating black anodized and gold irirdited  quadrants. FCal had brass hemispheres with an aluminum equator. Its surface comprised of alternating nickel plating and white paint (Figure 6).  146