
So... What Was the Point of Artemis II?
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The Artemis 2 mission recently returned to Earth after orbiting the Moon, capturing stunning images of Earth and the far side of the Moon. This mission marked the furthest humans have ever traveled from Earth, approximately 400,000 km (250,000 miles) away, a significant distance compared to the International Space Station's low Earth orbit of 400 km (250 miles). The last time humans left low Earth orbit was in 1972.
Artemis 2 is a crucial part of a long-term vision for spaceflight, aiming for regular moon landings every six months by 2028 and eventually establishing permanent bases on the Moon and Mars. Despite these ambitious goals, the mission involved substantial risks. The four astronauts traveled on a spacecraft, the Orion capsule, that had never carried humans before. Its test flight, Artemis 1, revealed unexpected damage to the heat shield, a design flaw that was not fully resolved before the crewed mission. The inspector general even noted that the heat shield's unexpected behavior posed a significant risk to future crewed missions.
Artemis 1, an uncrewed test flight in 2022, was designed to test the systems before human involvement. During its re-entry, the Orion capsule's heat shield experienced more damage than anticipated, with chipping and cracking. Despite this, the design was not fixed for Artemis 2, and the crew proceeded with the mission.
The Artemis 2 mission utilized two main components: the SLS booster, the most powerful human-rated rocket ever built, and the Orion spacecraft. The SLS booster stands over 300 feet tall, weighs around 6 million pounds, and generates about 8 million pounds of thrust. The Orion crew module, located at the top of the rocket, also includes an escape module designed to safely return the crew to Earth even at high speeds. The astronauts for this mission were Reed Wiseman, Victor Glover, Christina Cook, and Jeremy Hansen.
The crew did not land on the Moon but orbited it, setting a new record for the furthest human travel from Earth, surpassing the Apollo 13 mission. They spent about 10 days in space, traveling to the Moon in approximately six days at speeds of 40,000 km/h. Upon reaching the far side of the Moon, they spent six hours observing its surface, including areas never before seen by humans. During this time, Commander Reed Wiseman requested that a lunar feature be named "Carol" in memory of his late wife.
As the crew looped around the Moon, they used its gravity to slingshot back towards Earth. The re-entry into Earth's atmosphere was exceptionally challenging due to the immense return velocity, exceeding that of typical space missions. The spacecraft entered the atmosphere at Mach 32 (32 times the speed of sound), or 40,000 km/h. The friction from air molecules compressed against the spacecraft's surface created a bubble of hot plasma reaching approximately 2,800°C for several minutes. This re-entry was even more intense than that of a Soyuz spacecraft, which travels about 50% slower. After breaching the atmosphere, the crew parachuted safely into the Pacific Ocean, concluding a journey of 1.1 million kilometers (700,000 miles).
Beyond the risky journey, Artemis 2 had specific mission objectives. These included studying the Moon's surface and photographing its features, with the crew receiving geological training. Another key objective was to test the human body's response to deep space conditions, including zero gravity and radiation. This involved comparing astronaut data before, during, and after flight, and using human cell chips with integrated circuits to mimic tissue function, particularly bone marrow, to study the effects of cosmic radiation. The astronauts also tested a new lithium-ion battery and a radiation shelter for emergency use, such as during solar flares. Finally, the mission aimed to test maneuverability, with crew member Victor Glover conducting a simulated docking maneuver to assess the craft's performance for future missions.
Regarding the heat shield issue, the unexpected damage during Artemis 1 was attributed to hot gas bubbles trapped within the ablative material, which expanded and caused chunks to detach. This was suspected to be a result of NASA's decision to perform a double re-entry during Artemis 1, where the craft first skimmed the atmosphere to slow down, and then made a steeper re-entry. The skimming phase likely caused the bubbles to form, which then heated and exploded during the final re-entry. For Artemis 2, NASA opted for a single re-entry approach, and after extensive testing, they were confident in the heat shield's performance, despite some former NASA personnel expressing concerns. The decision not to redesign the heat shield was also influenced by the planned use of a new shield for the Artemis 3 mission, making delays and extra costs for Artemis 2 seem unwarranted in the long term.
Historically, the origins of the Artemis 2 mission are somewhat unconventional. The SLS rocket, often jokingly called the "Senate Launch System," was largely developed to create jobs in various congressional districts rather than solely to meet NASA's scientific needs. In 2004, President George W. Bush proposed the Constellation program with a new spacecraft, the Crew Exploration Vehicle, aiming for human missions to the Moon by 2020. However, the 2008 economic crisis led to the program's cancellation due to budget constraints, especially after the Ares 1 prototype rocket went significantly over budget. Congress, recognizing the job-creating potential of NASA projects, demanded that NASA develop a space shuttle, leading to the creation of the SLS without a clear mission objective. Similarly, the Orion capsule, chosen for Artemis missions, was an existing design from 2012. Both the SLS and Orion were thus retroactively fitted into mission plans based on their capabilities.
Concerns about NASA's ambitious goals and internal operations have been raised by the Aerospace Safety Advisory Panel, with Susan Helms calling Artemis 3 "high-risk" due to the simultaneous innovations being stacked. The panel recommended re-evaluating future mission objectives.
Looking ahead, Artemis 3, planned for 2027, will focus on a low Earth orbit docking test with a commercial lunar lander being developed by either SpaceX or Blue Origin. Artemis 4 in 2028 aims for the first human moon landing in decades, initiating regular moon landings every 6 to 12 months. Artemis 5, also in 2028, will mark the beginning of building a permanent moon base. Future plans include developing lunar infrastructure such as communication satellites, rovers like the Luna terrain vehicle and Viper for resource exploration, and a Toyota-built Japanese rover named the "Toyota Luna Cruiser" for missions up to 45 days. Other goals include developing solar and nuclear power on the Moon. These ambitious goals are seen by some as aspirational, but the new head of NASA, Jared Isaacman, is expected to bring changes to the organization.
In conclusion, despite its messy origins and inherent risks, Artemis 2 represents a significant stepping stone in space exploration, offering inspiring moments and valuable scientific data. The mission serves as a reminder of humanity's ingenuity and our capacity for positive achievements, even amidst global challenges.