”No more pigeons.” For many netizens who care about astronomy, whether Artemis 1 can be successfully launched recently is like whether it will rain tomorrow, which is full of variables.
After years of delays, the launch plan of Artemis 1 at the end of August this year was cancelled due to engine problems, and then the launch plan scheduled for the early morning of September 4th, Beijing time, was postponed again due to the detection of a liquid hydrogen leak.
People look up to the moon and are more eager to get close to the moon, and even hope to reach farther planets through the moon. Artemis 1 is carrying such hope, waiting to lift off.
Pioneering the return of humans to the moon
Artemis is the goddess of hunting in ancient Greek mythology, and her younger brother is Apollo, who is in charge of the light, the sun, etc. Just as later poets called Apollo the sun god, some poets compared Artemis to the moon goddess.
About half a century ago, the Apollo program successfully landed people on the moon six times; now, Artemis has taken over the baton of his “younger brother” and is preparing to return manned people to the moon, and even let humans set their sights on Mars.
From the U.S. government’s proposal to return to the moon in 2004, to the official launch of the Artemis program in 2017, and now the Artemis program has officially entered the first launch phase, returning to the moon has always been in financial controversy.
Artemis 1’s upcoming uncrewed mission around the moon is a “pioneer” for NASA’s efforts to land a manned (one woman and one astronaut of color) on the moon in 2025 “.
It is worth noting that this mission will realize the test flight of the super-large launch vehicle, the Space Launch System (SLS). After the SLS rocket lifts off from the Kennedy Space Center launch pad in Florida, its Orion spacecraft will enter lunar orbit and beyond. About 6 weeks after launch, the Orion spacecraft will return to Earth.
There are also 10 CubeSats for space travel. They have different divisions of labor, some are used to detect radiation, and some satellites are focused on studying the lunar surface, looking for water and near-surface hydrogen in the permanently shadowed area around the moon’s south pole in preparation for a later lunar landing.
This is also one of the reasons why the United States wants to return to the moon after half a century. In 2008, scientists detected the presence of moisture in lunar rock samples collected by the Apollo lunar spacecraft. Since then, according to the data sent by the Lunar Prospector probe, NASA believes that there is moisture at the north and south poles of the moon. Finding water on the moon has become an important research topic.
There’s also a reason to go back to the moon to go further. In 2004, the U.S. government proposed the constellation plan for the manned spaceflight project, which planned to return to the moon and establish a permanent base. But in 2010, then-President Barack Obama announced the termination of the Constellation program and moved to Mars. He even proposed in 2016 that he plans to send humans to Mars in 2030. At the same time, more and more scientists say that it is feasible to use the moon as a springboard to land on Mars.
In addition, in the view of NASA administrator Bill Nelson, returning to the moon is a “space race”. And his “imaginary enemy” China said that outer space is not an arena for countries to wrestle, but an important area for win-win cooperation.
Plan to land at the south pole of the moon
From 1969 to 1972, the Apollo program achieved a total of six successful moon landings.
Humans set the landing site for the first landing in an area with flat terrain, and the Apollo 11 landing site was located in the Sea of Tranquility on the lunar surface. In the next five landings, the lunar module landed in the vicinity of Storm Ocean Surveyor 3, Fra Mauro Crater, Apennine Mountains, Descartes Heights, and Tauras-Littrow Valley, but they were all located on the moon facing the earth. side. The Artemis program is preparing to land on the south pole of the moon and send humans to the moon at a completely different landing site.
The main reason for this is that there may be water ice at the south pole of the moon. In the Artemis program, some craters at the south pole of the moon are permanently in shadow, forming cold traps that are barely higher than minus 163 degrees Celsius. Scientists believe that water ice may be hidden in cold traps. If this idea proves to be true, not only the water needs of the future lunar base can be met, but also hydrogen and oxygen can be extracted from it to provide fuel for the engine.
NASA Administrator Bill Nelson
Landing at the south pole of the moon is also due to the consideration of the sustainability after landing on the moon. The highland where the moon’s south pole can be illuminated by sunlight has a continuous illumination time of up to 10 hours, avoiding the trouble of long dark nights; and, compared with the temperature difference of more than 250 degrees Celsius in low latitudes, the temperature here does not change much.
But this does not mean that landing from the south pole of the moon is easy, on the contrary, the difficulty is greatly increased. The lunar south pole has many mountains and canyons. Whether it is the initial landing or the take-off after completing the mission, it is difficult.
And returning to the moon to find the storage place of water-permanently dark craters, its advantages are also the challenges that researchers need to face-cannot be illuminated by sunlight, it is a real dark area, the detection of water ice detection Where does the energy for excavators and excavators come from? This needs to be supplied by bases built in advance on high ground. That is to say, after the base is built, the next step after finding the water ice can be carried out.
NASA’s most powerful rocket
During the Artemis 1 mission, the SLS rocket launch received much attention. It is the most powerful rocket NASA has ever built, with 4 main engines and 2 boosters.
Compared with the Saturn V launch vehicle in the previous Apollo program, the SLS rocket has more thrust, up to 8.8 million pounds. That’s the equivalent of the combined thrust of 126 of the largest civilian aircraft, which can lift 2.6 million kilograms of rockets, compared to the 7.6 million pounds of the Saturn V.
The excellent carrying capacity of the SLS rocket is also an important reason why it is responsible for this mission. NASA said the SLS rocket is the only existing vehicle capable of launching the Orion spacecraft, astronauts and cargo into low-Earth orbit all at once. The first stage is mainly based on the manned missions of the constellation plan of 70 tons to 110 tons. Although the carrying capacity is still different from that of the Saturn V of the year, it can basically be regarded as the same order of magnitude.
Artemis 1 is an unmanned test flight, and Shaun the Sheep will lift off together
A growing number of scientists say it is feasible to use the moon as a springboard to land on Mars.
There are also several data that can show its high performance as the strongest rocket: 4 engines burn 90,000 gallons of liquid hydrogen and liquid oxygen per minute for a total of 8 minutes; the rocket starts from the earth and can reach as far as 450,600 kilometers, far beyond The distance between the moon and the earth, which is also the farthest a manned space capsule has ever traveled.
After the SLS rocket sends the Orion spacecraft into space, the spacecraft will circle the moon in a large arc before returning to Earth after 6 weeks. The flight will test the functioning of the Orion spacecraft’s heat shield and other systems, and gather data for the next step in safely sending astronauts to the moon and back to Earth.
Although it was an unmanned flight, there was one mannequin wearing a special suit with sensors “sit” in the commander’s seat to measure radiation levels, and two other mannequins wearing radiation reduction vests with to understand how astronauts’ bodies will be affected during space travel in the future.
However, the high-profile rocket launch did not go smoothly, “dove after dove”. The launch pad has also suffered multiple lightning strikes, and the four fuel tests have also ended ahead of schedule.
But it will eventually rush out of the earth carrying human’s thirst for space, and human’s exploration of the unknown will never stop.
