VOA科学技术2024--SpaceX Mission to Include First Spacewalk for Private Citizens

（单词翻译）

A private space mission will seek to launch non-astronauts to a high orbit and include the first private spacewalks in history.

The American space company SpaceX's flight is cleared to launch from Florida's Kennedy Space Center beginning September 7. The American space agency NASA operates the center. The exact launch date will depend on weather conditions.

American businessman Jared Isaacman organized and paid for the mission, called Polaris Dawn. He and three people will crew the mission. Isaacman is the head of payment processing company Shift4Payments. He has an estimated personal worth of $2 billion. But he has not said publicly how much he paid SpaceX for the Polaris Dawn mission.

The crewmembers will travel in SpaceX's Crew Dragon spacecraft on a SpaceX Falcon¹ 9 rocket. The company expects the spacecraft to reach an altitude of about 1,400 kilometers. That would be the highest any crewed mission has reached since NASA's Apollo program ended in the early 1970s.

Isaacman is the mission commander for Polaris Dawn. Also taking part in the flight will be Scott Poteet, a retired² U.S. Air Force Colonel and two SpaceX employees, Sarah Gillis and Anna Menon. Gillis is a mission specialist at SpaceX, while Menon is a lead space operations engineer. The crew is expected to spend five days in orbit.

Polaris Dawn will reach its highest altitude on its first day. The Crew Dragon will briefly³ enter the Van Allen radiation belt, an area filled with high-energy charged particles that can present health risks to humans over extended periods.

This will provide a chance to test the effectiveness of SpaceX's newly designed spacesuits. SpaceX says the clothing is equipped with data instruments, cameras and improved mobility⁴ systems. SpaceX says tests of the spacesuit will help the company design and develop future space missions to the moon and Mars.

A statement by SpaceX said one main goal of Polaris Dawn will be to carry out research "with the aim of better understanding the effects of spaceflight and space radiation on human health."

Speaking about the mission's risks, Isaacman told reporters, "Whatever risk is associated with it, it is worth it." He added, "We have no idea what it could do to really change the trajectory⁵ of humankind ... there has to be some first steps in this direction."

The crew will orbit nearly three times higher than the International Space Station (ISS). But this is far short of the record-breaking distance of over 399,117 kilometers set by NASA's Apollo 13 crew in 1970.

Isaacman is expected to guide the other crew members on the mission's planned spacewalk on day three of the mission. Each member is expected to spend about 20 minutes in space.

So far, only government astronauts from the U.S., former Soviet⁶ Union and Russia, the European Space Agency, Canada and China have carried out spacewalks. More than 270 spacewalks, using American and Russian spacesuits, have been carried out from the ISS since its launch in 2000, Reuters news agency reports.

The next day will be spent testing laser-based satellite communication between the spacecraft and Starlink, SpaceX's internet satellite system. The laser method - which has also been tested by NASA - is designed to greatly increase space communication speeds.

The crew also plans to carry out 40 experiments aimed at improving our understanding of human health during long space missions. Among these will be tests with special contact lenses containing microelectronics that can continuously identify changes in eye pressure and shape.

At the end of the mission, Crew Dragon will aim for a parachute landing off the coast of Florida. A SpaceX recovery ship will be waiting for the crew's arrival.

Polaris Dawn is the first of three planned missions under the Polaris program. The second Polaris mission will also use a Dragon capsule, while the third and final is expected to use SpaxeX's Starship rocket. SpaceX chief Elon Musk⁷ has said his company plans to use Starship to carry future space travelers to the moon and Mars.

Words in This Story

mission - n. an important project or trip, especially involving space travel

mobility - n. the ability to walk and move freely

associate - v. to connect someone or something in your mind with someone or something else

trajectory - n. the curved path an object follows after it has been thrown or shot into the air