Apollo 13 mission阿波罗十三号

the circumlunar （revolving about or surrounding the moon） ） "free return" option, using the Moon's gravity to return the ship to Earth
CSM
Lunar Module The Apollo Lunar Module (LM) was the lander portion of the Apollo spacecraft built for the US Apollo program to carry a crew of two from lunar orbit to the surface and back. Six such craft successfully landed on the Moon between 1969–1972. The LM, consisting of an Ascent stage and Descent stage, was ferried to lunar orbit by its companion Command/Service Module (CSM), a separate spacecraft of approximately twice its mass, which took the astronauts home to Earth. After completing its mission, the LM was discarded. At launch, the Lunar Module sat directly beneath the Command/Service Module (CSM) with legs folded, inside the Spacecraft-to-LM Adapter (SLA) attached to the Saturn V rocket. There it remained through earth parking orbit and the Trans Lunar Injection (TLI) rocket burn to send the craft toward the Moon. Soon after TLI, the SLA opened and the CSM separated, turned around, came back to dock with the Lunar Module, and extracted it from the S-IVB. During the flight to the Moon, the docking hatches were opened and the LM Pilot entered the LM to temporarily power up and test its systems (except for propulsion). Throughout the flight, he performed the role of an engineering officer, responsible for monitoring the systems of both spacecraft.
Pictures from: Chicago Astronomer Forum
----Picture from Kennedy Space Center.
Service module
----A service module (or equipment module) is a spacecraft compartment containing a variety of support systems used for spacecraft operations. Usually located in the uninhabited area of the spacecraft, the service module is jettisoned (dumped) upon the completion of the mission, and usually burns up during atmospheric reentry. The Service Module was an unpressurized cylindrical structure, measuring 24 feet 7 inches (7.5 m) long and 12 feet 10 inches (3.9 m) in diameter. The interior was a simple structure consisting of a central tunnel section 44 inches (1.1 m) in diameter, surrounded by six pie-shaped sectors. The sectors were topped by a forward bulkhead(隔壁) and fairing(整流片), separated by six radial beams, covered on the outside by four honeycomb panels, and supported by an aft bulkhead and engine heat shield. The sectors were not all equal 60° angles, but varied according to required size.
After achieving a lunar parking orbit, the Commander and LM Pilot entered and powered up the LM, replaced the hatches and docking equipment, unfolded and locked its landing legs, and separated from the CSM, flying independently. After inspection of the landing gear by the Command Module Pilot, the LM was withdrawn to a safe distance, then the descent engine was pointed forward into the direction of travel to perform the 30 second Descent Orbit Insertion burn to reduce speed and drop the LM‘s perilune (近 月点) to within approximately 50,000 feet (15 km) of the surface
-------- National Space Science Data Center
A Trans Lunar Injection (TLI) is a propulsive maneuver (推动策略) used to set a spacecraft on a trajectory (轨道) which will arrive at the Moon.
CM SM LM (LEM)
The Command Module
---- A command module is a truncated cone (frustum) measuring 10 feet 7 inches (3.2 m) tall and having a diameter of 12 feet 10 inches (3.9 m) across the base. The forward compartment contained two reaction control engines, the docking(接合) tunnel, and the components of the Earth Landing System. The inner pressure vessel housed the crew accommodations, equipment bays, controls and displays, and many spacecraft systems. The last section, the aft compartment, contained 10 reaction control engines and their related propellant(推进) tanks, fresh water tanks, and the CSM umbilical(connection) cables.
MISSION
Apollo 13 was the seventh manned mission in the American Apollo space program and the third intended to land on the Moon. The Apollo 13 mission was to explore the Fra Mauro formation, or Fra Mauro highlands, named after the 80-kilometer-diameter Fra Mauro crater located within it. It is a widespread, hilly selenological area thought to be composed of ejecta from the impact that formed Mare Imbrium. The next Apollo mission, Apollo 14, eventually made a successful flight to Fra Mauro.
The Apollo 13 malfunction was caused by an explosion and rupture (to break open; burst) of oxygen tank no. 2 in the service module. The explosion ruptured a line or damaged a valve (阀) in the no. 1 oxygen tank, causing it to lose oxygen rapidly. The service module bΒιβλιοθήκη Baiduy no.4 cover was blown off. All oxygen stores were lost within about 3 hours, along with loss of water, electrical power, and use of the propulsion system.
From NASA gov.
A Trans Lunar Injection (TLI) is a propulsive maneuver (推动策略) used to set a spacecraft on a trajectory (轨道) which will arrive at the Moon.
selenological: The astronomical study of the moon. eiecta: ejected matter, as that from an erupting volcano.
------Dr. David R. Williams NASA Goddard Space Flight Center