Three Corner Satellite (or 3CS, or 3CornerSat) consisted of three student-built microsatellites flying in formation. Primary mission objectives were to demonstrate formation flying, provide stereoscopic imaging of cloud formations, and demonstrate distributed and autonomous operations. A pair of spacecraft, Ralphie and Sparkie, was developed by the

University of Colorado at Boulder The University of Colorado Boulder (CU Boulder, CU, or Colorado) is a public research university in Boulder, Colorado. Founded in 1876, five months before Colorado became a state, it is the flagship university of the University of Colorado sy ...

and

Arizona State University Arizona State University (Arizona State or ASU) is a public research university in the Phoenix metropolitan area. Founded in 1885 by the 13th Arizona Territorial Legislature, ASU is one of the largest public universities by enrollment in the ...

as part of the Air Force Research Laboratory's University Nanosat Program. A third satellite, Petey, developed by

New Mexico State University New Mexico State University (NMSU or NM State) is a public land-grant research university based primarily in Las Cruces, New Mexico. Founded in 1888, it is the oldest public institution of higher education in New Mexico and one of the state's ...

was originally also part of the 3CS. The 3CS stack was originally slated for launch aboard the

Space Shuttle The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program n ...

in 2003, but after the Shuttle Columbia tragedy, mission organizers switched to the first launch of the Boeing

Delta IV Heavy The Delta IV Heavy (Delta 9250H) is an expendable heavy-lift launch vehicle, the largest type of the Delta IV family. It is the world's third highest-capacity launch vehicle in operation, behind NASA's Space Launch System and SpaceX's Falcon H ...

rocket. Due to a problem with the rocket during launch, the 3CS satellites on board, Sparkie and Ralphie, failed to achieve orbit. The satellites were to have been dropped off at a low 180 km × 240 km, but they entered orbit at a height of only 105 km, which led to a rapid decay. The third 3CS satellite Petey was not aboard the 3CS launch on Delta IV Heavy (due to the fitting only being able to hold two spacecraft; Petey was used for ground software and communications testing ) and was later donated to the

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’s Steven F. Udvar-Hazy Center.

Project Mission

Primary mission objectives: * Stereoscopic imaging of

cloud In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may ...

s and other

atmospheric An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A ...

structures. * Formation flying - the satellites will operate as a network to synchronize targeting and

data acquisition Data acquisition is the process of sampling signals that measure real-world physical conditions and converting the resulting samples into digital numeric values that can be manipulated by a computer. Data acquisition systems, abbreviated by the acro ...

and to relay health and status information among the satellites in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellation ...

. * End-to-End Data Systems (EEDS) will support automated operations, react to unplanned faults and opportunities, and to optimize operations and data handling. Secondary mission objectives: * Demonstrate micro propulsion, by increasing the satellites' altitude to extend mission lifetime and improve data gathering capacity. * Demonstrate a

modular Broadly speaking, modularity is the degree to which a system's components may be separated and recombined, often with the benefit of flexibility and variety in use. The concept of modularity is used primarily to reduce complexity by breaking a s ...

spacecraft bus design. * Emphasize student education by allowing students to actively participate in the program. The spacecraft were equipped with robust execution management software (Spacecraft Command Language (SCL), Continuous Activity Scheduling Planning Execution and Replanning (CASPER) software, and Context-sensitive anomaly detection software (SELMON monitoring system)

References

Onboard Autonomy on the Three Corner Satellite Mission

External links

NASA's Three Corner Satellite Project Homepage

NASA.gov
* http://spacegrant.colorado.edu/3cs/ Student satellites {{AFRL spacecraft