Three Corner Satellite (or 3CS, or 3CornerSat) consisted of three student-built

microsatellites A microsatellite is a tract of repetitive DNA in which certain DNA motifs (ranging in length from one to six or more base pairs) are repeated, typically 5–50 times. Microsatellites occur at thousands of locations within an organism's genome. T ...

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 Ralphie is a masculine given name, often a diminutive form (hypocorism) of Ralph. It may refer to: * Ralphie May (1972–2017), American stand-up comedian and actor * List of The Sopranos characters#Ralph Cifaretto, Ralph "Ralphie" Cifaretto, a ch ...

and Sparkie, was developed by the

University of Colorado at Boulder The University of Colorado Boulder (CU Boulder, CU, or Colorado) is a Public university, public research university in Boulder, Colorado, United States. Founded in 1876, five months before Colorado became a Federated state, state, it is the fla ...

and

Arizona State University Arizona State University (Arizona State or ASU) is a public university, public research university in Tempe, Arizona, United States. Founded in 1885 as Territorial Normal School by the 13th Arizona Territorial Legislature, the university is o ...

as part of the Air Force Research Laboratory's

University Nanosat Program The University Nanosat Program is a satellite design and fabrication competition for universities. It is jointly administered by the Air Force Office of Scientific Research (AFOSR), the Air Force Research Laboratory (AFRL), the American Institute o ...

. 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 in Las Cruces, New Mexico, United States. Founded in 1888, it is the state's oldest public institution of higher education, and was the original land-g ...

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 launch system, 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. ...

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) was an expendable heavy-lift launch vehicle, the largest type of the Delta IV family. It had the highest capacity of any operational launch vehicle in the world after the retirement of the Space Shuttle in 20 ...

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 Decay may refer to: Science and technology * Bit decay, in computing * Decay time (fall time), in electronics * Distance decay, in geography * Software decay, in computing Biology * Decomposition of organic matter * Mitochondrial decay, in g ...

. 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

National Air and Space Museum The National Air and Space Museum (NASM) of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to history of aviation, human flight and space exploration. Established in 1946 as the National Air Museum, ...

’s

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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 gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere ...

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 ...

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 Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

. * 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 Module, modular and modularity may refer to the concept of modularity. They may also refer to: Computer science and engineering * Modular design, the engineering discipline of designing complex devices using separately designed sub-components ...

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