ShenZhou Manned Spacecraft

ShenZhou model

Summary

  • Chinese Name: ShenZhou
  • Contractor: China Academy of Space Technology (CASC 5th Academy), Shanghai Academy of Spaceflight Technology (CASC 8th Academy)
  • Type: Manned orbiter
  • Orbit: LEO
  • Launch Vehicle: CZ-2F
  • Launch Site: Jiuquan Satellite Launch Centre
  • No. of Launches: 7
  • No. of Manned Missions: 3

Design

ShenZhou (“Magic Vessel” or “Divine Vessel”) is a three-module manned spacecraft developed by China Academy of Space Technology (CAST) and Shanghai Academy of Spaceflight Technology (SAST) for PRC’s manned spaceflight programme—Project 921. The spacecraft was designed to carry up to three astronauts to fly in the low-Earth orbit (LEO).

ShenZhou comprises three modules (from front to back):

  • A forward cylindrical orbital module, with a pair of smaller solar panels attached;
  • An aerodynamic re-entry capsule;
  • An aft cylindrical service module, with a pair of larger solar panels attached;
 
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ShenZhou spacecraft being examined by engineers in the launch centre (Chinese Internet)

The spacecraft bears great similarity to the Russian Soyuz manned spacecraft. In particular, the spacecraft’s re-entry capsule and emergency escape system are believed to be direct copies of the Soyuz’s designs. The orbital module and re-entry capsule are fully pressurised and habitable living space, allowing the astronauts to take off their heavy pressure suits during the orbital flight. The spacecraft is capable of supporting up to three astronauts for a flight mission of up to a week. A control panel inside the re-entry capsule allows the crew to ‘fly’ the spacecraft independently of ground control. The spacecraft is protected during launch by a nose fairing, which is jettisoned after passing through the atmosphere.

The mission crew enters the spacecraft via the large cylindrical hatch on the orbital module, and then enters the re-entry capsule via the connecting hatch. They remain in the capsule with their pressure suits on during the launch, but can enter the orbital module to conduct various experiments during the orbital flight. When the re-entry procedure begins, the astronauts return to the re-entry capsule, put on their pressure suits, and seal the hatch to the orbital module. The capsule was then separated from the orbital and service modules. After the capsule has landed, the astronauts exit the capsule via the hatch on the top.

Orbital Module

 
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ShenZhou 7 spacecraft in the orbit, viewed from the BX-1 micro-satellite it released during the mission (Chinese Internet)

The orbital module is a Chinese indigenous design and completely differs to that of the Soyuz. The module contains a toilet as well as experiment equipments that will not be needed for re-entry. A hatch connecting it and the re-entry capsule can be closed and sealed. After the entry capsule and service module are separated for re-entry, the orbital module continues flying in the LEO (~343km) for another six months before it finally burns up in the atmosphere. During its autonomous flight, the orbital module can carry out various unattended scientific experiments.

The orbital module is also used for imagery intelligence (IMINT) role, with a 0.5m telescope camera onboard. The camera can work in one of two modes: photographic film and CCD. In the photographic film, the camera has a resolution of 1.1m. The films are retrieved from the orbital module by the astronauts, and returns to the Earth along with the astronauts inside the re-entry vehicle. Once the orbital module enters autonomous flight, the camera switched to the CCD mode, with a resolution of 1.2~1.6m.

The ShenZhou 7 spacecraft is fitted with a modified orbital module, which serves as an airlock for the extra-vehicular activity (EVA). The space-walking astronaut will leave and return to the spacecraft via the main hatch on the orbital module. Because of this, the orbital module of Shenzhou 7 lacks the pair of solar panel and the usual scientific and IMINT mission equipments.

In the future missions, orbital module will also include a Russian-style androgynous docking system at the forward end.

Re-Entry Capsule

 
Click to enlarge
Re-entry capsule of ShenZhou 6 (Chinese Internet)

The re-entry capsule in the middle is the only module protected by heat shielding to withstand the tremendous heat when entering the atmosphere. This design minimises the amount of material to be returned to earth, and therefore increases the space available to the spacecraft without increasing its weight.

ShenZhou's re-entry capsule was based on the capsule of the Soyuz. It uses the same landing technique as the Soyuz. After the capsule enters the atmosphere, the capsule deploys a single drogue, followed by a single main parachute. Just before the impact, the capsule ignite the landing rocket for soft-landing, which is another Soyuz trademark. The capsule is supposed to land upright (as shown in the Shenzhou 6 mission), but could also on side sometimes due to strong wind (as shown in the Shenzhou 4 and 5 mission).

The capsule provides Soyuz-style moulded seats for up to three crew. The astronauts control the spacecraft via a flight control panel. A Russian-style periscope provided a means of manually orienting the spacecraft for retrofire and a forward view during docking operations. Manual control of the spacecraft was via Soyuz-type hand controllers.

 
Click to enlarge
The control panel in the re-entry capsule of the Shenzhou spacecraft (Chinese Internet)

Service Module

The aft service module developed by Shanghai Academy of Spaceflight Technology (8th Space Academy) contains life support and other equipment required for the functioning of the ShenZhou. It is larger than that of the Soyuz, with adjustable solar panels to obtain maximum solar insulation regardless of the spacecraft’s flight status.

Launch Escape System

The emergency escape system of the ShenZhou spacecraft consists of the escape tower, the payload fairing, and the orbital and descent modules. The escape tower would fire to pull the ShenZhou capsule and orbital module away from the booster in the event of a major booster malfunction from 15 minutes before launch to the point of escape tower jettison at T + 120 seconds (39,000m altitude).

 
Click to enlarge
The emergency escaping system consisting of the escape tower and payload fairing (Chinese Internet)

The payload firing, which also has its own power, could also be used to pull the spacecraft capsule and orbital module away from the booster from the payload fairing jettison (T + 120 seconds) to T+200 seconds. The payload fairing is then separated from the spacecraft.

When the fault monitoring management system on CZ-2F launch vehicle senses an emergency situation, it automatically activates the launch escape system. Ground controllers could also activate the system by command if deemed necessary. On manned flights the astronauts could manually activate the system from within the capsule.

After T + 200 seconds, an abort would consist simply of booster shutdown, separation of the descent module, and an emergency re-entry leading to a recovery either on Chinese territory or off the southern coast of Japan.

Specifications

Length: 8.65m
Diameter: 2.80m
Solar Panel Span: 19.4m
Total Mass: 7,800 ~ 7,900kg

Last update: 1 March 2009

     
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