THE RACE TO THE MOON

For over six decades, humans have been launching spacecraft toward the Moon, yet successfully landing on its surface remains a challenging feat. As of the filming of this episode, four missions have endeavoured lunar landings this year, with only one achieving its goal. However, this solitary accomplishment holds great significance, marking the conclusion of a brief space race. Two international missions were in contention to be the first to touch down at the Moon's uncharted south pole. While some may frame it as Russia versus India, in reality, it was humanity's collective endeavour against the formidable lunar landscape.

Competing in this race were the Indian Space Research Organization (ISRO) and Roscosmos, the official space agencies of their respective nations. Their mutual objective wasn't solely driven by the desire to claim the "First!" title, although that is undeniably satisfying. The Moon's south pole held tremendous scientific significance, primarily due to the presence of water ice. Water is not only vital for sustaining human life but can also be used to produce rocket fuel. Consequently, the lunar south pole could potentially serve as a crucial waystation for future space missions into the far reaches of the cosmos. Nevertheless, for a moment, let's put the enticing scientific prospects aside and highlight the true essence of the matter: international recognition and acclaim. In the past, during the era of the USSR, several lunar landings were accomplished, even though human cosmonauts never set foot there.

The most recent Soviet visit to the Moon dates back to 1976, when the Luna 24 robotic mission successfully landed, collected a sample of lunar soil, and returned it to Earth. After half a century, Russia aimed to stage a triumphant comeback with Luna 25. Meanwhile, India's objectives carried a different tone. As a relatively new entrant in lunar exploration, India had previously achieved lunar orbit with its spacecraft. However, their first lander's descent ended in a crash in 2019. With the Chandrayaan-3 mission, India sought redemption and the distinction of becoming the fourth nation to achieve a gentle lunar landing, following the footsteps of the USSR, the USA, and China.

India initiated their mission on July 14 by taking an unconventional approach. Instead of the conventional method of launching a robust rocket with a direct, forceful trajectory to reach the Moon in the shortest distance possible, Chandrayaan-3 adopted a series of incremental orbits. This method allowed the spacecraft to gradually transition from Earth's orbit to lunar orbit.

The journey to the Moon entailed even more orbital maneuvers, culminating in a controlled powered descent. This entire mission was facilitated by ISRO's Launch Vehicle Mark 3 (LVM3). Initially designed for launching satellites into geosynchronous orbit, the LVM3 underwent upgrades to become a versatile launch vehicle capable of accommodating heavier payloads and reaching destinations ranging from low Earth orbit to beyond the Earth-Moon system. Impressively, the LVM3 boasts a flawless 100% launch success rate so far. ISRO envisions its potential for launching humans into space in the future, though that goal remains on the horizon. Nevertheless, it efficiently propelled Chandrayaan-3 on its trajectory.

Once the lander entered space, it executed a series of orbit-raising maneuvers spanning several days to ultimately enter lunar orbit.

Over the following days, Chandrayaan-3 initiated a gradual descent towards the lunar surface. In a simultaneous effort, Roscosmos launched Luna 25 on August 10, taking a more conventional trajectory to reach the Moon. As a result, Luna 25 swiftly entered lunar orbit just six days after its launch. At that point, Chandrayaan-3 was still in the process of narrowing its orbits, and Russia seemed poised to achieve the first landing. However, on August 19, a technical glitch caused Luna 25's thrusters to fire for 43 seconds longer than intended, sadly leading to the mission's premature end. Roscosmos later confirmed that the craft had "ceased to exist," which essentially meant it had crashed into the Moon. The impact crater it left behind was even detected by NASA's Lunar Reconnaissance Orbiter. With this setback, the Russian team was out of the competition. In contrast, Chandrayaan-3 was preparing to engage its propulsion system for its gradual descent

On August 23, the lander Vikram and its companion, the rover Pragyan, detached from the communications relay satellite and initiated a gradual descent until they accomplished a successful landing on the Moon. Although the landing site was not precisely at the lunar south pole, it was approximately 600 kilometers away, situated at a southern latitude of around 69 degrees. Nevertheless, Chandrayaan-3 had achieved its goal, showcasing the victory of a slow and steady approach in the race. This historic achievement firmly established ISRO's place in the annals of space exploration as the first agency to successfully land in close proximity to the lunar south pole and the fourth to land anywhere on the Moon. It was a remarkable accomplishment. Yet, ISRO didn't rest on their laurels. The following day, the lander and rover descended onto the lunar surface, commencing their scientific endeavors as a dynamic robotic duo.

While not equipped with as many instruments as Luna 25, the Chandrayaan-3 lander and rover had the capability to conduct temperature measurements and study local seismic activity. Unfortunately, their mission was relatively short-lived. Following a two-week-long, frigid lunar night, both the lander and rover failed to reactivate. The events of this mini space race in 2023 underscored the challenges of lunar exploration. It emphasized that achieving a successful lunar mission necessitates the right combination of mission design, planning, and the selection of an appropriate rocket. Even with all these elements in place, a degree of luck is still essential. Nevertheless, the inherent difficulties of space travel have never deterred humanity from pushing the boundaries of exploration. Thank you for tuning in to this episode of SciShow

Every month this year, we're commemorating a different rocket by honoring it with a stylish, limited-edition pin. In recognition of its pivotal role in delivering Chandrayaan-3 to the lunar surface, our second-to-last rocket pin pays tribute to ISRO's Launch Vehicle Mark 3. Don't miss the opportunity to order yours today by visiting DFTBA.com/Scishow.