The bones of about 60 mammoths were found at an under-construction airport north of Mexico City, reports AP.

Archaeologists say the discovery was made near the human-built 'traps' where more than a dozen mammoths were found last year. This could possibly indicate that humans may have been smarter — and mammoths clumsier — than people had previously thought.

"There are too many, there are hundreds," said archaeologist Pedro Sánchez Nava, of the National Institute of Anthropology and History.

The institute began digging in three large but shallow areas in October, when work started to convert an old military airbase into a civilian airport. In about six months, the bones of 60 mammoths were found, and Sánchez said that the pace — about 10 mammoths a month — may continue.

The airport project is scheduled for completion in 2022, at which the dig will end.

The excavations were conducted on the shores of an ancient lake, once known as Xaltocan and now disappeared. The shallow lake apparently produced generous quantities of grasses and reeds, which attracted mammoths who often ate 150kg of the stuff every day.

"It was like paradise for them," Sánchez Nava said.

But the new excavations at the airbase have not yet turned up any of the distinct cut marks that would suggest human butchering of the animals.

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Sánchez said the most recently discovered mammoths had apparently got stuck in the mud of the ancient lake and died, or were eaten by other animals.

But the bones will be subject to further study because Sánchez said humans might have carved up the mammoths once they got stuck.

And, he said, ancient human could possibly have used the mud pools and flats around the lake shore as a sort of natural trap. "It's possible they may have chased them into the mud," he noted, adding, "They (ancient humans) had a very structured and organised division of labour" for getting mammoth meat.

The discovery also challenges the notion that mammoth was a chance, sporadic item on our ancestors’ menu.

Sánchez Nava said the large numbers of remains will allow scientists to research how mammoths fed and whether they were already suffering genetic inbreeding or decline, which could have contributed — along with human hunting — to their extinction on the mainland about 10,000 years ago.

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NASA has selected three U.S. companies to design and develop human landing systems for the agency's Artemis program, one of which will land the first woman and next man on the surface of the moon by 2024.

The three companies are Blue Origin of Kent, Washington; Dynetics of Huntsville, Alabama; and SpaceX of Hawthorne, California, according to a release of the agency on Thursday night.

The human landing system awards are firm-fixed price, milestone-based contracts, and the total combined value for all awarded contracts is 967 million U.S. dollars for the 10-month base period, the release said.

"With these contract awards, America is moving forward with the final step needed to land astronauts on the Moon by 2024, including the incredible moment when we will see the first woman set foot on the lunar surface," said NASA Administrator Jim Bridenstine.

"This is the first time since the Apollo era that NASA has direct funding for a human landing system, and now we have companies on contract to do the work for the Artemis program," he said.

NASA's commercial partners will refine their lander concepts through the contract base period ending in February 2021. During that time, the agency will evaluate which of the contractors will perform initial demonstration missions.

NASA will later select firms for development and maturation of sustainable lander systems followed by sustainable demonstration missions. NASA intends to procure transportation to the lunar surface as commercial space transportation services after these demonstrations are complete, according to the release.

Charged with returning to the moon in the next four years, NASA's Artemis program will reveal new knowledge about the moon, Earth, and the origins in the solar system.

The human landing system is a vital part of NASA's deep space exploration plans, along with the Space Launch System rocket, Orion spacecraft, and Gateway.

An unmanned Russian cargo capsule docked with the International Space Station, bringing more than 2 tons of supplies to the three-person crew.

The Progress spacecraft docked at 0512 GMT Saturday, about 3 1/2 hours after blasting off from Russia's Baikonur launch complex in Kazakhstan.

The ship carried fuel, water, food, medicine and other supplies.

There are three astronauts aboard the space station: Russia's Anatoly Ivanishin and Ivan Vagner, and Chris Cassidy of the United States.

The Space Day of China, which falls on April 24, is more special this year, as it marks the 50th anniversary of the successful launch of Dongfanghong-1, the country's first man-made satellite.

It listed China as the fifth country in the world to develop and launch a man-made satellite on its own, and recorded the country's first step in exploring the vast space.

Affected by the novel coronavirus epidemic, China's space institutes and science popularization organizations held online forums and meetings, where the researchers engaged in the Dongfanghong-1 mission, mostly above 70, shared their stories with the satellite, a never-fading feat in the country's space history.

In the mid-1960s, in response to Chairman Mao Zedong's call, China began the research and development of its own man-made satellite.

In 1968, China Academy of Space Technology (CAST) was established, with Qian Xuesen, a founder of China's space industry, as its first president. The academy sped up the Dongfanghong-1 mission with specific planning and implementation steps.

Pan Houren, then deputy head of the overall design team of the satellite, recalled that the central government allocated 200 million yuan (about 28 million U.S. dollars) for the mission. "At that time, 200 million yuan was really not an easy sum."

However, China's elder space researchers still faced numerous difficulties. They knew little of the relevant technologies, and they did not have the satellite processing equipment and testing facilities. Nor could they seek help from outside, as Western countries blockaded China, and the Soviet Union also cut off the exchanges.

"At that time, China's industrial foundation was weak, and scientific research conditions were relatively poor. The international environment was unfavorable. So we had to make a satellite all by ourselves and from scratch," said Pan on an online forum initiated by SpaceD, a Beijing-based company spreading aerospace science.

To help young people understand the difficulty of the mission, Pan compared launching a satellite with making steamed bread. The researchers had to start from reclaiming wasteland, and then they could plant the seeds, grind the wheat and make steamed bread.

With a shape close to a globe, Dongfanghong-1 successfully entered its preset orbit on April 24, 1970. It is one meter in diameter and 173 kg in weight, heavier than the total of the first four manmade satellites launched by others.

Among the various technical problems, the most impressive one researchers had handled was to make it play in orbit "Dongfanghong," the folk song lauding Chairman Mao, and allow all the Chinese people to hear it through the radio.

According to CAST, researchers made a special musical device to simulate the song with electronic music, designing it to play the first eight sections of the music in 40 seconds and transmit the telemetry signals in the following 20 seconds.

However, the first sound from the musical device in a ground experiment was out of tune. After analysis, Liu Chengxi, a member of the research group, decided to turn to music experts for help. He went to a harmonica factory in Shanghai and found a master craftsman, who told him to add harmonic waves to make the sound cadenced and melodious.

Now that the tone problem was solved, how could people on the ground hear it?

Hu Qizheng, a member of the overall design team of the satellite, said they adopted the method of "relay transmission." First, "Dongfanghong" played by the satellite was decoded through the ground station. Then, it was sent to China National Radio and broadcasted. So all types of radios could receive it.

"Many of the people I know listened to 'Dongfanghong' from space on the radio during their childhood and decided to devote themselves to space exploration. It just had an invisible power," said Bai Ruixue, CEO of SpaceD.

"It is not only an important origin in China's space industry but also a milestone in Chinese people's minds. When the country was not yet open and life was so difficult, Dongfanghong-1 encouraged many Chinese to look up at the stars," Bai said.

Zhang Jihua, who gave the ignition order for the launching of Dongfanghong-1 at the Jiuquan Satellite Launch Center in northwest China, recalled that when the mission was confirmed successful, everyone was in tears, shaking hands and hugging each other.

Sun Jiadong, head of the overall design team of the satellite, said it is hard to depict the excited mood at that moment. "Under such (poor) conditions, we sent our first satellite into space, with everything, even a screw, made by ourselves. I felt very proud."

Hu Qizheng believed that Dongfanghong-1 has brought three important impacts to China's space industry. "First, it laid a solid foundation for the subsequent development of space technologies. Second, researchers set up a set of procedures for developing satellites. Third, the mission trained a team of space professionals, which might be even more important than the technologies."

NASA announced on Friday to launch its first SpaceX crewed flight to the International Space Station (ISS) on May 27.

NASA astronauts Robert Behnken and Douglas Hurley will fly on SpaceX's Crew Dragon spacecraft, which will lift off on a Falcon 9 rocket at 4:32 p.m. EDT May 27, from Launch Complex 39A in Florida.

It will be the first time since 2011 that NASA astronauts launch on an American-made rocket from American soil, said NASA.

It will also be the first crewed mission for SpaceX since its founding 18 years ago.

The upcoming Crew Dragon mission, dubbed Demo-2, will be the final test for SpaceX, including the launch pad, rocket, spacecraft, and operational capabilities. This also will be the first time NASA astronauts will test the spacecraft systems in orbit, according to NASA.

The mission duration will be determined once on station based on the readiness of the next commercial crew launch, although the Crew Dragon being used for this flight test can stay in orbit about 110 days, said NASA.

Behnken and Hurley were among the first astronauts to begin working and training on SpaceX's next-generation human space vehicle, and were selected for their extensive test pilot and flight experience, including several missions on the space shuttle, according to NASA.

Behnken will be the joint operations commander for the mission, responsible for activities such as rendezvous, docking and undocking, as well as Demo-2 activities while the spacecraft is docked to the ISS.

Hurley will be the spacecraft commander for the mission, responsible for activities such as launch, landing and recovery.

Lifting off atop a specially instrumented Falcon 9 rocket, Crew Dragon will accelerate the two astronauts to about 27,200 kilometers per hour, and put it on an intercept course with the ISS.

In about 24 hours, Crew Dragon will be in position to rendezvous and dock with the ISS, according to NASA.

The ISS has continually hosted a rotating crew of astronauts from all over the world since 2000. Russia has been the only country capable of transporting astronauts to and from the ISS since 2011.