On October 2, 2022, NASA had planned to launch the Artemis 1 Moon rocket mission for the third time from the Kennedy Space Centre, Florida. However, the launch of the keenly awaited space mission had to be aborted as Hurricane Ian threatened to travel north across Cuba and into Florida. The second attempt had to be aborted due to dangerous hydrogen leak issue on September 2, 2022. The fuel leak was discovered during the tanking. The first attempt to launch the spacecraft was on August 29, 2022 which had to be put off after engineers were unable to resolve the problem involving inadequate flow of liquid hydrogen to one of the four engines of the rocket. Also, a sensor showed that one of the four main engines of the rocket was too hot. Now, Artemis 1, is scheduled to launch around mid-November from NASA’s Kennedy Space Center, Florida. The launch window opens November 12 and closes November 27.
Space missions could not be launched anytime they are ready to go. Launch windows are very precise timeslots that are calculated for their launch because nothing in the space is stationary. The Earth keeps moving, and so is the Moon or any other planetary body the mission is headed to. So, the launch window is scheduled to look for the shortest distance to the destination for the purpose of fuel efficiency as there is no refuelling opportunity in space.
Background
Humans first landed on the Moon just 12 years after the first-ever satellite, Sputnik, had been launched in 1957. Between 1969 and 1972, in the Apollo Moon Mission Program, six humans had landed on the surface of the Moon for the first time. Since then, there has been huge progress in space exploration. Spacecrafts have now gone beyond the solar system. Exploratory missions have probed Mars, Jupiter, and Saturn. More than 500 astronauts have travelled to space and back. There are permanent space laboratories like the International Space Station (ISS) that have been set up. However, transporting humans to other worlds, and the possibility of landing and living on other planets or travelling deep into space, is still eagerly awaited. So far, twelve astronauts have set their feet on the Moon and returned. All of this had happened by 1972.
The 12 astronauts who walked on the Moon are Neil Armstrong, Edwin ‘Buzz’ Aldrin, Charles ‘Pete’ Conrad, Alan Bean, Alan B. Shepard Jr., Edgar D. Mitchell, David R. Scott, James B. Irwin, John W. Young, Charles M. Duke, Eugene Cernan, and Harrison H. Schmitt.
About Artemis 1
The Artemis 1 would be almost more than a month-long uncrewed mission of 40,000 miles beyond the Moon and back. The mission would technically be a lunar orbiter mission with no lander or rover component. The mission is aimed at exploring the Moon with the specific objective of getting human beings back on the lunar surface and possibly beyond that, including Mars. The mission would set up the foundation for more ambitious missions in the future. It also aspires to set up permanent base stations on the Moon so that the Moon would be used as the launch pad for deep space missions.
Rocket and the Spacecraft
NASA has spent more than US$ 40 billion to develop the rocket, named Space Launch System (SLS), and the capsule spacecraft, called the Orion. The SLS is the most powerful rocket available so far. The rocket is 98 metres tall and weighs about 2,500 tonnes. The SLS could help the Orion spacecraft achieve speeds of over 36,000 km per hour. SLS would take the Orion directly to the Moon, which is about 1,000 times farther than the ISS. Orion would get into a lunar orbit that would be about 97 km from the Moon’s surface at its closest. The capsule would fire its engines to get a distant retrograde orbit (DRO) of 40,000 miles beyond the Moon. However, unlike most other orbiter missions, Orion has a return-to-Earth target after it has orbited the Moon for about a month or so. The main objective is to test the heat shield of the capsule, which is 16 feet in diameter and the largest ever built.
Significance of the Mission
The Artemis 1 would carry several small payloads in the form of small satellites, called CubeSats. Each CubeSat is equipped with instruments meant for specific investigations and experiments. The focus of these investigations is to explore long-term stays of human beings in space and on the Moon. For instance, one CubeSat would search for water in all its forms, and another would map the availability of hydrogen, which could be used as a source of energy. Some CubeSats would conduct biology experiments such as behaviour of small organisms, like fungi and algae, in the outer space and the effect of radiation, especially the reaction on their genes, etc.
The Orion has been specifically designed to carry astronauts into deep space on its future missions. In its first mission, the Orion would carry three dummy passengers—mannequins made of material that are similar to human bones, skin, and soft tissue. The dummies would be equipped with a host of sensors to record the various impacts of deep space atmosphere on the human body.
Future Missions
The next mission, Artemis 2 would take astronauts to the Moon without landing on its surface, expectedly in 2024. The third mission, Artemis 3, would land on the Moon by 2025. Astronauts would be able to collect a large number of samples that are best for research, much quicker than robots. The later missions are intended for setting up of a lunar space station, and further, a sustainable presence on the lunar surface once these samples are examined and studied.
NASA is also planning a crewed trip to Mars with the Orion, which would last for many years. This mission could be attempted by the end of 2030s.
How to Calculate a Launch Window
In order to precisely calculate a launch window, several considerations have to be taken into account, such as on which side a satellite is headed to in space, the distance a satellite has to travel to get into an orbit, the nature of the probe a satellite has to carry out, etc. The launch windows could either be very narrow or sometimes comfortable.
Two heavenly bodies are closest in distance at a time when they are moving in opposite directions due to their circular or elliptical orbits. While launching a rocket, Earth’s rotation on its own axis is taken into account. The Earth rotates from West to East. So, if the rocket is launched towards the East, it again gains from the Earth’s rotation speed.
The Earth rotates faster at the equator than at the poles. So, some of the most prominent launching sites, especially for heavier satellites, are located near the equator. As a safety consideration, proximity to the sea and distance from heavily populated areas are taken into account, before launching. Similarly, temperature plays a great role in launching a space mission.
If the temperature is too cold or too hot; if the wind is blowing at a very strong speed, or if there is rainfall, humidity, lightning, cloud or smoke, a safe and successful launch is not possible.
Private Space Exploration Companies
The mission also includes some private space companies, such as SpaceX, which has a contract with NASA to build the lunar lander. SpaceX is also building a large launch vehicle, Starship, that could reduce the cost, in comparison to the government-owned, operated, and planned systems. The rocket is expected to have its first flight soon and is designed to be both reusable and inexpensive.
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