[Reading Science] Humanity's Journey to Mars: Horses, Carriages, and Boots Are Ready

The inflatable decelerator, which completed a low Earth orbit reentry test on the 10th, was recovered from the Atlantic Ocean. Photo by NASA

[Asia Economy Reporter Kim Bong-su] "Humanity's journey to Mars is ready with horses, carriages, and boots."

This is an evaluation of two recent successes by the United States National Aeronautics and Space Administration (NASA). Not only have they prepared rockets and spacecraft capable of traveling approximately six months beyond Earth's atmosphere to Mars and back, but they have also developed means for safe landing.

Artemis 1, launched on the morning of the 16th (local time) from Kennedy Space Center in Florida, USA, is akin to horses and carriages. The SLS (Space Launch System), the massive launch vehicle of Artemis 1, is the 'horse,' and the Orion spacecraft, currently heading to the Moon atop it, is the 'carriage.'

The SLS and Orion spacecraft are being developed by NASA with consideration for exploration not only of the Moon but also Mars. The SLS measures 98 meters in length and boasts the strongest thrust in human history, capable of carrying 27 tons of cargo beyond the atmosphere. The Orion spacecraft is also designed with a focus on ensuring long-term survival for two astronauts to travel to Mars and back. NASA plans to use the SLS and Orion spacecraft for manned Mars exploration scheduled for the 2030s, after further performance verification and improvements through a manned test launch in 2024 and an actual Moon landing in 2025.

[Image source=Yonhap News]

‘Boots’ to ensure the safety of astronauts traveling to Mars have also been prepared. In other words, a method to resolve the risks of landing spacecraft on Mars has been developed. Mars has a much thinner atmosphere than Earth, so existing probes and rovers weighing only 1 to 2 tons fall at a high speed of up to 19,000 km/h even when deploying parachutes. This is why the time from entering the Martian atmosphere to landing is called the "seven minutes of terror." Especially for manned spacecraft that will travel to Mars in the future, weighing at least 20 tons, special consideration is needed for safe landing. Equipping retro rockets is inefficient due to fuel and the spacecraft's own weight, considering the long distance to Mars.

This led to the development of the Inflatable Decelerator. It is attached to the bottom of the spacecraft, folded during departure, and unfolds into a flying saucer shape during landing. NASA engineers were inspired by children's ring stacking toys to develop this. It looks like a flying saucer. With a diameter of 6 meters, it maximizes the weak aerodynamic lift to slow down speed and protects the spacecraft from atmospheric friction heat. On the 10th, NASA conducted an experiment by deploying this device in low Earth orbit and then dropping it, after which it was recovered from the Atlantic Ocean to verify performance and analyze results such as damage from impact and friction heat.

The results were a great success. NASA officials said that the device looked remarkably intact from the moment of recovery, strongly indicating the experiment's success. Detailed inspections were conducted over the past week, and a tentative conclusion of "success" was reached. A NASA official explained, "(At recovery) it looked really beautiful and like new. It was so clean that words cannot describe it," adding, "We plan to conduct more detailed investigations by next year to perfectly analyze the experimental results."

Based on this experiment's results, NASA plans to manufacture an inflatable decelerator large enough to be attached to actual Mars-bound spacecraft. To safely land a spacecraft weighing about 20 tons, the size must be increased by about 3 to 4 times compared to the current model.