29.04.2020
HELSINKI — China rolled out a Long March 5B launcher Wednesday for a mission to prove space station launch capabilities and test a new spacecraft for deep space human spaceflight.
Images of the Long March 5B shared on Chinese social media indicated that the rollout at Wenchang Satellite Launch Center was completed early April 29.
Launch from the coastal Wenchang launch site can now be expected around May 5. However, an official announcement has not yet been made.
The primary goal of the test flight is testing the Long March 5B for launching to low Earth orbit (LEO). If successful, launch of the ‘Tianhe’ core module for China’s space station could take place as soon as early 2021.
The payload for the test launch—a prototype new-generation crewed spacecraft—will be loaded with nearly 10 tons of propellant. This will both make the spacecraft analogous to a 20-ton-plus space station module and allow the prototype to reach higher orbits and test a high-speed reentry.
The mission will resemble the 2014 Exploration Flight Test 1 of the Orion spacecraft. The new spacecraft is expected to reach an apogee of around 8,000 kilometers (4,970 miles),
The new launcher was rolled out in March for a wet dress rehearsal. Fit checks with a prototype of the roughly 22.5-metric-ton liftoff mass Tianhe core module were also conducted.
The mission had been initially planned for mid-late April. The apparent delay follows launch failures of the first Long March 7A in March and Long March 3B earlier this month. The Yuanwang-22 cargo vessel which transports Long March 5 rocket components recently made an apparently exceptional trip to Qinglan port near Wenchang.
A successful flight of the Long March 5B would clear the way for the two-month-long launch campaign for China’s 2020 Mars mission. A standard Long March 5 will be used to launch the Tianwen-1 orbiter and rover into a Mars transfer orbit from Wenchang in late July or early August.
New-generation crewed spacecraft
The as-yet-unnamed new-generation crewed spacecraft consists of a partially reusable crew module and expendable service module. It is designed to increase China’s human spaceflight capabilities, both to LEO and beyond.
The spacecraft has two variants of around 14 and 20 metric tons respectively. The mission will test the latter, which is designed for deep space. The mission will be uncrewed and will not include life support systems.
The spacecraft will be able to carry up to six astronauts, or three astronauts and 500 kilograms of cargo to LEO. The three-module Shenzhou can carry three astronauts to LEO and has been used for all six of the country’s crewed missions.
The new spacecraft also features improved heat shielding than that used by the Shenzhou. The advanced shielding is required to survive the higher-energy reentries involved deep space missions.
Once in low Earth orbit, the two-module, 8.8-meter-long, 21.6-ton uncrewed spacecraft will use its own propulsion to raise its orbit to an apogee of around 8,000 kilometers. It will then attempt a high-speed reentry to test new heat shielding.
The mission also will test avionics, performance in orbit, parachute deployment, a cushioned airbag landing, and recovery. Planned partial reusability — by replacing the heat shielding — will also be tested.
Long March 5B
The 53.7-meter-long Long March 5B has a takeoff mass of 837.5 metric tons. The payload capacity is greater than 22 metric tons to LEO, according to the China Academy of Launch Vehicle Technology (CALT), the launcher’s designer.
It is a variant of the standard Long March 5, which had an inaugural flight in late 2016. The The Long March 5B lacks the second stage of the former. The payload fairing measures 20.5 meters in length with a diameter of 5.2 meters.
The Long March 5B is part of a new generation of Chinese launch vehicles. The Long March 5, 6 and 7 variants use combinations of liquid hydrogen or kerosene fuel with liquid oxygen. These could eventually replace the older, hypergolic Long March launchers.
The 5-meter-diameter core stage is powered by two YF-77 hydrolox engines. Each of four 3.35-meter-diameter side boosters are powered by a pair YF-100 kerolox engines. A YF-77 turbopump issue was behind the failure of the second Long March 5 in 2017. That failure delayed the test launch of the 5B and the Chang’e-5 lunar sample mission.
The test launch is the first of numerous launches required for China’s three-module space station.
“China has planned about 12 flight missions for the construction of China’s space station. The first flight mission of [the] Long March-5B rocket is also to verify its performance,” Hao Chun, director of the China Manned Space Engineering Office, told state media in January.
Launches of modules, Tianzhou cargo and refueling craft and crewed Shenzhou missions make up the flight list.
Watch live: China to debut new version of powerful Long March 5 rocket Tuesday
Video credit: CCTV
A prototype for China’s next-generation human-rated spacecraft — flying on a test flight without astronauts — is scheduled to ride a new version of the country’s heavy-lift Long March 5 rocket into orbit this week.
The Long March 5B rocket could take off as soon as Tuesday from the Wenchang Satellite Launch Center on Hainan Island in southern China, but Chinese officials have not officially announced the target launch date.
Riding a mobile launch platform, the heavy-duty rocket rolled to its launch pad at Wenchang on April 29 for final preparations before liftoff, according to reports and images from the launch site shared on social media. Once at the launch complex on Hainan Island’s eastern coast, the Long March 5B was enclosed inside folding gantry structures inside a 300-foot-tall (92-meter) launch pad tower to give technicians access to the vehicle for final testing and inspections.
The 176-foot-tall (53.7-meter) Long March 5B rocket is a new version of the Long March 5 launcher, China’s most powerful rocket. Designed to loft massive payloads into low Earth orbit, the Long March 5B rocket will launch without a second stage.
The launcher’s lift capability to low Earth orbit is around 48,500 pounds, or 22 metric tons, according to Chinese state media. It’s tailored to launch large modules for China’s planned space station.
The Long March 5B’s four liquid-fueled boosters, each powered by two kerosene-fed YF-100 engines, will power the rocket off the launch pad along with two YF-77 core stage engines burning cryogenic liquid hydrogen. The rocket will jettison the four booster modules around three minutes after liftoff, and the core stage engines will burn for approximately eight minutes.
The Long March 5B rocket will also debut a new large payload fairing measuring more than 67 feet (20.5 meters) long and 17 feet (5.2 meters) in diameter. The payload launching inside the Long March 5B’s new nose shroud is a prototype for China’s next-generation crew capsule, designed to eventually replace the country’s Shenzhou spacecraft to ferry astronauts to a space station in Earth orbit.
The new capsule design is more capable than the Shenzhou, according to Chinese officials. It will be capable of carrying astronauts to the moon, and can accommodate up to six crew members at a time, more than the three astronauts that can fly on the Shenzhou, Chinese officials said.
In a different configuration, the crew capsule could launch and land with three astronauts, plus up to 1,100 pounds (500 kilograms) of cargo, according to China’s state-run Xinhua news agency. The capability will allow China to return research specimens and hardware from the country’s space station back to Earth.
The Shenzhou crew craft can return only a limited amount of cargo, and China’s Tianzhou supply ship for the country’s planned space station is not designed to bring any cargo back to Earth.
China’s next-generation crew carrier is also reusable for up to 10 flights, with a detachable heat shield built to handle higher-temperature returns through Earth’s atmosphere, such as those a capsule would encounter on a re-entry from a lunar mission.
The short-duration orbital test flight this week is expected to conclude with a re-entry and landing in remote northwestern China, perhaps as soon as one day after its launch on the Long March 5B rocket. Few details about the test flight have been released by the Chinese government.
The Xinhua news agency reported the primary purpose of the crew capsule test flight is to verify the ship’s re-entry technologies, such as its heat shield and recovery system. The capsule will return under parachutes and inflate airbags to cushion its landing on solid ground.
The Shenzhou landing module also returns under parachutes, but uses rocket thrusters to soften the blow of landing. That makes for a rougher ride for passengers.
With its propulsion and power module, the crew spacecraft measures nearly 29 feet (8.8 meters) long. It will weigh around 47,600 pounds (21.6 metric tons) fully loaded with equipment and propellant, according to the China Manned Space Engineering Office, or CMSEO.
Chinese officials said earlier this year that the crew capsule on the Long March 5B test flight will be loaded with 10 metric tons (22,000 pounds) of propellant, enabling extensive maneuvers in orbit. The fuel load will also match the spacecraft’s weight to the expected launch weight of the Tianhe core module for China’s space station, which is scheduled to be completed in 2022.
China launched a reduced-scale crew module on an unpiloted test flight in 2016.
Teams at the Wenchang launch base prepared the Long March 5B rocket and the prototype crew capsule for flight amid the coronavirus pandemic. Chinese state media said managers reduced staffing levels at the spaceport, and introduced telecommuting capabilities to allow some team members to participate in data reviews and meetings remotely.
China has conducted six space missions with astronauts since 2003. The most recent Shenzhou mission ended in November 2016 after a 32-day flight to the Chinese Tiangong 2 space lab with a two-man crew.
Plans to launch China’s first Mars rover later this year could depend on the success of this week’s Long March 5B launch. A Long March 5 rocket — in its previous configuration with an upper stage — is scheduled to launch the robotic Mars mission in July.
Chinese officials last month announced the Mars mission will be named Tianwen 1. Tianwen, or Questions to Heaven, is a poem written by the ancient Chinese poet Qu Yuan. The China National Space Administration — China’s space agency — said all of the country’s future planetary exploration missions will be named the Tianwen series.
Another Long March 5 rocket is scheduled to haul China’s Chang’e 5 robotic lunar mission into space later this year. Chang’e 5 will attempt to retrieve samples from the moon’s surface and return them to Earth.
Quelle: SN
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Update:
China to launch Long March-5B carrier rocket
WENCHANG, Hainan, May 5 (Xinhua) -- China's new large carrier rocket Long March-5B will make its maiden flight at 6:00 p.m. (Beijing Time) Tuesday, according to the China Manned Space Agency. Enditem
Quelle: Xinhua
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Update: 6.5.2020
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Long March-5B launch
