[Satnews] The LISA Pathfinder demonstrator for space-based observations of gravitational waves is undergoing checkout at the Spaceport, preparing it for a December 2 launch on Arianespace's sixth flight of the Vega light-lift launcher from French Guiana.

This activity is being performed in the S5C hall of the Spaceport's S5 payload processing facility, with the work being led by teams from LISA Pathfinder prime contractor Airbus Defence and Space. LISA Pathfinder is a mission organized by the European Space Agency (ESA). The probe is designed to test critical concepts and technologies related to the detection of gravitational waves—the ripples in space-time predicted by Albert Einstein's General Theory of Relativity.

LISA Pathfinder is installed on a work dolly (photo at left) that provides access to the spacecraft and its propulsion module during pre-launch checkout in the Spaceport’s S5 payload processing facility. In the Spaceport’s ZLV launch zone, Vega’s Zefiro 23 solid propellant second stage is ready for integration atop the launcher (right photo), which is partly visible inside the protective mobile gantry.

Photos are courtesy of Arianespace.

After being lofted by Vega on Arianespace Flight VV06, the spacecraft will enter an elliptical Earth orbit, then use its own propulsion module to reach the operational orbit for six months of scientific and technical operations around the first Sun-Earth Lagrange point (L1), located approximately 1.5 million kilometers from Earth.

LISA Pathfinder is unusual in design. Conceived to be the "quietest" spacecraft ever launched, it does not possess a typical payload structure, as the spacecraft, as a whole, is part of the experiment. At its core are two individual freely-falling test masses: cubes of gold-platinum alloy whose distance apart will be monitored by a complex laser system. The satellite's technology package was developed by European companies, research institutes and ESA; while a disturbance reduction system was provided by the U.S. NASA space agency.

LISA Pathfinder will have an estimated liftoff mass of 1,910 kg. and will be lofted from French Guiana atop the four-stage Vega, which currently is being integrated at the Spaceport's ZLV launch facility. In the latest step of its build-up, Vega's Zefiro 23 solid propellant second stage was mated this week to the P80 first stage, which is positioned on the launch pad inside a protective mobile gantry.

Vega began operation in 2012 and is designed to carry the growing number of small scientific spacecraft and other lighter-weight payloads under development worldwide.  As the smallest member of Arianespace's launcher family - which also includes the medium-lift Soyuz and heavyweight Ariane 5—Vega is produced under the responsibility of industrial prime contractor ELV, a company jointly owned by Avio and the Italian Space Agency.