Article written by Matt Williams Published on Universe Today February 21, 2017
In 2006, during their 26th General Assembly, the International Astronomical Union (IAU) adopted a formal definition of the term “planet”. This was done in the hopes of dispelling ambiguity over which bodies should be designated as “planets”, an issue that had plagued astronomers ever since they discovered objects beyond the orbit of Neptune that were comparable in size to Pluto.
Needless to say, the definition they adopted resulted in fair degree of controversy from the astronomical community. For this reason, a team of planetary scientists – which includes famed “Pluto defender” Alan Stern – have come together to propose a new meaning for the term “planet”. Based on their geophysical definition, the term would apply to over 100 bodies in the Solar System, including the Moon itself.
By Matt Williams – Matt Williams is the Curator of the Guide to Space for Universe Today, a regular contributor to HeroX, a science fiction author, and a Taekwon-Do instructor. He lives with his family on Vancouver Island in beautiful BC.
With help from NASA, a small research satellite to test technology for in-space solar propulsion launched into space Wednesday aboard an Atlas V rocket from Cape Canaveral Air Force Station, Florida, as part of the agency’s CubeSat Launch Initiative.
LightSail team members Alex Diaz and RikiMunakata prepare the spacecraft for a sail deployment test.
Credits: The Planetary Society
The Planetary Society’s LightSail satellite is a technology demonstration for using solar propulsion on CubeSats, a class of research spacecraft called nanosatellites. Using the momentum transferred from solar photons as they strike a large, thin, reflective sail would allow a spacecraft to accelerate continuously using only the sun’s energy. NASA is considering the use of solar sails on future exploration mission secondary payloads, and data from this mission will advance understanding of this form of propulsion.
This first LightSail mission specifically is designed to test the spacecraft’s critical systems, including the deployment sequence for the Mylar solar sail, which measures 32 square meters (344 square feet). The Planetary Society is planning a second, full solar sailing demonstration flight for 2016.
NASA selected LightSail as part of the agency’s CubeSat Launch Initiative, which provides opportunities for small satellites to fly as auxiliary payloads on planned missions. It was assigned to a launch as part of as the 11th installment of the Educational Launch of Nanosatellite (ELaNa) mission.
The upper stage of the Atlas V included the National Reconnaissance Office’s third auxiliary mission to launch CubeSats. The Ultra Lightweight Technology and Research Auxiliary Satellite (ULTRASat) carried 10 CubeSats — including LightSail — from five organizations. It was made possible through agreements between NASA, the Air Force’s Space and Missile Systems Center and the National Reconnaissance Office to work together on CubeSat integration and launch opportunities.
The cube-shaped satellites measure about four inches on each side, have a volume of about one quart and weigh less than three pounds each. LightSail consists of three CubeSats bundled together. Individual CubeSat research projects may address science, exploration, technology development or education. During the next month, the LightSail team will receive data from the satellite in space. As part of its agreement with NASA, the Planetary Society will provide the agency a report on outcomes and scientific findings.
Since its inception in 2010, the CubeSat Launch Initiative has selected 110 CubeSats primarily from educational and government institutions around the United States. NASA will announce the next call for proposals in August 2015.