DAVE (CP-7), or Damping And Vibrations Experiment, is a technology demonstration

nanosatellite A small satellite, miniaturized satellite, or smallsat is a satellite of low mass and size, usually under . While all such satellites can be referred to as "small", different classifications are used to categorize them based on mass. Satellites ca ...

developed by the PolySat laboratory at

California Polytechnic State University, San Luis Obispo California Polytechnic State University, San Luis Obispo (California Polytechnic State University, Cal Poly"Cal Poly" may also refer to California State Polytechnic University, Humboldt in Arcata, California or California State Polytechnic Univ ...

, in collaboration with

Northrop Grumman Northrop Grumman Corporation is an American multinational aerospace and defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one of the world's largest weapons manufacturers and military techn ...

. The spacecraft adheres to the 1U

CubeSat A CubeSat is a class of miniaturized satellite based around a form factor consisting of cubes. CubeSats have a mass of no more than per unit, and often use commercial off-the-shelf (COTS) components for their electronics and structure. CubeSats ...

standard and is currently in a 93° inclination orbit. DAVE will study the vibration of metal beams damped with

tungsten Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isol ...

particles in a micro-gravity environment. The test elements are driven by a piezoelectric actuator, and vibration data is collected via an accelerometer at the tip of each beam. DAVE was launched into a high-inclination orbit as a secondary payload on the final flight of the

Delta II Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 ...

launch vehicle as part of the ELaNa-18 ride-share mission with NASA's

ICESat-2 ICESat-2 (Ice, Cloud, and land Elevation Satellite 2), part of NASA's Earth Observing System, is a satellite mission for measuring ice sheet elevation and sea ice thickness, as well as land topography, vegetation characteristics, and clouds. ICES ...

primary payload. The launch occurred out of

Vandenberg Air Force Base Vandenberg may refer to: * Vandenberg (surname), including a list of people with the name * USS General Harry Taylor (AP-145), USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in K ...

, California on September 15 at 6:02 AM local time. DAVE was deployed alongside three other CubeSat spacecraft:

University of Central Florida The University of Central Florida (UCF) is a public research university whose main campus is in unincorporated Orange County, Florida. UCF also has nine smaller regional campuses throughout central Florida. It is part of the State University ...

's SurfSat, and two

ELFIN Elfin may refer to: * ELFIN, a CubeSat developed by University of California, Los Angeles * Elfin (steamboat), a steamboat that ran on Lake Washington from 1891 to 1900 * Elfin of Alt Clut, ruler of Alt Clut, seventh century Scotland *Elfin, a cha ...

spacecraft from

University of California, Los Angeles The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California St ...

. As of November 2018, the spacecraft was active and in good health.

Design

DAVE is a 1U CubeSat spacecraft, measuring approximately 10x10x11cm. The spacecraft was integrated into a PPOD (Poly Picosatellite Orbital Deployer) alongside the University of Central Florida's SurfSat. Fixed solar panels on the sides of the spacecraft provide power to the avionics and transmitter. DAVE is operated from UHF ground stations at California Polytechnic State University. As the satellite's experiment is contained entirely within the spacecraft and does not require any external influence (other than the existence of the low-Earth orbit environment), DAVE contains no attitude control system. A deployable UHF dipole antenna was used to provide fairly omnidirectional coverage, negating the need for spacecraft pointing.

Payload

DAVE contains three aluminum beams which will be used to study the effects of microgravity on vibration damping. Each beam contains a mass on the tip which is attached to an

accelerometer An accelerometer is a tool that measures proper acceleration. Proper acceleration is the acceleration (the rate of change of velocity) of a body in its own instantaneous rest frame; this is different from coordinate acceleration, which is accele ...

, used to identify the resonance peaks of each beam. One beam acts as an undamped control system, while the other two beams contain two types of tungsten particle dampers. Each beam is driven by a high-voltage

piezoelectric Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied Stress (mechanics), mechanical s ...

element over a range of frequencies. The data from the vibration payload can be used to potentially develop systems to dampen out harmful vibrations on future spacecraft. Payload data is downlinked from the spacecraft and processed on the ground.

Amateur Radio Beacon

DAVE transmits a radio beacon on the amateur

70-centimeter band The 70-centimeter or 440 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio and amateur satellite use. The ITU amateur radio allocation is from 430 to 440 MHz; however, some countries, such as the U ...

to allow

ham radio Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communic ...

operators to track and monitor the satellite. The beacon has been received and decoded by amateur radio operators internationally. The spacecraft transmits a periodic radio packet on 437.150 MHz, which contains sensor telemetry recorded just prior to the transmitter turning on. The beacon contains information from various sensors including temperature sensors, a magnetoresistive magnetometer, and voltage sensors on various electronics.

References

{{reflist CubeSats California Polytechnic State University