TiPS

American tether technology satellite. The 53 kg satellite consisted of 2 end masses connected by a 4 km tether. NRO (the National Reconnaissance Office) provided funding for the TiPS project. Tether technology satellite for Naval Research Laboratory (NRL), USA. Launched 1996.

The TiPS payload was placed in an 1019 x 1024 km x 63.4 deg orbit.

The Naval Research Laboratory's (NRL's) Naval Center for Space Technology designed, built and deployed the first in a series of small satellites to research the gravity-gradient dynamics and survivability of a tethered system in space, known as the Tether Physics and Survivability (TiPS) experiment. TiPS consisted of two end masses separated by a four-kilometer tether. The end masses were named Ralph and Norton after Ralph Kramden and Ed Norton from the 1950's Television Show "The Honeymooners". Ralph and Norton weigh 37.7 and 10.8 kilograms, respectively.

TiPS was among the first successful tether deployments in space and was the first experiment designed for long duration. The TiPS tether, made by AlliedSignal, was in two layers. The outer layer was Spectra 1000 braid for strength, the core was acrylic yarn which puffed the other braid out to a 2 millimeter diameter and give it a larger cross section to improve its resistance to debris and small micrometeoroids. The tether could be severed by a space particle as small as 1-mm traveling at a relative velocity of 14 km/s (31,318 mph).

Satellite laser ranging to TiPS was used to determine the precise orbit and attitude of the tethered system. This was the first time SLR data had been converted into attitude knowledge, in order to validate analytical models and simulations of a tethered system. TiPS SLR tracking support was discontinued 15 October 1997.

TiPS had the following instrumentation onboard:

• Telemetry system located on Ralph
  
• Turn-count recorder located on Ralph
  
• Temperature sensors located on Ralph
  
• Retroreflector arrays on both Ralph and Norton The TiPS RRA consisted of 18 retroreflectors were mounted on each exterior surface of both Ralph and Norton, for long-term passive monitoring of the tethered system. End-mass discrimination was accomplished by coating the retroreflectors of Ralph to reflect only the green wavelength, while the uncoated retroreflectors on Norton reflected both green and infrared wavelengths.

Advanced Tether Experiment (ATEx) was the follow-on mission to TiPS and was launched in 1998. However the tether only deployed to 21 m when it snagged and the satellite was jettisoned from its STEX mother satellite and abandoned. ATEx carried a GPS receiver, which was to be used in precision orbit determination combined with satellite laser ranging. There were three ATEx mission objectives: 1) Demonstrate tether system stability and control, 2) demonstrate end-body attitude determination and control, 3) fly a tether designed for survivability. ATEx had the following instrumentation onboard: 1) GPS receivers; 2) Retroreflector arrays.

TiPS parameters (ATEX in parentheses where different)

Sponsor: US Naval Research Laboratory
Life: 6 months design, SLR support of TiPS was discontinued on September 30, 1997. ATEX deployment failed.
Reflectors: 18 corner cubes per end mass (ATEX:43 corner cubes per end mass)
Mass: 54 kg (ATEX 53 kg)