The Crew Dragon spacecraft, manufactured by the private company SpaceX, is scheduled to return from the International Space Station (ISS) and fly into the Atlantic Ocean on August 2. If dependent on favorable weather forecasts and a successful last week at the ISS, NASA. astronauts Robert Behnken and Douglas Hurley will begin the dismantling process on August 1 and re-enter the Earth’s atmosphere the next day, a total of 64 days after takeoff.
The historic start took place on May 30th. From NASA’s Kennedy Space Center in Florida. It was the first time a commercial space company had taken humans into orbit around the Earth. While the launch was a nail-biting watch, the return will be even more risky ̵1; provide a tense moment of mission control. SpaceX founder Elonas Muskas said the return was indeed his “biggest concern”.
The joint mission of SpaceX and NASA was successful in merging the ISS to allow astronauts to carry out scientific and surveillance work, including four space orbits.
Importantly, the main purpose of the mission is to test and demonstrate the vehicle’s ability to safely transport crew to and from Earth’s orbit as a first step in planning the launch of regular ISS missions and commercial space flights.
Return danger points
The extreme speed and temperature a vehicle has to endure is a major challenge for engineers and makes a return to the most dangerous part of the mission.
The danger begins with finding the right angle of trajectory when the spacecraft enters the upper atmosphere. If it is too stiff, astronauts will experience potentially lethal g-forces, and friction with air friction can cause the spacecraft to explode. If the capsule is too shallow, the capsule catastrophically escapes the atmosphere and returns to Earth orbit.
The spacecraft will enter the upper atmosphere at a speed of 27,000 km / h. This is 7.5 km / s, or more than 20 times the speed of sound. Whichever unit you prefer is fast. At this speed, a very strong shock wave is generated around the front of the vehicle, compressing and superheating the air. Managing a huge heat load is a huge engineering challenge.
Extremely, the temperature of the air in the shock layer exceeds 7000 ° C. By comparison, the surface temperature of the Sun is about 5500 ° C. As a result, the heat shield of a vehicle becomes so hot that it starts to glow – a process called heat. The new and improved SpaceX PICA-X material heat shield was able to protect the capsule during test flights, later recovering from a severe burn.
Air molecules around a vehicle are also broken down into positively charged atoms and free electrons – called plasma. When some molecules recombine, the excess energy is released as photons (light particles) – the air around the vehicle gives the amber a glow.
This layer of plasma can be nice, but it can cause a radio receiver. When an electron passes through a conductive wire, we have electricity. Similarly, when free electrons move through the plasma around a vehicle, we have an electric field. If the electric field becomes too strong, it can reflect and attenuate radio waves trying to reach the spacecraft.
Not only does detection lose contact with the ship’s crew and flight data, but it can also make remote control and management impossible. The Apollo missions, the Mars Pathfinder, and the recently collapsed 2018 Soyuz rocket launched all communications eclipses in minutes. The NASA mission board expects a nervous six-minute eclipse during the Crew Dragon’s return-heating phase – if anything happens in the meantime, it’s in the hands of the astronauts.
The next risky stage is parachuting. The crew dragon will deploy four parachutes in the final stage of the return, as the vehicle lands towards a gentle splash in the Atlantic Ocean off the coast of Florida. This maneuver was tested by SpaceX 27 times before next week’s crew landing, so it should work.
A successful landing will have a major impact on reducing the cost of space exploration through the use of reusable missiles and enabling private space exploration. With SpaceX producing the Crew Dragon vehicle under contract to NASA, the company is free to use the spacecraft for commercial flights without NASA’s involvement, subject to an operating license.
SpaceX is partnering with commercial airline Axiom Space, whose main goal is to build the world’s first commercial space station. The station’s proposed commercial activities are wide: from space exploration and production in space to support for space exploration.
Then there is space tourism. Private citizens are already lining up for their space ticket and will not wait long after the successful appearance of Crew Dragon. American space tourism company Space Adventures (in collaboration with SpaceX) until 2021. The end plans to offer zero-gravity atmospheric flights, space-travel orbital flights, and lunar orbits.
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It is debatable whether space tourism is justified by the costs, environmental impacts and risks of space travel. As these articles show, the safety briefing required for Space Adventure ticket holders will be much more comprehensive than usual, “please take a moment to read the safety card in the seat pocket in front of you.”