The U.S. executes manned lunar mission rocket launch

Local time on the evening of April 1, the United States’ new-generation Moon rocket “Space Launch System” (“SLS”) launched from the Kennedy Space Center in Florida to carry out the crewed lunar-orbiting mission “Artemis 2.” This is the first crewed flight to the Moon from the United States since 1972.

Further Reading

Tolerating risk and rushing the schedule—why is the U.S. eager to achieve humanity’s first “return to the Moon” in more than 50 years?

Unless interfered with by factors such as weather, at 6:24 p.m. local time on April 1, the NASA “Artemis 2” mission at the Kennedy Space Center in Florida entered its first launch window.

With the new-generation Moon rocket “Space Launch System” (SLS) and the “Orion” spacecraft aboard, four astronauts will begin a 10-day journey in lunar orbit.

This marks the first time in more than 50 years, following the “Apollo Program,” that humanity has headed for the Moon in a crewed mission—while also serving as a key preparation for the next stage of the United States’ crewed lunar landing plan. Considered highly engaging, but with risks throughout it as well.

Two key meanings

NASA introduced the Moon-landing “Artemis” program in 2019, aiming to build a permanent lunar base, develop natural resources, and lay a springboard for future deep-space exploration such as landing on Mars.

After completing the three-years-ago unmanned lunar-orbit test flight of “Artemis 1,” “Artemis 2” advanced to its first crewed lunar-orbit mission.

If everything goes smoothly, within three and a half hours after liftoff, the “Orion” spacecraft will fully separate from the rocket.

The spacecraft will first enter Earth orbit, then after about a day, maneuver toward the Moon. After reaching lunar orbit, the spacecraft will use the Moon’s gravity to perform “U-shaped loop” lunar-orbit flight.

Finally, under Earth’s gravity, it is expected that on April 10 the spacecraft will splash down in the Pacific Ocean off the U.S. West Coast.

The mission’s primary goal is, in a real deep-space environment, to comprehensively test the “Orion” spacecraft’s life-support systems, navigation and communication systems, and the performance of its heat shield.

What draws attention is that “Artemis 2” has set multiple “firsts.”

On the hardware side, this is the first time the new-generation Moon rocket “Space Launch System” and the “Orion” spacecraft will team up to carry out a crewed flight mission.

The new-generation Moon rocket is about 98 meters tall. It is the heaviest rocket NASA has ever launched. With its propellant tanks fully loaded, it weighs about 2,500 metric tons and can send a 27-ton payload to the Moon.

The “Orion” spacecraft has a maximum diameter of about 5 meters, an inhabited volume of 8.95 cubic meters, and is equipped with 33 engines.

This is the crewed “Orion” spacecraft’s debut, and its reliability will be validated for the first time through real-flight human testing.

As for personnel, the four astronauts are not only among the first people to “return to the Moon” since 1972, but will also “represent” humanity by getting the first close-up view of the Moon’s far side and by collecting and analyzing data from observations of the Moon’s far side.

At the same time, some data is expected to refresh crewed spaceflight records.

One is that humanity may break the deep-space flight record and create the greatest distance from Earth.

In 1970, “Apollo 13” set a record of over 248,000 miles (about 400,000 kilometers). This time it is expected to reach 252,000 miles, breaking 400,000 kilometers.

Another historic datum is that when the “Orion” spacecraft reenters the atmosphere, its reentry speed will reach 40,000 kilometers per hour.

Wang Yanan, an aviation expert at Beihang University and editor-in-chief of “Aviation Knowledge,” pointed out that the “Artemis 2” mission has drawn worldwide attention for two important reasons.

First, after the “Apollo Program” was terminated, only unmanned probes entered lunar orbit—this is the first crewed mission to send humans into lunar orbit in more than 50 years. Completing crewed lunar orbit is the first key step and the risk threshold before a crewed lunar landing, and it is an important prerequisite for achieving a soft landing on the lunar surface.

Second, both the launch vehicle and crewed spacecraft being used this time are newly developed equipment rather than products left over from the “Apollo era.” Crew-orbit operations are a “field test” of the new equipment and present a high level of challenge. The completion level of this engineering objective is directly related to whether crewed lunar landing has a solid foundation.

Three risk points

However, as humanity’s first venture to the Moon in more than half a century, whether “Artemis 2” can achieve a “perfect launch and flight” is believed to face some challenges.

Wang Yanan is concerned about three risk points.

The first is safety risks related to the heat shield.

During the return flight, the “Orion” spacecraft will reenter Earth’s atmosphere at a speed of 40,000 kilometers per hour. The heat shield must withstand temperatures exceeding 2,700 degrees Celsius—about half the temperature on the surface of the Sun.

“If the thermal protection system doesn’t pass, and humans are unable to rescue, then when the spacecraft reenters the atmosphere, it could be damaged in the mild case, or in the worst case, the ship could be destroyed and lives lost,” Wang Yanan said.

During the 2022 unmanned “Artemis 1” lunar-orbit mission, the “Orion” heat shield once experienced an “incident” during reentry into the atmosphere, with multiple heat-shield tiles cracking and coming off.

NASA chose not to replace the heat shield this time, but instead to adjust the spacecraft’s reentry flight trajectory to reduce thermal load, which was harshly criticized by a former U.S. astronaut as “insane.”

The second is the stability of the environmental control system.

During the spacecraft’s journey in lunar orbit, in-cabin indicators such as oxygen concentration, carbon dioxide concentration, temperature, and humidity must remain stable; otherwise, it could affect the astronauts’ work and life, and even endanger survival.

Given that the environmental control system had issues during previous unmanned lunar-orbit tests, the complexity and danger of the mission this time are higher under crewed conditions.

“Astronauts’ operations and activities will affect the environment, bringing more human-variable factors,” Wang Yanan said.

The third is the reliability of the propulsion and power system.

In earlier rehearsals, the SLS rocket had multiple failures in succession, such as liquid hydrogen leaks and interruptions in helium gas supply, leading to repeated delays of the launch.

If the failures repeat, it will affect the stability of the lunar-orbit flight, including the precision of orbit control and the spacecraft’s attitude.

Wang Yanan said that many technical “stubborn problems” have not yet been properly resolved, yet NASA has loosened its tolerance for risk and hastily launched the lunar-orbit mission—clearly showing a rush.

In his view, the United States’ urgency stems from Cold War thinking born of great-power competition, especially the desire to achieve a crewed lunar landing before China.

Since the “Apollo Program,” humanity has made major achievements in the field of unmanned lunar exploration.

In particular, China’s “Chang’e” series of probe missions have achieved key breakthroughs, including lunar polar landing and return sample collection from lunar soil.

As unmanned lunar exploration becomes highly mature, a new opportunity for crewed lunar exploration has arrived—multiple countries, including China and the U.S., have developed crewed lunar landing plans.

But unlike the United States, before executing crewed lunar exploration or lunar landing missions, China prioritizes leaving sufficient safety margins. It sets backups in risk-related areas and formulates rescue plans to fully protect personnel safety.

“For space engineering, any unexpected event is a major setback,” Wang Yanan said.

He also emphasized that the fundamental purpose of advancing humanity’s space endeavors is not to “be first,” but to ensure that the engineering, technical, and scientific research returns are shared with more people.

An Uncertain Outlook

Although the U.S. is eager to compete, as the saying goes, you can’t eat hot tofu before it cools down.

Since the “Artemis” program was introduced, despite pouring in huge amounts of money, the progress has not gone smoothly.

Over seven years, the only unmanned lunar-orbit test flight of “Artemis 1” was completed in November 2022.

The crewed lunar-orbit mission “Artemis 2,” originally planned for 2024, was also delayed again and again due to technical failures and other uncontrollable factors.

Even the entire “Artemis” program underwent major adjustments.

Under the original plan, after completing the crewed lunar-orbit flight mission, the U.S. would carry out the crewed lunar landing mission “Artemis 3” in 2027.

Now, the “3” mission has been changed to conduct systems and operational capability testing in near-Earth orbit.

The crewed lunar landing missions will be implemented by “Artemis 4” and “Artemis 5” in 2028 and 2030, respectively.

For this reason, the “Artemis” program has been mocked as NASA’s least efficient space project in history.

Wang Yanan believes that while the U.S. still remains among the world’s leaders in the field of aerospace engineering, there is uncertainty as to whether the “Artemis” program can be completed on schedule.

First, time is tight, the mission is heavy, and the risks of schedule-driven work are high.

Achieving a crewed lunar landing involves multiple key steps: completing the crewed lunar-orbit mission; ensuring all hardware is in place, including successful tests of heavy rockets and timely delivery of new lunar landers; sending the entire crewed lunar landing system—including spacecraft, personnel, and supplies—to lunar orbit and achieving a soft landing on the lunar surface; topping up fuel during the lunar stay period; igniting and launching off the lunar surface upon return, and so on.

“It’s far more difficult than the ‘Apollo Program.’ Each key step involves necessary testing, and it must be completed before 2030. The schedule is extremely tight. Rushing and ‘spurring on the horses’ means compressing the margin validation time to the extreme, sacrificing safety and reliability.”

Second, domestic and international cooperation may not go smoothly.

On the domestic front, the “Artemis” mission introduces private companies to participate in research and development—for example, SpaceX and Blue Origin developing lunar landers—forming an architecture in which multiple parties coexist, including NASA, traditional defense and aerospace contractors, aerospace giants, and new technology startups. The parties’ organizational attributes, ways of doing business, and cultural backgrounds are all fundamentally different, creating coordination and communication problems.

On the international front, the U.S. chose to move forward with the “Artemis” program via international cooperation. But currently, the U.S. and its Western allies have conflicts emerging one after another over issues such as territory and defense, and fluctuations in their relationship are likely to affect major space project cooperation.

The U.S. intends to seize an advantage in the space race track of the new era, but whether it can get what it wants—everyone worldwide will be the witness.

(Source: CCTV News)