Gallery: Monsters of the skies: giant beasts that ruled the air

The US should be aiming to put astronauts on Mars in the long term and on asteroids in the short term, according to a new from the .

Instead of trying to recapture the thrill of the Apollo era of lunar exploration by putting people back on the Moon by 2020 – the outlined by President Bush in 2004 – the space advocacy organisation is urging the incoming Administration and Congress to set its sights farther beyond Earth.

NASA should begin a new era of human exploration with relatively modest excursions to nearby destinations, such as asteroids, before stepping up to more ambitious missions, including to Mars, the society says.

“We’d like to see a human exploration programme with specific milestones that gets people out above low-Earth orbit, out to other destinations,” says society president Jim Bell of Cornell University.

“We’re not against going to the Moon,” Bell told New ĐÓ°ÉÔ­´´, “but there’s perhaps a more logical flow that could be developed. Going to the Moon may make sense at the right time.”

Mars is “new and different and exciting. Scientifically, it also has the potential to be very rewarding”, Bell added (see NASA urged to focus on sending people to Mars).

International collaboration

NASA is facing a gap in its access to space, since the space shuttles are now scheduled to be retired in 2010 and their replacements will not be ready until 2015.

While some experts have proposed postponing the shuttle’s retirement to bridge that gap – a move estimated to cost $2.5 billion to $4 billion per year, the Planetary Society says NASA should stick to the 2010 retirement date. A US government oversight office said last week that unless NASA’s budget was increased, extending the shuttle’s lifetime could delay the development of its replacement.

The agency’s budgetary pressures could be relieved with more international collaboration, including with relative newcomers to the space scene like China, South Korea and Brazil.

“Some nations may choose to participate, some may not,” Bell says. “Let’s get it out there and leave the door open to those possibilities. Pragmatically, it may save NASA some money.”

The new report also stresses the importance of robotic missions, such as the Mars rovers, and NASA’s Earth observation programmes. The “international spirit of cooperation” that the Planetary Society hopes to see for space exploration “can also be applied to other problems like climate change,” Bell says.

Continued from part I of our extreme life feature, which lists life-forms that set records for surviving in the hottest, coldest and saltiest conditions.

The acid test

Acidic hot springs and geysers that would eat away at human flesh are no match for some organisms that also make themselves at home in the acid runoff from mines.

The most extreme acidophiles known are microbes of the genus Picrophilus. They thrive at a pH of 0.7, and can grow down to a drain-clearing pH of 0. Both Mars, Europa and the clouds of Venus are thought to be acidic environments, so Earthly acidophiles intrigue scientists looking for life elsewhere.

Europa’s icy surface may be a potent mix of hydrogen peroxide and strong acids with a pH approaching 0, according to scientists who studied the spectral fingerprint of light reflected off the ice. If the acid on the surface is coming up from the ocean below, any life in the ocean would have to be tough.

Caustic customers

The most alkaline environments in the world are soda lakes, which can have a pH as high as 12, akin to ammonia. A number of microbes enjoy those caustic conditions, including Natronomonas pharaonis, which was first isolated from soda lakes in Egypt and Kenya in the 1980s.

Alkalis are substances that accept protons, while acids donate them. Because alkaline conditions damage cells, so-called alkaliphiles pump protons across their cell membranes to reduce the pH inside their cells.

There are places on Mars, like Gusev Crater, which resemble soda lakes on Earth, according to an . The crater was formed by a meteorite impact billions of years ago, and if there were water on the planet back then, it would have accumulated in the crater, turning it into an evaporative lake.

Deep comfort

Recently, living cells – many of which are Archaea from the Pyrococcus and Thermococcus genera – were found in a mud core taken from 1.6 km below the sea floor off the coast of Newfoundland. Though they represent the deepest life ever discovered beneath the sea floor, microbes of various kinds have been discovered at even greater depths under the continents. Communities of microorganisms have been found hunkered down in groundwater as far as 5 km below the surface of the land. ĐÓ°ÉÔ­´´s think life exists even further down – to the point where the subsurface heat becomes unbearable for life.

Even the deepest part of the ocean, the Mariana Trench, which plunges 11 km below the surface of the Pacific Ocean near Guam, is inhabited. Globs of mud pulled from the trench have yielded an assortment of bacteria, fungi and primitive single-celled organisms called . Video taken by an unmanned submersible that explored the area captured a sea cucumber, a scale worm and a shrimp in the trench, where the pressure would crush a human.

All dried up

In the most parched place on Earth, the Atacama Desert, which stretches nearly 1,000 km across South America, it rains only a few times a century. It’s no coincidence that the desert has been used by filmmakers as a stand-in for Mars, and by NASA to test instruments bound for the cold, dry planet.

Microbes like the bacterium Chroococcidiopsis have been found in the Atacama. But in its arid core, “finally we think we’ve found an environment where it’s too dry for life”, McKay says.

Water is thought to be crucial for life because it provides a medium for nutrients to diffuse into cells and wastes to drift out, and a solvent for critical metabolic reactions.

Even though Mars appears to be dry as a bone, it may have boasted liquid water in the past. And some researchers say liquid water may periodically form just below the planet’s surface – which may provide just enough of a toehold for life to survive there.

Living in a dump

Some microbes like nothing better than to be nestled in a toxic sludge of heavy metals like zinc, arsenic and cadmium. They thrive in hazardous waste dumps and in mine tailings, making a meal out of metal. , for example, convert dissolved uranium into a solid form, so it could be put to work cleaning up contaminated land.

Life’s a blast

Incredibly, the bacterium Deinococcus radiodurans can withstand about 2000 times the dose of ionising radiation that would kill a human, making it the most radiation-resistant organism known. A blast like that shatters the bacterium’s chromosomes, but it can repair itself within hours. That kind of resistance to radiation is likely to be important on worlds that don’t have a thick protective atmosphere, such as Mars.

And it means life might survive an extended trip through space. That raises the possibility that life on Earth arrived here on a meteorite – a concept called panspermia. Alternatively, it suggests life from Earth may have landed on other planets or moons on boulders blasted off Earth in an impact, though whether it could survive on those bodies is another matter.

Ageing well

Microbes can survive for many, many millennia, though scientists are still debating how long.

In 2007, active bacteria were isolated from permafrost samples drilled in Siberia, northwestern Canada, and Antarctica that were estimated to be up to half a million years old.

There are reports of microbes surviving for much longer in a kind of suspended animation. In 1995, researchers said they’d revived a bacterium taken from the gut of a bee preserved in amber for at least 25 million years.

In 2000, scientists made an even more astonishing claim – that they had brought to life a 250 million-year-old bacterium dubbed Bacillus permians. According to the team, bacterial spores in a drop of water became trapped in a cavity inside salt crystals as they formed 250 million years ago. But other scientists countered that water often moves through salt deposits, potentially contaminating the ancient salt crystals with younger microbes.

Those reports remain controversial, but nevertheless, the ever growing list of long-lived microbes gives scientists hope that life may exist elsewhere in the solar system.

Such tenacity might come in particularly handy on Mars, which appears to have been cold and mostly dry for most of its 4.5-billion-year history but which may periodically become more hospitable to life.

For example, the planet tilts over on its axis on timescales of about 50,000 years. The Sun thus warms its poles, potentially allowing liquid water to appear in thin films between ice crystals and mineral grains. Any dormant bacteria in the polar ice could thus spring to life during these relatively balmy periods.

Read part 2 of this article

While scientists find ever more planets around other stars and contemplate missions to probe the far reaches of our own solar system, researchers are looking to the extremes of the Earth for clues about what kind of organisms could exist in the brutal conditions elsewhere.

There’s hardly a niche on Earth that hasn’t been colonised. Life can be found in scalding, acidic hot pools, in the driest deserts, and in the dark, crushing depths of the ocean. It has even found a toehold in the frigid polar regions and in toxic dumps.

“Life on Earth has radiated into every conceivable – and in some cases almost inconceivable – ecological niche,” says of the University of Arizona in Tucson, US.

The very existence of these hardy organisms hints that life might be able to eke out an existence in the cold, dry climate of Mars, the icy, acidic conditions of Jupiter’s moon Europa, or in countless other spots beyond our solar system.

So here are some of Earth’s toughest organisms – although the record-setters are subject to debate.

Some like it hot

Steaming hot pools and scalding undersea hydrothermal vents provide a cosy habitat for heat-loving extremists.

Such ‘thermophiles’ produce enzymes that are stable at high temperatures. Some have been isolated and put to work in everything from laundry detergents to food production.

The upper limit for life had been widely recognised as 113 °Celsius, thanks to a microbe called Pyrolobus fumari that was in 1997 inside a single hydrothermal vent in the Atlantic Ocean, 3650 metres below the surface.

However, a microbe collected from a vent in what’s known as the Faulty Towers neighbourhood, 2400 metres down in the Pacific Ocean, has upped the ante.

It survived – and multiplied, scientists say – during a 10-hour blast in a 121 °C autoclave, an oven used to sterilise medical equipment. Researchers finally managed to kill the hardy microbe by cranking the temperature up to 130 °C. It’s been given the preliminary name of “Strain 121” and is in the same family as Pyrolobus fumari.

Hydrothermal vents may have existed once on Mars and may still exist in an ocean under Europa’s icy crust, some scientists say, making them prime targets in the search for extraterrestrial life.

Cold comfort

The most frigid polar regions and the darkest depths of the ocean are home for a few organisms that like a good chill.

Many are bacteria or similar single-celled organisms called Archaea, but some lichens called cryptoendoliths go to extremes by colonising pores in Antarctic rock. There’s also an alga that creates reddish ‘watermelon snow’ – a phenomenon first described by Aristotle.

Cold-loving organisms, called psychrophiles, have specialised cell membranes that don’t stiffen in frigid temperatures, and many produce a kind of protein antifreeze.

It’s difficult to figure out the lowest temperature limit for life, says , a NASA scientist who studies life in cold, dry environments. That’s because as the mercury drops, growth slows – to the point where it’s almost imperceptible.

Microbes are known to grow at -12 °C, and they survive at -20 °C. Some studies even hint that a bacterium called Colwellia psychrerythraea strain 34H can withstand -196 °C, the temperature of liquid nitrogen.

Research on cold-loving Earth organisms is especially valuable, McKay says, because “all the places in the solar system that may harbour life” – like Mars and Europa – “are cold and icy”.

Salt of the Earth

Despite its name, the Dead Sea does harbour life. It’s the saltiest body of water on Earth, but a few microbes thrive there, in water eight times saltier than the ocean. ĐÓ°ÉÔ­´´s studying one of them, Haloarcula marismortui, discovered that it has specialised proteins that protect it from the effects of salt.

ĐÓ°ÉÔ­´´s have theorised that any microbes living on Mars would have to be something like terrestrial halophiles in order to cope with the planet’s high salinity.

However the results of recent explorations by the rover Opportunity, which found magnesium sulphate deposits that may have been left by salty water, have some scientists saying Mars may have been too salty to sustain any kind of life.

Other scientists say it’s too soon to draw that conclusion, however, and McKay says there are probably regions on Mars that were not as harmful to life. “It can’t be too salty everywhere,” he told New ĐÓ°ÉÔ­´´.

Click here to continue reading about extremophiles that can withstand high doses of radiation, acids and more.

A miniature detector could pick out magnetic rocks on Mars that might harbour telltale signs of ancient life.

The instrument could select rocks that contain a magnetic compound – magnetite – that is also produced by bacteria on Earth. The rocks could then be brought back to Earth for closer examination.

Other efforts to find signs of life on Mars have focused on organic molecules, but Soon Sam Kim of NASA’s in Pasadena, California, US, wants to look for crystals of magnetite like those made by terrestrial bacteria.

“Because it’s just a mineral, it has a better chance of survival over billions of years,” Kim told New ĐÓ°ÉÔ­´´.

, a physics professor at the University of Houston in Texas, US, who has worked on ways of finding life on Mars, says: “It looks like a very interesting idea – to look for signatures of these crystals on Mars directly.”

Global field

Some terrestrial bacteria make magnetite so they can orient themselves with the Earth’s magnetic field and move along it in search of the most favourable conditions.

Mars doesn’t have a global magnetic field now, but evidence suggests it once did. “If that’s the case, then there could have been some impetus for organisms of that nature to evolve – if indeed life took hold,” Miller told New ĐÓ°ÉÔ­´´.

Other microbes produce magnetite as a byproduct of using iron in their metabolism. So if life took hold on Mars, it might have taken advantage of the abundance of iron on Mars, whose distinctive red hue comes from iron oxide, says Miller.

Size matters

Bacteria produce magnetite crystals in a very narrow size range, whereas ‘non-biogenic’ minerals occur in a variety of sizes and shapes. The variations in size mean that different kinds of magnetite have distinct magnetic properties.

Kim designed an instrument that scans rock samples to find these magnetic signatures. It is about twice as long as a shoebox, weighs about 2 kilograms and requires just 5 watts of power.

Researchers have previously used microscopes to examine magnetite in Mars rocks. With the new detector, “we don’t have to study particle after particle under the microscope”, Kim told New ĐÓ°ÉÔ­´´.

Muddled signal

Kim has already used his technique on a found in Antarctica. The rock created a stir in 1996, when scientists suggested it contained fossils of tiny Martian microorganisms, an idea that has since widely been discredited.

The meteorite does contain magnetite, but the results of an analysis by Kim and other scientists in 1999 proved inconclusive – the magnetite’s magnetic signature looked like something in between the signals expected for biogenic and non-biogenic magnetite.

Kim says there may not have been enough magnetite crystals in the sample to obtain a clear magnetic signature – a mixture of the two kinds of magnetite might have produced the “muddled” signal.

The detector has not been assigned to any specific Mars missions, but Kim says it could offer a good “preliminary sample selection tool” for a future Mars sample return mission.

Astrobiology – Learn more in our out-of-this-world .

Mars Rovers – Mars is full of surprises, learn more in our continually updated .

The White House requested $4.4 billion for the agency’s science programmes in 2009 – $264.7 million less than the previous year.

On Thursday, at a hearing of the US House Committee on Science and Technology’s , members expressed concern about how NASA will accomplish its goals under the planned budget.

“NASA is an organisation straining to do too much with too little,” said ranking member .

At the hearing, subcommittee members questioned NASA officials about whether they’ll be able to achieve ambitious ‘flagship’ programmes such as a mission to moons of the outer solar system and a long-awaited Mars Sample Return (MSR) mission within the constraints of the science budget.

NASA’s high-profile , which currently has two trundling around the planet, is one of the areas that’s getting cut: by $918 million from 2009 until 2012.

Shrinking budget

NASA is planning more missions to Mars in 2013 and 2016, and intends to collaborate with international partners on the sample return mission, currently scheduled to be underway by 2020. But subcommittee members are worried that NASA won’t be able to fly all those missions given the programme’s shrinking budget.

, chief scientist of the Mars rover mission, told the committee the Mars programme has “big problems”. The only way to keep the MSR mission on schedule is to not fly the earlier two missions, he said. Alternatively, to do all three, Squyres said the MSR mission would have to be delayed. “I think it’s an either or proposition,” he said.

However , NASA’s associate administrator for the Science Mission Directorate, believes the missions can go ahead on schedule, although he said the earlier endeavours may have to be scaled back to leave enough money for the MSR mission.

But with the scramble to fund flagship missions like MSR, Feeney said they “should not be able to crowd out smaller but still scientifically significant missions“.

“It’s robbing Peter to pay Paul,” said committee chairman . “I’m very concerned that such an approach will not be sustainable or credible.”

Climate change

Despite the tight budget, NASA is “is doing well with what it has”, , Chair of the Space Studies Board at the US , testified.

Stern said the good news is the 2009 budget puts more resources into research and analysis and into robotic missions to the Moon, and begins a $3 billion mission to the outer planets.

It will also increase NASA’s emphasis on earth science missions, which Berrien Moore III, co-chair of the NASA decadal survey for Earth sciences, says is crucial with the world facing “significant environmental challenges” such as water shortages, declines in fisheries and .

To help manage NASA’s budget, Stern says the agency is putting more emphasis on international collaboration and on having experienced principle investigators keeping programmes within budget and on time “so overruns become rare instead of routine”.

“We haven’t uncovered an issue,” Ellen Ochoa, deputy director of NASA’s Johnson Space Center in Houston, Texas, US, said at a press conference on Wednesday.

The anonymous, web-based survey was completed by all of NASA’s 31 flight surgeons and 87 of its 98 current astronauts. They were asked about the level of communication and trust among astronauts and flight surgeons, their knowledge of safety procedures and policy, and whether they would be comfortable raising safety concerns.

Astronauts and flight surgeons were also questioned about reports that an astronaut was drunk on launch day. The allegations surfaced in an independent review of astronaut health care, which was released in July 2007. That report was ordered after astronaut Lisa Nowak donned diapers and drove 1500 km across the US before assaulting a romantic rival in February.

In response to the independent review, NASA officials interviewed hundreds of personnel and reviewed two decades of records. After that effort, agency chief Michael Griffin likened tales that astronauts flew drunk to urban myths.

This latest survey is an attempt to flush out any other safety concerns. It did turn up accounts of what NASA describes as “a single isolated incident of perceived impairment of a crew member.”

Prescription drugs

The problem occurred “in the final days before launch, but not on launch day or within 12 hours of a launch or aviation event”, according to the report. Ochoa said the astronaut was apparently suffering ill effects from a combination of prescription drugs and alcohol. She declined to give further details, citing privacy concerns.

While the original independent review committee reported that NASA had repeatedly ignored safety concerns, the latest report by the agency paints a much rosier picture. Astronauts and flight surgeons now have a better working relationship than ever, NASA says, and they feel comfortable raising safety concerns.

“They’re extremely competent and extremely professional and concerned about doing a great job,” Ochoa says.

NASA doesn’t plan to make specific changes to its policies or procedures in response to the survey, according to Jeff Davis, director of the Space Life Sciences Directorate at Johnson Space Center, but he says there’s now a heightened awareness of safety issues.

The chair of the US Congressional subcommittee on space and aeronautics, Mark Udall, who called a hearing on NASA’s astronaut health care system in 2007, says the latest report provides “useful data” but adds that he intends to press NASA to provide a plan of action to address the issues raised over the last year.

A paper plane might not seem ideally suited to space travel, but a Japanese engineering professor is collaborating with origami masters to design a small paper spacecraft that could be launched from the International Space Station and survive a descent to Earth.

A prototype was successfully tested in a wind tunnel last week.

“This origami airplane might some day actually fly,” says , an expert in aeronautics and astronautics at Purdue University, West Lafayette, Indiana, in the US.

Longuski, who was not involved in the project, says that offbeat notions often generate exciting new ideas. “I don’t think it’s crazy at all,” he told New ĐÓ°ÉÔ­´´.

The novel craft could inspire new designs for lightweight re-entry vehicles, or for planes to explore the upper reaches of the atmosphere, according to , from the Department of Aeronautics and Astronautics at the University of Tokyo.

Heat resistant

Suzuki worked with members of the Japan Origami Airplane Association on the design for the plane.

They first collaborated a decade ago to design a 3-metre long paper plane shaped like a space shuttle, which was launched from the top of a mountain.

The origami space plane will be a similar design, Suzuki says, but only about 20 centimetres long and with a rounded nose to minimize aerodynamic heating.

It will also be chemically processed to incorporate silicon in the paper structure, increasing its heat resistance, although the plane shouldn’t be subjected to the fiery temperatures endured by heavier objects as they hurtle toward Earth.

When released from the International Space Station, it would be travelling at Mach 20, Suzuki says, but thanks to a large surface area and low weight it should slow considerably as it falls through the upper layers of the Earth’s atmosphere.

A smaller prototype paper plane was tested up to Mach 7 and about 200 °C in a hypersonic wind tunnel in Tokyo last week.

‘Nice gimmick’

In theory, the plane could come all the way down to the ground without ever getting that hot, says , at Purdue University, who was also not involved with the project.

If the paper spaceplane is ever launched, however, we might never find out what happens to it.

Suzuki plans to write a message on the plane in many languages, asking anyone who finds it to return it to the Japan Origami Airplane Association, but that’s unlikely, according to Schneider, because the plane could land almost anywhere on Earth.

A paper plane wouldn’t show up on radar and would be extremely difficult to observe through a telescope. “You’ll drop it off and it’ll disappear,” Schneider told New ĐÓ°ÉÔ­´´. “It’s a nice gimmick, but without a way to observe the thing it’s not much more than a nice idea.”

Suzuki says he would like to develop an ultra small tracking device to attach to the plane.

At a US congressional hearing on Wednesday, Griffin said a NASA employee “misspoke” in using those reasons to withhold the survey results.

The data comes from a four-year airline safety survey based on telephone interviews of 24,000 commercial pilots and 5000 private pilots in the US about events that can cause crashes – such as bird strikes and engine failure, and about near-misses in the air and on runways.

According to the results, they’re much more common than had been indicated by other air safety monitoring efforts (about 30,000 near misses are voluntarily reported each year to the national Aviation Safety Reporting System, for example).

The Associated Press requested the results of the $11 million, taxpayer-funded survey – known as the National Aviation Operations Monitoring Service (NAOMS) – more than a year ago under the US Freedom of Information Act, but a NASA representative refused to hand them over. That caused a ruckus in the US and landed Griffin in front of the House Committee on Science and Technology on Wednesday.

“NASA should be in the business of putting information in front of the public, not withholding it,” said comittee member Ralph Hall.

Tough questioning

Committee chair Bart Gordon agreed: “[The agency] needs to focus on maintaining and increasing the safety of the air-travelling public – not protecting the commercial air carriers.”

Responding to tough questioning from the committee, Griffin said NASA mismanaged the project, which was carried out by a contractor, and that a NASA employee gave the wrong reason to withhold the results.

In fact, Griffin said, the data could not be legally released because they contained information about specific incidents that could identify a pilot or airline. Griffin said the data are now being scrubbed to remove such identifying information and should be released by the end of the year.

Multiple reports

Griffin’s apologies did not satisfy some committee members. “I don’t call it a mistake, I call it negligence,” said Laura Richardson, whose California district includes Los Angeles International Airport, one of the busiest in the world. Daniel Lipinski, vice chairman of the committee, characterised the situation as a result of “either complete incompetence, or I could use the word ‘cover-up’.” Griffin denied allegations that NAOMS was closed down prematurely and that data were destroyed.

Robert Dodd, an aviation safety consultant hired for the NAOMS project, testified that it should be restarted and said he was “disappointed and perplexed” that NASA hasn’t released the results. He doesn’t think they would dissuade Americans from flying. “US air travel is the safest mode of travel in the world,” he added.

Jon Krosnick, a professor at Stanford University in the US and an expert on survey methodology, said he suspects the reason that NAOMS revealed more frequent safety problems than other safety monitoring efforts is that the data were not corrected to account for multiple reports of a single event by several pilots.

Aviation – Learn more in our comprehensive .

The world’s first purpose-built commercial spaceport will be a “green” building rising out of the desert of New Mexico, US, according to plans made public on Tuesday.

The designers of Spaceport America opted for a “low-lying, organic shape” that they say will blend into the surrounding landscape while conveying “the thrill of space travel”.

The spaceport will be the headquarters of Virgin Galactic, which will begin test flights of its passenger spaceliner, SpaceShipTwo, in 2008 and aims to be taking paying passengers to the edge of space by 2010.

The 9300-square-metre, $31 million facility features a circular terminal topped with an undulating concrete roof and flanked by berms of earth rising out of the desert.

Visitors will enter the spaceport through a channel cut in the landscape, walking between retaining walls covered with exhibits on the history of the area and of space exploration. They will be able to look down on spacecraft parked in the hangar and watch them rolling down the runway through the terminal’s expansive windows.

“It’s really science fiction becoming reality,” says David Wilson, a spokesperson for the New Mexico Spaceport Authority (NMSA). “We think it’ll become a destination people want to come and see even if they’re not one of the passengers to space.”

Highest rating

The spaceport was designed to meet the standards of the Leadership in Energy and Environmental Design Platinum certification, the highest rating from the US Green Building Council. The building will be dug into the ground so it’s protected from the extremes of the desert climate, and it will be fitted with solar panels, a water recycling system and a passive heating and cooling setup.

The design is the product of a partnership between global engineering design firm and London architects , who designed their home city’s Millennium Bridge (see some of their previous work in our blog).

‘Out of this world’

The design team is now working with NMSA and Virgin Galactic to finalise the plans, which Virgin Group founder Richard Branson describes as “truly out of this world”.

Construction is expected to begin in 2008 if the NMSA gets a site operator’s license for the spaceport from the US Federal Aviation Administration. That will require an environmental impact study but “we don’t expect any problems”, Wilson told New ĐÓ°ÉÔ­´´.

If all goes according to plan, the spaceport should be open by early 2010. Watch a .