SMAs have been used in various applications in the past, including in space. CubeSats are a great way to  verify and increase the capabilities of state-of-the-art SMA technology. SMAs have many advantages that  can be utilized by CubeSats. In addition to being lightweight with a small footprint, SMAs are not  pyrotechnics, produce low shock, do not create debris, and can be designed to be resettable. As part of the  ALBus CubeSat technology development, two SMA forms were used. First, novel thermally activated SMAs  with higher transition temperatures (compared to commercially available counterparts) were used for the  R&R mechanism. Second, novel mechanically-activated SMAs (superelastic alloys) were used as  deployment springs to specifically deploy ALBus’ SAs and transmit the electrical power from the arrays.  Reference [6] discusses more details of SMA functional behavior and types.  This paper will discuss the design and development process of the ALBus CubeSat deployable SA R&R  and hinge deployment mechanisms. This includes the mechanisms’ final design and capabilities, details on  the SMAs, requirements of the design, design evolution and reasons for the design changes, analysis  methods used, and the final flight hardware assembly and testing activities.  Design Requirements  The design requirements for the mechanisms are divided up into three categories: CubeSat standards,  requirements specific to the ALBus mission and design, and mechanism specific requirements. The  CubeSat specific requirements come from the CubeSat design specification [1] and the CubeSat deployer  interface control document [7]. These requirements provide several sizing constraints such as keep-in  zones for exterior dimensions, mass, and center of gravity. Other constraints include restrictions on creating  space debris and use of pyrotechnics. These specifications also provide guidance on design environments.  For example, they require using the launch random vibration environment in GSFC-STD-7000A if  environments from the launch service provider are unavailable or if the launch provider is unknown while  designing the CubeSat.  The ALBus mission’s needs, goals, and configuration drove several of the SA deployment mechanism’s  performance and design requirements. The ALBus design is configured to use four deployable SA panels  with seven of the ultra-triple-junction type solar cells installed on a FR-4 Printed Circuit Board (PCB)  substrate. These deployable SAs run the length of the 340-mm-long CubeSat and are to be deployed along  one of the short 100-mm sides of the CubeSat. This deployment configuration was chosen since the ALBus  does not have an attitude control and determination system. It is designed to utilize gravity gradient masses  installed on the ends of the deployable SAs to eventually point the CubeSat radiator down toward Earth.  The final deployment angle was determined to be 135° from the stowed configuration for optimal power  generation. However, a power analysis has shown that a 90° deployment angle is sufficient to recharge the  batteries with acceptable power generation degradation.   The underlying goal for the ALBus mission is to design improved and reliable SA deployment mechanisms  to reduce mission failures. This drove the design goals for the mechanism to be resettable in order to test  and retest the actual flight hardware prior to launch. Reliability also drove the design goal to release all four  SAs with one mechanism to minimize failure points. The ALBus mission chose to use new SMAs being  developed at the NASA Glenn Research Center over traditional deployment methods. Finally, as the  mechanism designs matured the desire to pass the electrical power from the solar cells on the deployable  arrays through the SMAs was added in an effort to save the mass of a wiring harness.  The final mechanism’s design converged on a two-stage SMA actively driven pin-puller type mechanism  used to retain the arrays during ascent and release them in orbit (R&R mechanism). Once released, a  passively driven SMA hinge mechanism, one for each of the four arrays, deploys each array to the desired  deployment angle. To complete the designs, several specialized requirements were added specific to the  R&R and hinge to ensure the desired functionally. NASA’s mechanism design and development  requirements specification, NASA-STD-5017 revision A [8], was used as a design guide and drove several  of the performance requirements on the force and torque margin, mechanism design, and material  NASA/CP—2018-219887 376