Jonathan Sauder

CubeSat Deployable Ka-Band Mesh Reflector Antenna Development for Earth Science Missions

CubeSats are positioned to play a key role in Earth Science, wherein multiple copies of the same RADAR instrument are launched in desirable formations, allowing for the measurement of atmospheric processes over a short evolutionary timescale. To achieve this goal, such CubeSats require a high-gain antenna (HGA) that fits in a highly constrained volume. This paper presents a novel mesh deployable Ka-band antenna design that folds in a 1.5 U (10 × 10 × 15 cm3) stowage volume suitable for 6 U (10 × 20 × 30 cm3) class CubeSats. Considering all aspects of the deployable mesh reflector antenna including the feed, detailed simulations and measurements show that 42.6-dBi gain and 52% aperture efficiency is achievable at 35.75 GHz. The mechanical deployment mechanism and associated challenges are also described, as they are critical components of a deployable CubeSat antenna. Both solid and mesh prototype antennas have been developed and measurement results show excellent agreement with simulations.

The Mechanical Design of a Mesh Ka-band Parabolic Deployable Antenna (KaPDA) for CubeSats

A Ka-band high gain antenna would provide a 10,000 times increase in data communication rates over an X-band patch antenna and a 100 times increase over state-ofthe-art S-band parabolic antennas. Unfortunately, such a design does not exist as current CubeSat high gain antennas have focused on S-band. JPL has initiated a research and technology development effort to design a half-meter Ka-band parabolic deployable antenna (KaPDA) which would stow in 1.5U (10 cm x 10 cm x 15 cm) and provide 42dB of gain (50% efficiency). The KaPDA design must solve conflicting mechanical requirements on surface accuracy, stowed space, and ability to deploy. The development of a conceptual design that satisfies each requirement is discussed in this paper. The design uses folding ribs to fit in the stowage space, deep rib sections with precision hinges to maintain surface accuracy, and a combination of an innovative inflating bladder and springs to deploy the antenna. RF simulations show that after losses, KaPDA would have about 42 dB gain, at 50% efficiency. KaPDA would create opportunities for a host of new CubeSat missions by allowing high data rate communication which would enable using data intensive instruments or venturing further into deep space, including interplanetary missions.

Designing, Building, and Testing a Mesh Ka-band Parabolic Deployable Antenna (KaPDA) for CubeSats

While the capabilities of CubeSats have greatly increased in the past years, one of the key problems hindering interplanetary CubeSats are data communication rates. To compensate, a Ka-band high gain antenna would provide a 10,000 times increase in data communication rates over an X-band patch antenna and a 100 times increase over state-of-the-art S-band parabolic antennas. Unfortunately, high gain antenna developments to this point have only focused on S-band, which does not provide the required gain. Two years ago, JPL initiated a research and technology development effort to design a half-meter Ka-band parabolic deployable antenna (KaPDA) which would stow in 1.5U (15 cm x 10 cm x 10 cm) and provide 42dB of gain (or 50% efficiency). The process of designing, building, and testing of KaPDA is discussed in this paper. The design uses folding ribs to fit in the stowage space, deep rib sections with precision hinges to maintain surface accuracy, and a combination of an innovative gas and spring system to deploy the antenna. The constructed antenna was demonstrated to achieve a gain of 42.5 dB before deployment, and a gain of 42 dB after deployment. KaPDA would create opportunities for a host of new CubeSat missions from enabling high rate deep space communications to radar science.

Ka-Band Parabolic Deployable Antenna (KaPDA) Enabling High Speed Data Communication for CubeSats

ubeSats are at a very exciting point as their mission capabilities and launch opportunities are increasing. But as instruments become more advanced and operational distances between CubeSats and earth increase communication data rate becomes a mission-limiting factor. Improving data rate has become critical enough for NASA to sponsor the Cube Quest Centennial Challenge where one of the key metrics is transmitting as much data as possible from the moon and beyond. Currently, many CubeSats communicate on UHF bands and those that have high data rate abilities use S-band or X-band patch antennas. The CubeSat Aneas, which was launched in September 2012, pushed the envelope with a half-meter S-band dish which could achieve 100x the data rate of patch antennas. A half-meter parabolic antenna operating at Ka-band would increase data rates by over 100x that of the Aneas antenna and 10,000x that of X-band patch antennas. A number of deployable parabolic and parabolic like antennas have been developed in the past for CubeSats. Concepts have included a gore-wrap composite reflector, a reflector transformed from the CubeSat body, an inflatable parabolic reflector with reflecting material on one side and transparent material on the other, a mesh reflector supported by ribs, and a reflectarray. While these designs provide unique solutions, they are all designed to operate at S-band (with the exception of the reflectarray). A Ka-band antenna would have much greater gain, which translates to greater data rate, but requires a much higher surface accuracy than S-band. It should be noted are several other high gain, high frequency antennas under development, such as the DaHGR but thus far additional data has not been published on them. Two knit mesh antennas have been developed for CubeSats, but both were designed for S-band operation. They were a spiral stowed rib design and the Aneas parabolic deployable antenna (APDA) folding rib design that was flown on USC/ISI’s Aneas spacecraft. The spiral stowed rib design, while very compact, would be challenging to extend to Ka-band as the ribs could not apply adequate force required to stretch Ka-band mesh to achieve the required surface accuracy. The APDA architecture would work well for Ka-band, as it uses straight folding ribs, which

Inflatable antenna for CubeSats: Development of the X-band prototype

CubeSats1 and small satellites have potential to provide means to explore space and to perform science in a more affordable way. As the goals for these spacecraft become more ambitious in space exploration, moving from Low Earth Orbit (LEO) to Geostationary Earth Orbit (GEO) or further, the communication systems currently implemented will need to be improved to support those missions. One of the bottlenecks is the antennas size, due to the close relation between antenna gain and dimensions. Hence, a possible solution is to develop inflatable antennas which can be packaged efficiently, occupying a small amount of space, and they can provide, once deployed, large dish dimension and correspondent gain. A prototype of a 1 m inflatable antenna for X-Band has been developed in a joint effort between JPL and ASU. This paper will detail the principle challenges in developing the antenna technology focusing on: design, EM analysis, fabrication and tests.

One meter deployable reflectarray antenna for earth science radars

This paper describes the development of a 1-m deployable reflectarray antenna which is designed to fit in a 6U (10×20×30cm3) class CubeSats. It operates at 35.75 GHz for the measurement of atmospheric processes over a short, evolutionary timescale. It deploys into a 98.6 cm × 82.1cm flat reflector. This antenna provides a gain of 48.0 dBi and an aperture efficiency of 44%. It consists of a cassegrain reflectarray using 14 deployable panels, one fixed panel and a telescoping feed and subreflector.

An automaton rover enabling long duration in-situ science in extreme environments

The Automaton Rover for Extreme Environments (AREE) is a NASA Innovative Advanced Concept (NIAC) funded study focused on enabling long duration science on Venus by replacing vulnerable electronics with an entirely mechanical design. By utilizing high temperature alloys, the rover would survive on the surface of Venus for weeks if not months. The rover concept harvests wind energy using a turbine and stores it in a constant force spring. The mobility system would be guided by a mechanical computer and logic system, programed to carry out the mission. It would collect basic science data such as wind speed, temperature, and seismic events. Communicating the data back to Earth is the most challenging aspect of the system design with multiple options being explored in a trade: a simple electronic high temperature transponder, a retroreflector target or inscribing phonograph style records to be launched via a balloon to a high altitude drone capable of transmitting the data back to Earth. AREE is not only a new exciting in-situ rover concept, but also a paradigm shift to conducting in-situ science in extreme environments. Traditional extreme environment vehicles collect as many diverse data points as possible in the short period of time before system failure. AREE breaks that trend by exploring what can be done with only a few basic scientific measurements, but recorded over long periods of time. In addition to Venus, the concept can be useful in other extreme environments in the solar system including Mercury, Jupiters radiation belts, the interiors of gas giants, the mantle of the Earth and volcanoes throughout the solar system.

Inflatable antenna for CubeSat: A new spherical design for increased X-band gain

Interplanetary1 CubeSats and small satellites have potential to provide means to explore space and to perform science in a more affordable way. As the goals for these spacecraft become more ambitious in space exploration, the communication systems currently implemented will need to be improved to support those missions. One of the bottlenecks is the antennas size, due to the close relation between antenna gain and dimensions. Hence, a possible solution is to develop inflatable antennas which can be packaged efficiently, occupying a small amount of space, and they can provide, once deployed, large dish dimension and correspondent gain. A prototype of a 1 m inflatable antenna for X-Band has been developed in a joint effort between JPL and ASU. After initial photogrammetry tests and radiation tests, it was discovered that the design was not able to meet the required gain. As a result, a new design, based on a spherical inflatable membrane, is proposed. This new design will allow reaching a more stable inflatable surface, hence improving the electromagnetic performance. This paper will detail the principle challenges in developing this new antenna focusing on: design, EM analysis, fabrication and tests.