India’s Chandrayaan-3 mission successfully measures plasma in polar region with Vikram’s RAMBHA instrument.

BENGALURU: One of the three Indian payloads on the Chandrayaan-3 lander (Vikram) has completed the first in-situ measurements of the surface-bound lunar plasma environment over the south polar region.

Isro said that the measurements have been carried out by the Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere-Langmuir Probe (RAMBHA-LP) payload onboard the lander. These quantitative measurements could assist in mitigating the noise that lunar plasma introduces into radio wave communication and contribute to enhanced designs for upcoming lunar visitors.

The initial assessment indicates that the plasma encompassing the lunar surface is relatively sparse, characterized by a number density ranging from approximately 5-30 million electrons per cubic meter. Isro stated that these ongoing observations hold significant implications for comprehending the process of charging within the lunar near-surface region, particularly in response to fluctuations in solar space weather conditions.

The RAMBHA Langmuir probe, named after US chemist and physicist Irving Langmuir, is a device used for characterizing a plasma. It features a 5cm metallic spherical probe mounted on a 1-meter boom attached to the lander’s upper deck. The probe is deployed using a hold-release mechanism after the lander’s lunar touchdown. The extended boom length ensures that the spherical probe operates within the undisturbed lunar plasma environment, isolated from the lander’s body.

The system can detect minute return currents, as low as pico-amperes, with a dwell time of 1 millisecond. By applying a sweeping bias potential ranging from -12 to +12 V in increments of 0.1 V to the Langmuir probe, the system can accurately determine ion and electron densities as well as their energies based on the measured return current.

This development is a significant achievement for the Indian Space Research Organisation (Isro) and its Chandrayaan-3 mission. It provides valuable data on the surface-bound lunar plasma environment, which can aid in improving future lunar missions and communication systems.

News Summary:
★One of the Indian payloads on the Chandrayaan-3 lander has completed the first in-situ measurements of the lunar plasma environment.
★The measurements were carried out by the Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere-Langmuir Probe (RAMBHA-LP) payload.
★The plasma around the lunar surface is relatively sparse, with a number density ranging from 5-30 million electrons per cubic meter.
★The RAMBHA Langmuir probe, developed by Isro, is used for characterizing plasma.
★The probe operates within the undisturbed lunar plasma environment and can accurately determine ion and electron densities.
★The data collected will contribute to the improved design of future lunar missions and communication systems.