Category: Space Exploration

Artist illustration of a robotic ice miner. Image credit: NASA/John Frassanito & Associates. Click to enlarge
NASA’s new vision for space exploration hopes to send humans back to the Moon and then onto Mars over the next decades. The Chief Scientist for NASA’s Mars Program, David Beaty, has spent more than 20 years searching the Earth for metals and oil, and this makes the right man to help future astronauts survive off-Earth. Astronauts will become more like prospectors, searching the Moon and Mars for reserves of water to make air and rocket fuel. The more they can live off the land, the less they have to bring from Earth.

Long before David Beaty became associate Chief Scientist for NASA’s Mars Program, he was a prospector. Beaty spent 10 years surveying remote parts of Earth for precious metals and another 12 years hunting for oil.

And this qualifies him to work for NASA? Precisely.

Beaty has the kind of experience NASA needs as the agency prepares to implement the Vision for Space Exploration. “Mining and prospecting are going to be key skills for settlers on the Moon and Mars,” he explains. “We can send them air and water and fuel from Earth, but eventually, they’ll have to learn to live off the land, using local resources to meet their needs.”

On the Moon, for instance, mission planners hope to find water frozen in the dark recesses of polar craters. Water can be split into hydrogen for rocket fuel and oxygen for breathing. Water is also good for drinking and as a bonus it is one of the best known radiation shields. “In many ways,” notes Beaty, “water is key to a sustained human presence.” Ice mining on the Moon could become a big industry.

Beaty has learned a lot from his long career prospecting, exploring and mining on Earth. Now, with an eye on other worlds, he has distilled four pieces of wisdom he calls “Dave’s Postulates” for prospectors working anywhere in the solar system:

Postulate #1: “Wishful thinking is no substitute for scientific evidence.”

“On Earth, banks won’t lend money for less than proven reserves. From a bank’s viewpoint, anything less than proven is not really there. This lesson has been learned the hard way by many a prospector,” he laughs.

For NASA the stakes are higher than profit. The lives of astronauts could hang in the balance. “Proven reserves on the Moon can perhaps be thought of as having enough confidence to risk the lives of astronauts to go after it.”

What does it take to “prove” a reserve?that is, to know with confidence that a resource exists in high enough concentration to be produced?

“That depends on the nature of the deposit,” explains Beaty. “Searching for oil on Earth, you can drill one hole, measure the pressure and calculate how much oil is there. You know that oil probably exists 100 feet away because liquids flow. However, for gold you must drill holes 100 feet apart, and assay the concentration of gold every five feet down each hole. That’s because the solid earth is heterogenous. 100 feet away the rocks may be completely different.”

Deposits on the Moon aren’t so well understood. Is lunar ice widespread or patchy, deep or shallow? Does it even exist? “We don’t know,” says Beaty. “We still have a lot to learn.”

Postulate #2: “You cannot define a reserve without specifying how it can be extracted. If it can’t be mined, it’s of no use.” Enough said.

Postulate #3: “Perfect knowledge is not possible. Exploration costs money, and we can’t afford to buy all the information we want. We have to make choices, deciding what information is critical and what’s not.”

He offers the following hypothetical example:

“Suppose we decide to send a robot with a little drill and an onboard laboratory into Shackleton Crater, a place on the Moon with suspected ice deposits. We’re going to have to think pretty carefully about that lab. Maybe it can contain only two instruments. What are the two things we most need to know?”

“Suppose further that someone on Earth has invented a machine that can extract water from lunar soil. But it only works if the ice is close to the surface and if the ice is not too salty.” The choice is made. “We’d better equip the robot with instruments to measure the saltiness of the ice and its depth in the drill hole.”

Finally, Postulate #4: “Don’t underestimate the potential effects of heterogeneity. All parts of the Moon are not alike, just as all parts of Earth are not alike. So where you land matters.”

Ultimately, says Beaty, if geologists and engineers work together applying these rules as they go, living off the land on alien worlds might not be so hard after all.

Original Source: Science@NASA Article

The sun is a major source of radiation for life on Earth. Image credit: NASA/ESA/SOHO. Click to enlarge
Space travel has its dangers. One of the biggest risks will come from the various types of radiation that flood space. Scientists are learning how life on Earth has evolved different kinds of tricks to resist radiation. Some animals and plants have evolved protective covering or pigmentation, but some forms of bacteria can actually repair damage to its DNA from radiation. Future space travelers might take advantage of these techniques to minimize the harm they get from long exposure.

In Star Wars and Star Trek movies, people travel between planets and galaxies with ease. But our future in space is far from assured. Issues of hyperdrive and wormholes aside, it doesn’t seem possible that the human body could withstand extended exposure to the harsh radiation of outer space.

Radiation comes from many sources. Light from the sun produces a range of wavelengths from long-wave infrared to short-wavelength ultraviolet (UV). Background radiation in space is composed of high-energy X-rays, gamma rays and cosmic rays, which all can play havoc with the cells in our bodies. Since such ionizing radiation easily penetrates spacecraft walls and spacesuits, astronauts today must limit their time in space. But being in outer space for even a short time greatly increases their odds of developing cancer, cataracts, and other radiation-related health problems.

To overcome this problem, we may find some useful tips in nature. Many organisms already have devised effective strategies to protect themselves from radiation.

Lynn Rothschild of the NASA Ames Research Center says that radiation has always been a danger for life on Earth, and so life had to find ways to cope with it. This was especially important during the Earth’s earliest years, when the ingredients for life were first coming together. Because our planet did not initially have much oxygen in the atmosphere, it also lacked an ozone (O3) layer to block out harmful radiation. This is one reason why many believe life originated underwater, since water can filter out the more damaging wavelengths of light.

Yet photosynthesis ? the transformation of sunlight into chemical energy ? developed relatively early in the history of life. Photosynthetic microbes like cyanobacteria were using sunlight to make food as early as 2.8 billion years ago (and possibly even earlier).

Early life therefore engaged in a delicate balancing act, learning how to use radiation for energy while protecting itself from the damage that radiation could cause. While sunlight is not as energetic as X-rays or gamma rays, the UV wavelengths are preferentially absorbed by DNA bases and by the aromatic amino acids of proteins. This absorption can damage cells and the delicate DNA strands that encode the instructions for life.

“The problem is, if you’re going to access solar radiation for photosynthesis, you’ve got to take the good with the bad — you’re also exposing yourself to the ultraviolet radiation,” says Rothschild. “So there’s various tricks that we think early life used, as life does today.”

Besides hiding under liquid water, life makes use of other natural UV radiation barriers such as ice, sand, rocks, and salt. As organisms continued to evolve, some were able to develop their own protective barriers such as pigmentation or a tough outer shell.

Thanks to photosynthetic organisms filling the atmosphere with oxygen (and thereby generating an ozone layer), most organisms on Earth today don’t need to contend with high energy UV-C rays, X-rays or gamma rays from space. In fact, the only organisms known to survive space exposure ? at least in the short term – are bacteria and lichen. Bacteria need some shielding so they won’t get fried by the UV, but lichen have enough biomass to act as a protective spacesuit.

But even with a good barrier in place, sometimes radiation damage does occur. The lichen and bacteria hibernate while in space ? they do not grow, reproduce, or engage in any of their normal living functions. Upon return to Earth, they exit this dormant state and, if there was damage inflicted, proteins in the cell work to piece together DNA strands that were broken apart by radiation.

The same damage control occurs with organisms on Earth when they’re exposed to radioactive materials such as uranium and radium. The bacterium Deinococcus radiodurans is the reigning champion when it comes to this sort of radiation repair. (Complete repair is not always possible, however, which is why radiation exposure can lead to genetic mutations or death.)

“I live in eternal hope of unseating D. radiodurans,” says Rothchild. Her search for radiation-resistant microorganisms has brought her to Paralana hot spring in Australia. Uranium-rich granite rocks emit gamma rays while lethal radon gas bubbles up from the hot water. Life in the spring is therefore exposed to high levels of radiation ? both below, from the radioactive materials, and above, from the intense UV light of the Australian sun.

Rothschild learned about the hot spring from Roberto Anitori of Macquarie University’s Australian Centre for Astrobiology. Anitori has been sequencing the 16S ribosomal RNA genes and culturing the bacteria that live quite happily in the radioactive waters. Like other organisms on Earth, the Paralana cyanobacteria and other microbes may have devised barriers to shield themselves from the radiation.

“I have noticed a tough, almost silicone-like layer on some of the microbial mats there,” says Anitori. “And when I say “silicon-like,” I mean the sort you use on window pane edging.”

“Apart from possible shielding mechanisms, I suspect that the microbes at Paralana also have good DNA repair mechanisms,” adds Anitori. At the moment, he can only speculate about the methods used by the Paralana organisms to survive. However, he does plan to closely investigate their radiation resistance strategies later this year.

In addition to Paralana, Rothschild’s investigations have brought her to extremely arid regions in Mexico and the Bolivian Andes. As it turns out, many organisms that evolved to live in deserts are also quite good at surviving radiation exposure.

Prolonged water loss can cause DNA damage, but some organisms have evolved efficient repair systems to combat this damage. It’s possible that these same dehydration repair systems are used when the organism needs to repair radiation-inflicted damage.

But such organisms may be able to avoid damage altogether simply by being dried out. The lack of water in desiccated, dormant cells makes them much less susceptible to the effects of ionizing radiation, which can harm cells by producing free radicals of water (hydroxyl or OH radical). Because free radicals have unpaired electrons, they eagerly try to interact with DNA, proteins, lipids in cell membranes, and anything else they can find. The resulting wreckage can lead to organelle failure, block cell division, or cause cell death.

Eliminating the water in human cells is probably not a practical solution for us to minimize our radiation exposure in space. Science fiction has long toyed with the idea of putting people into suspended animation for long space journeys, but turning humans into shriveled, dried-out raisins and then rehydrating them back to life isn’t medically possible – or very appealing. Even if we could develop such a procedure, once the human raisinettes were rehydrated they would again be susceptible to radiation damage.

Perhaps someday we can genetically engineer humans to have the same super radiation-repair systems as microorganisms like D. radiodurans. But even if such tinkering with the human genome was possible, those hardy organisms aren’t 100 percent resistant to radiation damage, so health problems would persist.

So of the three known mechanisms that life has devised to combat radiation damage – barriers, repair, and desiccation – the most immediately practical solution for human spaceflight would be to devise better radiation barriers. Anitori thinks his studies of the Paralana Spring organisms could someday help us engineer such barriers.

“Perhaps we will be taught by nature, mimicking some of the shielding mechanisms used by microbes,” he states.

And Rothschild says radiation studies also could provide some important lessons as we look toward establishing communities on the moon, Mars, and other planets.

“When we start to build human colonies, we’re going to take organisms with us. You’re ultimately going to want to grow plants, and possibly make an atmosphere on Mars and on the moon. We may not want to spend the effort and the money to protect them completely from the UV and cosmic radiation.”

In addition, says Rothschild, “humans are just full of microbes, and we couldn’t survive without them. We don’t know what effect the radiation will have on that associated community, and that may be more of a problem than the direct effect of radiation on the humans.”

She believes her studies also will be useful in the search for life on other worlds. Assuming that other organisms in the universe also are based on carbon and water, we can postulate what sort of extreme conditions they could survive in.

“Each time we find an organism on Earth that can live further and further into an environmental extreme, we’ve increased the size of that envelope of what we know life can survive within,” says Rothschild. “So if we go to a place on Mars that has a certain radiation flux, desiccation, and temperature, we can say, ‘There are organisms on Earth that can live under those conditions. There’s nothing that precludes life from living there.’ Now, whether life is there or not is another matter, but at least we can say this is the minimum envelope for life.”

For instance, Rothschild thinks life could be possible in the salt crusts on Mars, which are similar to salt crusts on Earth where organisms find shelter from solar UV. She also looks at life living under ice and snow on Earth, and wonders if organisms could live a comparatively radiation-protected existence under the ice of Jupiter’s moon Europa.

Original Source: NASA Astrobiology

Surgery in space might be not that far away. Image credit: NASA Click to enlarge
If scientists can put a man on the moon, or send him into space for a few years at time, can they enable astronauts to perform complex surgical procedures there, too?

Professor Adam Dubrowksi of surgery doesn’t see why not, and he’s making space surgery a focus of his research. There’ll be a need for it once astronauts in the International Space Station begin to stay on board for extended periods, says Dubrowski, who is also a kinesiologist in the Surgical Skills Centre at Mount Sinai Hospital. The U.S. National Aeronautics and Space Administration (NASA) and the Canadian Space Agency (CSA) are also looking towards a mission to Mars, a journey that will take three to four years each way.

“The longer you stay, the more potential there is for things to happen,” Dubrowski points out, noting that lacerations and trauma injuries are certainly possible. Currently, astronauts get a few hours of medical training on the ground, which is insufficient for treating more serious injuries, he says. Although typically a medical doctor is on board the space station, “everybody has to know a bit of everything.” On longer missions, he anticipates having a physician and a highly skilled medical assistant who are both trained in surgery, while the rest of the crew will be trained in the basics.

Currently, emergencies are dealt with on board the space station and surgery can be performed using a remote-controlled robot. But as spaceships get further away from Earth, robotic surgery is no longer possible because the signals take longer to reach the mission, Dubrowski explains. And “no one understands what happens when you’re in zero gravity” and need to suture or staple a wounded person.

So Dubrowski, his wife, Waterloo kinesiology professor Heather Carnahan, and Dr. Gary Gray, a Canadian Space Agency consultant from Defence Research and Development Canada, hope to explore these questions with CSA funding. The three have already conducted zero-gravity research into basic motor skills such as touching one’s nose or tying one’s shoes. A weightless environment affects a person’s hand-eye co-ordination, aim and ability to apply a certain amount of force when undertaking tasks, he says. Dubrowski’s interest in space research began after he received his PhD in kinesiology in 2001 from the University of Waterloo. A native of Poland who immigrated to the Toronto area, Dubrowski was influenced by a visit to Dr. Otmar Bock, a leading German researcher in zero-gravity, following completion of his doctoral studies. The two maintained a collaboration, which helped Dubrowski get funding from the European Space Agency and the German Space Agency.

Now, the Canadian Space Agency plans to develop a surgery training protocol for astronauts and Dubrowski, Carnahan and Gray ? with the support of the experts from the Surgical Skills Centre and the Wilson Centre ? plan to bid for the contract. At the same time, they will be applying for smaller funds for parabolic flight research.

Space-surgery training will be three-pronged, Dubrowski explains. The first step is adaptation to zero gravity using an inverted paradigm in which experimental participants are placed upside down on something similar to a bed to “get more of an idea of weightlessness.”

The second step will be simulating zero gravity in a swimming pool; Dubrowski and Surgical Skills Centre manager Lisa Satterthwaite are working on procuring something similar to the huge swimming pool with the replica of the space station used in the NASA centre in Houston. “You can adjust the buoyancy of the person so they’re suspended in water,” Dubrowski says. “That’s another way of simulating zero gravity.”

Third, trainees will take their basic surgery skills on parabolic flights in which an airplane ascends and descends roughly 40 times, creating a transient zero-gravity environment on the descents. Dubrowski uses a variety of simple and complex simulators to allow students at the Surgical Skills Centre to practise skills such as stitching with skin patches.

Surgery in space isn’t that far away, Dubrowksi predicts; there are plans to put a manned lunar base on the moon in the next five to 10 years, which will necessitate better surgical skills for the longer missions. And the sooner the better, he says.

Original Source: U of T News Release

A time lapse sequence of self-repair taking place. Image credit: ESA Click to enlarge
Building spacecraft is a tough job. They are precision pieces of engineering that have to survive in the airless environment of space, where temperatures can swing from hundreds of degrees Celsius to hundreds of degree below zero in moments. Once a spacecraft is in orbit, engineers have virtually no chance of repairing anything that breaks. But what if a spacecraft could fix itself?

Thanks to a new study funded by ESA’s General Studies Programme, and carried out by the Department of Aerospace Engineering, University of Bristol, UK, engineers have taken a step towards that amazing possibility. They took their inspiration from nature.

“When we cut ourselves we don’t have to glue ourselves back together, instead we have a self-healing mechanism. Our blood hardens to form a protective seal for new skin to form underneath,” says Dr Christopher Semprimoschnig, a materials scientist at ESA’s European Space Technology Research Centre (ESTEC) in the Netherlands, who oversaw the study.

He imagined such cuts as analogous to the ‘wear-and-tear’ suffered by spacecraft. Extremes of temperature can cause small cracks to open in the superstructure, as can impacts by micrometeroids – small dust grains travelling at remarkable speeds of several kilometres per second. Over the lifetime of a mission the cracks build up, weakening the spacecraft until a catastrophic failure becomes inevitable.

The challenge for Semprimoschnig was to replicate the human process of healing small cracks before they can open up into anything more serious. He and the team at Bristol did it by replacing a few percent of the fibres running through a resinous composite material, similar to that used to make spacecraft components, with hollow fibres containing adhesive materials. Ironically, to make the material self-repairable, the hollow fibres had to be made of an easily breakable substance: glass. “When damage occurs, the fibres must break easily otherwise they cannot release the liquids to fill the cracks and perform the repair,” says Semprimoschnig.

In humans, the air chemically reacts with the blood, hardening it. In the airless environment of space, alternate mechanical veins have to be filled with liquid resin and a special hardener that leak out and mix when the fibres are broken. Both must be runny enough to fill the cracks quickly and harden before it evaporates.

“We have taken the first step but there is at least a decade to go before this technology finds its way onto a spacecraft,” says Semprimoschnig, who believes that larger scale tests are now needed.

The promise of self-healing spacecraft opens up the possibility of longer duration missions. The benefits are two-fold. Firstly, doubling the lifetime of a spacecraft in orbit around Earth would roughly halve the cost of the mission. Secondly, doubling spacecraft lifetimes means that mission planners could contemplate missions to far-away destinations in the Solar System that are currently too risky.

In short, self-healing spacecraft promise a new era of more reliable spacecraft, meaning more data for scientists and more reliable telecommunication possibilities for us all.

Original Source: ESA Portal

Helicon reactor in operation. Image credit: ESA Click to enlarge
ESA has confirmed the principle of a new space thruster that may ultimately give much more thrust than today?s electric propulsion techniques. The concept is an ingenious one, inspired by the northern and southern aurorae, the glows in the sky that signal increased solar activity.

?Essentially the concept exploits a natural phenomenon we see taking place in space,? says Dr Roger Walker of ESA?s Advanced Concepts Team. “When the solar wind, a ?plasma? of electrified gas released by the Sun, hits the magnetic field of the Earth, it creates a boundary consisting of two plasma layers. Each layer has differing electrical properties and this can accelerate some particles of the solar wind across the boundary, causing them to collide with the Earth?s atmosphere and create the aurora.”

In essence, a plasma double layer is the electrostatic equivalent of a waterfall. Just as water molecules pick up energy as they fall between the two different heights, so electrically charged particles pick up energy as they travel through the layers of different electrical properties.

Researchers Christine Charles and Rod Boswell at the Australian National University in Canberra, first created plasma double layers in their laboratory in 2003 and realised their accelerating properties could enable new spacecraft thrusters. This led the group to develop a prototype called the Helicon Double Layer Thruster.

The new ESA study, performed as part of ESA?s Ariadna academic research programme in association with Ecole Polytechnique, Paris, confirms the Australian findings by showing that under carefully controlled conditions, the double layer could be formed and remains stable, allowing the constant acceleration of charged particles in a beam. The study also confirmed that stable double layers could be created with different propellant gas mixtures.

?The collaboration has been absolutely excellent,? says Dr Pascal Chabert, of Laboratoire de Physique et Technologie des Plasmas, Ecole Polytechnique. ?It has been a real kick-off for me and has given me lots of new ideas for plasma propulsion concepts to investigate with the Advanced Concepts Team. The new direction for our laboratory had led to a patent on a promising new electric propulsion device called an Electronegative Plasma Thruster.?

To create the double layer, Chabert and colleagues created a hollow tube around which was wound a radio antenna. Argon gas was continuously pumped into the tube and the antenna transmitted helicoidal radio waves of 13 megahertz. This ionised the argon creating a plasma. A diverging magnetic field at the end of the tube then forced the plasma leaving the pipe to expand. This allowed two different plasmas to be formed, upstream within the tube and downstream, and so the double layer was created at their boundary. This accelerated further argon plasma from the tube into a supersonic beam, creating thrust.

Calculations suggest that a helicon double layer thruster would take up a little more space than the main electric thruster on ESA?s SMART-1 mission, yet it could potentially deliver many times more thrust at higher powers of up to 100 kW whilst giving a similar fuel efficiency.

In the next steps, ESA will now construct a detailed computer simulation of the plasma in and around the thruster and use the laboratory results to verify its accuracy, so that the in-space performance can be fully assessed and larger high power experimental thrusters can be investigated in the future.

Original Source: ESA Portal

WISE bed rest study participant Dorota. Image credit: ESA Click to enlarge
When the first women astronauts set foot on Mars, they may spare a thought for the 24 women who paved the way for lengthy space trips by giving three months of their lives to space science, two months of which involved staying in bed.

From March to May and from September to November, two different groups of 12 volunteers from eight European countries – the Czech Republic, Finland, France, Germany, the Netherlands, Poland, Switzerland, and the United Kingdom – took part in the Women International Space Simulation for Exploration (WISE) campaign on behalf of the European Space Agency (ESA), the French space agency (CNES), the Canadian Space Agency (CSA) and the US National Aeronautics and Space Administration (NASA).

The volunteers of the WISE femal bedrest study underwent numerous medical tests
They gathered at the MEDES Space Clinic in Rangueil Hospital in Toulouse, France, to take up an extraordinary challenge: a 60-day campaign of female bedrest. For two months, they had to lie down and undertake all daily activities in beds tilted at an angle of 6? below horizontal, so that their heads were slightly lower than their feet. This unusual position induces physiological changes similar to those experienced by astronauts in weightlessness.

The last volunteers of the second WISE campaign got up on 30 November, and are now undergoing rehabilitation and medical tests lasting until 20 December. Similar tests were conducted in the pre-bedrest period for comparison.

MEDES, the French Institute for Space Medicine and Physiology, organised the selection of the volunteers and provided medical, paramedical and technical staff to support the extensive science experiments.

The main objective of the WISE campaign has been to assess the roles of nutrition and physical exercise with adapted equipment in countering the adverse effects of prolonged microgravity conditions, in order to develop the counter-measures that will be required when future astronauts venture beyond the Earth orbit to explore other worlds.

The data collected by the international science teams during the WISE study will improve our knowledge of muscle condition, blood parameters, cardiovascular condition, coordination of movements, changes in endocrine and immune systems, metabolism, bone status, as well as psychological wellbeing. This will serve not only the future of human spaceflight, but our everyday lives on Earth too, by providing clues as to how to deal with osteoporosis, fight the ”metabolic syndrome?, which affects millions of sedentary workers who take insufficient physical exercise, assist recovery of bedridden patients, or prevent some cardiovascular conditions.

Twelve scientific teams from 11 countries – Belgium, Canada, Denmark, France, Germany, Italy, the Netherlands, Sweden, Switzerland, the United Kingdom and the United States – are involved in the study. It will take them several months to analyse their data and start publishing their findings. In order to answer certain scientific questions, a follow-up of the volunteers will continue for three more years.

?The WISE campaign has now come to a successful conclusion and I look forward to further campaigns in the future where there is this degree of international involvement and complexity?, said Didier Schmitt, Head of the Life Sciences Unit in ESA?s Directorate of Human Spaceflight, Microgravity and Exploration. ?Planning for future research is already under way with a programme of bedrest campaigns being prepared, covering the next three years. This will be a combination of short-term, intermediate and long-term bedrest studies, lasting 5, 21 and 60 days, respectively. A research announcement covering this period is due to be released in the near future as part of the European programme for Life and Physical Sciences and Applications using the ISS (ELIPS). A further two bedrest studies are planned, one in Berlin and the other at the DLR in Cologne and they have already been selected as part of the ESA Microgravity Applications Programme (MAP). These studies are currently awaiting the necessary funding, also from the ELIPS Programme.?

To mark the completion of the WISE 2005 campaigns, ESA, CNES and MEDES are to hold a press conference, together with representatives from NASA and CSA, science teams and volunteers from the second WISE campaign, at the “Cit? de l?Espace” in Toulouse on 13 December.

Media representatives wishing to attend this press conference are requested to apply using the attached form, which should be returned to the address shown at the bottom of the form.

For additional information, ESA has created a website on the WISE study at:
http://www.spaceflight.esa.int/wise

Original Source: ESA Portal

Planetary MicroBots. Image credit: NASA Click to enlarge
Interview with Penny Boston, Part I

If you want to travel to distant stars, or find life on another world, it takes a bit of planning. That’s why NASA has established NIAC, the NASA Institute for Advanced Concepts. For the past several years, NASA has been encouraging scientists and engineers to think outside the box, to come up with ideas just this side of science fiction. Their hope is that some of these ideas will pan out, and provide the agency with technologies it can use 20, 30, or 40 years down the road.

NIAC provides funding on a competitive basis. Only a handful of the dozens of proposals submitted are funded. Phase I funding is minimal, just enough for researchers to flesh out their idea on paper. If the idea shows merit, it then may get Phase II funding, allowing the research to continue from the pure-concept to the crude-prototype stage.

One of the projects that received Phase II funding earlier this year was a collaboration between Dr. Penelope Boston and Dr. Steven Dubowsky to develop “hopping microbots” capable of exploring hazardous terrain, including underground caves. If the project pans out, hopping microbots may some day be sent to search for life below the surface of Mars.

Boston spends a lot of time in caves, studying the microorganisms that live there. She is the director of the Cave and Karst Studies Program and an associate professor at New Mexico Tech in Socorro, New Mexico. Dubowsky is the director of the MIT Field and Space Robotics Laboratory at MIT, in Cambridge, Massachusetts. He is known in part for his research into artificial muscles.

Astrobiology Magazine interviewed Boston shortly after she and Dubowsky received their Phase II NIAC grant. This is the first of a two-part interview. Astrobiology Magazine (AM): You and Dr. Steven Dubowsky recently received funding from NIAC to work on the idea of using miniature robots to explore subsurface caves on Mars? How did this project come about?

Penny Boston (PB): We’ve been doing quite a lot of work in caves on Earth with an eye to looking at the microbial inhabitants of these unique environments. We think they can serve as templates for looking for life forms on Mars and other extraterrestrial bodies. I published a paper in 1992, with Chris McKay and Michael Ivanov, suggesting that the subsurface of Mars would be the last refuge of life on that planet as it became colder and drier over geological time. That got us into the business of looking into the subsurface on Earth. When we did, we discovered that there is an amazing array of organisms that are apparently indigenous to the subsurface. They interact with the mineralogy and produce unique biosignatures. So it became a very fertile area for us to study.

Getting into difficult caves even on this planet is not that easy. Translating that to robotic extraterrestrial missions requires some thought. We have good imaging data from Mars showing distinct geomorphological evidence for at least lava-tube caves. So we know that Mars has at least that one type of cave that could be a useful scientific target for future missions. It’s plausible to think that there are also other types of caves and we have a paper in press in an upcoming Geological Society of America Special Paper exploring unique cave-forming (speleogenetic) mechanisms on Mars. The big sticking point is how to get around in such rigorous and difficult terrain.

AM: Can you describe what you did in the first phase of the project?

PB: In Phase I, we wanted to focus on robotic units that were small, very numerous (hence expendable), largely autonomous, and that had the mobility that was needed for getting into rugged terrains. Based on Dr. Dubowsky’s ongoing work with artificial-muscle-activated robotic motion, we came up with the idea of many, many, tiny little spheres, about the size of tennis balls, that essentially hop, almost like Mexican jumping beans. They store up muscle energy, so to speak, and then they boink themselves off in various directions. That’s how they move.

credit:Render by R.D.Gus Frederick
Planetary Setting For Large-Scale Planetary Surface & Subsurface Exploration. Click image for larger view.
Image Credit: Render by R.D.Gus Frederick

We’ve calculated that we could probably pack about a thousand of these guys into a payload mass the size of one of the current MERs (Mars Exploration Rovers). That would give us the flexibility to suffer the loss of a large percentage of the units and still have a network that could be doing recon and sensing, imaging, and perhaps even some other science functions.

AM: How do all these little spheres co-ordinate with each other?

PB: They behave as a swarm. They relate to each other using very simple rules, but that produces a great deal of flexibility in their collective behavior that enables them to meet the demands of unpredictable and hazardous terrain. The ultimate product that we’re envisioning is a fleet of these little guys being sent to some promising landing site, exiting from the lander and then making their way over to some subsurface or other hazardous terrain, where they deploy themselves as a network. They create a cellular communication network, on a node-to-node basis.

AM: Are they able to control the direction in which they hop?

PB: We have aspirations for them ultimately to be very capable. As we move into Phase II, we’re working with Fritz Printz at Stanford on ultra-miniature fuel cells to power these little guys, which would enable them to be able to do a fairly complex array of things. One of those capabilities is to have some control over the direction in which they go. There are certain ways that they can be built that can allow them to preferentially go in one direction or another. It’s not quite as precise as it would be if they were wheeled rovers just going on a straight path. But they can preferentially cant themselves more or less in the direction that they wish to go. So we’re envisioning that they will have at least crude control over direction. But a lot of their value has to do with their swarm motion as an expanding cloud.

As wonderful as the MER rovers are, for the kind of science I do, I need something more akin to the insect robot idea pioneered by Rodney Brooks at MIT. Being able to tap into the model of insect intelligence and adaptation for exploration had long appealed to me. Adding that to the unique mobility provided by Dr. Dubowsky’s hopping idea, I think, can enable a reasonable percentage of these little units to survive the hazards of subsurface terrain – that just seemed like a magical combination to me.

HB: So in Phase I, did any of these actually get built?

PB: No. Phase I, with NIAC, is a six-months-long brain-straining, pencil-pushing study, to scope out the state of the art of the relevant technologies. In Phase II, we’re going to do a limited amount of prototyping and field-testing, over a two-year period. This is far less than what one might need for an actual mission. But, of course, that is NIAC’s mandate, to examine technology 10 to 40 years out. We’re thinking this is probably in the 10- to 20-year range.

AM: What kinds of sensors or scientific equipment do you imagine being able to put on these things?

PB: Imaging is clearly something that we would like to do. As cameras become incredibly tiny and robust, there are already units in the size range that could be mounted on these things. Possibly some of the units could be fitted with magnification capability, so one could look at the textures of the materials that they are landing on. Integrating images taken by tiny cameras on lots of different little units is one of the areas for future development. That’s beyond the scope of this project, but that’s what we’re thinking of for imaging. And then, certainly chemical sensors, being able to sniff and sense the chemical environment, which is very critical. Everything from tiny laser noses to ion-selective electrodes for gases.

We are envisioning having them not all identical, but rather an ensemble, with enough of the different kinds of units fitted out with different kinds of sensors so that the probability would still be high, even given fairly high losses of numbers of units, that we would still have a complete suite of sensors. Even though each individual unit cannot have a giant payload of sensors on it, you could have enough so that it could give significant overlap with its fellow units.

AM: Will it be possible to do biological testing?

PB: I think so. Particularly if you imagine the time frame that we’re looking at, with the advances that are coming online with everything from quantum dots to lab-on-a-chip devices. Of course, the difficulty is getting sample material to those. But when we’re dealing with little ground-contacting units like our hopping microbots, you might be able to position them directly over the material that they wish to test. In combination with microscopy and wider-field imagery, I think that the capability is there to do some serious biological work.

AM: Do you have an idea of what the milestones are that you’re hoping to hit during your two-year project?

PB: We’re anticipating that by March we may have crude prototypes that have the relevant mobility. But that may be overly ambitious. Once we do have mobile units, our plan is to do field testing in real lava-tube caves that we are doing science on in New Mexico.

The field site’s already tested. As part of Phase I the MIT group came out and I taught them a little bit about caving and what the terrain was actually like. It was a big eye-opener for them. It’s one thing to design robots for the halls of MIT, but it’s another thing to design them for real-world rocky environments. It was a very educational experience for us all. I think they have a pretty good idea what the conditions are that they have to meet with their design.

AM: What are those conditions?

PB: Extremely uneven terrain, lots of crevices that these guys could get temporarily jammed in. So we’ll need modes of operation that will allow them to extricate themselves, at least with a reasonable chance of success. The challenges of line-of-sight communication in a highly rough surface. Getting over big boulders. Getting stuck in little cracks. Things of that sort.

Lava is not smooth. The interior of lava tubes is intrinsically smooth after they’re formed, but there is a lot of material that shrinks and cracks and falls down. So there are rubble piles to get around and over, and a lot of elevational change. And these are things that conventional robots don’t have the capability to do.

Original Source: NASA Astrobiology

EAFTC computers in a space-ready flight chassis. Image credit: NASA/Honeywell. Click to enlarge
Unfortunately, the radiation that pervades space can trigger such glitches. When high-speed particles, such as cosmic rays, collide with the microscopic circuitry of computer chips, they can cause chips to make errors. If those errors send the spacecraft flying off in the wrong direction or disrupt the life-support system, it could be bad news.

To ensure safety, most space missions use radiation hardened computer chips. “Rad-hard” chips are unlike ordinary chips in many ways. For example, they contain extra transistors that take more energy to switch on and off. Cosmic rays can’t trigger them so easily. Rad-hard chips continue to do accurate calculations when ordinary chips might “glitch.”

NASA relies almost exclusively on these extra-durable chips to make computers space-worthy. But these custom-made chips have some downsides: They’re expensive, power hungry, and slow — as much as 10 times slower than an equivalent CPU in a modern consumer desktop PC.

With NASA sending people back to the moon and on to Mars–see the Vision for Space Exploration–mission planners would love to give their spacecraft more computing horsepower.

Having more computing power onboard would help spacecraft conserve one of their most limited resources: bandwidth. The bandwidth available for beaming data back to Earth is often a bottleneck, with transmission speeds even slower than old dial-up modems. If the reams of raw data gathered by the spacecraft’s sensors could be “crunched” onboard, scientists could beam back just the results, which would take much less bandwidth.

On the surface of the moon or Mars, explorers could use fast computers to analyze their data right after collecting it, quickly identifying areas of high scientific interest and perhaps gathering more data before a fleeting opportunity passes. Rovers would benefit, too, from the extra intelligence of modern CPUs.

Using the same inexpensive, powerful Pentium and PowerPC chips found in consumer PCs would help tremendously, but to do so, the problem of radiation-induced errors must be solved.

This is where a NASA project called Environmentally Adaptive Fault-Tolerant Computing (EAFTC) comes in. Researchers working on the project are experimenting with ways to use consumer CPUs in space missions. They’re particularly interested in “single event upsets,” the most common kind of glitches caused by single particles of radiation barreling into chips.

Team member Raphael Some of JPL explains: “One way to use faster, consumer CPUs in space is simply to have three times as many CPUs as you need: The three CPUs perform the same calculation and vote on the result. If one of the CPUs makes a radiation-induced error, the other two will still agree, thus winning the vote and giving the correct result.”

This works, but often it’s overkill, wasting precious electricity and computing power to triple-check calculations that aren’t critical.

“To do this smarter and more efficiently, we’re developing software that weighs the importance of a calculation,” continues Some. “If it’s very important, like navigation, all three CPUs must vote. If it’s less important, like measuring the chemical makeup of a rock, only one or two CPUs might be involved.”

This is just one of dozens of error-correction techniques that EAFTC pulls together into a single package. The result is much better efficiency: Without the EAFTC software, a computer based on consumer CPUs needs 100-200% redundancy to protect against radiation-caused errors. (100% redundancy means 2 CPUs; 200% means 3 CPUs.) With EAFTC, only 15-20% redundancy is needed for the same degree of protection. All of that saved CPU time can be used productively instead.

“EAFTC is not going to replace rad-hard CPUs,” cautions Some. “Some tasks, such as life support, are so important we’ll always want radiation hardened chips to run them.” But, in due course, EAFTC algorithms might take some of the data-processing load off those chips, making vastly greater computer power available to future missions.

EAFTC’s first test will be onboard a satellite called Space Technology 8 (ST-8). Part of NASA’s New Millennium Program, ST-8 will flight-test new, experimental space technologies such as EAFTC, making it possible to use them in future missions with greater confidence.
The satellite, scheduled for a 2009 launch, will skim the Van Allen radiation belts during each of its elliptical orbits, testing EAFTC in this high-radiation environment similar to deep space.

If all goes well, space probes venturing across the solar system may soon be using the exact same chips found in your desktop PC — just without the glitches.

Original Source: NASA News Release

Pete Conrad’s self portrait. Image credit: NASA. Click to enlarge.
Picture this: An astronaut, on the Moon, hunched down over a rock, hammer in hand, prospecting. Suddenly, over his shoulder, there’s a flash of light on the sun.

The radio crackles: “Explorer 1, come in. This is mission control.”

Explorer 1: “What’s up?”

Mission Control: “There’s been a solar flare, a big one. You need to take cover. The radiation storm could begin in as little as 10 minutes.”

Explorer 1: “Roger. I’m heading for the Moon Buggy now. Any suggestions?”

Mission control: “Yes. Make sure you protect your hips.”

Protect your hips?

That’s right. Protecting the hips may be a key to surviving solar storms. Other sensitive areas are the shoulders, spine, thighs, sternum and skull.

Why this odd list of body parts? The bones in these areas contain marrow — the “blood factory” of the body. Delicate bone marrow cells are especially vulnerable to solar storms; a major dose of solar protons coursing through the body could wipe them out. And without these blood-forming marrow cells churning out a steady stream of new blood cells, a person would run out of blood in as little as a week. A bone marrow transplant would be required–stat!–but they don’t do those on the Moon.

So to survive a solar radiation storm, your first priority must be to protect your bone marrow.

With NASA sending people back to the Moon by 2018, the issue of surviving solar radiation storms is more important than ever. Outside the protection of Earth’s magnetic field and with virtually no atmosphere overhead, an astronaut walking on the lunar surface is exposed to the full brunt of solar storms.

The best solution is to take cover, to get back to a radiation shelter. But if shelter is too far away to reach in time, wearing a spacesuit with extra radiation shielding over these key marrow-rich areas — shoulders, hips, spine, etc. — could mean the difference between living and dying.

“Bulking up the entire spacesuit with extra shielding might not be practical,” says Frank Cucinotta, NASA’s Chief Scientist at the Johnson Space Center, “because then the spacesuit would be too cumbersome.” Astronauts have to be able to walk, hop, bend over, reach for objects and tools. Too much shielding would make these simple moves impossible–hence the idea of selective shielding:

A layer of a plastic-like material called polyethylene only 1 cm thick could prevent acute radiation sickness. “For all but the worst flares, this would be enough to keep the astronaut’s blood system intact,” Cucinotta says. If as few as 5% of those marrow cells survive, the bone marrow will be able to regenerate itself, and the person will survive, no transplant required.

An astronaut, so shielded, might still develop long-term health problems: cancer, cataracts and other maladies. “No spacesuit can stop all solar protons,” explains Cucinotta. But if the blood supply survives, the astronaut will too, long enough to worry about the long term.

At the moment, this idea of designing a spacesuit to selectively shield the astronaut’s bone marrow is just that: an idea. Cucinotta says that many strategies are being considered for protecting the astronauts on the Moon. But the response to the idea of selective shielding has been positive, Cucinotta says. It might work.

If the idea catches on, post-Apollo spacesuits would look a little different, with beefy shoulders, wide hips, and bulbous helmets, among other things. Fashions change, sometimes for the better.

Original Source: Science@NASA Article

Spirit’s view of Mars. Image credit: NASA/JPL. Click to enlarge.
Remote-sensing orbiters, probes, landers and rovers are returning astonishing discoveries about our solar system. But some of the most exciting geological and potentially astrobiological places in our family of planets and moons are dangerous and difficult to explore.

University of Arizona, California Institute of Technology, and U.S. Geological Survey Flagstaff researchers propose a novel space mission concept for finding and exploring the most scientifically important surfaces and subsurfaces throughout the solar system.

These next-generation robotic missions will simultaneously explore distant locales at several levels – from orbit, from the air and on the ground – to home in on important geology, hydrology, climate and possibly astrobiology in distant worlds, said James M. Dohm of The University of Arizona. Dohm, a planetary geologist in UA’s department of hydrology and water resources, has mapped Mars at local to global scales. He is involved with autonomous long-range roving, sensor web and orbiting spacecraft experiments.

Wolfgang Fink, a visiting associate at Caltech, Dohm and others discuss the new mission concept in an article, “Next-generation robotic planetary reconnaissance missions: A paradigm shift,” to be published in Elsevier?s journal of Planetary and Space Science (http://www.elsevier.com/, go to Article in Press link). They spearheaded a team effort that includes Mark Tarbell, who is Fink’s associate in Caltech’s Visual and Autonomous Exploration Systems Research Lab; Trent Hare of the U.S. Geological Survey office in Flagstaff; and Victor Baker, Regents’ Professor of the UA departments of hydrology and water resources, planetary sciences and geosciences.

The new mission concept would feature orbiting spacecraft, blimps and balloons at planets or moons with sufficient atmospheres, such as Titan, and numerous simple, deployable mobile and immobile ground sensors. These spaceborne, airborne, and ground agents would be programmed to look smartly at the environment and interact with each other, offering a true “tier-scalable” perspective needed for a science-driven mission, Dohm said.

“We are now at an optimal window in time when spacecraft and airborne units can coordinate with ground-based sensors, especially since much of the technology is already available,” said Fink, a physicist and an expert in imaging systems, autonomous control and space mission science analysis systems. “Even technology not currently available — software, primarily — is quite attainable.”

?It’s important to look at layers and layers of evidence, not just one type,” Dohm said.

For example, Fink said, a rover with feature-recognition software can look for a unique rock that could contain a critical piece of the history of Mars. “If you add an airborne perspective, you also see what?s on the other side of the hill at the same time, and you know the rover’s exact field location as well,” he said. The orbiter has the global picture of what’s going on and commands the airborne and ground tiers below it.

The orbiter in a tier-scalable mission is equipped with current information about the surface, atmosphere and other features of its destination. Its sensor suite might include optical and thermal cameras, spectrometers, and ground-penetrating radar. These instruments would collect information on areas that the orbiter’s software recognizes as possible interesting targets given the overall mission science goals.

“The orbiter can deploy the airborne agents for a closer look,” Fink said. “The orbiter also can command the airborne agents to safely deploy ground agents to the prime targets. The airborne agents help detect and confirm prime targets.”

“The ground agents can measure information such as heat or moisture,” Dohm said. “Or they can sample or collect diverse rocks and, in the case of Mars, possible near-surface water. There could be numerous lightweight, expendable sensors, so that even if you lost a few, you’d still have mission.”

The sensors send information back to their respective airborne probes, and ultimately to the orbiting spacecraft. Based on this new information, the orbiter sends new commands that drive the mission.

“The spaceborne, airborne, and ground agents all work together as a field geologist,” Dohm said. “They analyze information to form a working hypothesis.” They would be ideal for exploring Valles Marineris, the expansive canyon system of Mars, or Europa’s putative ice-covered ocean, he added.

In the case of Valles Marineris, for instance, Dohm said, the orbiting spacecraft would deploy sensors that would transmit weather conditions back to the spacecraft. If the sensors give the spacecraft a good weather report – no high winds, for example – the spacecraft would then release the balloons or blimps. These airborne agents would start their searches for targets important to mission goals, collecting and adding new information as they go and deploying ground agents at promising candidate sites. The ground agents would collect and return data to the higher-level airborne probes, or the orbiter, or both. “If the goal at Valles Marineris was to find possible water seeps or near-surface water, a drill rig might even be deployed at the most promising site,” Dohm said.

Fink and Dohm say the new concept needs further design, testing and ground-truthing in diverse Earth environments. They envision field camps for international researchers for designing and testing possible tier-scalable reconnaissance systems.

Intelligent, science-driven robotic space missions are a decade or two in the future, they will be international, and they will have significant corporate and private sponsorship, Dohm and Fink predict.

Original Source: University of Arizona News Release