- Version 2 improves overall detail
- Adds side support struts, enhances solar array & adds telescopes within the light shields
- Beefed up the high-gain antennas & their supports (reports indicated earlier version's could occasionally break off during polishing)
On Dec. 3, 2015, the European Space Agency (ESA) launched a spacecraft called LISA Pathfinder, which will be used to demonstrate technology for observing ripples in the fabric of space-time itself. These gravitational waves are generated by the acceleration of massive objects, such as orbiting black holes. They were predicted by Albert Einstein’s General Theory of Relativity a century ago but have yet to be detected because the ripples are extremely small.
This model is one of three spacecraft of a proposed constellation that would operate as a space-borne gravitational wave detector. Called the Laser Interferometer Space Antenna (LISA), the project was studied in great detail as a collaborative mission between NASA and ESA, although neither agency decided to proceed with it. Space is the best place to detect gravitational waves, so sooner or later a mission similar to LISA will fly (in my humble opinion, anyway).
The plan for LISA was that three identical spacecraft would fly in an Earth-trailing orbit. Each would form the vertex of an equilateral triangle spanning several million kilometers. The spacecraft would fire lasers at each other to measure their relative displacements with picometer (trillionth of a meter) accuracy, allowing scientists to measure the tiny distortions of space-time caused by a passing gravitational wave.
The propulsion module for the spacecraft is available at the same scale here.
LISA's gravitational wave sensor is a "proof mass," an object allowed to follow a pure free-fall trajectory that the spacecraft tracked. A full-scale model of the proof mass used by LISA Pathfinder is available here.