Over the years, NASA has successfully sent several rovers (飞行器) to Mars. While the science laboratories continue to provide important information on the Red Planet, they keep the space exploration rovers staying close to the original landing place.To get a more comprehensive (详尽的) view of Mars, the US Space Agency plans to make a small test helicopter with the Mars 2020 Rover, which will be sent off in July 2020.

The football-sized “marscopter” weighs about four pounds. It can fly at about ten times the speed of helicopters on Earth. The light weight and fast speed are important for the helicopter to be able to fly in the thin Mars atmosphere, which is about just one percent of that of Earth. “To make it fly in that thin Mars atmosphere, we had to make everything ready, and make it as light as possible while being as strong and powerful as it can possibly be. “Mimi Aung, Mars helicopter project manager, said in a meeting.

Upon landing on the Red Planet, the Mars 2020 Rover will find a proper location to send of the helicopter. The helicopter will start with a short climb, no higher than 10 feet, and hover (盘旋) for just 30 seconds before landing back on the Mars surface. If all goes well, five more flights of longer distances, for 90 seconds each, will be conducted over the next 30 days. The short journeys will be recorded by a small camera and sent back to the scientists on Earth.

If the plan goes on well, the first helicopter to fly in another world, will open up a whole new way to explore Mars. The Mars helicopter's first flight will be a great invention. For those of us whose research is about flight, that would be a wonderful, historic moment.

Concerns about health, animals and the environment are leading more people to remove meat from their diet. Plant-based meat alternatives (替代品) increasingly appear in supermarkets and restaurants. But what some people call clean meat-meat grown from cells in a laboratory—is still an idea that is just beginning.

More than 24 companies are testing lab-grown fish, beef and chicken. These businesses hope to enter the alternative meat market, which could be worth $140 billion by 2029. One of the companies, Shiok Meats, grows its product by taking shrimp cells and keeping them at a fixed temperature. They are then given nutrients in a solution (溶液). The cells become meat in four to six weeks.

This lab-grown meat’s price is high. One kilogram of it now costs $5,000, said Shiok Meats’ chief executive Sandhya Sriram. At that cost, a single pork and shrimp dumpling could be as much as $300. Sriram, a vegetarian, hopes to cut the cost to $50 for one kilogram by the end of this year. “We are looking at next year, so we might be the first ever company to launch a cell-based meat product in the world,” Sriram said. “Shiok Meats still needs approval from the city’s food regulator, and that matters the most at present.”

Although people increasingly demand meat alternatives, cell-based meat companies still face resistance (抵制) to their products. In Singapore, some people said they would give lab grown meat a second thought. “I may not exactly dare to eat it, but I do find the idea appealing because the animals in the oceans are declining,” said 60-year-old Pet Loh, while she shopped for shrimps in a Singapore market.

Any alternative way of making animal protein without harming the environment is positive, said Paul Teng, a specialist in agriculture technology at Nanyang Technological University. But, he added, more studies are needed to understand any negative result of making cellular protein.

A Dutch company is starting deliveries of the world’s first production-ready solar car to customers later this year, promising months of charge-less driving in summer conditions.

Lightyear, founded in the Netherlands in 2016, is making 949 of the models featuring curved (曲面的) solar panels across the car’s hood (引擎盖) and roof. Power coming from the sun will add as much as 70 kilometers of driving range per day from the sun.

The company says the car will be able to drive around 624 kilometers without stopping to recharge, and each hour in the sun will add up to nearly 9 kilometers of charge to the battery.

“Electric cars are a step in the right direction, but they are dependent on the grid (电力), which is still dependent on mostly fossil fuel energy,” Chief Executive Officer and Co-Founder Lex Hoefsloot said at the reveal of the $263,000 Lightyear 0 model.“Adding a new source, the sun, adds certainty that you will always have that charge and you will have to charge a lot less often.”

According to Lightyear the better solar roof and design mean that the car can drive for weeks, even months, without charging.In cloudy climates, based on the average travelling of around 35 kilometers per day, the car can drive for up to two months before needing to be charged.In sunnier countries, that could be up to seven months. Plugged into a regular home socket (插座), Lightyear 0 can still charge 32 kilometers of range per hour. In fall Lightyear will start up production, with the first cars reaching their drivers in November.