The space shuttle Endeavour is spending its last hours in space today, soaking up the cosmos before returning to Earth for the 25th and final time early Wednesday morning. The shuttle's six-man crew will fly back to Cape Canaveral, Fla,. at 2:35 a.m. Eastern time Wednesday, ending not only Endeavour's 16-day mission, but also its 19-year career — and bringing NASA's 30-year shuttle program one step closer to its finale. "Endeavour's performed really, really well for us over these 16 days, as it has since its first flight," commander Mark Kelly said Tuesday. "When we land in Florida tomorrow, it's going to roll into the hangar and get prepared for the next step, the next phase of its life, which is in a museum. ... [I]t is a bittersweet moment. It's been a great spacecraft."
The weather forecast for Wednesday's landing looks "promising," NASA flight director Tony Ceccacci said in a statement released this morning, adding that he's "very confident that trend is going to stay the same until tomorrow." NASA had been concerned in recent days about high crosswinds that could have interfered with landing, the AFP reports, but those forecasts have since improved. Crosswinds are now expected around 10 knots, below the maximum of 12 knots for a nighttime touchdown at Kennedy Space Center. "It's usually not that windy at night," mission manager LeRoy Cain tells Space.com. "A lot of times, we're able if not on the first opportunity, at least the second opportunity, if things die down." There had also been concerns about the shuttle's fuel cells, since a monitor that tracks their performance has been repeatedly failing self-tests, although NASA engineers now believe the problem is with the monitor rather than the fuel cells themselves. "We think it's really just an issue with this performance monitor box," says lead shuttle flight director Gary Horlacher. "Looking at the fuel cell performance in real time, the fuel cell was performing great."
Endeavour is the youngest of NASA's three space shuttles, having joined the fleet in 1992 to replace the Challenger, but it still managed to rack up a lengthy résumé in that time. When it returns to Earth Wednesday morning, it will have traveled 123 million miles and spent 299 days in orbit, and played a major role in making the International Space Station what it is today. Endeavour departed from the space station over the weekend, after its crew finished installing a $2 billion cosmic-ray detector, an extension beam and platform of spare parts. "The space shuttle has been the workhorse of the U.S. space program for better than 30 years now, so it'll be sad to see it retired," Kelly said Monday. "But we are looking forward to new spacecraft and new destinations and we're all excited about the future." Atlantis, the last NASA shuttle to retire, is scheduled to make its final liftoff on July 8.
As historic floods continue to suffocate the Mississippi River Delta this week, people in the Northern Plains face a flood fight of their own — and it could last for months, the Mitchell (S.D.) Daily Republic reports. An unusually heavy snowmelt this spring has pushed the Missouri River to historic heights, spurring it to follow in the Mississippi's footsteps and reach flood levels not seen in at least half a century. Although no mandatory evacuations have been ordered yet, officials say some residents may have to flee for a while. "Residents should plan to be away from their homes for as long as two months," says Eric Stasch, operations manager at Oahe Dam in north-central South Dakota.
The governors of Montana, Wyoming and the Dakotas have called up hundreds of National Guard troops to lay sandbags and blockade flooded roads, Reuters reports, while days of heavy rain have added to the intense flooding from record snowmelt in the Rockies. The central Montana community of Roundup has already been cut off by up to 8 feet of floodwaters after the Musselshell River breached its banks last week, forcing the state to deliver food and fresh water to the town's 2,000 residents. "There's a whole heck of a lot of water everywhere," says Ed Tinsley, head of Montana Disaster and Emergency Services. "This could be a pretty significant week for flooding," adds Monique Lay, spokeswoman for the Montana Emergency Coordination Center, "and it might expand."
Controlled releases from the Garrison Dam in North Dakota reached record levels Monday, Reuters reports, and authorities have begun going door-to-door in the capital city of Bismarck, as well as nearby Mandan, encouraging voluntary evacuations. "We're in completely uncharted territory," says Cecily Fong, spokeswoman for the North Dakota Department of Emergency Services. A spokesman for the U.S. Army Corps of Engineers says the Missouri River is already between 3 to 7 feet above flood stage from Omaha, Neb., to St. Louis, Mo., where it connects with the similarly flooded Mississippi River.
Humans are slurping up so much groundwater that it has affected how the Earth wobbles through space, the New York Times reports, further raising concerns about the stability of one of society's top drinking-water sources. Using two satellites that monitor each other while orbiting the planet, scientists at the University of California-Irvine have detected small shifts in Earth's gravity, allowing them to identify places where people are extracting water from subterranean aquifers at an unsustainable pace. The problems are spread around the globe, the Times reports, and could worsen rapidly as global warming and overpopulation stress the world's freshwater supplies.
"Look, water has been a resource that has been plentiful," says Jay Famiglietti, director of UC-Irvine's Center for Hydrologic Modeling. "But now we've got climate change, we've got population growth, we've got widespread groundwater contamination, we've got satellites showing us we are depleting some of this stuff. I think we've taken it for granted, and we are probably not able to do that any more." Despite this growing wealth of information about groundwater woes, however, some policy makers are hesitant to embrace the new satellite data, the Times reports. In California's dry but agriculture-driven Central Valley (pictured above), for example, Famiglietti found that aquifers were reduced by 25 million acre-feet between October 2003 and March 2010, nearly enough to fill Lake Mead. That, says one member of the Association of California Water Agencies, raises fears of even tighter rules governing the state's scarce water supplies: "There's a lot of paranoia about policy wonks saying, 'We've got to regulate the heck out of you."
Using satellites to measure groundwater via gravity is unorthodox, yet surprisingly simple and straightforward, Famiglietti explains. "It gives you just one number," he says. "It's like getting on a scale." But it's not just in California that the findings are being met with skepticism — in India, where intensive farming has led to one of the fastest rates of groundwater depletion on the planet, the novelty of measuring aquifers from space isn't exactly being welcomed with open arms. "It is odd if you're a hydrologist, especially a traditional hydrologist, to imagine a satellite up in the air that determines groundwater," geophysicist John Wahr tells the Times.
The global economy may not be firing on all cylinders quite yet, but there is a new sign the recession is over — it's just not a very encouraging one. Energy-related carbon dioxide emissions reached a record level in 2010, the International Energy Agency announced today, after taking a major nosedive in 2009 amid the economic slowdown. China and India helped fuel most of the record rise, the IEA reports, but emissions have also grown in developed countries.
Global CO2 emissions dropped in 2009 after years of increases, ultimately reaching a mere 5 percent of the previous record in 2008. But that turned out to be just a minor setback for the overall growth of heat-trapping emissions, which hit a record 30.6 gigatonnes last year. That, the BBC reports, raises doubts about the ability of U.N. climate talks to yield real, achievable reductions in the near future. World leaders agreed at a 2010 meeting in Cancun, Mexico, that dramatic emissions cuts are needed to prevent a climatic catastrophe, but genuine action has been elusive during two decades of such negotiations.
"The world has edged incredibly close to the level of emissions that should not be reached until 2020 if the 2 [degree Celsis] target is to be attained," says Faith Birol of the IEA. "Unless bold and decisive decisions are made very soon, it will be extremely challenging to succeed in achieving this global goal agreed in Cancun."
Johnstown Flood kills 2,200 in Pennsylvania, earthquake devastates Peru, and more
Photo (space shuttle Endeavour on May 28): NASA
Photo (Missouri River in Montana): U.S. Geological Survey
Photo (California's Central Valley): David McNew/Getty Images
Photo (coal-fired power plant in Germany): ZUMA Press