In this part we will continue with the description of the structure of the station and the spaceships that launch the crews to it
For the first part of the series
The air barrier compartment
The air barrier cell is the nerve center of the space lab. This is the link between the laboratory and the attachment dock and it carries the mechanism of the telescope. In the chamber, the gases are stored to create the environmental conditions and it is the basis for the supervision of the electric power and its distribution to the laboratory and the chamber itself, temperature maintenance, instrumentation, data management, an internal communication system, a command system and the supply of the experimental facilities, a warning system and a system for breaking circuits.
The cell is at the front end of the lab and is rigidly attached to the attachment dock. It is 5.3 meters long and is made of four parts. Its weight is 22.226 tons and its volume is 17.4 cubic meters. The diameter of the cell at the point of connection to the laboratory is 1.6 meters and at the point of connection to the attachment dock is 3 meters. The wide part is adjusted and completes the attachment platform.
Parts of the cell:
- 1. The transit chamber - connected to the platform, stores most of the laboratory's control systems, it is made of aluminum and has 4 portholes made of double glass like in the Gemini spacecraft, but different from them in size and shape. The windows are at a distance of 90 degrees from each other, each porthole has a sliding outer cover that is operated from the inside and its function is to protect it from meteorite impacts and prevent heat loss.
- 2. Rigid channel - made of an aluminum tube with a diameter of 1.6 meters and a length of 3.89 meters. to the channel an exit compartment for extra-rail activity. The cabin volume is 4.33 mXNUMX and can accommodate two astronauts in space suits. In the cabin there is a valve for various supplies, a case for holding containers, tape recorders and other equipment.
- 3. Flexible channel - connects the air barrier chamber to the laboratory dome. It is made of aluminum in the shape of a flexible bellows with a length of 33 cm and an internal diameter of 1.07 meters. Its flexibility is sufficient to withstand (tolerance) the movement between the barrier cell and the laboratory. A fiberglass sheath inside the blower protects it from damage while moving equipment and passing through it.
- 4. Carrier complex - 4 carrier complexes made of aluminum tubes located around the cell at an angle of 90 degrees between them and connecting the cell to its hard cladding. In addition to carrying the barrier cell, the trusses also support battery cells - two cases of 8 batteries of the solar racks and the nitrogen and oxygen tanks. There are 6 oxygen tanks here, each 2.28 meters long and 1.14 meters in diameter. and six spherical nitrogen tanks (made of titanium) with a diameter of 1.02 meters. The trusses are intended for the capture of several experimental devices that must be in space conditions.
There are three parts attached to the barrier cell and they are:
- Fixed Cover - This cover carries the barrier chamber, the telescope and the attachment platform during launch. The cover remains attached to the laboratory after the injection of the compact charge and is a supporting structure for the oxygen tanks.
- Cooler - cools the laboratory and protects the barrier chamber and the attachment dock from meteorites.
- The telescope mounting system.
The attachment dock
The dock allows the attachment of Apollo spacecraft to the laboratory and serves as a place to perform some experiments, stores the control panel for the base of the telescope and the terrestrial research instruments. The length of the platform is 5.2 meters, its diameter is 3 meters, its weight is 6.26 tons and its volume is 32.2 m2. The platform has 36.8 attachment openings. One is installed at the front end of the cylindrical structure and the other at its side. The cell has only one window and it is used by the multi-spectral camera. The length of the window is 28.8 cm, its width is 2.56 cm and its thickness is 7.5 cm. The coolers of the environmental control system of the air barrier chamber that serve the entire laboratory are attached to the outer wall. The meteoroid shield was deployed at a distance of XNUMX cm from the side of the platform. The observations towards the sun are made by the astronauts while on the dock, so this part is also very important in the current work done in the space laboratory. Four boxes of film are stored at the dock. After using them, they are put in boxes until they are returned to Israel.
The attachment dock is similar to a submarine passageway and its function is to maintain the air pressure in the laboratory while the astronauts exit or enter it. The compartment has two openings. One faces outside and the other inside the lab. When an astronaut enters from the outside, he locks this door behind him and only then opens the laboratory door. In this way the pressure in the laboratory is maintained. Upon docking, the porthole between the nose of the spacecraft and the docking chamber is opened to equalize pressures. At the end of the process, the astronauts can move in a two-way direction between the laboratory and the spacecraft in person.
the telescope
The telescope is a system with a total length of 4.4 meters, a diameter of 3.3 meters and a weight of 11.18 tons. The system has 2 parts: the telescope system and the base on which they rest. The base includes a 2.1 meter long instrument compartment. A crossed and vertical internal structure 3.05 meters long divides it into four equal parts. The telescopes are placed on this structure. This system is cooled by a cold liquid that flows near the wall and maintains a temperature of 10 degrees. Around the base there are 100 "black boxes" whose temperature is also controlled and they prevent the heating of the base. The supervision of the system is automatic and can also be supervised manually from the control panel.
There are 8 doors on the shield of the telescopes, 6 are locked on the objective lenses of the telescopes when not in use and two are openings for the compartments where the photographic films are. Another film chamber is in a lower part of the telescope. The instrument compartment can be tilted by 25 square arc/second in any direction and also rotated in any direction by 120 degrees. The telescope is adjusted by three biaxial gyroscopes - three round rings weighing 181 kg each, with each ring generating an angular momentum of 966 kg/second. They have a roll of 0.56 meters and rotate on their axis at a speed of 8000 rpm.
The accuracy of the gyroscopes is 2.5 arc/second for 15 minutes. To monitor the condition of the lab, the sensing devices include coarse sun sensors and sensing rings. Accurate measurements of the position of the instrument compartment are completed by a closed loop with a rotary torque that actuates a compass pendant. All this under the supervision of solar sensing devices and delicate sensing rings. Power is supplied to the telescope by four solar racks and batteries charged by them. The shelves can produce 10.48 kilowatts and are divided into 18 accumulators of 20 ampere/hour. Each collector is 13.2 meters long and 2.7 meters wide. The solar cells are of two different sizes.
The spacecraft to launch the crews
The spacecraft to launch the crews to man the space laboratory is an improved Apollo spacecraft adapted to the Skylab program. An additional fuel tank weighing 680 kg was added to the spaceship. To increase the maneuverability of the spacecraft, the sensitivity of the heat regulators in the spacecraft was increased. Most of the time one side of the spacecraft is exposed to the heat of the sun and the other side is exposed to intense cold. The role of the regulators on the side exposed to the sun is to lower the temperature and on the other side to raise it to a minimum of 75 degrees below zero.
A 190-liter water tank was added to the toilet cubicle in cases where it is necessary to supply it with power when it is adjacent to the laboratory. The fourth battery that was put into the toilet compartment (40 amp/hour) from the Apollo 14 flight was replaced with a more powerful battery (500 amp/hour). This battery provides initial power for activity on the national route. One of the three fuel cells was removed since the amount needed for Skylab is less than that needed for lunar flights. Two of the four fuel tanks of the navigation engines and one of the two helium tanks were removed. The empty space created is used to transfer supplies to the laboratory and return equipment from it.
the launcher
The space laboratory is launched using the Saturn 5 launcher and the crews reach it on the Saturn B1. The length of the launcher is 71.94 meters and the total weight is 580,000 kg.
The structure of Saturn B1
First stage height 24.5 meters, diameter 6.4 meters, weight 440,000 kg, thrust 738,000 kg.
Second stage height 17.83 meters, diameter 6.6 meters, weight 118,000 kg, thrust 102,000 kg.
Instrumentation unit 1 height 0.91 meters, diameter 6.6 meters, weight 29,050 kg
Adapter 2 height 8.53 meters, diameter 3.91 meters 3
6.6 meters 4
spaceship 5
Escape system height 10.06 meters, diameter 1.22 meters, weight 4000 kg, thrust 66,700 kg.
1. Guidance and control of the launch vehicle
2. The connection between the second stage and the service cell is shaped like a truncated cone
3. Upper diameter
4. Bottom diameter
5. See the Apollo chapter the structure of the spacecraft without the lunar lander.
the caterpillar
The launcher and the Apollo spacecraft attached to it therefore arrive on the rover that was used by the Apollo spacecraft that flew to the moon, on their way therefore the launch. Since the Saturn B1 launcher is shorter than the Saturn 5, it was placed on a scaffolding and their total height is the same as that of the Saturn 5. The length of the scaffolding is 37.2 meters.
means of rescue
For the first time in space flights there is a possibility of rescue. In the event that a serious malfunction occurs in the laboratory or does not allow access to the spacecraft at all or the spacecraft cannot return to Earth, the astronauts can be saved. In the event that the malfunction arises immediately after docking with the laboratory, the rescue spacecraft reaches them 48 days later (due to the necessary preparations for the launch - assembly, refueling, etc.). If the malfunction is while the astronauts were in the laboratory, the preparations for the launch of the rescue spacecraft are 28 days, close to the end of the mission of the first team and ten days close to the end of the mission of the third team. The rescue spacecraft is an Apollo spacecraft used for Skylab 3 or Skylab 4 respectively, but most of the equipment comes from it. Only two astronauts are launched with space for the three survivors and a place to return equipment.
The rescue methods
- The astronauts move from the laboratory to the spacecraft. The rescue while floating in space.
- Disconnecting the damaged spacecraft and attaching the second spacecraft.
- In the event that it is not possible to detach the damaged spacecraft, the rescue spacecraft is attached to the second docking port and the astronauts move to it, but there are risks in this method. Two spaceships adjacent to the laboratory may cause instability and shaking of the laboratory itself. The solution to this is to temporarily activate the navigation engines of the laboratory until all the astronauts move to the rescue spacecraft.
Laboratory instruments
1. A system for national measurements - Erep - Earth Resources experiment Package and it includes:
A. A camera with a long focus for photographing the continent.
B. Six cameras in different areas of the spectrum from ultraviolet to infrared.
third. A multi-spectral surveyor with the help of which it is possible to identify typical spectra for agricultural, geographical, hydrological areas and more.
d. Infrared spectrometer.
The surveillance is done this way: six 160x160 km area cameras. At the same time, the spectral tester divides these areas into areas of 65 square kilometers and the infrared spectrometer focuses on areas with a radius of 0.5 km.
God. A long-range L-band passive radiometer.
and. A radiometer that transmits in short waves.
G. altimeter.
The weight of the system is 975 kg and it is able to work as one unit or each device separately. This equipment was used for research in the fields of forestry, ecology, geology, geography, meteorology, hydrology, hydrography, oceanography, geomorphology, mapping of snow-covered areas, pollution mapping, seashores and their origin, water potential, determining the state of water in the sea and the structure of the land. These instruments were later placed on research satellites. The work is done in close contact with aircraft, ground observations and satellites. The laboratory faces away from the sun and its position is at a fixed point relative to the curvature of the earth.
2. Telescope - the importance of this device lies in the ability to perform astronomical measurements without atmospheric disturbances. The telescope greatly increases the accuracy of the study of the sun and the stars. The telescope must make measurements of the Sun's chromosphere and its corona (corona) along its entire length and across its full temperature range. The measurement range ranges from 3940 angstroms to photons with a size of less than XNUMX angstroms.
During launch, the telescope is above the front end of the docking platform, after entering orbit, the entire rigid structure carrying the telescope rotates 90 degrees and brings it to the side of the docking platform.
The instruments attached to the telescope are:
A. White light coronagraph - performs "artificial eclipses" of the sun by hiding most of the area of the sun's disc to photograph the corona in white light up to a distance of six solar radii and checks for visible solar flares.
B. X-ray telescope.
third. X-ray spectrographic telescope - continuously monitors and photographs the events occurring on the surface of the Sun and their X-ray effects. Photographing eruptions and magnetic storms in the active parts of the Sun.
d. Spectrograph and spectroheliograph of Xu-v for photographing radiation for photographing ultraviolet radiation in the 150-650 angstrom range emitted by the sun.
God. Three H-alpha telescopes, one for photographing the hydrogen released from the sun and another for detecting the particles that hit the telescope.
and. Ultraviolet polychromator and spectrometer - records the temporal changes in ultraviolet radiation in the range between 300-1350 angstroms.
G. Ultraviolet spectrograph.
The cameras are placed in instruments A, B, C, D, E and two of the H-alpha telescopes transmit their data directly to Israel. In the second opening in the wall of the laboratory is placed a camera that picks up X-rays and ultraviolet radiation from quiet areas on the surface of the sun and places where explosions occur. In the solar observations, the laboratory orbits the Earth while it is at a relatively fixed point towards the Sun, so the telescope is constantly pointed towards it to exclude those cases where the Earth hides the Sun.
3. A special cell for electronic welding and soldering work - the cell is placed in the attachment dock and contains a tiny spherical electric reactor with a radius of 20 cm capable of producing heat of 1000 degrees. Two groups of experiments are planned for this cell:
A. 14 trials of fusion, soldering and brass-making techniques using beam beams with a power of 1.6 kW on samples of stainless metal, aluminum and tantalum of different thicknesses. These processes require melting and resolidification of the metals and are necessary for the construction and connection of large structures in space.
B. 11 experiments on 33 samples in the production of special materials such as crystals, alloys, assembling materials and semiconductors. These experiments are done while using the electric reactor. The samples are heated to special temperatures and cooled at a constant rate.
The purpose of the experiments is to check if the lack of weight can uniformly increase the strength, homogeneity and critical characteristic properties of materials. It was known that the finest metals have a strength 100-1000 times lower than the theoretically expected strength and that cooled blades of turbines can theoretically work at temperatures much higher than the known limits.
On Earth it is not possible to perform these experiments since the force of gravity and the convection flow that followed in the liquid phase of the materials cause a gradient of material in the melt, which prevents the formation of solids with an optimal and homogeneous structure. In an environment of weightlessness, convection processes do not exist, so there was hope that these conditions would allow advanced material processes.
Other advantages of these experiments in the space laboratory are a huge space and maneuverability in terms of volume - place of execution and time of execution. Factors that did not exist in most or in part in the Apollo flights, rockets and test towers. The time factor was small in rockets and towers since the time of zero gravity in them is very limited. It was obtained only under certain conditions and for a limited time.
