Description: The goal of this project is to develop an offset-fed paraboloidal mesh reflector antenna for operation onboard small, low cost satellites such as CubeSats, in the frequency range up to 100 GHz. The Phase II component of this goal is to fully test the performance characteristics of a prototype deployable antenna reflector, with an aperture greater than 0.5 m under controlled conditions. The mesh used in the reflector is gold plated molybdenum. The weave of the mesh will be developed early in Phase II to achieve the tight tolerances required for operation up to 100 GHz (W-Band). Characterization measurements of the currently available mesh have been completed and will be used as a baseline to quantify improvements measured from the newly developed mesh samples. Analysis of surface error contributions from faceting, thermal stresses, manufacturing tolerances, and operational forces will be performed. Micro-machining and small-scale manufacturing techniques will be refined to achieve an overall reflector surface accuracy of less than 60 micrometers (1/50 of the wavelength at 100 GHz).The fully constructed mesh reflector antenna with feed will be measured to obtain the full gain pattern of the antenna to characterize the antenna performance and determine the overall efficiency of the mesh reflector. The deployment mechanism will also be tested and refined to ensure repeatable operation of the antenna.The proposed antenna can be stowed within less than 1.5 U of a CubeSat. Doing so can significantly lower the cost of any satellite system requiring a high gain reflector antenna, including radars, scatterometers, radiometers, and deep space communication links. Successful completion of the Phase II goals will increase the technical readiness of the project from TRL 3, at the end of Phase I, to TRL 6.

Benefits: Any NASA mission that requires a microwave antenna, or a microwave sensor, will benefit from the compact deployable offset parabolic reflector antenna proposed here. Such a reflector antenna can be used for active and passive microwave remote sensing, communication systems, and other applications. Apertures up to 2 m can use a similar approach, operating up to 100 GHz. A 0.55 meter aperture stows in a diameter of 55 mm, a length of 117 mm, and a mass of 0.25 kg; a 1.2 m aperture stows in a diameter of 14.4 cm, a length of 21.3 cm, and a mass of 0.6 kg; and a 2 m aperture stows in a diameter of 24 cm, a length of 35.4 cm, and a mass of approximately 1 kg. Such compact antennas have a potential to significantly lower NASA costs for Earth observing systems and enable Solar system exploration with much more compact spacecrafts, such as CubeSats. This reduction in costs and the increased operational frequency of the proposed antenna would allow the creation of CubeSat constellations for the same cost as a single traditional satellite, such as ATMS. This has the potential to significantly increase the revisit time of a specific area for a given mission, drastically improving the utility of such applications. Several existing NASA funded programs, such as TROPICS and TEMPEST-D, could also greatly benefit from the inclusion of an antenna like the one proposed here.

Compact antennas stowable within CubeSats, NanoSats and SmallSats have a potential to open new observational capabilities to private markets. Several private companies are in or are entering into the nano/microsatellite market, with companies like Spire and PlanetLabs already operating constellations of CubeSats, and with constellations planned by OneWeb, SpaceX, Boeing, and Samsung. While these companies are not specifically focused on Earth Observations (EO), they pave the way for privatization of EO and signal a growing need for antennas such as the one proposed here. Military agencies could also benefit from this technology, with a desire for constellations of smaller satellites due to cost reductions and the opportunity of frequent technology refesh. The proposed antenna is not limited to remote sensing applications, and could equally be applied to communication purposes, with its high stowing efficiency enabling larger apertures.