Four LP-PWI Langmuir probes are to be mounted on the JUICE spacecraft in order to gather crucial information about the surrounding bulk plasma in Jupiter’s magnetosphere
The main goal of the mechanism is to position the Langmuir Probes at the desired angle of 135º and 3 m from the spacecraft. To achieve this, the LP-PWI unit consists of two CFRP links joint with hinges and driven by clock springs.
The major design challenges are the large scale of the system, the extreme ranges of temperatures in a space environment (below -200degC near Jupiter to above 200degC during Venus flyby), the dynamic deployment principle due to the light-weight design requirement (<1.4kg per unit) and its low natural frequencies.
Despite these challenges, the design went through successful breadboarding, including deployment tests in simulated zero-gravity conditions, as well as vibration and thermal-vacuum tests.
Radio Wave Instrument (RWI) was chosen as an antenna for JUICE mission thanks to the successful accomplishment of the E-ANTENNA project
The RWI system makes use of three 2.5 m-long (tip-to-tip length), mutually perpendicular electric dipole antennas to measure three components of the high-frequency electric field ranging from 0.08 to 45 MHz.
As a result of Phase B, a mechanical breadboard of a single dipole antenna was successfully designed, manufactured, assembled and subjected to a test campaign which included functional (deployment), vibration and thermal-vacuum tests. The test campaign was successful and the proposed antenna achieved TRL 5.
RWI Single Dipole Antenna parameters:
- Antenna type: dipole,
- Tubular boom used: Ø 10 mm beryllium bronze,
- Length: 2.5 m (tip-to-tip),
- Overall dimensions (stowed): 256 x 76 x 43 mm,
- Mass: 236 g,
- Power consumption: 8 W per 4 s (for lock & release mechanism), 1.25 W per 30 s (for electromagnet, when necessary),
- No additional driving units,
- Lack of deployment speed control,
- Non-explosive Lock & Release Mechanism based on a thermal cutting system (Vectran holding string)
- Single shot device – once deployed, the antenna cannot be retracted