The space shuttle Atlantis pierced the sky one last time Friday morning, blasting off its launch pad at Kennedy Space Center to begin the 135th and final mission in NASA's 30-year shuttle program. The launch was nearly delayed by stormy weather swirling around eastern Florida, but the clouds parted just enough to let the historic liftoff proceed as planned. Some 1 million people crowded onto Florida's Space Coast to watch as Atlantis roared toward the heavens, while countless more watched online and on TV around the world.

"Atlantis is flexing its muscles one final time," ascent commentator Rob Navias said from Mission Control in Houston, as the shuttle thundered skyward at more than 2,600 mph (it was up to 15,000 mph a few minutes later). Atlantis' final voyage will be a 12-day mission to bring supplies to the International Space Station, which orbits 220 miles above the Earth and owes its existence to the shuttle program. NASA's space shuttles have been the main workhorses carrying parts and supplies to the orbital outpost for more than a decade, and even though Reuters describes this final mission as "among the most routine of any of the 134 that preceded it," it could prove crucially important for the ISS. The station will be relying largely on private companies to deliver supplies in the post-shuttle era, and could be left in the lurch if those companies encounter delays in developing their rockets. Atlantis' final flight, therefore, will help tide the ISS over with supplies until the private space industry gets its sea legs. Atlantis is scheduled to arrive at the ISS Sunday morning.

Atlantis first soared into space in October 1985, when the shuttle program was still in its infancy. The first shuttle, Columbia, had inaugurated the program just four years earlier in 1981, and the idea of a reusable spacecraft wasn't yet old hat. In the three decades since, space shuttles have launched and fixed scores of satellites, performed hundreds of scientific experiments, deployed and repaired the Hubble Space Telescope, built and maintained the ISS, and carried 355 astronauts across half a billion miles of space, among many other feats. For people at NASA, in Florida, across America and all around the world, the final flight of Atlantis is a bittersweet end to a 30-year run that transformed humanity's relationship with its home planet. "I don't think we'll see another vehicle like it, for decades perhaps," Atlantis Commander Chris Ferguson told CNN before Friday's launch. "I mean, just the technology involved in flying back from space. It's an amazing vehicle, and its legacy will live on."

To read more about the shuttle program and other NASA milestones, check out MNN's interactive history of U.S. manned space flight.

(Sources: NASA, Space.comCNN, Reuters, Washington Post)


Now that the space shuttle program is ending, what will NASA do next? Shuttles have spent most of the last decade schlepping up to the International Space Station, a job that will now fall to other countries and private companies. And even though NASA programs have ended before, they've always passed the torch: Mercury begat Gemini, Gemini begat Apollo, Apollo begat Skylab, and so on. The shuttle program, however, is ending with no immediate successor in sight — raising questions not just for NASA, but also for its would-be heroes waiting in the wings.

"We tell kids, 'When you grow up, you can be an astronaut,'" science teacher Guytri Still tells USA Today. "What do we tell them now?" Still teaches at Florida's Ronald McNair Magnet School, named after the Challenger astronaut, and says she fears the end of the shuttle program will dampen her students' dreams of flying in space. But according to Peggy Whitson, head of NASA's astronaut corps, those fears are unfounded. "The biggest misconception with the shuttle program coming to an end: We're not going to be flying astronauts," Whitson tells USA Today. "We are. I still want young people to dream to be astronauts. There will be jobs out there." Some of those jobs will be in the private sector, flying for companies like SpaceX, Sierra Nevada or Virgin Galactic. NASA will still employ astronauts, too, just fewer of them: Russian Soyuz spacecraft will take just four U.S. astronauts to space per year, down from the six or seven who rode shuttles into orbit several times annually. More than 3,000 people applied for the last astronaut class, in 2009; just nine were selected. 

But as TIME reports, there are new missions on the distant horizon for NASA: Orion, aka "multi-purpose crew vehicle" or MPCV, could revive Apollo-era technology to send astronauts beyond low-Earth orbit as soon as 2016. "We are building Orion with capabilities to do deep-space missions exclusively at the moment," says program manager Mark Geyer. "The ship can carry six people, but we'd configure it for four to provide more room for the astronauts to move around."

(Sources: USA Today, TIME)


The EPA issued sweeping new emissions rules for power plants in 28 states on Thursday, regulations that would slash the release of chemicals known to damage ecological as well as human health. Set to take effect in 2012, the rules would reduce emissions of sulfur dioxide and nitrogen oxide from coal-fired power plants, compounds that contribute to soot, smog and acid rain. The EPA says the improved air quality could prevent up to 34,000 premature deaths, 15,000 nonfatal heart attacks, and hundreds of thousands of asthma cases and other breathing problems every year.

As EPA Administrator Lisa Jackson tells the New York Times, the rules will benefit some 240 million Americans living in states where pollution is produced or where it blows downwind from elsewhere. "No community should have to bear the burden of another community's polluters, or be powerless to prevent air pollution that leads to asthma, heart attacks and other harmful illnesses," Jackson says. "This is a long-overdue step to protect the air we breathe." The regulations will apply to all states east of the Rocky Mountains except the Dakotas, Delaware and the six New England States, the Times reports, and significantly strengthens an existing acid-rain program that was part of the 1990 Clean Air Act amendments.

While public health and environmental advocates are heralding the rules as much-needed upgrades to U.S. law, some industry representatives argue power companies can't afford to comply. "The EPA is ignoring the cumulative economic damage new regulations will cause," says Steve Miller, president of the American Coalition for Clean Coal Electricity. "America's coal-fueled electric industry has been doing its part for the environment and the economy, but our industry needs adequate time to install clean coal technologies to comply with new regulations. Unfortunately, EPA doesn't seem to care." The executive director of another power-industry coalition, however, says critics like Miller are just blowing smoke. "The bottom line is, the industry is well positioned to comply with this, has been anticipating this for three to four years now," says Michael Bradley of the Clean Energy Group. The EPA estimates the new rules will cost the industry less than $1 billion a year overall.

(Sources: New York Times, MSNBC)


Polar bears are icons of the Arctic, symbolizing the region's stark beauty as well as its swift decline due to global warming. But according to a new study published in the journal Current Biology, all polar bears alive today descend from a single female brown bear that lived 20,000 to 50,000 years ago in what's now Ireland. DNA samples from all corners of polar bear country reveal that every individual can be traced back to this single Irish ancestor, the AFP reports.

In addition to finding polar bears' Irish roots, the study also shows they periodically interbred with brown bears over the past 100,000 years. Grizzly bears are now migrating north into polar bears' habitats as global temperatures rise, a trend some experts have worried could further threaten the already-endangered Arctic bears — but in light of the two species' history together, that interbreeding may not be such a bad thing, the study's authors suggest. "Hybridization could certainly result in the loss of unique genetic sequences, which could push them toward extinction," says lead author Beth Shapiro, a professor at Pennsylvania State University. "But scientists should reconsider conservation efforts focused not just on polar bears but also on hybrids, since hybrids may play an underappreciated role in the survival of certain species."

It has long been known that polar bears descended from ancient brown bears, but the new study shows that polar bears have plenty of evolutionary experience in adapting to changing circumstances — suggesting their romantic past with grizzlies could help them endure the upheavals of climate change. "Generally, this [interbreeding] seems to happen when climate changes force the bears to move into each others' habitat," Shapiro says. "When they come into contact, there seems to be little barrier to them mating."

(Sources: Agence France-Presse, London Independent)


Oil baron John D. Rockefeller is born, USS Jeannette crashes in the Arctic, and more.

Russell McLendon

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Photo (space shuttle Atlantis lifting off on July 8, 2011): NASA/ZUMA Press

Photo (Kennedy Space Center Visitor Complex): Chip Somodevilla/Getty Images

Photo (emissions wafting up from a coal-fired power plant): ZUMA Press

Photo (mother polar bear and her cubs): U.S. Fish and Wildlife Service

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

Weekend Briefing 7/8/2011
Space shuttle Atlantis lifts off, EPA issues new air rules, polar bears are Irish, and more.