Disco-ball in orbit

• Messages sorted by: [ date ][ thread ][ subject ][ author ]
• Next message: Kurt Jonckheere: "81- 33 B, Superbird and others"
• Previous message: Agapov Vladimir: "Soyuz TM-27 launch"

Thanks to Patrick Wiggins for the URL.
The "disco-ball" is going to launched from a Hitchhiker
payload on the planned December 1998 ISI assembly flight.
An extract from the technical overview illustrates the
information seesaters would like to know.
===============================
The STARSHINE spacecraft consists of a hollow aluminum sphere, 19 inches (48 cm) in diameter, covered with 1000 polished, coated aluminum mirrors, each one inches(now  in diameter. It will be mounted in and deployed from a 20-inch-diameter(50 cm) Get Away Special canister with a Hitchhiker ejection system.
The weight of the sphere will not exceed 150 pounds(68 Kg); its exact value will be determined by a tradeoff between the priorities of orbital lifetime and atmospheric density measurement sensitivity. (A heavier sphere will stay in orbit longer but will be less sensitive to atmospheric density variations.) The weight of the sphere will be set by the project team after NASA assigns STARSHINE to a specific orbit. 

The spacecraft's longitudinal axis will be maintained parallel to the Earth's local magnetic field by on-board, and it will be spun about that axis by solar photon pressure photon vanes that are coated to produce alternating patterns of high and low optical absorptivity and emissivity. Induced eddy currents in its aluminum shell will limit its spin rate to a value of approximately 
one revolution every minute. 
============================================
1 rev minute means the the flash from an individual mirror should
last 1/12 second, probably slightly effecting the perceived brightness.
Tony Beresford

• Next message: Kurt Jonckheere: "81- 33 B, Superbird and others"
• Previous message: Agapov Vladimir: "Soyuz TM-27 launch"