In today’s Bulldog wrapup of science and technology news:

  • The world’s first four-person plane powered bu fuel cells flies
  • Watch a video with highlights of the flight
  • The FCC beefs up emergency text alerts
  • A “smog-free” tower tackles Beijing’s pollution
  • The comet-chasing space mission coming to a close

The details:

  • World’s first 4-seater fuel-cell plane takes off in Germany

Aircraft engineers in Germany have successfully tested the world’s first four-seater plane that uses emission-free hybrid fuel cells to fly.

The 10-minute test flight Thursday at Stuttgart Airport in southwestern Germany involved two pilots and two dummy passengers.

The twin-cabin plane, known as HY4, was developed by aircraft maker Pipistrel, fuel cell specialist Hydrogenics, the University of Ulm and the German Aerospace Center DLR.

It uses hydrogen to generate electricity in-flight, giving it a cruising speed of 165 kilometers per hour (102.5 mph) and a range of up to 1,500 kilometers (932 miles), while relying on batteries for take-off and landing.

Boeing and Airbus have also tested smaller fuel cell planes in recent years as the aircraft industry searches for ways to reduce emissions.

  • VIDEO: Watch a video about the flight (captions in German) at:

  • FCC beefs up emergency cellphone alerts

The federal government is beefing up emergency cellphone alerts like the one used in New York to advertise a search for a bombing suspect earlier in September.

The Federal Communications Commission approved a measure Thursday that will let messages be up to four times longer than the current 90-character limit. Cellphonecompanies will have to support Spanish messages under the new rules. The changes will also let officials target messages more narrowly and include links in messages. The New York alert had an awkward phrasing, “See media for pic,” rather than a link to Ahmad Khan Rahami’s photo.

The FCC also says it’s seeking comments on how to attach photos inside actual alerts themselves.

  • Beijing’s latest answer to pollution: the Smog Free Tower

In a city where smog routinely blankets the streets, a Dutch artist has offered an eccentric solution: a 7-meter (23-foot) metal structure that takes in smog and expels cleaner air.

Daan Roosegaarde’s Smog Free Tower opened Thursday on a small, grassy lot inBeijing’s famed 798 arts district. Comprised of 45 silver plates resembling partially open window blinds, the tower contains an air-purifying machine that runs continuously with a low hum.

“That is not noise!” Roosegaarde told a visitor standing next to the tower. “That is the beautiful sound of clean air moving toward you!”

There’s hardly a more scarce resource than clean air in Beijing on a high-pollution day, particularly in wintertime when the region’s coal-fired electrical plants are running at full capacity. The levels of dust and harmful particles in Beijing’s air are among the highest in the world.

Government researchers have linked the pollution to higher rates of lung cancer and on particularly bad days, schools keep children inside during playtimes and many pedestrians don masks designed for hospitals or construction zones.

Roosegaarde, whose projects focus on connecting people with nature and energy, came up with the idea for the tower after a visit to Beijing three years ago during which he saw the view outside his window blocked by the thick gray haze.

“I couldn’t even see the next street,” he said. “That image changed me.”

  • Europe’s comet chaser gets final commands to end its mission

Europe’s comet-chasing space probe Rosetta has received its last commands putting it on course to crash-land on the icy surface of the alien world it’s been following for more than a decade.

Scientists say Rosetta fired its thrusters for 208 seconds late Thursday and is now expected to hit the surface of comet 67P/Churyumov-Gerasimenko at 1038 GMT Friday.

During its final descent the probe will carry out a series of pre-programmed commands including taking unprecedented low-altitude images of the comet that could reveal surface features as small as an inch (2.5 centimeter).

The European Space Agency’s Rosetta probe and its sidekick Philae, which landed on the comet in November 2014, have provided scientists with new insights into the composition of comets and the formation of celestial bodies.