Saturday, April 26, 2014

Cubesats pack big opportunities in small packages

     KENNEDY SPACE CENTER, Fla — On April 18, 2014 Space Exploration Technologies (SpaceX) launched one of the company’s Falcon 9 v1.1 rockets from Cape Canaveral Air Force Station’s Space Launch Complex 40 in Florida. Perched atop was one of the NewSpace firm’s Dragon spacecraft. While much was made about the primary payload of scientific equipment, components, spare parts and crew supplies – not so much was said about the mission’s secondary payload – five cubesats contained within four four Polly Picosatellite Orbital Deployers (P-PODs). This, however, is just one step on a journey to increase capability – while reducing cost.

     CubeSats are one of the next “big things” in terms of future technology development for satellites. However, in terms of scale – they are actually quite small, typically comprising only 10 cubic centimeters or one liter in volume. Their compact size and low-cost to develop provide a valuable research vehicle to test and advance new components without spending millions of dollars to build and send as primary payload into orbit.

     The satellites ferried aloft by SpaceX is the fifth in a series of Phonesat nanosatellite technology demonstration flights. Phonesat 2.5 follows the successful Phonesat 1.0, 2.0 Beta and 2.4.

(Click above to watch video)

     Satellites and spacecraft come in a wide array of shapes, sizes and complexity ranging from the first satellite, Sputnik 1, with a 23 inch diameter, all the way up to the International Space Station (ISS), which is 356 ft long and has 29,600 cubic feet of interior pressurized volume. A single CubeSat is 10 by 10 by 11 centimeters or one cubesat unit (1U) in size or between one and 10 kilograms in weight, which classifies it as a nanosatellite.

     The concept of miniature satellites started in 1999 as a way for universities to build and test advancing components in space at reasonable costs. Several launches in the last decade have placed more than 70 CubeSats into orbit, with a majority of them built by graduate students around the world. Several large-scale satellite builders like Boeing have also designed and built CubeSats, and NASA has created the Small Spacecraft Technology Program (SST) to focus on several CubeSat demonstration missions over the coming years.

     One of the ongoing CubeSat missions led by NASA’s Ames Research Center is the Edison Demonstration of Smallsat Networks (EDSN), which began in 2012. It is comprised of eight nanosatellites that will test cross-link communications in a loose formation in low-Earth orbit (LEO), and help advance new affordable technology for scientific, commercial, and academic research projects by lowering costs as well as the time required to develop similar systems.

     Each EDSN nanosatellite is 1.5 cubesat units, weighing in at a whopping 4 lbs (2 kilograms). Not only are they small (about the size of a tissue box) – they also are built on the cheap. One example of this what the spacecraft use as antennas – metal tap measure tips. If one were to peer inside – one can (easily) see components originating from cell phones.

     All of the EDSN CubeSats will be able to collect their own data and share with each other, along with the ability to send this data to a ground station when required. Each unit will carry a sensor designed to take multipoint space radiation measurements over the course of a mission designed to last for 60 days, but could be extended if operations go better than expected.

     If network-based CubeSats like this can be successfully developed and tested, they could potentially be mass-produced by the hundreds and provide unparalleled amounts of data gathering and communication capabilities over vast areas by the use of this swarm constellation concept.

     EDSN CubeSats are currently scheduled to be launched this year as a secondary payload within the Super Strypi launch vehicle which will depart from Kauai, Hawaii.

     Optical Communication and Sensor Demonstration (OCSD) is another SST flight demonstration project currently scheduled to launch in 2015. Two CubeSats will attempt optical communication with each other in LEO using a laser beams to increase the amount of data that can be shared between satellites compared to standard radio communications. This is not only a goal for CubeSats, but also a major goal for other large-scale spacecraft that can benefit from this small-scale testing.

     Another CubeSat mission looking to test enhanced data transmissions is the Integrated Solar Array and Reflectarray Antenna (ISARA) mission. This will essentially use the back of the CubeSats’ solar panel as a reflecting array to increase the effectiveness of its Ka-band radio transmitter. Using this technique in conjunction with its ultra-high frequency (UHF) telemetry antenna, this mission will hope to transmit data at 100 Megabit per second (Mbps), which is comparable to the combined rate of 20 high-speed household internet connections.

     SST also plans to launch the Cubesat Proximity Operations Demonstration (CPOD) in 2015, which will test the ability of nanosatellites to perform advanced maneuvers in LEO. Two CubeSats will demonstrate remaining at determined points relative to each other and also perform docking rendezvous, which would allow long chains of CubeSats to link up and work together in space.

     The Phonesat project a three overarching objectives. The first is to discover if low-cost (and commercially available) attitude determination and control system or “ADCS” can perform in the hostile environment of space. Next, to validate whether-or-not Google’s Android processor is capable of supporting a space-based communications system. Finally, can, within a six-week orbital life provide enough confidence in this emerging technology – in the hard radiation and vacuum of space.

By James Tutten

(All photos provided by Jason Rhian / SpaceFlight Insider)

(Published at on April 26, 2014.)

Tiny spacecrafts like this will swarm together in order tom study space. Photo Credit: Jason Rhian / SpaceFlight Insider

All Phonesats are constructed from inexpensive components. Photo Credit: Jason Rhian / SpaceFlight Insider.


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