Live CRaTER data from LRO re-broadcast as music

CRaTER, now half way through its fifth year in lunar orbit onboard LRO, is providing a solid data set on the real health hazards and possible mitigation of high-energy radiation from deep space in Earth's vicinity and in low lunar orbit, where the Moon effectively shields half the sky. Using proven technologies cosmic - not solar - radiation is a significant block to long-term human spaceflight beyond the Moon [NASA/GSFC/UNH/SwRI].

Elizabeth Zubritsky
Goddard Space Flight Center

The latest tool for checking space weather is an internet radio station fed by data received from NASA's Lunar Reconnaissance Orbiter (LRO).

The radio station essentially operates in real time, receiving measurements of how much radiation the spacecraft is experiencing and converting into a constant stream of music. The radiation levels determine which instrument is featured, the musical key being used and pitches played.

"Our minds love music, so this offers a pleasurable way to interface with the data," said the leader of the music project, Marty Quinn of the University of New Hampshire, Durham. "It also provides accessibility for people with visual impairments."

The radiation levels are determined by LRO's Cosmic Ray Telescope for the Effects of Radiation (CRaTER). Equipped with six detectors, CRaTER monitors the energetic charged particles from galactic cosmic rays and solar events.

The instrument makes two kinds of crucial measurements. One type studies the interaction of radiation in space with a material that is like human tissue; this is helping scientists assess the effects that exposure would have on people and organisms. The other type looks at radiation hitting the moon and the products generated by that interaction, which provides a way to explore the composition of the regolith on the moon.

"CRaTER has discovered wide-ranging and fundamental aspects of such radiation," said Nathan Schwadron, the principal investigator for CRaTER. "For example, we have discovered that tissue-equivalent plastics and other lightweight materials can provide even more effective protection than standard shielding, such as aluminum."

Each detector on CRaTER reports the number of particles registered every second. These counts are relayed to CRaTER Live Radio, where software converts the numbers into pitches in a four-octave scale. Six pitches are played every second, one for each detector. Higher, tinkly pitches indicate less activity, whereas lower, somber-sounding pitches indicate more activity.

The software selects the primary instrument and a musical key based on recent activity. At the lowest radiation levels, the main instrument will be a piano, playing pitches from one of the major scales. But as the peak radiation level climbs, one of the minor scales will be selected instead, and the piano will be replaced by one of seven other instruments.

For example, when CRaTER picked up elevated radiation counts caused by the solar flare January 7, 2014, the primary instrument changed to a marimba, which is two instruments up from the piano. A steel drum or guitar instead of a marimba would mean the radiation level had ramped up more. A banjo would mean the peak had climbed to the top of the normal operating range.

If the counts climb beyond the top of the normal operating range – as might happen during a very big event – the software would switch into a second operating range. The piano would again represent the bottom of this range, and the banjo would represent the top. To indicate which range is current, a violin and a cello play sustained notes in the background. If those sustained notes are played at the highest pitches on the scale, the normal operating range is in effect; if those notes drop by even one pitch, the second range is being used.

The radio station is one of CRaTER's official data products and is available online and through an app. The data feed from LRO is live, with one caveat. Whenever the spacecraft moves behind the moon, it cannot line up with data-collecting antennas on Earth, so there is a blackout period of about an hour. During that time, the station reuses the previous hour's data. To indicate that the music is not live, the sound of the bongo drum in the background is changed, and the chiming of the triangle is muted.

The most familiar example of data sonification – conversion into sound – is a simple one: The Geiger counter produces a click every time it detects a radioactive particle.

In the past few decades, scientists in many fields have experimented with sonification, hoping to capitalize on humans' ability to hear small changes instantly, even against a noisy background. Music has the added advantage of making it easy to process many changes at once through variations in pitch, rhythm, tempo, scale, loudness and instrumentation.

"Music makes it easy for people to take in the data, and it seems to be a natural fit for space missions," said LRO's project scientist, John Keller of NASA's Goddard Space Flight Center, Greenbelt, Maryland.

Sonification has been used to present data from several NASA spacecraft, especially Voyagers 1 and 2 and the Kepler observatory. Quinn previously worked on sonification for other NASA missions, including Mars Odyssey, the Solar TErrestrial RElations Observatory, the Advanced Composition Explorer and the Interstellar Boundary Explorer.

Cosmic ray threat to manned spaceflight tested on MSL

The MSL cruise phase as unmanned proxy for Orion, testing the deep space radiation environment [NASA].

Employing present, proven technology manned space travel to Mars exceeds NASA’s own limits on astronaut radiation exposure. That limit is calculated in terms of risk of “Radiation Exposure Induced Death,” or “REID,” over an individual astronaut’s life expectancy.

Ironically, as astronauts age their risk of eventually dying from causes unrelated to radiation exposure steadily increase. It’s the kind of risk coldly calculated by insurance providers. Though dying of undiagnosed heart disease is fed into the calculus, such other threats to the older astronaut's long-term survival overshadow their cumulative risk of REID.

None of this is news. This fly in the ointment in need of being overcome before humans can safely experience long-duration spaceflight beyond Earth’s magnetic field was starkly spelled out in the influential “ (2007),” a report put together by the National Academy of Science before the Constellation program was cancelled. The hard numbers have been gathered from the opening of the Space Age, from Explorer 1 through Apollo, from the Voyagers through the International Space Station.

Now these projections have been verified again by an instrument that traveled to Mars with Curiosity.

The lead investigators for these sensors announced their results during a NASA audio press conference Thursday. Dr. Cary Zeitlin, a principal scientist in the Southwest Research Institute’s (SwRI) Space Science and Engineering Division discussed detailed measurements of energetic and highly-ionizing particle radiation gathered during the 253 day, 560 million km journey to deliver the Mars Science Laboratory (MSL) “Curiosity” rover to the floor of Gail crater on Mars.

The Radiation Assessment Detector (RAD) made detailed measurements of the energetic particle radiation environment inside the spacecraft, providing important insights for future human missions to Mars.

NASA/JPL/SwRI

"In terms of accumulated dose, it's like getting a whole-body CT scan once every five or six days," said Dr. Cary Zeitlin, a principal scientist in SwRI's Space Science and Engineering Division and lead author of Measurements of Energetic Particle Radiation in Transit to Mars on the Mars Science Laboratory, scheduled for publication in the journal Science on May 31.

"Understanding the radiation environment inside a spacecraft carrying humans to Mars or other deep space destinations is critical for planning future crewed missions," Zeitlin said. "Based on RAD measurements, unless propulsion systems advance rapidly, a large share of mission radiation exposure will be during outbound and return travel, when the spacecraft and its inhabitants will be exposed to the radiation environment in interplanetary space, shielded only by the spacecraft itself."

Titanium alloy in the hull of a manned spacecraft is a good shield
against most solar particle events, but counter-productive against
the heaviest cosmic rays. These heavy nucleons split and shower
damage into human tissue.

Two forms of radiation pose potential health risks to astronauts in deep space: a chronic low dose of galactic cosmic rays (GCRs) and the possibility of short-term exposures to the solar energetic particles (SEPs) associated with solar flares and coronal mass ejections. Radiation dose is measured in units of Sievert (Sv) or milliSievert (1/1000 Sv). Long-term population studies have shown that exposure to radiation increases a person's lifetime cancer risk; exposure to a dose of 1 Sv is associated with a 5 percent increase in fatal cancer risk.

GCRs tend to be highly energetic, highly penetrating particles that are not stopped by the modest shielding provided by a typical spacecraft. These high-energy particles include a small percentage of so-called heavy ions, which are atomic nuclei without their usual complement of electrons. Heavy ions are known to cause more biological damage than other types of particles.

The solar particles of concern for astronaut safety are typically protons with kinetic energies up to a few hundred MeV (one MeV is a million electron volts). Solar events typically produce very large fluxes of these particles, as well as helium and heavier ions, but rarely produce higher-energy fluxes similar to GCRs. The comparatively low energy of typical SEPs means that spacecraft shielding is much more effective against SEPs than GCRs.

"A vehicle carrying humans into deep space would likely have a 'storm shelter' to protect against solar particles. But the GCRs are harder to stop and, even an aluminum hull a foot thick wouldn't change the dose very much," said Zeitlin.

"The RAD data show an average GCR dose equivalent rate of 1.8 milliSieverts per day in cruise. The total during just the transit phases of a Mars mission would be approximately .66 Sv for a round trip with current propulsion systems," said Zeitlin. Time spent on the surface of Mars might add considerably to the total dose equivalent, depending on shielding conditions and the duration of the stay. Exposure values that ensure crews will not exceed the various space agencies standards are less than 1 Sv.

"Scientists need to validate theories and models with actual measurements, which RAD is now providing. These measurements will be used to better understand how radiation travels through deep space and how it is affected and changed by the spacecraft structure itself," says Donald M. Hassler, a program director at Southwest Research Institute and principal investigator of the RAD investigation. "The spacecraft protects somewhat against lower energy particles, but others can propagate through the structure unchanged or break down into secondary particles."

Only about 5 percent of the radiation dose was associated with solar particles, both because it was a relatively quiet period in the solar cycle and due to shielding provided by the spacecraft. Crew exposures during a human mission back and forth to Mars would depend on the habitat shielding and the unpredictable nature of large SEP events. Even so, the results are representative of a trip to Mars under conditions of low to moderate solar activity.

"This issue will have to be addressed, one way or another, before humans can go into deep space for months or years at a time," said Zeitlin.

SwRI, together with Christian Albrechts University in Kiel, Germany, built RAD with funding from the NASA Human Exploration and Operations Mission Directorate and Germany's national aerospace research center, DLR.

The radiation environment and its effects on human
spaceflight: A Lunar Mission (January 5, 2013)
Cosmic ray flux effects lunar ice (March 19, 2012)
"a perfect storm of cosmic rays" (September 29, 2009)
Cosmic rays and manned space travel (September 16, 2009)
Cosmic ray flux highest ever recorded (September 3, 2009)
Returning to the Moon (August 9, 2009)
LUNAR-TEX radiation blanket: Skeptical (May 11, 2009)
NASA cataract detection down to Earth (January 18, 2009)
NASA and Congress sacrifice radiation shielding flexibility
by removing dry landing hardware (May 17, 2008)

Managing Space Radiation Risk in the New Era of Space Exploration (2008)
Committee on the Evaluation of Radiation Shielding for Space Exploration
National Research Council

Scientific Context for the Exploration of the Moon (2007)
Space Studies Board
National Research Council

The Radiation environment and its effect on human spaceflight: A Lunar Mission

Relative monthly infall of galactic cosmic rays from 1958 through December 2012 shows the inverse relationship with solar activity. The highest GCR infall rate (since the beginning of the Space Age) was recorded in late 2009 (arrow), occurring at the same time was the latest and unusually lengthy solar minimum [Moscow Neutron Monitor].

João Sabino
Instituto Superior Técnico
Lisboa, Portugal

This work is an overview of the quantities and concepts common in radiation physics and describes the types of radiation important to planning crewed missions to the Moon. Radiation effects on biological tissue and the consequences to astronaut health are addressed.

The environment of a mission to the Moon was simulated based on data obtained with the CREME program along with data from Lunar Prospector neutron measurements. The virtual mission was divided into stages of a trajectory: Low Earth Orbit, traversing the Van Allen Radiation Belts (VARB), the geostationary orbit radiation environment (GEO), lunar orbit and surface radiation environments. 

Major details in the development of a software application in Geant4 (CERN) are presented. The application was used to reproduce the transport of radiation particles through matter, to simulate the physics involved and to obtain the resulting absorbed dose, equivalent dose and the spectre of secondary radiation. The quantities were evaluated for solar minimum, solar maximum, and solar conditions wre evaluated for each mission phase.

The radiation environment in the solar system presents the main constraint to human spaceflight outside Earth's protecting radiation belts.

As the human presence in space tends to increase, or the will to reach other planets grows, radiation in space becomes a more compelling obstacle that needs to be dealt with. The risks that radiation exposure presents to space missions directly effects mission planing. For this reason a good knowledge of the radiation environment in all mission phases is essential. Development of reliable prediction tools is of major importance to assist mission planing and assure minimum safety for the crew.

This work pretends to explain subjects that need to be taken into account to understand problems space radiation pose to human spaceflight, taking as an example the case of a real lunar mission scenario and also documenting the development of software simulating the radiation environment and analyzing the effects of exposure.

Robotic space exploration looks promising in the immediate future, but despite huge advantages many scientists acknowledge it is not sufficient alone, that humans are needed in space to perform more complex research tasks such as field geology and the acquisition and analysis of samples.

This is a strong incentive towards human spaceflight and also a natural drive based on curiosity and adventure the human being has shown in this kind of challenge that lead us to go farther and farther; not to mention technological and industrial advancements always associated with meeting such challenges. Nowdays, even the tourism industry has begun to recognize space as an interesting destination for the wealthy, and some companies have already flown tourists to the International Space Station.

Human space exploration beyond LEO is presumably going to reemerge very soon, especially if some of the present risk it poses are minimized.

Download or read the study (pdf), HERE.

Cosmic ray flux effects lunar ice (March 19, 2012)
“a perfect storm of cosmic rays” (September 29, 2009)
Cosmic rays and manned space travel (September 16, 2009)
Cosmic ray flux highest ever recorded (September 3, 2009)
LUNAR-TEX radiation blanket: Skeptical (May 11, 2009)

Managing Space Radiation Risk in the New Era of Space Exploration (2008)
Committee on the Evaluation of Radiation Shielding for Space Exploration
National Research Council

Radiation effects on materials on the Moon

Rojdev, O'Rourke & Koontz, et.al.
NASA Johnson Space Center

NASA is focused on developing technologies for extending human presence beyond low Earth orbit. These technologies are to advance the state-of-the-art and provide for longer duration missions outside the protection of Earth's magnetosphere.

One technology of great interest for large structures is advanced composite materials, due to their weight and cost savings, enhanced radiation protection for the crew, and potential for performance improvements when compared with existing metals. However, these materials have not been characterized for the interplanetary space environment, and particularly the effects of high energy radiation, which is known to cause damage to polymeric materials. Therefore, a study focusing on a lunar habitation element was undertaken to investigate the integrity of potential structural composite materials after exposure to a long-term lunar radiation environment. An overview of the study results are presented, along with a discussion of recommended future work.

NASA Scientific and Technical Information knowledge base
National Space and Missile Materials Symposium
Scottsdale, Arizona, June 28, 2010

View the presentation slides (PDF) HERE.

Tubular structures on lunar surface, ideal landing sites

R. Ramachandran
The Hindu

Remnant tubular structures or tunnel-like formations from lunar volcanic flows in the past, which extend a couple of kilometres on the moon’s surface, could serve as ideal landing as well as human settlement sites for future lunar missions, including Chandrayaan-II, according to some new findings from India’s Chandrayaan-1.

These findings were reported on Monday at the Sixth Chandrayaan-1 Scientific Meeting being held at the Physical Research Laboratory (PRL) here.

Data from the Terrain Mapping Camera (TMC), one of the Indian instruments on-board the spacecraft, has revealed one such volcanic tube in the Oceanus Procellarum area of the moon (central longitude 58.317 deg. W and latitude 14.111 deg. N). The remnants of volcanic tubes on the moon whose roofs have capsized and a trench or valley is created is called a rille system, which is a groove or long narrow depression on the lunar surface. The volcanic tube identified by the TMC comprises two cobra hood-shaped rilles, the longer one measuring 3.65 km in NE-SW direction and the smaller one measuring 0.73 km. The interesting feature is that these rilles seem connected by an intermediate stretch of a two km-long and 360-metre-wide uncollapsed portion (see picture), which seems to be the roof of the lava tube that did not collapse for some reason, said A. S. Arya of the Indian Space Research Organisation’s Space Applications Centre (SAC), Ahmedabad, who described the findings at the meeting.

More significantly, the uncollapsed part is very close to the surface, only 160 metre below. Its hollow interiors could be safe spots for lunar habitation, or even parking lunar landers for protection from the harsh impacts of interplanetary material, meteorite showers, solar wind and radiation. “For future missions aimed at creating permanent base stations and human settlements on the moon, there is a need to identify such locales that have survived the onslaught of the past impacts and would provide safe shelters to human beings on the moon,” Dr. Arya said. For instance, the Japanese mission Kaguya discovered a vertical hollow structure, but that is not suitable for habitation, Dr. Arya said. In a horizontal tubular structure, however, any lunar vehicle can just move along the rille into the tunnel structure for safe parking.

But the TMC findings could even become the starting point for identifying suitable locations for immediate missions such as Chandrayaan-II, which plans to land two lunar rovers, said M. Annadurai, Project Director, Chandrayaan-1 and Chandrayaan-II. Chandrayaan-II has set itself the ambitious goals of sustaining the two rovers in the harsh lunar environment for as long as six months. All previous missions have landed in the sunlit area and have not been able to survive beyond a few weeks. “We need to see how Chandrayaan-1 data can be used from an engineering point of view in terms of site terrain information and soil interactions to know where to land our rovers from this perspective,” Dr. Annadurai said.

Like Chandrayaan-1, its follow-up mission, which is likely to be flown during 2012-13, will also focus mostly on the higher lunar latitudes, Dr. Annadurai said. “From an engineering point of view, we need to look at the rovers spending longer night hours. For optimal power utilisation, they will function in the hibernation mode when there is no sunlight for generating power,” he said. “So a suitable site could be the edge of some crater or a site near such volcanic tubes where they can retreat for hibernation. But a cross comparison of data from different Chandrayaan-1 experiments can tell us much more than just the TMC data. And such a trend has been evident at this meeting.”

With Russia already part of the project, Chandrayaan-II is also likely to have international collaboration, especially with all the principal investigators of the various experiments keen on carrying the work forward by collaborating among themselves in the future.

PETA protests target radiation testing

Dave Wedge
Boston Herald

While about two dozen animal rights supporters gathered outside McLean Hospital in Belmont this morning to protest controversial radiation tests on monkeys, researchers defended the testing as adhering to government guidelines.

Wearing T-shirts and holding signs, People for the Ethical Treatment of Animals members voiced their opposition to a NASA project that will zap about 20 squirrel monkeys with radiation. The primates will be hit with radiation doses equivalent to three years of space travel at a New York facility and then will be shipped to McLean to live under the watch of Harvard Medical School researchers.

PETA officials say the testing is cruel because it could lead to cancer, premature aging and cognitive damage in the monkeys. Six PETA protesters donned monkey masks and sat in cages during the peaceful protest.

Follow this story HERE.

Advanced avionics and processor systems for space and lunar exploration

Andrew S. Keys and James H. Adams, (NASA MSFC) et.al.

In response to the Constellation Program's need for environmentally hardened electronics and avionics, the AAPS technology development project is actively working to provide advancements in the areas of modeling of the radiation environment and its effect on advanced, modem electronics, FPGAs designed such that they are hardened against the radiation environment, High Performance Processors that will provide high efficiency, radiation hardened performance, Reconfigurable Computin g capabilities that allow a single processor board to fulfill multiple finctions, and SiGe-based electronics that allow operation in the low-temperature and radiation environments of the lunar surface. This overview paper provides a summary of each of these technology development tasks with an emphasis on the significant progress of the past fiscal year and identification of the additional development milestones planned for the coming fiscal year.

Download the full Presentation (pdf) HERE.
AIAA SPACE 2009 Conference and Exposition Pasadena, CA 14-17 Sept. 2009

More on the Skylight at Marius Hills

Terrain Camera on-board JAXA lunar orbiter Kaguya (SELENE-1) captured data formulated into this image showing what appears to be an approximately 65 meter-wide 'Skylight,' extending down at least 90 meters deep among the domes and rima of Marius Hills (12°N, 306°E) in Oceanus Procellarum [ISAS/JAXA/Junichi Haruyama et al.].

Rachel Courtland
New Scientist

A deep hole on the moon that could open into a vast underground tunnel has been found for the first time. The discovery strengthens evidence for subsurface, lava-carved channels that could shield future human colonists from space radiation and other hazards.

The moon seems to possess long, winding tunnels called lava tubes that are similar to structures seen on Earth. They are created when the top of a stream of molten rock solidifies and the lava inside drains away, leaving a hollow tube of rock.

Their existence on the moon is hinted at based on observations of sinuous rilles – long, winding depressions carved into the lunar surface by the flow of lava. Some sections of the rilles have collapsed, suggesting that hollow lava tubes hide beneath at least some of the rilles.

But until now, no one has found an opening into what appears to be an intact tube. "There's sort of a chicken-and-egg problem," says Carolyn van der Bogert of the University of Münster in Germany. "If it's intact, you can't see it."

Finding a hole in a rille could suggest that an intact tube lies beneath. So a group led by Junichi Haruyama of the Japanese Aerospace Exploration Agency searched for these "skylights" in images taken by Japan's Kaguya spacecraft, which orbited the moon for almost two years before ending its mission in June.

Deep cave

The team found the first candidate skylight in a volcanic area on the moon's near side called Marius Hills. "This is the first time that anybody's actually identified a skylight in a possible lava tube" on the moon, van der Bogert, who helped analyse the feature, told New Scientist.

The hole measures 65 meters across, and based on images taken at a variety of sun angles, the the hole is thought to extend down at least 80 meters. It sits in the middle of a rille, suggesting the hole leads into a lava tube as wide as 370 meters across.

It is not clear exactly how the hole formed. A meteorite impact, moonquakes, or pressure created by gravitational tugs from the Earth could be to blame. Alternatively, part of the lava tube's ceiling could have been pulled off as lava in the tube drained away billions of years ago.

Radiation shield

Finding such an opening could be a boon for possible human exploration of the moon. Since the tubes may be hundreds of meters wide, they could provide plenty of space for an underground lunar outpost. The tubes' ceilings could protect astronauts from space radiation, meteoroid impacts and wild temperature fluctuations.

"I think it's really exciting," says Penny Boston of the New Mexico Institute of Mining and Technology in Socorro. "Basalt is an extremely good material for radiation protection. It's free real estate ready to be exploited and modified for human use."
Blocked passage?

But even if astronauts were to rappel into the hole, they might not be able to travel far into the tube it appears to lead into. "I would bet a lot of money that there's a tube there, but I would not bet nearly so much that we could gain access to the tube," says Ray Hawke of the University of Hawaii at Manoa, who has also hunted for lunar lava tubes.

Rubble or solidified lava might block up the tube. "It could be closed up and inaccessible," Hawke told New Scientist.

NASA's Lunar Reconnaissance Orbiter (LRO), which should be able to snap images of the area that are at least 10 times as sharp, could help reveal more about the hole. And more lava tube openings may be found.

The Kaguya team is still combing over images of other areas in search of additional skylights. And Hawke says a proposal is in the works to use LRO's main camera to snap oblique shots of the lunar surface. This could help reveal cave entrances that are not visible in a bird's-eye view.

Radiation-hardening could lighten spacecraft

"The space community is eager to find ways to produce space-hardened microelectronic devices using only everyday commercial chip-making technologies, Cressler says. The savings in cost, size and weight could be very significant.

"Silicon-germanium is a top candidate for this application because it has intrinsic immunity to many types of radiation. The catch is that, like other materials, SiGe cannot stand up to the extremely destructive heavy ions present in galactic cosmic rays. At least, not yet. "

Read the report of work at Georgia State, HERE.

Cosmic Ray flux highest ever recorded

The percentage of Cosmic Rays repelled by the Interplanetary (Solar) Magnetic Field, as recorded continuously over fifty years at the Moscow Neutron Monitor. [Monthly resolution corrected for changes in atmospheric pressure.] Detail of 2009, upper right, is shown in a similarly generated plot at the end of this post.

Joel Raupe
Lunar Pioneer Research Group

Without the Sun's magnetic field, it is believed, in-falling of "Galactic" Cosmic Rays (GCRs) at Earth arriving from every direction from outside the solar system is more or less constant.

If true, the evidence may be uncovered eventually by the twin U.S. probes Voyager-1 and Voyager-2 expected to reach interstellar space and beyond the influence of the Sun's interplanetary magnetic field (IMF) in five to eight years.

At its most active, at solar maximum, cosmic rays of a very wide variety, in mass and energy, are deflected from the inner solar system by the Sun when passing perpendicularly to the lines of force of its magnetic field. At these times, at the peak of the Sun's Sunspot Cycle, more than half of these highly ionizing and often very heavy atomic nuclei are kept from reaching the inner Solar System.

Put another way, at solar minimum a background Cosmic Ray flux impending on the inner solar system increases by more than 100 percent.

At the moment the Sun's remains in an unusual and lengthy quiet spell surpassed in the record book of the past hundred years only by the solar minima of 1913.

Since 1958, originally set up by the Soviet Union in celebration of the International Geophysical Year, the Moscow Neutron Monitor has continuously measured variations from an average background neutron flux as a method to gauge the strength of the Sun's interplanetary magnetic field. A haze of neutrons not otherwise associated with other celestial objects (like the Galactic Disk) is one remnant of those cosmic rays that manage to reach Earth's atmosphere, where they meet their doom, becoming short-lived aerosols or added electrical charge in the lower atmosphere. There is evidence and theory of more profound effects, as well.

The chart above begins a minute before midnight December 31, 1958 and runs through August 31, 2009, or 50.67 years (18,506 days). The website of the MNM invites users to similarly plot this percentage of variation over any period or resolution within their 51 year dataset.

The chart demonstrates an inverse relationship with the Sunspot Cycle, going up when the Sun is quiet, as it is today, and down when the Sun is magnetically active at solar maximum. It is not a measure irradiance (which seems to varie no more than a tenth of a percent during the Solar Cycle.)

Sunspots and the Solar Cycle are outward manifestations of a torturous process underway as the Sun is forced to change the polarity of it's magnetic field by an uneven rotation, and repelling of highly ionizing GCRs depends upon that fields strength, extent and continuity.

From Lunar Pioneer

Fortunately, there are more direct detectors of Cosmic Rays besides Earth-bound neutron detectors that can only indicate GCR flux by inference. Voyager 1 and Voyager 2 are "just years away," we believe, from directly measuring these curious particles and their rates of incidence beyond the noisy Sun. Both imaging systems were shut down years ago but on-board experiments are collecting data, among these are Cosmic Ray Subsystems. Every six hours the aging probes, each powered by three radioisotope thermal generators, record the rate of ionizing atomic nuclei that populate two classes: those with energies greater than 500 keV and those with energies greater than 70 MeV. As of May 2009 Voyager-1 was 16.4 billion km (110 AU) from the Sun as Voyager-2 reached 13.3 billion km (89 AU). Voyager-1 crossed the termination shock, the beginning of the end of the solar wind and the IMF in 2004, at ~ 94 AU, and Voyager-2 crossed this area in 2007 at ~84 AU (confirming theories of the "squashed" shape of the heliosphere. Both are expected to reach interstellar space in 5 to 8 years. Strangely (or not) this plot of Voyager-1 data of encounters with nucleon with energies >500 keV is considered "a good indicator of GCR activity" by the present-day Voyager team. A less rapid change occurred near the time the Moscow Neutron Monitor data inferred an increase in GCRs in the inner solar system. In the outer solar system, Voyager-1 data seem s to show a recent decline, perhaps showing the effect of a fluttering solar wind at its extremes. Similar plots made over the same period showing one year of nucleon at higher energies (>70 MeV /nuc ion) show a slow but steady increase. Only time and patience, and the continued good health of the thirty-year-old Voyagers may tell if these data show a steady but declining influence from the Sun with increasing distance or a true measurable variation in Cosmic Ray flux outside the interplanetary magnetic field.


At the present time the Sun's magnetic field is as weak as has ever been accurately recorded, having recently surpassed the length and magnitude of the former record-holding weak moment in the Sun's IMF back in 1964.

Though the Sun's present unusually long solar minimum has been well-noted, the Home Star had been interpreted as showing signs and sputters heralding, finally, a poorly-predicted beginning of Solar Cycle 24; increased activity ahead of the next solar maximum finally underway that revised predictions now show occurring in 2013.

If the Moscow chart at the beginning of this thread and measurements of the IMF are bona fide indication of the Sun's changing mood, however, it has never been recorded as more gloomy. The IMF met and then surpassed the weak plateau in solar activity from 1964 only recently, in the past few months, after the nadir out of this present solar minimum was thought to have occurred.

Perhaps it is all normal, or at least not atypical. Closer study is needed to show how closely the percentage of neutron flux variation match data from other indicators of solar activity (and inactivity).

As seen on the graph at the top, (but easier at the MNM website) 1959 began with neutron flux repelled by the IMF by less than 12 percent, corresponding to an active Sun slowly quieting after the strong solar maximum in 1954. The repelling of cosmic rays then appears to fall off data collection continued through a deep solar minimum between 1964-65. The highest horizontal dotted line on the graph at the top of this page represents a mean, or "Zero Percent" variation in the background of neutrons detected.

After reaching that earlier recorded low in GCR deflection recorded in 1964, the Sun rapidly fires up for a peak just in time for the Apollo missions, and man's first voyages outside Earth's own magnetic field. Solar Particle Events (SPEs), Coronal Mass Ejections and such, occur at any time in the a Solar Cycle, but are admittedly more common and energetic when Sunspot numbers are high, and the Solar Cycle peak in 1968 did, in fact, worry Apollo planners.

Additional research done by NASA and the Department of Energy, in Space and on Earth in the years since has changed thinking about the real dangers of ionizing radiation for space travelers. An active Sun may make the situation less dangerous, as it turns out.

An active Sunspot maximum does not pose the greatest hazard to astronauts in Deep Space. It would be confirmed that the aluminum alloy hull of the Apollo command module and that of the Space Shuttle actually offered good protection from most effects of solar activity. And the Sun's strong interplanetary magnetic field repells 50 to 60 percent of GCRs.

Because Cosmic Rays are dangerous and can't yet be practically shielded against. A very high energy ionizing iron nucleon, for example, is not stopped by those aluminum hulls. Instead these heavy particles simply shatter and become instead miniature showers of secondary and tertiary ionizing radiation that quickly spreads into a cone the size of a human head, or torso.

Rather than being unnecessarily worried about the danger posed by an active Sun, NASA's researchers are now concerned more by energetic, ionizing cosmic rays. An active Sun may be a Deep Space astronaut's best friend, warding off microscopic energetic atomic nuclei that pack a wallop without being immediately felt.

For more than a year, while closely monitoring other indicators of solar activity, a slow negative trend in neutron flux seemed to indicate the present long solar minimum was at last coming to an end. But in April the Interplanetary Magnetic Field noticeably retreated over mere hours. The neutron flux variation has since lingered in unfamiliar territory, actually 2 to 6 percent more than average, perhaps corresponding to a greater cosmic ray incidence and breaking and exceeding the 1964 record. [Resolution plotted hourly; corrected for atmospheric pressure.]

Thank you to SpaceWeather.com,
Moscow Neutron Monitor, and NASA.

(NOTE: This is posting number 1,500 at the Lunar Pioneer/Lunar Networks Service Blog)

Radiation blanket claims utterly fantastic, without hard numbers

Notional habitat on the Moon shielded from radiation by Lunatex, developed under supervision of Dr. Warren Jaspers at North Carolina State University in Raleigh. The fabric-system as described in print purports to protect human life from the wide range of radiation hazards outside Earth's atmosphere and magnetic field. All reports so far, however, fail to mention the certain limitations of the fabric. (Specialty Fabrics Review)

For months, we've taken the quiet, modestly skeptical approach as to Dr. Warren Jaspers LUNAR-TEX, especially matter-of-fact news releases advertising a textile with super powers. Then, on Sunday (and, most peculiarly, just after a private discussion here about mitigating space radiation hazards) the LUNAR-TEX miracle surfaces again, following weeks with little mention anywhere.

Blanket protects lunar outposts
Specialty Fabrics Review

"Textile engineering students at North Carolina State University (NCSU) have the next manned moon landing covered with a blanket that protects lunar outposts from radiation while storing energy for astronauts’ use. The project, one of 10 finalists in the Revolutionary Aerospace Systems Concepts Academic Linkage competition, tackles one of NASA’s key concerns about moon missions that will likely last months at a time—cosmic rays and solar flares that make dangerous radiation hard to stop."

"The “lunar texshield” is made from a lightweight polymer composite with a layer of radiation shielding that deflects or absorbs radiation. The outer shield layer includes solar cells to generate electricity. The design is flexible, lightweight, has a large surface area, and is easy to transport and deploy. “We understand the properties associated with different textile materials,” says Dr. Warren Jasper, NCSU professor of textile engineering and project advisor. “That gives us unique insight on how to troubleshoot some of these issues.”"

To which we replied:

"As much as we admire NC State's engineers and proven science department, this is not the first time we have been casually informed of an astounding claim, without sufficient detail about how well it works.

"According to the National Academies, in "Managing Space Radiation in the New Era of Space Exploration (2008) [http://www.nap.org/catalog/12045.html] a round-trip manned expedition to Mars, for example, would result in each crew member exceeding NASA's present individually assessed lifetime probable risk of radiation exposure induced death (4%).

"A fabric mitigating this risk on the lunar surface is reasonable, but affording protection from such risk as effectively as does Earth's magnetic field and atmosphere is not reasonable, most especially the risk from cosmic rays at or above 100 MeV. (Ed. Probably more like 500 MeV to 10 GeV, though the "ceiling" and incidence of the highest-energy particles are not yet known, data collected since 1958 show the rate of infall of Galactic Cosmic Rays into the inner Solar System is 50 to 60 percent higher at solar minimum.)

Since reports of this fabric's usefulness have not touched on any detail regarding its certain limitations, we are understandibly skeptical. It begs clarification as to just how this fabric changes hard numbers on well-established risk probabilities. With such numbers, we're prepared to salute a revolutionary development, equal to shielding equal to 11 meters of regolith. But, without such numbers these claims made for Lunatex seem utterly fantastic."

But, that is, as they say, academic. The claims made on behalf of Dr. Jaspers are, indeed, "utterly fantastic." At face value, the reports about LUNAR-TEX might as well claim protection against space debris or meteor bombardment, or hail and lightning. In fact, those claims would be more "probable."

What we have in Dr. Jasper's development is an innovation in systems and materials that are "probably" a real mitigation against the full range of space radiation over spectrum and time. It's probably a real breakthrough, and one that might make round-trips to Mars using present acceleration capability less than life threatening. As such, it may be a real breakthrough.

But enough is enough.

More reports about the development of a panacea cannot go unchallenged. This one is really starting to bug us because space radiation is, as far as we can tell, one of the things that appears to be totally misunderstood or ignored by all parties in the far-flung public space policy debate, currently underway in the United States.

NASA selects four proposals to study radiation

NASA has selected four proposals for research to help understand space radiation's effects on humans living in space. NASA selected proposals from the New York University School of Medicine in New York, the University of Texas Medical Branch in Houston, Loma Linda University in California and Georgetown University in Washington. The universities will work with collaborating organizations around the country.

These institutions will become NASA Specialized Centers of Research. They will consist of teams of investigators who have complementary skills and work together to solve a closely focused set of research questions. The proposals support the space radiation program element within NASA's Human Research Program.

NASA is investing $28.4 million for research into carcinogenesis and central nervous system risks from spaceflight. Research from the peer-reviewed proposals during the five-year award period will pave the way for development of effective countermeasures for space travelers.

NASA's Human Research Program provides knowledge and technologies to improve health and performance during space exploration. The program also develops possible countermeasures for problems experienced during space travel. Goals include the successful completion of exploration missions and preservation of astronauts' health throughout their lives. The program quantifies crew health and performance risks during spaceflight and develops strategies that mission planners and system developers can use to monitor and mitigate these risks.

Winners are listed below:

• Gregory Nelson, Loma Linda University, Charged Particle Radiation and Resultant Oxidative Stress Elicit Deleterious Functional Changes in the Central Nervous System
• Mary Barcellos-Hoff, New York University School of Medicine, The contribution of non-targeted effects in HZE cancer risk
• Robert Ullrich, University of Texas Medical Branch, NASA Specialized Center of Research on Radiation Carcinogenesis
• Albert Fornace, Jr., Georgetown University, Space Radiation and Intestinal Tumorigenesis: Risk Assessment and Counter Measure Development

Where will the Sun's magnetic field hit bottom?

At the moment the Sun's magnetic field, "the interplanetary magnetic field," is bottoming out with a long solar minimum, a low point in solar activity between the slow dying of Cycle 23 and the unexpectedly slow start to Cycle 24.

The Sun's relative quiet presents an opportunity to further determine any natural floor, what the "absolute" bottom background might be, to the interplanetary magnetic field, without the background noise of its eleven-year swing between often dramatic and chaotic peak activity.

This may not seem as immediately important to the earthbound as the health of Earth's magnetic field (though Earth's magnetic field's shielding energy is, in some measure, determined by our orbital vector perpendicular through the Sun's particle streams and magnetic field lines) but for machines and humans traveling outside Earth's magnetic field an improved understanding if the interplanetary magnetic field is essential.

Between its peak strength at solar max and its weakest at solar minimum , the in-fall of sometimes very heavy and energetic cosmic rays varies by half. The stronger the interplanetary magnetic field the greater the protection against interstellar cosmic rays, and it is literally a toss up if travel beyond Low Earth Orbit is "safer" for humans and their equipment at solar max or solar minimum.

At solar max the interplanetary magnetic field is strongest, providing a statistically important shield against Galactic Cosmic Rays, but it also increases likelihood travelers will encounter a dangerous "Solar Particle Event."

Solar Flares and attendant Coronal Mass Ejections can, of course, occur at anytime,though they are more likely at solar max. Even during the present protracted solar minimum, flares have been observed, along with coronal holes allowing the hot breath of solar wind, consisting mostly of protons, to gust away from the Sun's photosphere.

It is within today's design and materials technologies and spacecraft design to greatly shield life and equipment from most solar wind. Though rarer, a heavy cosmic ray consisting of a stripped nucleon of primordal metal and traveling near the speed of light might be shattered by its encounter with an aluminum-titanium hull of sufficient thickness but a resulting shower of secondary particles actually would increase the likelihood that an astronaut would receive a wider cone of ionizing radiation.

Generating a magnetic field has been suggested as a way to change the direction of infalling cosmic rays. But the effective size and strength of such a field's strength would need to be more than hundreds of kilometers in radius, to name just one known issue with this solution.

The fact remains that reducing the probability of radiation exposure induced death to below 4 percent, over an individual astronaut's lifetime, for a trip to Mars using presently available speeds is still beyond our capability. Though this will change, reducing the likelihood of being dosed by a wide range of cosmic rays by 50 percent, possible within the interplanetary magnetic field at solar max, is not a small factor in mitigating risk in long periods traveling in deep space.

Living on the Moon immediately provides a shield from half the infall of interstellar radiation, and under 15 meters of lunar regolith doses come down to levels on Earth at sea level.

It may be possible, where it would be unthinkable on Earth, to build interplanetary transport vessels shielded by lunar concrete and propelled on trips to Mars and elsewhere using rail guns and unimpeded by atmospheric drag.

Of a more basic concern to engineers and policy makers, it may prove very unwise to travel to Mars without first building an infrastructure on Earth's Moon. This is especially likely if the Sun's present solar minimum persists.

It may be that the downslope from solar max may be driven by CMEs, carrying away kinks of the Sun's internally twisted magnetic field, up and away from the Sun and temporarily reducing the interplanetary magnetic field by as much as ten percent. A CME may be the way the Sun balances out the tensions in its magnetic field that wind up as portions of the Sun rotate at different speeds.

Because the Sun's magnetic field swaps out polarity between its hemispheres from one cycle to the next, the interplanetary magnetic field changes polarity.

On first glance it may seem finding an absolute bottom, a basic and unchanging level to the interplanetary magnetic field, would be impossible. Scientists at the Russian Academy of Sciences, however, have published an examination of the interplanetary magnetic field between 1976 and 2000. They claim there is no point when the interplanetary magnetic field reaches "zero," and this is backed by observations of the Sun over this past year's lengthy solar minimum.

In 2008-2009, the sun has produced brief outcroppings of sunspots at polarities and latitutdes that clearly mark them as a beginning to the next solar maximum, with its next expected peak in activity now expected in 2013. Over the past summer however, months after Cycle 24 officially started, sunspots from Cycle 23 briefly appeared.

In The floor in the interplanetary magnetic field (Yermolaev, et. al. 2009) predicts a floor to the interplanetary magnetic field at 4.65 ± 6.0 nT.

Today's measurement of the interplanetary magnetic field on Spaceweather.com was 4.1 nT, and their report also "agrees well" with observations over the past thirty years.

NASA and Congress sacrifice radiation shielding flexibility by removing dry landing hardware

As money at federal budget time comes down to crunch time in House Appropriations, 500 kilos of dead weight and an unecessary need to establish the credibility of the timeline as a selling point for NASA, the Program has been forced to abandon dry land landings for Orion Block One.

It's back to splashdowns, and a forced long-term cost-per-mission is squeezed into the "out years" of the program by the Will of Almighty Congress. Penny-wise and pound foolish, the mission directorates congressional liasons have made safety a more difficult problem for engineers, and ultimately more expensive.

Forcing a larger cost into the out years for a micro-managed short-term "gain" is congressional traditional, however, and like it or not, NASA - just like every federal agency - is a "Creature of Congress."

In the long run, dropping 500 kilos from Orion's design will save the future timeline only at its very beginning, in 2015. Future safety delays, future "Hydrogen Summers," will delay missions in an out year domino effect. If NASA has learned anything from the long Space Shuttle experiment, that should be obvious.

Cost to the Department of Defense for what is essentially Sea Search and Rescue may or may not be a hidden cost to future taxpayers, but dependence made into a necessity, and sacrificing an advance into precision terra firma landings never a feature of NASA capsule-type missions, but a staple of Soviet/Russian missions for almost fifty years is deliberate ignorance.

The most important reason for NASA not to abandon what appears to a clever congressional staff to be merely 500 kilos of "dead weight" is not so obvious and not so easy to communicate in budget hearings.

If only Congress bothered to read the carefully written, easy to follow reports on deep space radiation hazards so carefully and respectfully laid out by the National Academies in two recent reports commissioned by NASA.

That 500 kilos of "dead weight" was integral to flexibility vehicle designers will now be forced to part with in accounting for essential shielding against Galactic Cosmic Rays and Solar Particle Events.

In two well-crafted, peer-reviewed studies the National Academies repeated an generous allowance given designers of the Constellation's Altair lunar lander and Orion CEV to incorporate shielding into the placement of components in the very design of those vehicles.

NASA safety protocol allows an astronaut only a 3 percent probability, over the course of that individual's lifetime, of "Radiation Exposure Induced Death," or REID. Even when incorporating shielding into the design of Orion's components and hull, a nominal trip to Mars guarantees a greater than 3 percent probability, over the course of a Human lifetime, of REID.

That assessment by the National Academies made brief headlines when their latest report, in draft form, was made public at the beginning of this year's budget rounds. The news about Mars being outside the REID protocols was highlighted while similarly nominal trips to the Moon being within those same safety demands did not.

Either way, testimony blasting NASA for having any kind of manned program whatsoever, and in favor of JPL's ground-pounding vision of pure robotics, quickly absorbed the National Academies circumspect report. Apparently neither congressional staff or NASA's lobbyists had time to read their important report.

With the loss of shielding flexibility, design difficulties and safety demands will make the timeline less credible, and not more. In the end, it will make for either a more dangerous Orion, future Liberty Bell Sevens, or, more likely, the addition of another 500 kilos of aluminum inside and outside the Orion command module - without the ability to land on dry ground.

Radiation Safe Worlds

In a light-hearted premier, Colony Worlds passed along this morning some basic context and perspective to remind would-be spacefarers of the harsh, unforgiving realities for living awash in myriad kinds of radioactivity beyond the Blue Shore.

And that's just the neighborhood.

First among the worlds said to be available for human colonization, circling our own humble mid-sequence variable star, is Earth's Moon. In the short-term and long-term, however naked she is, we will need to start by taking this pier if we are to set sail beyond. To live on stark and dusty Mars, it follows we must first learn how to live on the Moon. Perhaps to live and work and stay on the Moon we will first have had to live and work and stay in Antarctica, and so on.

"We are known best in hindsight." - Eric Hoffer

Read more HERE