Session
Session VI:Propulsion
Abstract
Cubesats is rapidly maturing beyond educational projects and low cost technology demonstrators. Today we want cubesats to provide useful data with a scientific or commercial value. One of the unique advantages of cubesats is that the size and cost enables large numbers of satellites to be built and launched at the same time. Both commercial examples such as Planet Labs or SPIRE as well as scientific mission like QB50 are utilizing fleets of cubesats to achieve valuable or unique data that was not thinkable a decade ago. However, there are still a few more steps to be taken in order to make fleets or constellations of cubesats even more viable or efficient in providing useful data. One field that is still immature is propulsion. Propulsion capability on every cubesat in a large constellation can provide faster deployment, better dispersion, longer life time and possibly also controlled de-orbit of the satellites at end of life.
NanoSpace has for more than a decade worked on a various types of miniaturized propulsion using MEMS (Micro Electro Mechanical Systems) technology. In 2015 the first flight of a MEMS-based propulsion system for cubesats was peformed onboard a 3U cubesat STU-2A that was part of a three satellite constellation built and launched by Shanghai Engineering Centre for Microsatellite (SECM). The CubeSat MEMS Propulsion Module comprises of four individually controlled thrusters, each containing a proportional valve and sensors for closed-loop thrust control. The nominal thrust is 1 mN per thruster. Total mass is 330g including 50g propellant. The size of the module is less than ½ U even including a control and interface electronics board. Apart from the proportional valve, there are two additional valves to create independent barriers between each thruster and the propellant tank. It has the capability of 40Ns total impulse (specific impulse is rated as 81s). The average power consumption during operation is about 3W.
Since the launch and initial tests of the system, the propulsion system has been activated tested multiple times. The propulsion system has demonstrated both the ability to raise the orbit of STU-2A and has also been used to de-spin the spacecraft after and accidental spin up. In this case the spacecraft was despun from about 65 to 13 deg/s using thrusters, after which magnetic tourqers could be used to stabilize and fine tune the spin rate. Further details and results from the tests already done and the upcoming rendezvous with STU-2C will be given in the presentation.
In-Orbit Demonstration of a MEMS-based Micropropulsion system for Cubesats
Cubesats is rapidly maturing beyond educational projects and low cost technology demonstrators. Today we want cubesats to provide useful data with a scientific or commercial value. One of the unique advantages of cubesats is that the size and cost enables large numbers of satellites to be built and launched at the same time. Both commercial examples such as Planet Labs or SPIRE as well as scientific mission like QB50 are utilizing fleets of cubesats to achieve valuable or unique data that was not thinkable a decade ago. However, there are still a few more steps to be taken in order to make fleets or constellations of cubesats even more viable or efficient in providing useful data. One field that is still immature is propulsion. Propulsion capability on every cubesat in a large constellation can provide faster deployment, better dispersion, longer life time and possibly also controlled de-orbit of the satellites at end of life.
NanoSpace has for more than a decade worked on a various types of miniaturized propulsion using MEMS (Micro Electro Mechanical Systems) technology. In 2015 the first flight of a MEMS-based propulsion system for cubesats was peformed onboard a 3U cubesat STU-2A that was part of a three satellite constellation built and launched by Shanghai Engineering Centre for Microsatellite (SECM). The CubeSat MEMS Propulsion Module comprises of four individually controlled thrusters, each containing a proportional valve and sensors for closed-loop thrust control. The nominal thrust is 1 mN per thruster. Total mass is 330g including 50g propellant. The size of the module is less than ½ U even including a control and interface electronics board. Apart from the proportional valve, there are two additional valves to create independent barriers between each thruster and the propellant tank. It has the capability of 40Ns total impulse (specific impulse is rated as 81s). The average power consumption during operation is about 3W.
Since the launch and initial tests of the system, the propulsion system has been activated tested multiple times. The propulsion system has demonstrated both the ability to raise the orbit of STU-2A and has also been used to de-spin the spacecraft after and accidental spin up. In this case the spacecraft was despun from about 65 to 13 deg/s using thrusters, after which magnetic tourqers could be used to stabilize and fine tune the spin rate. Further details and results from the tests already done and the upcoming rendezvous with STU-2C will be given in the presentation.
