The journey into space is a long and dangerous one, and not many people are able to do it. Lots of training is in need before one gets on the spaceship. But soon, it may be as simple as riding an elevator.

A group of Japanese scientists from Shizuoka University have been working on a “space elevator”, which will allow easy access to space.

On Sept 22nd, 2018, two tiny satellites were sent to the International Space Station（ISS）as a test for the space elevator. The mini elevator has a 10-merer steel cable. It works as a tiny model of a full-size “space elevator”, which might reach from Earth all the way to outer space. “It’s going to be the world’s first experiment to test elevator in space,” the spokesman of Shizuoka University said.

According to Science Daily, the research team hopes to build the elevator by 2050. The space elevator may be able to carry up to 30 people. The trip will be about 36,000 km, which will take around eight days to complete. If it is successful, space elevators will greatly cut the cost of transporting cargo into space from $22,000（154,000 yuan）to $200（1,400 yuan）per kilogram. More importantly, they will produce less pollution during spree travel.

Still, there are many hurdles along the way. According to the official website of the US-based Smithsonian Institution, until now, researchers haven’t found a material strong enough to hold the stress placed on the elevator cable. Even carbon nanotubes, the strongest material they have found so far, would break under the stress.

The challenges facing the space elevator are massive, but they have not stopped Japan from working on it. “Japanese researchers believe the idea of space elevator will be realised. since there are many scientists in the fields of robotics and carbon nanotube technology in the team,” Michelle Z. Donahue, Smithsonian science reporter, wrote in 2016.

What do black holes look like? We finally got the answer: They look like dark circles with a bright ring around the outside. Scientists took the world’s first photo of a black hole. The black hole is very far from the Earth—about 55 million light years away. This is not the only black hole in the universe.

Black holes are mysterious in the universe. A photo can help us learn more about them. How much do you know about black holes? Try to answer the following questions.

Q: What is a black hole?

A: A black hole comes from a dying star. The star turns into a small point. The point has much mass and strong gravity. The strong gravity of a black hole pulls things. The black hole “eats” these things. Black holes can even “eat” light. That’s why a black hole looks “black”.

Q: If black holes are “black”, how do scientists know they are there?

A: We cannot see black holes. But we can see how their strong gravity works on the things around them. A black hole’s gravity pulls dust and gas into it. And if a star is orbiting a point in space, scientists can study the star’s orbit. They can tell if the star is orbiting a black hole.

Q: How did scientists take the picture of the black hole?

A: Scientists didn’t use a camera to take the picture. They used eight radio telescopes in different places across the world. The telescopes got information from the black hole. Scientists used computers to deal with the information. It took them two years to get the final picture.

Q: Will the sun turn into a black hole? And if it does, will it “eat” the Earth?

A: The sun won’t become a black hole. According to NASA, it does not have enough mass to turn into one. When the sun dies, it will become a smaller and cooler star. Even if the sun becomes a black hole, the Earth would still be safe.

Have you ever seen people building houses? To build a house, you need workers. They use their hands, tools and machines to put things together. Building the ISS(国际太空站) is the same. The difference is that the workers are astronauts. They walk in space and use robots' arms and hands to do their work.

In the space station, astronauts are comfortable. The temperature there is about 21℃. But outside the station, it can be too hot or cold for people. In the sunlight, it's about 120℃. In the shadow, it's about-85℃. So when astronauts walk in space, they have to wear heavy clothes—spacesuits.

Spacesuits also keep astronauts safe from flying litter in space. Astronauts should be careful because there's a lot of rubbish. Some rubbish goes a lot faster than a plane! Space walking is not easy, and it can be dangerous. So getting ready for it takes a lot of time. Astronauts will need to do 160 space walks to finish their work in the ISS. That will take about 1,900 hours of work.