Question

In physics, environment phenomenology is how a particular environment arises. For example, if you were to design an underwater base, you might consider the pressure on the system and how that environment arises, which is through the weight of the column of water above the base. Give a brief explanation of an environment phenomenology for each system below:

1. Lunar greenhouse

2. Nuclear fission reactor on the moon

3. Lunar rover

4. Spacesuits

Answer 1

1. Environment phenomenology for the lunar greenhouse

*  To protect from radiation in space, the greenhouse units would likely be buried under surface soil or regolith thus requiring specialized lighting.

*  Solar light could be captured with light concentrators that track the sun and then convey the light to the chamber using fiber optic bundles.

* Scientists noted astronauts exhale carbon dioxide, which is then introduced into the greenhouse, and the plants then generate oxygen through photosynthesis.

*    The water cycle begins with water that is brought along or found at the lunar or Martian landing site. Water is oxygenated, given nutrient salts, and it continuously flows across the root zone of the plants and returned to the storage system.

*  NASA scientists and engineers are developing systems to harness resources such as water that should be available in certain areas of the lunar or Martian surface to support missions lasting for months or years.

2) . Environment phenomenology for the nuclear fission reactor on the moon

*  Electricity may come from nuclear reactors, solar panels, batteries, fuel cells, or some combination of these technologies connected in a power grid.

*   But each power source has distinct pros and cons to consider. Solar arrays have reliably delivered renewable power in space for decades but are useless in places that never get any light, like the potentially resource-rich craters on the moon.

*   One type of nuclear device that has been used to power spacecraft is a radioisotope thermoelectric generator, which runs on the heat produced by the decay of plutonium-238

*   While nuclear power remains controversial, the researchers say that the reactor would be designed to be completely safe and would be buried a safe distance from the astronauts to shield them from any radiation it would generate.

* The recent tests examined technologies that would see a nuclear reactor coupled with a Stirling engine capable of producing 40 kilowatts of energy–enough to power a future lunar or Mars outpost.

* The nuclear core, which is about the size of a paper towel roll and weighs 28 kg, comprises a solid alloy of about 8% molybdenum and 92% highly enriched uranium.

* The nuclear material is surrounded by a beryllium oxide reflector that bounces neutrons into the core to drive the fission reaction. Lodged inside the core is a rod of pure boron carbide that absorbs neutrons, quenching fission reactions.

* When the boron carbide rod is slowly removed, neutrons start to strike uranium atoms, occasionally splitting them, creating more neutrons and releasing energy as heat. Once the number of neutrons lost equals the number of neutrons being produced, the reactor becomes self-sustaining. The fission-generated heat travels through sodium-filled heat pipes to a set of Stirling engines

*   A radiator is provided to remove the excess heat, sloughing it off into space.

3). Environment phenomenology for the lunar rover

Rover Design Requirements

* The guidelines developed by scientists for this rover are as follows: 1 kilowatt nominal power supply without using batteries greater than 500 kilogram carrying capacity, minimum of 250 kilometer range, five year mission design life, and continuous operation.

* A five year design life requires that the rover survive for approximately 62 lunar days. Power will need to be available to supply a scientific payload that will be selected after the rover is designed and developed.

* The rover, therefore, will need to be a lunar mule, capable of carrying a variety of payloads to explore a wide range of possible landing sites. Another important constraint placed on the development is that the rover be designed utilizing current technologies.

* There can be no advanced research and development on any component involved with the construction. No current designs, already in operation or in development, utilize a hydrogen-oxygen fuel cell, making the off-the-shelf requirement significantly more difficult.

Mission Requirements

* The primary mission requirement is that the rover be capable of traversing the lunar surface, both mare, or darker areas, and highland regions. The mare regions are flat, relative to the mountains and valleys of the highland areas however varying sized craters 11 are present in both .

* In order to navigate these terrains it is recommended all lunar roving vehicles be able to climb and descend a slope of 25⁰ since craters commonly have only 5-10⁰ slopes and this leaves a significant margin of mission flexibility.

*   Any successful mission exploring that lunar surface will have to navigate and investigate these different regions effectively and without constant reroute to avoid obstacles that commonly occur. Another important aspect in the mission is to continually survive the lunar night and the temperature flux that occurs during the transition between night and day.

* During lunar night, which lasts for approximately 14 Earth days, the temperature can reach as slow as -150⁰C and can reach 100⁰C during the day .  In addition to the electrical power dedicated to lighting the rover’s way, a significant amount of heat needs to be generated to keep vital components operating during night.

*   In order for this design to be feasible, the rover must be able to fit on a conceivable lunar lander. The recently cancelled Ares V rocket was designed to be compatible with a lander capable of supporting any future lunar landing attempt with the rover.

* The complete regenerative fuel cell system could be integrated on the rover, but in order to optimize performance, several components can be separated into a base station and operate in parallel with the rover systems. Solar activity will require protection to prevent damaging effects during the rover’s operation.

* Radiation, coronal mass ejections, and magnetic anomalies will have to be considered in order for the rover to survive its five year primary mission

4). Environment phenomenology for the spacesuits

*A spacesuit is a pressurized (filled with air pressure) garment worn by astronauts during space flights. It is designed to protect them from potential dangerous conditions they may experience in space. A spacesuit is also called an Extravehicular Mobility Unit (EMU) because it is worn when an astronaut leaves the spacecraft in order to perform a variety of tasks, including the repair of satellites, collection of samples, taking of pictures, and assembling of equipment.

*   The spacesuit is designed to recreate the environmental conditions of Earth's atmosphere. It provides the basic necessities for life support, such as oxygen, temperature control, pressurized enclosure, carbon dioxide removal, and protection from sunlight, solar radiation, and micrometeoroids.

*   The spacesuit is reusable and has a product life expectancy of about fifteen years. The suit is pressurized to 4.3 pounds per square inch (0.302 kilogram per square centimeter) and can be recharged by hooking up to the orbiter (piloted part of a spacecraft).

* Unlike previous spacesuits, which were tailor-made for each astronaut, today's spacesuits can be assembled from standard-sized parts to fit any body size. The basic interchangeable sections include the helmet, the hard upper torso, the arms, and the lower torso. These parts are adjustable and can be resized. Each complete spacesuit has fourteen layers and costs over $12 million to make.

*  The white spacesuit weighs about 275 pounds (124.8 kilograms) on Earth. However, above Earth's atmosphere, or in space, it has no weight at all due to the near absence of gravity. Contrary to popular belief, it is not true that there is absolutely no gravity in space. What is commonly referred to as zero gravity in space is more accurately called microgravity, or very little gravity. Just the same, spacesuits are weightless in space.