Starshine 3 (SO-43)

Launch data: Designation  26929 / 01043A Launch date  30 Sep 2001 - 02:40 UT Launch site  Kodiak, LP-1 Launch vehicle  Athena-1 (#LM-001) Mission  Science Perigee / Apogee   km Eccentricity   Inclination   deg Period   min

Photo of Starshine-3 (image credit: Project Starshine)

Description:

• STARSHINE is a US cooperative program of small optically reflective spherical student satellites, designed and built by NRL/NCST (Naval Research Laboratory/Naval Center for Space Technology). They are being deployed by NASA from Hitchhiker canisters in Space Shuttle cargo bays, as well as from an Athena unmanned launch vehicle, into highly inclined low earth orbits at a rate of once every year or so.
• Each of the satellites is covered by approximately 850 small, front-surface aluminum mirrors (2.54 cm diameter) that are machined by technology students in Utah and polished by tens of thousands of students in schools and other participating organizations around the world. These mirrors have been coated with a scratch-resistant, anti-oxidizing layer of Silicon Dioxide by optical engineers and technicians at the Hill Air Force Base in Utah and the NASA Marshall Space Flight Center in Alabama.
• During the satellite′s orbital lifetime, faint sunlight flashes from its mirrors were naked-eye visible against the star background, during certain recurring morning and evening twilight periods, to student and adult observers around the world between the latitudes of 60 degrees north and 60 degrees south.
• These observers measured the satellite′s right ascension and declination by reference to known stars, and they recorded the precise timing of their observations by the use of stopwatches synchronized with international time signals. They used GPS receivers or United States Geological Survey 7 ½ minute quadrangle maps, or their equivalents in other countries, to measure the latitude, longitude and altitude of their observing sites. They posted their observations and station locations on the Starshine web site to permit computation of the classical elements of the satellite′s orbit by the angles only method of LaPlace.
• From day to day, the period of the satellite′s orbit grew shorter, due to the afore-mentioned aerodynamic drag. Students measured the magnitude of the daily decrease of period and deduced the density of the earth′s upper atmosphere that produced the drag that shortened the satellite′s orbital period. They also kept track of fluctuations in intensity of extreme ultraviolet radiation from the sun, as measured by instruments on the SOHO satellite. They related fluctuations in intensity of solar activity to changes in the rate of decay of the satellite′s orbit and thereby to variations in atmospheric density.
  • Starshine 3 is an American microsatellite that was launched from the Kodiak Launch Complex (KLC) on Alaska's Kodiak island (located 400 km south of Anchorage) at 02:40 UT on 30 September 2001. (Foul weather and auroral conditions had delayed the launch many times.) The 80 kg NASA satellite is basically a passive light-reflecting sphere of one meter diameter, consisting of 1,500 student-built mirrors (polished by kindergarten and grade school students from many countries) and 31 laser "retroreflectors". A few solar cells provide enough power to send a beacon at 145.825 MHz every minute. Ham operators around the world are expected to obtain signal strengths from which the decay (due to magnetic torque) of its spin rate can be determined.
  • Communication system: One of Starshine-3 primary objectives is to involve more school children in radio science. As part of this mission, science data from experimental solar cells is downlinked in a manner that permits schools and radio amateurs to participate in collecting the data.
  • For this reason, the downlink has been designed for compatibility with the affordable Kenwood THD-7 hand-held radio terminal and also for compatibility with other amateur radio terminals. The THD-7 radios contain built-in AX.25 Terminal Node Controllers (TNCs) and RS-232 ports. Consequently, they can receive Starshine-3 downlink signals directly. Schools that purchase THD-7 or similar radios will be able to receive the Starshine 3 signals with their identifying “STRSHN3 N7YTK” data header very simply. This helps the students to see that they really are receiving data from the satellite for which they polished mirrors. They are able to forward the received data to the Starshine Project Internet site. This should be an excellent science and technology project for the school children.
  • The Starshine-3 downlink uses VHF-band communications at 145.825 MHz (data rate of 9.6 kbit,s, FSK modulation, NRZ encoding). The AX.25 packet protocol is being used. RF communications (amateur standard) between S/C and the ground, consists of a telemetry transmitter, a command receiver, rechargeable batteries (IMPS), a secondary solar array, signal-conditioning circuitry, and an antenna. The data is transmitted to ground receiving stations at the University of Alaska, Fairbanks, the US Naval Academy, Annapolis, MD, Santa Clara University in Santa Clara, CA, and to numerous amateur radio stations around the world.

Mission details:

• The launch of Starshine-3 took place on Sept. 30, 2001 on an Athena-1 vehicle from the Kodiak Launch Complex on Kodiak Island, Alaska. The entire launch payload consisted of four small satellites: Starshine-3, PICOSat, a technology demonstration microsatellite of DoD/AFRL, PCSat (Prototype Communications Satellite) a microsatellite designed and built by Midshipmen of the United States Naval Academy (USNA), Annapolis, MD, and SAPPHIRE (Stanford AudioPhonic Photographic IR Experiment) of Stanford University. The launch of all satellites represented also the inauguration of launch services from this site.
• This is the first orbital launch from the Kodiak Launch Complex.
• The launch sequence of the mission was designed in such a way as to deploy first the primary payload, PICOSat, into an 800 km orbit at an inclination of 67º, followed by successive deployments of SAPPHIRE and PCSat (with no specific requirements on orbit). Then the OAM (Orbital Adjust Module) of the launch vehicle performed an orbit change maneuver to lower the orbit from 800 km to 500 km circular altitude (requirement of Starshine-3). At about this altitude, the Starshine satellite was deployed.

External links:

• EOportal.org Satellite description