Arm & Glove Assembly
At the end of the Arm Assembly is added Glove Assembly. It covers the astronaut's wrists, fingers, etc. and protects it from external injuries. Here rotary bearings are used to facilitate the rotation of the wrist on the wrist part. A hot pad attached to the inside of the assembly protects the astronaut's hand from excessive heat and cold. The astronaut also has a 'finger tip heater' that controls the temperature of the fingers.
Lower Torso Assembly (LTA)
The whole part of the spacesuit below the HUT is collectively called the LTA.
The lower LTA and the upper HUT of the spacesuit are connected to each other by the Body Seal Closer part. In addition, due to the Waist Bearing of the LAT and the flexible part of the foot, the astronaut can move the waist and legs well. Finally, special boots are attached to it.
Portable Life Support System (PLSS)
A complete system is in the ‘backpack’, which is attached to the rear of the spacesuit’s HUT to provide the necessary oxygen inside the spacesuit and to prepare the environment necessary for the astronauts to survive in space or on alien soil. This system as a whole is called PLSS.
EMU's PLSS Backpack is 28 "× 20.5" × 10.5 "in size. It weighs 104 pounds with the whole system. The PLSS is powered by a 16.6-volt silver-zinc battery.
PLSS consists of five subsystems.
Primary oxygen supply
Oxygen ventilating circuit
Water transport loop
Feed water loop
Space suit communication system
The control of each of these subsystems is connected to the DCM attached to the chest of the HUT by means of a Remote Control Unit (RCU). Through this you can control the astronaut systems.
Primary Oxygen Supply
The 18 ”long and 6” diameter cylinder contains about 1.5 pounds of oxygen gas at a pressure of 1380-1440 PSI which provides oxygen to the astronauts. From here oxygen flows inside the spacesuit and helmet and maintains a pressure of 3.9 PSI there, which creates a comfortable environment for the astronauts.
Oxygen ventilating circuit
In this system, 5.5 cubic feet of oxygen flows from the primary oxygen supply system inside the spacesuit per minute. In order to keep the astronaut's breathing effective, this flowing oxygen is refined inside the system with moisture, heat and carbon dioxide from inside the suite and flows back into the spacesuit. It is also a part of the spacesuit's ventilation system.
Water Transport Loop
This part controls the flow of water through the LCVG of the spacesuit. A battery-powered pump carries 4 pounds of cold water per minute through LCVG's tube network. This removes the metabolic heat generated in the astronaut's body, leaving the astronaut's body cool. It is capable of removing 1600-2000 Btu of heat per hour.
Feed Water Loop
This is another part of thermal management. A total of 11.6 pounds of water is contained in the rubber bladder and reservoir tank, which helps maintain thermal normality while being connected to the spacesuit's internal heat exhaust system.
Space suit communication system
The PLSS integrates the astronauts' interpersonal communication and overall communication with the Earth. It is mainly a specialized radio signal transmission and receiving system.
This communication system collects data from the conversations of the astronauts, their physical condition, the effective state of the internal management of the spacesuit, performance, etc. and sends it to the control center of the spacecraft and the earth. Another important function of the system is to control the oxygen supply rate, temperature and pressure of the spacesuit, the voltage and current in the sensors and electrical parts connected to the measuring instruments and other places. This information is exchanged on ten separate channels.
A part of the communication system warns the astronaut to take necessary action by conveying that information to the indicator of the DCM part fitted to the HUT of the spacesuit in case of high oxygen supply rate, low pressure, cooling and any instability of the ventilation system.
In addition to the five core systems mentioned above, two additional backup systems are connected to PLSS. These additional measures are placed in two spacesuits to save the life of the astronaut in case of emergency due to mechanical disturbances or environmental reasons. E.g.
Oxygen Purge System (OPS)
Buddy Secondary Life Support System (BSLSS)
Oxygen Purge System (OPS)
Attached to the PLSS is a relatively small 18 ”× 10” × ৮ ”35.1 pound safety backup oxygen supply system. Here 5.7 pounds of oxygen is stored at 6950 PSI for emergency use. A separate battery keeps the system running.
If the original PLSS does not work due to an accident or mechanical malfunction, the oxygen supply drops at an alarming rate, or the pressure inside the spacesuit decreases, the astronaut can activate the system with a lever attached to its DCM part When this system is activated, it is able to stay active for 30 minutes. This arrangement maintains a pressure of 3.7 PSI inside the spacesuit for 30 minutes and delivers 6.3 pounds of oxygen per hour. At the same time, the system keeps the astronaut's breathing normal, controls the internal temperature, removes carbon dioxide and keeps the visceral part of the helmet clean and transparent.
Safety Emergency Extra Second Measures If this system is activated simultaneously with BSLSS, it operates at half its capacity and is able to save the astronaut from being in operation for about 75 minutes.
Buddy Secondary Life Support System (BSLSS)
If for some reason the astronaut's body temperature cooling system does not work or there is a problem, another astronaut's PLSS backpack provides cooling water to the astronaut's backpack to keep his cooling system running.
Cooling water flows through one of the two flexible pipes 8.5 feet long from the spacesuit, the cooling system flows through the cooling system of the useless astronaut and back through the other flexible pipe keeps the flow active so that the body temperature of the astronaut remains normal. In this case, the astronauts' spacesuit is attached with a 6-foot-long shackle so that the two BSLSS pipes do not go to the maximum distance and become disconnected.
Thank you.
I need me a space suit for temperature moderation. The temperature here is really radical so it would be nice to live on a constant temp like what that space suit has?