Hello and welcome to PointOrview. China today added another chapter in its ambitious space
station mission. Today it successfully launched a Tiannzhou-3 cargo spacecraft from the new coastal
Wenchang center on the southern island of Hainan.
Tianzhou-3 was launched atop a Long March 7 carrier rocket,
carrying the 2nd resupply mission for the Tiangong 3 Space Station.
It was the 3rd launch of a Tianzhou spacecraft and the 6th mission of a Long March 7 rocket.
This was China’s 34th orbital launch of the year. Overall, this is the 4th China
space station mission & will deliver supplies for Shenzhou-13 crew that is due to launch in October.
There are a total of 11 launches needed for the construction phase
of the China’s Space Station (CSS), Tiangong. The Tianzhou 3 mission will supply the Tianhe
core module with enough propellant to maintain its orbital altitude. The
spacecraft is expected to dock with the Space Station within 24 hours of launch.
The Tianzhou (which means “heavenly boat”) is an automated cargo spacecraft that will function
as the main resupply vehicle for the Tiangong Space Station.
The first Tianzhou spacecraft, Tianzhou 1, launched on a Long
March 7 rocket from Wenchang in April 2017. This spacecraft is 10.6 meters long and has a
diameter of 3.35 meters. It consists of two main parts: a cargo cabin and a propulsion section.
The Tiangong Space Station (which means “heavenly palace”) is a space station
currently under construction in Low Earth Orbit. When complete, the station will be
roughly one-fifth the mass of the International Space Station. The Tiangong Space Station
will operate in orbit for at least ten years. Its construction began on April 29, 2021, when the
core module, the Tianhe (meaning “harmony of the heavens”), was launched on a Long March 5B rocket.
The Tianhe core module is able to accommodate three crew members
with a built-in life support system. It is 16.6 m long and has a diameter of 4.2 m.
This module can also provide propulsion to maintain the orbital altitude of the station.
Later, it will be joined by the two other modules, Mengtian and Wentian that will host
Chinese and international science experiments. China aims to construct the three-module space
station with 11 launches across 2021-2022. Once completed, it will include three module launches,
four cargo spacecraft, and four crewed missions. While the station will comprise three modules, it
will have the ability to expand to six, and it is expected to be operational for at least ten years.
The first crewed flight to the station took place on June 17, 2021.
The three astronauts from that mission have already returned home on September 17, 2021.
The Long March 7 is a three-stage medium-lift launch vehicle, capable of placing a
13,500 kg payload into low earth orbit (LEO), or a 7,000 kg payload
into geostationary transfer orbit (GTO). The standard version of the Long March 7 can
be upgraded by adding more boosters, allowing it to be capable of reaching higher orbits
or executing multiple orbital deployments. The rocket has been upgraded for the
Tianzhou-3 mission. For example, its water- and moisture-proof function was improved to ensure a
smooth launch in unfavourable weather conditions. The center core of the Long March 7 can be
supported by either 2 or 4 boosters, which use refined kerosene and liquid oxygen propellant.
The boosters are powered by an oxidizer-rich staged combustion YF-100 engine. At sea level,
each booster provides 1,200 kN of thrust. The center core of the rocket is 3.35
meters in diameter and has two YF-100 engines. Like the boosters,
this first stage uses refined kerosene and liquid oxygen. At sea level, this stage produces 2,400 kN
of thrust, increasing to 2,860 kN in a vacuum. Like the first stage, the second stage is also
3.35 meters in diameter and uses refined kerosene and liquid oxygen. This stage is powered by
four oxidizer-rich staged combustion YF-115 engines, two of which are fixed and two of
which can gimble. The second stage offers 706 kN of thrust in a vacuum.
Here’s wishing the mission success and smooth docking with Tianhe.
That’s a wrap. Thanks for watching.