Report urges timetable for human mission to Mars

by David Shiga

The Obama administration should set a concrete schedule for human Mars missions, says a new report (Illustration: NASA)

The Obama administration should set a concrete schedule for human Mars missions, and make sure new hardware developed for NASA's return to the Moon can be adapted for missions to other destinations, a new report says.

With a new US president set to take charge of the White House and many questions hanging over NASA's future, many have been trying to advise the agency about where it should go from here.

President-elect Barack Obama's transition team has been very tight-lipped, but if the Obama administration takes its cue from the preponderance of advice it's getting, then human missions to Mars may well move up in priority.

Back in November, the Planetary Society, a space advocacy group, released a report called "Beyond the Moon", which called for delaying new missions to the Moon and channelling more resources into paving the way for human missions to Mars instead (see Moon takes a backseat in new space plan).

Now, an independent group of space experts, led by David Mindell of MIT, is calling for a timeline for human Mars missions, and urging that any Moon hardware be designed with other destinations in mind as well.

Moon rethink

On Monday, the panel released its report, called "The Future of Human Spaceflight". It was produced by a group of experts including former shuttle astronaut Jeff Hoffman and John Logsdon, the former director of the Space Policy Institute at George Washington University in Washington, DC.

There are some links between the panel and the Planetary Society - Logsdon is a member of the group's advisory council - but the new report was an independent effort.

While the new report stops short of endorsing the Planetary Society's plan, it does urge a rethink of where and when to send astronauts. "The Obama administration and Congress should examine the Bush vision, assess its limitations . . . [and provide] clarification of the moon/Mars strategy with a timetable for the Mars component," it says.

"Even if it means somewhat easing the 2020 deadline for lunar return, NASA must ensure that the new architecture provides a solid foundation for the next generation of human spaceflight," it adds.

It expresses concern that "critical technologies for long-duration missions and Mars landings are not being actively investigated". Previous reports by the US National Research Council have found that technologies including propulsion, lunar dust mitigation and robot vehicles are being designed for the Moon and not Mars, for example.

Cooperation with China

The report also says the US should consider cooperative space efforts with China. Relations between the US and China have been tense at times, notably in the wake of China's test of an anti-satellite weapon in 2007. But Mindell argues that tensions were higher between the US and the Soviet Union when the two countries docked an Apollo capsule with a Soyuz spacecraft in Earth orbit in 1975.

Though some in the US fear space cooperation could allow China to gain new technologies useful for military applications, Mindell says it should be possible to avoid this. For example, joint space missions might involve sharing information about the design of innocuous items such as docking rings, he says.

"It's possible to ask what of the technologies involved are unique to human spaceflight, and then to say, can you devise a collaboration that involves sharing those technologies and not other kinds of things," he told New Scientist. "Now, we've gone the complete other way . . . and it's not clear that's been in the US interest."

Ironically, the lack of cooperation may be boosting China's international prestige, by reinforcing public perceptions that the two countries are in a closely competitive race to the Moon, the report says.

Mindell says members of the panel met with Obama's transition team last week and gave them a copy of the report.

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Lightning-Storm Gamma Rays Could Harm Air Travelers

By Alexis Madrigal

SAN FRANCISCO, California — The most energetic particles in the electromagnetic spectrum could pose a danger to commercial airline passengers.

About every 3000 hours of flying time, a plane is hit with a bolt of lightning. Recently, spacecraft have found gamma rays can be created by thunder storms, and according to new research presented at the American Geophysical Union annual meeting this week, the rays could be intense enough to cause radiation sickness.

"Everywhere we look, we're seeing x-rays and gamma rays flying out of thunderstorms and lightning," said Joseph Dwyer, a physicist at the Florida Institute of Technology and lead author of the study. "The gamma rays coming out of thunderstorms are so intense we can measure these 600 kilometers away and so bright that it almost blinds the spacecraft."

Finding particles flying around at what physicsts call "ultrarelativistic speeds,," i.e. very close to the speed of light, came as a shocker to physicists. Gamma rays had previously been associated with only the most extreme environments in the universe, like supernovae. Now, scientists believe that about 50 terrestrial gamma ray flashes occur per day on Earth.

It turns out that these highly-energetic particles can be created by thunderstorms at altitudes that airplanes regularly fly. While planes generally avoid thunderclouds, sometimes they get surprised or can't avoid them. And it's those situations that worry Dwyer.

"We just don't know enough. The consequences are bad enough that people could potentially get hurt from this," he said. "This is a call for more research. We really need to find out where we are and how big these things are. Could people be hit by these things and get sick? And how would you know?"

His team and others across the country have measured the number of gamma rays that reach satellite observatories, which has allowed them to back into how many particles are created in the thunderstorms.

What remains unclear is just how large and concentrated the source of the gamma rays is. If it's large — hundreds of meters across — then airplane passengers are probably safe. But if the gamma rays are created in a small area, they could be delivering doses of radiation in one millisecond that are many times beyond what the government sees as safe.

"If the source is a little bit smaller — and there are some arguments you can make that the source should be smaller — then the dose someone would get inside an aircraft, through a quarter inch of aluminum, is getting to the point where we'd be worried."

Dwyer's data shows that as the size of the gamma ray source shrinks under 100 meters across, the dose of radiation accelerates to levels that could cause very serious radiation sickness — and even death.

Dwyer is a leader in the emerging field of terrestrial gamma rays who has refined scientists' notions of how lightning works. Back in 2003, while experimenting with triggering lightning by launching specialized rockets into clouds, his team accidentally triggered a gamma ray flash.

"His stuff is fabulous," Dave Sentman, a physicist at the University of Alaska-Fairbanks, who also studies terrestrial gamma rays.

Sentman noted that Dwyer, trained as a nuclear physicist, has a different perspective on the atmospheric physics than most of their colleagues, which has allowed him to gain insight into the high-energy particles

"He has a different way of thinking," Sentman said.

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Hawking Predicts Discovery of Alien Life: But Asks, Will It be Carbon Based?

On the 50th anniversary of NASA, Stephen Hawking, Newton's heir as the Lucasian Professor of Mathematics at the University of Cambridge, answered the question, “Are we alone?”

His answer was short and simple; probably not!

Hawking presented three options. One, being that there is no life out there, and two – somewhat pessimistically, but subsequently, a little too realistic – being that when intelligent life gets smart enough to send signals in to space, it is also busying itself with making nuclear bombs.

Hawking, known not only for his sharp mind, but his sharp sense of humor, prefers option number three. "Primitive life is very common and intelligent life is fairly rare," he quickly added: "Some would say it has yet to occur on earth."

Alien abductions, in Hawking’s view, are nothing more than claims made by “weirdos,” but we should be careful if we ever happen upon an alien. Because alien life may not have DNA like ours, Hawking warns "Watch out if you would meet an alien. You could be infected with a disease with which you have no resistance."

Other prominent astrobiologists have warned that we humans may be blinded by our familiarity with carbon and Earth-like conditions. In other words, what we’re looking for may not even lie in our version of a “sweet spot”. After all, even here on Earth, one species “sweet spot” is another’s species worst nightmare. In any case, it is not beyond the realm of feasibility that our first encounter with extraterrestrial life will not be a solely carbon-based occasion.

Alternative biochemists speculate that there are several atoms and solvents that could potentially spawn life. Because carbon has worked for the conditions on Earth, we speculate that the same must be true throughout the universe. In reality, there are many elements that could potentially do the trick. Even counter-intuitive elements such as arsenic may be capable of supporting life under the right conditions. Even on Earth some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Several other small life forms use arsenic to generate energy and facilitate growth. Chlorine and sulfur are also possible elemental replacements for carbon. Sulfur is capably of forming long-chain molecules like carbon. Some terrestrial bacteria have already been discovered to survive on sulfur rather than oxygen, by reducing sulfur to hydrogen sulfide.

Nitrogen and phosphorus could also potentially form biochemical molecules. Phosphorus is similar to carbon in that it can form long chain molecules on its own, which would conceivably allow for formation of complex macromolecules. When combined with nitrogen, it can create quite a wide range of molecules, including rings.

So what about water? Isn’t at least water essential to life? Not necessarily. Ammonia, for example, has many of the same properties as water. An ammonia or ammonia-water mixture stays liquid at much colder temperatures than plain water. Such biochemistries may exist outside the conventional water-based "habitability zone". One example of such a location would be right here in our own solar system on Saturn's largest moon Titan.

Hydrogen fluoride methanol, hydrogen sulfide, hydrogen chloride, and formamide have all been suggested as suitable solvents that could theoretically support alternative biochemistry. All of these “water replacements” have pros and cons when considered in our terrestrial environment. What needs to be considered is that with a radically different environment, comes radically different reactions. Water and carbon might be the very last things capable of supporting life in some extreme planetary conditions.

Posted by Josh Hill with Rebecca Sato.

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