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ExoplanetSat


A CubeSat space telescope to discover transiting exoplanets

ExoplanetSat is a nanosatellite space telescope that will search for transiting exoplanets around the brightest Sun-like stars in the sky. The spacecraft is a 3U CubeSat, measuring 10 x 10 x 34 cm with a mass of approximately 5 kg, and will monitor a single star at a time from low Earth orbit (LEO). The optical payload consists of a combined star camera and science photometer. The star camera provides inertial attitude estimates and the photometer precisely measures stellar brightness, seeking the characteristic dip in intensity that indicates a transiting exoplanet. The ExoplanetSat prototype will serve as the basis of an eventual fleet of nanosatellites that provides more complete coverage of the sky. Given sub-pixel sensitivity variations in the science detector, image jitter and the resulting impact on photometric precision is of concern. The attitude determination and control subsystem (ADCS) mitigates this effect using a two-stage pointing control architecture that combines 3-axis reaction wheels for arcminute-level coarse pointing with a piezoelectric translation stage at the focal plane for fine image stabilization to the arcsecond level.

MicroMAS


A CubeSat radiometer for collecting atmospheric profile data

MicroMAS (Micro-sized Microwave Atmospheric Satellite), is a three-unit CubeSat being developed by the Space Systems Laboratory to integrate an MIT Lincoln Laboratory microwave radiometer payload with a three-axis stabilized CubeSat bus. The payload is a multispectral passive microwave radiometer that collects observations in the 118 GHz range, complementing existing on-orbit radiometer capability delivered by larger systems that operate in other spectral bands. MicroMAS will provide unprecedented observations of the dynamics of hurricane and other large storm systems with significantly improved revisit times and comparable resolution to large polar-orbiting satellites. The implementation of the atmospheric science mission using low-cost commercial components and the standard CubeSat launch vehicle interface will demonstrate a transformative satellite architecture for future meteorological satellites. The MicroMAS mission enables the persistent collection of data from multiple low-cost distributed platforms to greatly improve operational numerical weather predictions, climate records, and other scientific objectives. In order to effectively collect data with the radiometer sensor, the spacecraft must simultaneously sweep the radiometer field of view perpendicular to the groundtrack while maintaining a 3-axis stabilized orientation fixed in the local vertical local horizontal frame. Analysis determined that it would not be possible to spin the entire satellite and simultaneously maintain the LVLH orientation. This attitude control problem led to a novel design solution to implement a dual-spinner design on the CubeSat architecture, in which a custom designed spinner assembly, would join the rotating payload module to the rest of the satellite.

MotherCube/DSS


A distributed satellite system for locating radio sources

The primary objective of the MotherCube, also called Distributed Satellite System (DSS), payload is to identify the locations of radio sources by using three formation-flying satellites with receiver antennas to triangulate its position. On this mission, the radio sources will be VHF sources located on Earth. In addition, the mission aims to demonstrate the on-orbit behavior of electrospray thrusters and satellite formation flight. The thrust from electrospray thrusters is produced by electrostatic acceleration of microscopic charged droplets, providing high specific impulse, precision control, scalability, and simple plumbing. Satellite formation provides the advantages of flexibility in reconfiguration, robustness, and cost-effectiveness and stands as an important technology needed for next-generation space telescopes. Attitude Determination and Control System (ADCS) algorithms are used to control the satellites attitudes and positions, maintaining desired formation configurations. Each satellite in the system is a 3U CubeSat consisting of electrospray thrusters, solar panels, GPS antenna, patch antenna, payload antenna, omni-directional antenna, IMU, and magnetic torque coils.

TERSat


A University Nanosat Program satellite to remove radiation from Earth's atmosphere.

TERSat will complement the Air Force Research Labs’ (AFRL) Demonstration Scientific Experiment (DSX). Research in the scattering high-energy particles is of interest to all space-based military and civilian missions. The orbital space in the Van Allen belts offers many opportunities but is currently under-utilized due to the high flux of energetic particles. Even with radiation hardening techniques, space systems will rapidly degrade in a plasma severely shortening their lifespan. TERSat provides a solution for operating within the radiation belts at a reduced monetary and mass cost. TERSat shall pulse Electromagnetic Ion Cyclotron waves from deployed antennas at a frequency of 50-150 Hz, to resonate with the trapped particles and induce a greater loss cone. TERSat satisfies its mission by operating in an orbit of 550 km with 20° of inclination. Using deployed rigid antennas, TERSat shall pulse every six orbits for duration of at least 30 seconds. The incoherent scatter radar in Arecibo, Puerto Rico will serve as the scientific ground station for validating and measuring the scattering of particles into the loss cone. The TERSat bus is a 16’x12’x12’ skinned ISO grid structure with a total mass of 40.3 kg. The TERSat payload consists of a high voltage electrical system to drive two 2.5-meter dipole antennas. Power for the system comes from body mounted solar cells to charge batteries and a capacitor bank for the payload. During nominal operations, the satellite will draw 9.1 watts of power; active mission operations requires1 kW of power. Further, TERSat will utilize the HETE 2 ground stations for communications.