SSP
The Surface Science Package (SSP) contains a number of sensors designed to determine the physical properties of Titan's surface at the point of impact, whether the surface is solid or liquid.
An acoustic sounder, activated during the last 100 metres of the descent, will continuously determine the distance to the surface, measuring the rate of descent and the surface roughness (e.g., due to waves).
If the surface is liquid, the sounder will measure the speed of sound in the 'ocean' and possibly also the subsurface structure (depth). During descent, measurements of the speed of sound will give information on atmospheric composition and temperature, and an accelerometer will accurately record the deceleration profile at impact, indicating the hardness and structure of the surface.
A tilt sensor will measure any pendulum motion during the descent and will indicate the probe attitude after landing and show any motion due to waves. If the surface is indeed liquid, other sensors will measure its density, temperature and light reflecting properties, thermal conductivity, heat capacity and electrical permittivity.
The Open University (UK), manages this with support from ESA, Italy and the United States.
