Category Science

On Apollo 17, the last manned mission to the Moon, the astronauts took with them a small buggy called the Lunar Rover. It was battery powered and could travel at just under 20k-min. (12mph), enabling astronauts to explore much more of the Moon than their predecessors had been able to do on foot. It had a small television camera and a satellite dish that sent the footage back to Earth. The Moon Buggy, as it is often called, had rubber tyres that could not be punctured, and was steered by a small hand control. It could be folded up and stored away when it was not needed.

The Apollo lunar roving vehicle was a battery-powered space buggy. The astronauts on Apollo 15, 16, and 17 used it to explore their landing sites and to travel greater distances than astronauts on earlier missions. The lunar rover neatly folded up inside the lunar lander during trips to the Moon. Once on the Moon’s surface, it unfolded with the help of springs. The lunar rover carried two astronauts and was manually driven. It was designed to climb steep slopes, to go over rocks, and to move easily over the Moon’s regolith. It was able to carry more than twice its own weight in passengers, scientific instruments, rocks, and regolith samples. The wheels on the rover were made of wire mesh (piano wire) with titanium cleats for treads. Engineers did not use solid or air-filled rubber tires because they would have been much heavier than were the wire mesh wheels. The Apollo spacecraft had a fixed amount of mass (payload) it could deliver to the surface, including the rover, rover batteries, scientific instruments, sample collection devices, etc. Hence, the wire-mesh wheels were important to the overall payload mass. This rover was not designed for prolonged use, and it is uncertain if future lunar explorers would use similar designs and materials for their vehicles, use new, more durable components, or turn to robotic rovers.

The LRV (Lunar Roving Vehicle) was technically a car, in that it had four wheels and two seats. Fenders over the wheels kept dust from flying everywhere, and the suspension incorporated double-swing A-arms, so overall it had a rather car-like look. Otherwise, it was radically different, starting with the exposed aluminum frame that was completely absent of bodywork. It also had no interior or even traditional controls like pedals and a steering wheel. A simple T-lever accessible by either astronaut was used to control turning, acceleration, and braking.

It did have four wheels, but instead of using solid rubber tires, a metallic mesh tire was developed using aluminum wires. Small titanium blocks arranged in a V-shape served as the tread, and it worked extremely well on the Moon’s very fine, powder-like surface.

They didn’t absorb impacts quite like air-filled tires, but astronauts remained secure in the LRV (Lunar Roving Vehicle) thanks to Velcro straps that kept them in the seats. To ensure the LRV (Lunar Roving Vehicle) could traverse the decidedly off-road environment on the Moon’s surface, four DC electric motors were installed in each wheel. That’s right – the LRV (Lunar Roving Vehicle) is a four-wheel-drive EV not unlike many modern electric hypercars, but it’s not nearly as powerful. Each motor produced the equivalent of just 0.25 horsepower. That power was transmitted to the wheels through a cycloidal gearbox with an 80:1 ratio, which allowed the rover to reach a top speed of approximately 8 mph (14 km/h).

Unlike modern EVs, the LRV was not rechargeable. Electricity was supplied via two zinc-silver batteries weighing a total of 119 pounds (54 kilograms). Total output was 8.7 kWh, and the LRV range was just 56 miles (90 kilometers). Another interesting tidbit about the individually-powered wheels is that all four could turn, giving the LRV a turning radius of just 9.8 feet (3 meters).

Sending a rocket into space is a very expensive procedure, especially considering that each launcher can be used only once. The Space Transportation System (STS), better known as the Space Shuttle, was designed to be the world’s first reusable space vehicle.

The Space Transportation System, also known internally to NASA as the Integrated Program Plan (IPP), was a proposed system of reusable manned space vehicles envisioned in 1969 to support extended operations beyond the Apollo program. (NASA appropriated the name for its Space Shuttle Program, the only component of the proposal to survive Congressional funding approval). The purpose of the system was twofold: to reduce the cost of spaceflight by replacing the current method of launching capsules on expendable rockets with reusable spacecraft; and to support ambitious follow-on programs including permanent orbiting space station around the Earth and Moon, and a human landing mission to Mars.

In February 1969, President Richard Nixon appointed a Space Task Group headed by Vice President Spiro Agnew to recommend human space projects beyond Apollo. The group responded in September with the outline of the STS, and three different program levels of effort culminating with a human Mars landing by 1983 at the earliest, and by the end of the twentieth century at the latest. The system’s major components consisted of:

The tug and ferry vehicles would be of a modular design, allowing them to be clustered and/or staged for large payloads or interplanetary missions. The system would be supported by permanent Earth and lunar orbital propellant depots. The Saturn V might still have been used as a heavy lift launch vehicle for the nuclear ferry and space station modules. A special “Mars Excursion Module” would be the only remaining vehicle necessary for a human Mars landing.

As Apollo accomplished its objective of landing the first men on the Moon, political support for further manned space activities began to wane, which was reflected in unwillingness of the Congress to provide funding for most of these extended activities. Based on this, Nixon rejected all parts of the program except the Space Shuttle, which inherited the STS name. As funded, the Shuttle was greatly scaled back from its planned degree of reusability, and deferred in time. The Shuttle first flew in 1981, and was retired in 2011.

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There have been six Apollo missions to the Moon, during which 12 astronauts have explored its composition and conditions. Thousands of photographs have been taken, and 176kg (3881bs) of Moon-rock were brought back to Earth to be studied. Scientists are interested in finding out what the Moon is made of because this may determine its origin and history. Astronauts also measured the amount of solar particles reaching the lunar surface, the amount of dust in the air, and the power of moonquakes, which are slight movements in the Moon’s crust.

After the Lunar Module landed on the Moon’s Sea of Tranquility, Aldrin and Armstrong conducted a series of landmark scientific experiments. Aldrin deployed the Early Apollo Scientific Experiments Package (EASEP), which included instruments for several tests to be left on the lunar surface. The Passive Seismic Experiment contained seismometers to measure moonquakes or effects of meteoroid and other impacts on the Moon. The Laser Ranging Retro-reflector allowed for a precise measurement of the distance between Earth and the Moon, obtained by timing how long it took for a laser beam to travel from Earth to the lunar surface and back.

Another experiment created by Swiss Scientists, collected solar-wind particles that researchers could analyze the composition of solar wind. The team also recorded extensive observations of the lunar surface, photographed the terrain and each other, and gathered 22 kilograms of rock, soil, and dust samples—all in the course of approximately two hours.

The observations and material collected by the Apollo 11 crew led to exciting discoveries. Among the most important findings: analysis of the chemical composition of lunar rocks helped strengthen the theory that the Moon was actually a chip off the young Earth.

Researchers now think that soon after the formation of the solar system, Earth was struck by a Mars-sized object, intimately mixing the two bodies. Some of the resulting vapor and rock later congealed into the single satellite that is our Moon today. This origin story would explain why the Moon doesn’t have a large iron core and is mostly composed of materials found in Earth’s crust, and why the ratios of many isotopes on the Moon’s surface are identical to those found in rocks on Earth. It was a stunning finding,” says Shara.

One of the instruments left on the Moon’s surface—the Laser Ranging Retro-reflector—allowed scientists to collect data for decades after Apollo 11’s return to Earth. Findings include that the Moon is moving farther away from Earth and that the universal force of gravity is stable.

Research based on materials gathered during the Apollo missions continues to this day.

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Saturn V held the Apollo spacecraft, which was made up of three parts — the Command, Service and Lunar Modules. Neil Armstrong and Buzz Aldrin touched down on the Moon’s surface in the Lunar Module. As well as providing their transport, the Lunar Module was the astronauts’ home for the three days they spent on the Moon. Michael Collins remained in orbit aboard the Command and Service Module. When it was time to leave the Moon, Aldrin and Armstrong blasted back into orbit in the top half of the Lunar Module, before docking with the Command and Service Module and beginning the journey back to Earth.

Armstrong and Aldrin stayed on Moon for just more 21 hours-two-and-a-half hours of which were spent outside the Lunar Module exploring and conducting scientific experiments. At 1:53 pm on July 21 the astronauts lifted off from the Moon in the module’s ascent stage and then rendezvoused with Collins and the orbiting spacecraft. The three explorers fired away from lunar orbit on July 22 and returned to Earth on July 24.

The Apollo 11 Lunar Module ascent stage, with Astronauts Neil A. Armstrong and Edwin E. Aldrin Jr. aboard, is photographed from the Command and Service Modules (CSM) during rendezvous in lunar orbit. The Lunar Module (LM) was making its docking approach to the CSM. Astronaut Michael Collins remained with the CSM in lunar orbit while the other two crewmen explored the lunar surface. After docking, astronauts Armstrong and Aldrin transferred to Columbia with Collins, the LM ascent stage was jettisoned, and the return trip to Earth began.

The large, dark-colored area in the background is Smyth’s Sea, centered at 85 degrees east longitude and 2 degrees south latitude on the lunar surface (nearside). This view looks west. The Earth rises above the lunar horizon.

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The Apollo lunar programme was launched in 1961 by the President of the USA, John F Kennedy. He ambitiously claimed that human beings would set foot on the Moon by the end of the decade. It was one of the most complicated and technically challenging projects of the twentieth century, but resulted in a manned mission being sent to the Moon in 1969. A very powerful rocket, called the Saturn V, was built especially for the journey. It was able to carry the 52 tonnes of equipment needed for a successful visit to the lunar surface. Apollo 8 carried the first men around the Moon in 1968, but it was not until one year later, in July 1969, that humankind first set foot on the surface of the Moon.

In the method ultimately employed, lunar orbit rendezvous, a powerful launch vehicle (Saturn V rocket) placed a 50-ton spacecraft in a lunar trajectory. The spacecraft had three parts. The conical command module (CM) carried three astronauts. The service module (SM) was attached to the back of the CM and carried its fuel and power to form the command/service module (CSM). Docked to the front of the CSM was the lunar module (LM). One astronaut stayed in the CSM while the other two landed on the Moon in the LM. The LM had a descent stage and an ascent stage. The descent stage was left on the Moon, and the astronauts returned to the CSM in the ascent stage, which was discarded in lunar orbit. The LM was flown only in the vacuum of space, so aerodynamic considerations did not affect its design. (Thus, the LM has been called the first “true” spacecraft.) Before reentering Earth’s atmosphere, the SM was jettisoned to burn up. The CM splashed down in the ocean. The lunar orbit rendezvous had the advantages of requiring only one rocket and of saving fuel and mass since the LM did not need to return to Earth.

Uncrewed missions testing Apollo and the Saturn rocket began in February 1966. The first crewed Apollo flight was delayed by a tragic accident, a fire that broke out in the Apollo 1 spacecraft during a ground rehearsal on January 27, 1967, killing astronauts Virgil Grissom, Edward White, and Roger Chaffee. NASA responded by delaying the program to make changes such as not using a pure oxygen atmosphere at launch and replacing the CM hatch with one that could be opened quickly.

In October 1968, following several uncrewed Earth-orbit flights, Apollo 7 made a 163-orbit flight carrying a full crew of three astronauts. Apollo 8 carried out the first step of crewed lunar exploration: from Earth orbit it was injected into a lunar trajectory, completed lunar orbit, and returned safely to Earth. Apollo 9 carried out a prolonged mission in Earth orbit to check out the LM. Apollo 10 journeyed to lunar orbit and tested the LM to within 15.2 km (9.4 miles) of the Moon’s surface. Apollo 11, in July 1969, climaxed the step-by-step procedure with a lunar landing; on July 20 astronaut Neil Armstrong and then Edwin (“Buzz”) Aldrin became the first humans to set foot on the Moon’s surface.

Apollo 13, launched in April 1970, suffered an accident caused by an explosion in an oxygen tank but returned safely to Earth. Remaining Apollo missions carried out extensive exploration of the lunar surface, collecting 382 kg (842 pounds) of Moon rocks and installing many instruments for scientific research, such as the solar wind experiment and the seismographic measurements of the lunar surface. Beginning with Apollo 15, astronauts drove a lunar rover on the Moon. Apollo 17, the final flight of the program, took place in December 1972. In total, 12 American astronauts walked on the Moon during the six successful lunar landing missions of the Apollo program.

Apollo CSMs were used in 1973 and 1974 in the Skylab program to take astronauts to an orbiting space station. In July 1975 an Apollo CSM docked with a Soviet Soyuz in the last flight of an Apollo spacecraft.

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Gravity on the moon is only one-sixth of that on Earth, which means that astronauts can jump several metres effortlessly. There is no atmosphere on the Moon, so sound cannot be carried even over a small distance. Radios have to be used to communicate over a few centimetres. Because there is no weather, the astronauts’ footprints will last for thousands of years.

The moon has no atmosphere no weather and no oceans of water. Its surface is in a perpetual vacuum. Pairs of astronauts have lived on its surface only up to three days at a time, in the tiny Lunar Module of the Apollo program. 

Only 12 humans (the crews of Apollo 11, 12, 14, 15, 16 and 17) have ever walked on the moon’s surface. Because the moon’s gravity is only one-sixth that of the Earth’s gravity, Apollo astronauts had to tread carefully or else risk stumbling or falling. They ultimately perfected a bouncing gait and bunny hops to walk along the lunar surface. 

One of the best places to set up a moon base turns out to be the lunar south pole, which has an enormous reserve of water ice and a relatively stable surface temperature around 32 degrees Fahrenheit (0 Celsius).

Because it lacks an atmosphere, the moon undergoes tremendous daily swings in surface temperature, from a daytime average of 253 degrees F (123 C) to minus 387 F (minus 233 C) at night.