China’s Tianzhou-1 cargo ship readied for launch toward Tiangong-2
Crucial to China’s goal of sustaining and resupplying its own space stations, a Long March 7 rocket has been rolled out to the launch pad at the Wenchang Satellite Launch Center (WSLC) with the Tianzhou-1 cargo spacecraft encapsulated in its payload fairing.
Although no definite window has been announced, reports indicate April 20–24, 2017, as the likeliest launch dates. Spaceflight Now lists the launch occurring as early as 7:40 a.m. EDT (11:40 GMT) April 20.
Fresh on the heels of last week’s successful launch of the ChinaSat-16 communications satellite, China appears to be in the home stretch of what could arguably be one of their more important missions to date: launching a spacecraft capable of docking with its Tiangong-2 space station and transferring propellants to the orbiting outpost.
Tiangong-2 was launched on Sept. 15, 2016, from China’s Jiuquan satellite launch center. A month later, the two-person Shenzhou-11 docked with the outpost for a month-long stay aboard the one-room laboratory. The station has remained unoccupied since.
In order to maintain a crewed space station, it’s just as important to be able to deliver supplies – food, fuel, consumables, spare parts – as it is to get people on board. China is hoping to master this process before fielding a permanently crewed presence in space.
To this end, the China Academy of Space Technology (CAST) was contracted to design and build the Tianzhou series of cargo resupply spacecraft. Meaning “Heavenly Vessel” in Chinese, the cargo ship will be capable of delivering about 13,000 pounds (6,000 kilograms) of cargo to its Tiangong space stations.
Tianzhou-1 will reportedly dock with Tiangong-2 multiple times throughout the course of its mission, transferring fuel each time, to demonstrate the spacecraft’s capability to perform the automated transfer tasks.
Long March 7 for the ride to space
China has tapped its Long March 7 – also known as the Chang Zheng 7 (CZ-7) – medium-class rocket to deliver Tianzhou-1 to orbit.
The first stage consists of a core with two YF-100 engines, which is surrounded by four strap-on boosters – each with a single YF-100. At liftoff, the six engines produce a combined 1.6 million pounds-force (7,200 kilonewtons) of sea-level thrust.
The four boosters operate for approximately three minutes before being jettisoned, followed shortly by the first stage.
The second stage is outfitted with four YF-115 engines, each producing about 40,470 pounds-force (180 kilonewtons) of vacuum thrust. Like its first stage and booster counterparts, the YF-115 burns a mixture of highly refined kerosene and liquid oxygen propellant.
The two-stage vehicle is relatively new to the Chinese launch fleet, having taken its maiden flight on June 25, 2016. That first launch saw the test of a next-generation crewed capsule as well as the inaugural launch from the WSLC.
Video courtesy of CGTN
Curt Godwin has been a fan of space exploration for as long as he can remember, keeping his eyes to the skies from an early age. Initially majoring in Nuclear Engineering, Curt later decided that computers would be a more interesting - and safer - career field. He's worked in education technology for more than 20 years, and has been published in industry and peer journals, and is a respected authority on wireless network engineering. Throughout this period of his life, he maintained his love for all things space and has written about his experiences at a variety of NASA events, both on his personal blog and as a freelance media representative.