FINDINGS of India's first successful un manned touchdown lunar mission. Chandrayaan-3, made pub-lic on December 9. may force a rethink on the way future manned hu nar missions are prepared for, keeping safety of astronauts, equipment and the missions themselves in mind. The Radio Anatomy of the Moon Bound Atmosphere-Langmuir Probe (RAMBHA-LP) payload onboard Chandrayaan-3's lander Vikram, has made the first-ever direct on site measurements of the plasma environment, and found that the electrical envi ronment near the Moon's sur face at the south Polar Region is far more active than previ ously known and the lunar south Polar Region is where Moon-faring space agencies are planning to set up bases for longterm lunar explorations. The key findings are based on data from August 23 to Septem ber 3, 2023, yielding significant first-of-its-kind results on the Moon's surface at the southern higher latitudes. It has revealed that electron density near the landing site of Chandrayaan-3, named as shiv shakti Point near the south Pole of Moon, was measured to be between Plasma is the fourth state of matter, a mixture of charged particles, including ions and free electrons and is highly conductive, responding strongly to electromagnetic fields. The Moon's thin plasma environment is governed by solar wind, a continuous stream of electrons, hydrogen and helium ions ejected from the Sun's upper atmosphere. This, along with high-energy photons from the Sun, knock out outer-shell electrons from atoms on the surface and in the atmosphere, causing ionization. The lunar plasma is further influenced by charged particles originating from the Earth's magnetosphere when the Moon passes through that region, resulting in a changing and dynamic electrical environment near the surface.

380 and 600 electrons per cubic centimeter. This is significantly higher than estimates derived from observations taken at higher altitudes, which are primarily based on observing the changes in the phase of electromagnetic sig-nals from satellites passing the Moon's thin atmosphere at grazing angles.

It was further found that the electrons near the Moon's surface possess remarkably high energy, with equivalent tem-peratures (called kinetic tem-perature) soaring between 3,000 and 8,000 Kelvin.

WHAT's HAPPENING

The study uncovered that the lunar plasma is not static, but constantly modulated by two distinct factors, depending on the Moon's orbital position around the Earth. When the Moon is facing the sun (Junar daytime) and outside the Earth's magnetic field, changes in the near-surface plasma are driven by particles from the solar wind interacting with the sparse neutral gas (exosphere) on the Moon. On the contrary when the Moon passes through Earth's geomagnetic tail, the plasma changes are caused by charged particles streaming from the tapered region of Earth's long magnetic tail (to-wards the opposite side of the sun)

Furthermore, in-house de veloped Lunar ionospheric Model (LIM) suggests that apart from the elemental ions, the molecular ions (likely originating from gases like CO2, H2O) also play a crucial role in creating this electrically charged layer close to the lunar surface near the Moon's south pole. These results from the RAMBHA-LP experiment pro vide essential ground truth needed for the next phase of bu nar exploration, which is not too far into the future.

SERIOUS CONCERNS

Chandrayaan-3 's lander Vikram's RAMBHA-LP pay load's findings are an alert to US' National Aeronautics & Space Administration (NASA), the Chinese National Space Ad iministration (CNSA), and its a own maker, the Indian Space Research Organisation (ISRO). And these are serious concerns.

Most future Moon landing missions by these space agen cies involve setting up hases near the lunar south pole the same region where the RAMB HA-LP payload detected a high gher density plasma environment than earlier known.

The dense, energetic ions 100 and free electrons can disrupt sensitive electronic circuits in landers, rovers, and astronaut gear, potentially causing fail ures. The charged particles can interfere with radio signals. making communication with Earth or orbiting spacecraft difficult. Energetic particles pose radiation hazards to astro nauts and could damage space-suit components, requiring en-hanced shielding. Basically, the RAMBHA LP findings have re vealed that the Moon's south pole is more dynamic than thought, requiring robust engi neering and operational chang es to safely and effectively ex plore it. While all the six successful Apollo manned lu nar missions (Apollo 11, 12, 14, 15, 16 and 17) clocked a total of 296 hours of astronauts being on the Moon's surface, the fu ture missions are looking at spending weeks, months and years there. Manned lunar missions will be resumed 53 years after NASA completed its six successful manned lunar mis sions (1968-1972) with the Apollo-17 mission.

The missions ahead begin with NASA'S Artesnis Program. commencing with Artemis II in April 2025, which will be the first crewed flight of the space Launch system (SLS) rocket and Orion spacecraft, sending four astronauts on a 10-day Journey around the Moon to test systems for future deep space missions. But they will not land on the Moon. Artemis III, scheduled to be launched in mid-2027, is looking at landing the first woman and the next man on the lunar surface, uti lizing the starship Human Landing system (HLs) for the descent. Artemis IV in 2028 and Artemis V in 2000 aim to build infrastructure, including the Lunar gateway with later mis-sions planning regular land-ings and surface expeditions. The CNSA plans to send its own crewed mission to the Moon around 2030, using its Long March 10 (LM-10) rocket and Mengzhou spacecraft for a multi-day lunar surface stay: while India's own ISRO is look-ing at sending the first Indians to the Moon by 2040.

This has been written by Nirad Mudur of The New Indian Express.