STARSHINE-1

Spacecraft n°:

US spacecraft n°:

Launch data: Designation  257xx / 99030 Launch date - time  27 May 1999 - 10:49:42 UT Ejected from STS-96 on 05 Jun 1999 - 07:21 UT Launch site  KSC, LC39B Launch vehicle  Shuttle STS-96 Mission   Earth orbit: Perigee / Apogee  379 x 396 km Eccentricity   Inclination  51.6 deg Period   min

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.
• The Starshine 1 satellite consisted of a hollow aluminum sphere, 48 centimeters (19 inches) in diameter, covered with 878 polished aluminum mirrors, each of which was 2.5 centimeters (one inch) in diameter. These mirrors were polished by 25,040 children in 660 schools in 18 countries. The spacecraft was mounted in and spring-deployed from a Hitchhiker canister in the orbiter′s cargo bay. The weight of the hollow sphere was 39 kilograms (86.6 pounds). The plane of its orbit at deployment was inclined to the earth′s equator by 51.6 degrees.

Mission details:

• At 0721 UTC on Jun 5, 1999, the first of these satellites, called Starshine 1, was deployed into a 379 x 396 km x 51.6 deg orbit from a canister at the rear of Discovery′s STS-96 payload bay.
  Starshine 1 circled the earth every 90 minutes, descending and speeding up slightly during each orbit due to the effects of atmospheric drag, until February 18, 2000, when it was consumed by aerodynamic heating on its 4212th circuit of the earth at an altitude of approximately 80 kilometers above the Atlantic Ocean off the coast of Brazil.

External links:

• EOportal.org Satellite description