Archive for the 'Research' Category

Was Mars Ever Habitable?

If all goes according to plan, on November 25th the Mars Science Laboratory (MSL) rover Curiosity will leave the Earth and begin its journey to Mars. Any delays due to weather or other factors should be accommodated by a launch window that extends until December 18th. The spacecraft will use a new landing system to arrive at its landing site on Mars in August, 2012, and the rover carries an impressive array of scientific instruments. The rover is about twice as large as the Mars Exploration Rovers Spirit and Opportunity, thereby enabling it to navigate terrain characterized by larger obstacles (such as rocks) as it travels up to about 200 meters (219 yards) per Martian day.

 

Curiosity

This artist concept features NASA's Mars Science Laboratory Curiosity rover, a mobile robot for investigating Mars' past or present ability to sustain microbial life.

The new landing system for the Mars Science Laboratory replaces the airbag system utilized by the Pathfinder and Mars Exploration Rovers during landing. The new landing system enables much larger rovers and science instrument payloads to be delivered to the surface of Mars than was previously possible and opens the door for future missions geared towards the eventual return of samples for the Red Planet. Upon entering the Martian atmosphere, the MSL spacecraft will first steer itself through the upper atmosphere before deploying a parachute and then using rockets and a tether to lower the Curiosity rover to the surface.

Curiosity’s mission is geared towards understanding whether Mars is or ever could have been habitable. Recent data from NASA’s orbiting spacecraft (Odyssey and the Mars Reconnaissance Orbiter) and the Mars Exploration Rovers suggests the planet has had a long and complicated history of changing environmental conditions and landscapes. Curiosity will follow those missions by deploying a diverse complement of instruments to interrogate the rocks and soils in the vicinity of the landing site. The “next generation” of instruments carried by Curiosity comprises a “mobile laboratory” and should lead to a quantum leap in our understanding of Mars’ potential habitability and how the surface of Mars evolved over time.

landing site

Images of Gale Crater, the selected landing site for the Mars Science Laboratory. The first image shows the regional context of Gale Crater (labeled on the left and discussed above) with colors representing the elevation of the land surface (purple lowest and red highest). The second image shows an example of high priority science targets for exploration near the ellipse (yellow box in first image shows the location) and the last image shows science targets within the target landing ellipse (white box in the first image shows the location).

Advances in landing precision enable consideration of smaller landing sites than was possible during prior missions and made it possible to access the selected landing site within Gale crater. Gale crater is attractive to scientists because there is a five kilometer (three mile)-thick section of layered rocks deemed likely to enable study of changing conditions on Mars over a time when the abundance and duration of water on the surface was decreasing over time. As water is an important factor in evaluating potential habitability, the chance to access the rocks that record the changes from relatively wetter to drier present an opportunity to learn a great deal about Mars as a planet and its potential as a possible abode for life.

Curiosity is an important step in the long term study of Mars and sets the stage for future missions that will be focused on whether there is or ever was life on Mars. By helping to understand whether the planet was habitable and, if so, for how long, MSL will help identify the likely environments and potential targets for future sample return and the eventual search for possible life.

The excitement should begin the day after Thanksgiving, so while resting after eating all that turkey, tune in to NASA TV and watch as Curiosity counts down towards lift-off and the start of an exciting new chapter in our understanding Mars and the solar system.

Visitors to our Museum in DC can also watch the launch, targeted for 10:25 am ET Nov 25, on the giant screen in the Moving Beyond Earth gallery.

John Grant is a geologist in the Center for Earth and Planetary Studies at the National Air and Space Museum, and co-led the process for selecting the landing site for the 2011 Mars Science Laboratory rover.

 

Alien Hoax Revealed at the National Air and Space Museum!

Last Friday, the Museum hosted an online conference devoted to critical thinking in the Internet age. Using four conspiracy theories in aerospace history to demonstrate effective research techniques, staff from our Museum, the US Department of the Navy, and National History Day engaged with students and teachers from across the globe.

Here are the topics we examined:

  1. What happened to Amelia Earhart? Did she crash in the Pacific, or was her disappearance fabricated as part of a government plot?
  2. Did Franklin Delano Roosevelt know about the attack on Pearl Harbor before it happened?
  3. What are UFOs and are we being visited by extra terrestrials?
  4. Did Americans actually land on the Moon? Or was it all an elaborate hoax?

 

Buzz

Buzz Aldrin salutes the American flag on the Moon.

We chose this theme because it provides excellent examples of why it is important to examine every story with a critical eye. Conspiracy theories always challenge the accepted narrative, interpreting details that institutional analysis either deliberately omits or cannot explain. As such, the people who question these official stories have already begun the process of critical thinking, but they haven’t necessarily followed through to the end.

In order to conduct a more thorough inquiry into each of these subjects, our presenters stepped through a critical thinking checklist that can be described in further detail on the Virtual Salt website. Shortly put, when examining any topic, one should evaluate its Credibility, Accuracy, Reasonableness and Support (CARS). If we apply this tool to any of the conference topics, we discover that the likelihood of conspiracy is very low, but it should be noted that this isn’t always the case. These questions are helpful for any historian or researcher and can be applied to any resource being considered — from newspaper articles to archival photos to historic artifacts.

 

close encounters

The mother ship model used for the 1977 film "Close Encounters of the Third Kind" currently on display at the Steven F. Udvar-Hazy Center in Chantilly, VA.

The conference concluded with a panel discussion during which our historians described some of their most exciting discoveries. Our own Tom Crouch, senior curator in the Aeronautics Division, discussed how he determined that the wing tips of the world’s first powered airplane, the 1903 Wright Flyer were actually made from carriage spreaders. This contribution to the historical record shed light on who Orville and Wilbur Wright really were and how they worked. It was an exciting moment in his career.

Another panelist, Randy Papadopoulos, secretariat historian at the Department of the Navy, probably summed it up best when he described a particular “aha” moment he once had:

You realize, wow! This is a singular event. This is something that no one else has considered… The devil is in the details — you have to do some digging to find out, but when you do, you feel this tremendous sense of relief. [You realize] okay, I actually made a contribution that’s original. I’ve done something new here.

We’d like to thank all of our panelists for continuing to contribute original insights through their dedicated and thoughtful research. And thanks to everyone from around the world who participated in our online event.

For those who couldn’t attend, please check out the recordings online.

We enjoyed producing this conference, and we hope to do more. Please let us know what kind of topics you’d like to see us examine in future online events.

Ivey Doyal is a content manager in the Web and New Media Division of the National Air and Space Museum.

Where are the Voyagers now?

The remarkable twin Voyager spacecraft continue to explore the outer reaches of the solar system decades after they completed their surveys of the Outer Planets.  Launched in 1977 (September 5 for Voyager 1 (V1) and August 20 for Voyager 2 (V2), whose trajectory took it past Jupiter after Voyager 1), the spacecraft pair made many fundamental discoveries as they flew past Jupiter (March 1979 for V1, July 1979 for V2) and Saturn (November 1980 for V1, August 1981 for V2).  The path of Voyager 2 past Saturn was targeted so that it continued within the plane of the solar system, allowing it to become the first spacecraft to visit Uranus (January 1986) and Neptune (August 1989).  Following the Neptune encounter, both spacecraft started a new phase of exploration under the intriguing title of the Voyager Interstellar Mission.

Voyager

Voyager Spacecraft

Five instruments continue to collect important measurements of magnetic fields, plasmas, and charged particles as both spacecraft explore different portions of the solar system beyond the orbits of the planets.  Voyager 1 is now more than 118 astronomical units (one AU is equal to the average orbital distance of Earth from the Sun) distant from the sun, traveling at a speed (relative to the sun) of 17.1 kilometers per second (10.6 miles per second).  Voyager 2 is now more than 96 AU from the sun, traveling at a speed of 15.5 kilometers per second (9.6 miles per second).  Both spacecraft are moving considerably faster than Pioneers 10 and 11, two earlier spacecraft that became the first robotic visitors to fly past Jupiter and Saturn in the mid-70s.

 

Jupiter

This processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager image captured in 1979.

As seen in the night sky at Earth, Voyager 1 is within the confines of the constellation Ophiuchus, only slightly above the celestial equator; no telescope can see it, but radio contact is expected to be maintained for at least the next ten years.  Voyager 2 is within the bounds of the constellation Telescopium (which somehow sounds quite appropriate) in the far southern night sky.

 

Heliosphere

Diagram of the Voyager and Pioneer spacecrafts leaving the solar system.

Both spacecraft have already passed something called the Termination Shock (December 2004 for V1, August 2007 for V2), where the solar wind slows as it starts to interact with the particles and fields present between the stars.  It is expected that both spacecraft will encounter the Heliopause, where the solar wind ceases as true interstellar space begins, from 10 to 20 years after crossing the Termination Shock.  Theories exist for what should be present in interstellar space, but the Voyagers will become the first man-made objects to go beyond the influences of the Sun, hopefully returning the first measurements of what it is like out there.  Each spacecraft is carrying a metal record with encoded sounds and sights from Earth, along with the needle needed to read the recordings, and simplified instructions for where the spacecraft came from, in case they are eventually discovered by intelligent extra-terrestrials.

 

Voyager Record

The Voyager "Sounds of Earth" Record, placed on board the Voyager spacecraft contains sounds and images selected to portray the diversity of life and culture on Earth.

 

Keep track of the Voyager spacecraft on the official Voyager Interstellar Mission website or follow @NASAVoyager2 on Twitter.

 

Jim Zimbelman is a geologist in the Center for Earth and Planetary Studies at the National Air and Space Museum.

The sun ejects a continuous stream of charged particles (electrons, protons, etc) that is collectively termed the solar wind.  The particles are traveling extremely fast and are dense enough to form a very tenuous atmosphere; the heliosphere represents the volume of space where the effects of the solar wind dominate over those of particles in interstellar space.  The solar wind particles are moving very much faster than the local speed of sound represented by their low volume density.  When the particles begin to interact with interstellar particles and fields (the interaction can be either physically running into other particles or experiencing an electromagnetic force resulting from a charged particle moving within a magnetic field), then they start to slow down.  The point at which they become subsonic (rather than their normal hypersonic speed) is the Termination Shock.

Curiosity Landing Site

Here is a riddle: What takes more than 60 locations, 5 years, and 150 scientists to decide? The landing site for the Mars Science Laboratory (MSL) rover Curiosity. Picking the landing site for a spacecraft to land on another planet is always serious business. And the job of finding the best location for Curiosity to set down on Mars was no exception.

Curiosity’s mission is geared towards understanding whether Mars could have ever been habitable. And recent data from NASA’s orbiting spacecraft (Odyssey and the Mars Reconnaisance Orbiter) and the Mars Exploration Rovers suggests the planet has had a long and complicated history of changing environmental conditions and landscapes. Combine that with the fact that the landing site could be anywhere between 30 degrees north and south of the equator and below an elevation of 0 kilometers (relative to the Martian datum) and there is a lot of territory to consider.

 

Curiosity Landing Site

This map of Mars shows all of the landing sites proposed for the Mars Science Laboratory (red dots) and the four final candidate sites (blue dots). From the four final sites of Eberswalde crater, Gale crater, Holden crater, and Mawrth Vallis, Gale eventually was selected as the landing site. The white shaded areas are more than 30 degrees north and south of the equator and off limits to MSL because of seasonally harsh (cold) conditions expected there. The black areas are above 0 kilometer in elevation and too high to be considered for landing.

The vast majority of the sites proposed for consideration (Figure 1) were within the general bounds outlined above and many possess attributes making them attractive as possible landing sites. Moreover, the design of the rover enables consideration of a variety of sites. So science merit became the major discriminator of which site would eventually win out.

Over a series of workshops, the science community and MSL science team came together to discuss and evaluate the various proposed sites. The diverse expertise represented at the workshop coupled with ample discussion time ensured each site got a good look. As the process went along, more and more sites were dropped from consideration as potential issues were identified. Finally, four sites remained, all of which were deemed satisfactory for MSL and each with a substantial group of science advocates. These four sites include a relict river delta in Eberswalde crater, a 5 kilometer (3.1 mile) thick section of layered rocks in Gale crater, ancient alluvial and possible lake beds in Holden crater, and ancient sequence of clay-bearing rocks near Mawrth Vallis (Figure 2). The four sites became the focus of intense study and discussion at the final two workshops, with efforts geared towards understanding how the rocks in and near the sites were emplaced and whether they might be accessible to Curiosity once on the ground. As data related to the sites poured in and evaluations went on, the four final sites have become arguably the best imaged and studied locations on the surface of Mars. In the end, there was no “smoking gun” that was found to rule out any of the four final candidate sites and the community reiterated their satisfaction with any one of them. Much more information about each of the proposed landing sites can be found on Marsoweb.

 

Curiosity Landing Site

Summaries of each of the final four candidate landing sites for the Mars Science Laboratory. The left column shows the regional context of each of the four sites (labeled on the left and discussed above) with colors representing the elevation of the land surface (purple lowest and red highest). The middle column shows examples of high priority science targets for exploration near the ellipse (yellow box in left column shows the location of each) and the right column shows science targets within each target landing ellipse (white box in left column shows the location of each). At Eberswalde crater, Curiosity would land on the crater floor and probe ancient river and possible lake beds on the way to a large delta on the western wall of the crater. At Gale crater, the site chosen as the landing site for Curiosity, landing will occur on an alluvial fan near the northern wall of the crater and the rover will than traverse to a thick stack of layered rocks to the south. At Holden crater, landing would take place on broad alluvial fans flanking the western wall of the crater and the rover would traverse down to underlying and finely layered rocks that may have been deposited in a lake. At Mawrth Vallis, landing would occur directly on a layered sequence of clay-bearing rocks that extend regionally across the surface. The images comprising the panels in the middle and right columns are from the HiRISE camera on the Mars Reconnaissance Orbiter. The scale bars in each panel indicate distance in kilometers.

The Curiosity science team then met and considered all of the information related to the sites. Both science potential and risks to rover landing and traversing were considered. In the end, Gale crater was selected as the landing site because the thick section of rocks (Figure 2) was deemed likely to enable study of changing conditions on Mars over a time when the abundance and duration of water on the surface was decreasing over time. As water is an important factor in evaluating potential habitability, the chance to access the rocks that record the changes from relatively wetter to drier present an opportunity to learn a great deal about Mars as a planet and its potential to support life.

Curiosity lifts off towards the Red Planet late in 2011 and will arrive at Mars in mid-2012. In the days and months leading up to landing at Gale crater, the MSL science team will continue to pore over existing and new images to plan the best path towards rocks they feel hold the clues to understanding Mars’ habitability. Once on Mars and on the move, Curiosity will provide images and information from its science payload of instruments that will enable all of us to follow along in the excitement of exploration and learn more about how one of our neighboring planets evolved over time.

John Grant is a geologist in the Center for Earth and Planetary Studies at the National Air and Space Museum and served as the co-chair of the Mars Landing Site steering committee for the Mars Science Laboratory.

A New Curiosity

There is a strange looking car parked in the west end of the National Air and Space Museum in downtown Washington, DC. For now, it is only visible behind its security screen from the second floor landing above. From that vantage, the vehicle’s six wheels, robotic arm, mast, and other protrusions are clearly visible. But since this is the Air and Space Museum, it must be more than just a normal car.

Soon the barriers will be gone and the public will be able to view the vehicle up close and personal. And what they will see is a model of the next Mars rover, NASA’s 2011 Mars Science Laboratory. The rover, dubbed “Curiosity” will be launched to Mars later this year and will begin its mission to explore whether places on the Red Planet were ever habitable. Information on the mission can be found at: http://marsprogram.jpl.nasa.gov/msl/. The rover carries a suite of instruments geared towards understanding conditions on the planet and a full description of the payload can be found at: http://marsprogram.jpl.nasa.gov/msl/mission/instruments/.

NASA Mars Rover Curiosity at JPL, Side View. The rover for NASA's Mars Science Laboratory mission, named Curiosity, is about 3 meters (10 feet) long, not counting the additional length that the rover's arm can be extended forward. The front of the rover is on the left in this side view. The arm is partially raised but not extended. Rising from the rover deck just behind the front wheels is the remote sensing mast. Image Credit: NASA/JPL-Caltech

The landing site for Curiosity will be one of four final candidate sites all deemed to possess a variety of features suited to evaluating whether Mars could have been habitable in the past. It is expected that NASA will announce the landing site in the coming weeks. Much more information on the landing sites proposed for Curiosity can be found at: http://marsoweb.nas.nasa.gov/landingsites/index.html.

The model of Curiosity will be on display through Labor Day of this year.

See the model of Curiosity and learn more about its mission at this year’s Mars Day! on July 22.

John Grant is a geologist in the Museum’s Center for Earth and Planetary Studies and co-chair of the Mars Landing site steering committee leading the MSL landing site selection process.

Collecting Popular Culture

From April 20 to April 23, curators from the Aeronautics Division and the Space History Division attended the 2011 National Conference of the Popular Culture Association/American Culture Association (PCA/ACA) in San Antonio, Texas. Tom Crouch of the Aeronautics Division organized a session on museum collecting and collectors titled “Collecting the Popular Culture of Flight at the Smithsonian National Air and Space Museum,” and the participants presented papers on collections that we curate. Tom spoke about the Balloonomania Collection of balloon-related furniture and furnishings; Alex Spencer of the Aeronautics Division talked about the Mother Tusch Collection, which contains many significant personal artifacts of military aviation; Margaret Weitekamp of the Space History Division discussed the O’Harro Collection of space memorabilia and popular culture; and I talked about the Stanley King Collection of Lindbergh memorabilia and popular culture.

 

Balloonomania

This colorful early 19th-century ceramic plate, part of the Museum's Balloonomania Collection, depicts the 1804 ascension in Paris of Joseph Louis Gay-Lussac and Jean-Baptiste Biot in an early scientific investigation of the Earth’s atmosphere.

This PCA/ACA meeting was one of the largest academic conferences I had ever attended, and a far cry from the small, homey gatherings of the organization I went to in the mid to late 1980s in Charleston and St. Louis. The 2011 meeting sessions usually began at 8:00 am and went on until very late in the evening every day, occupied conference rooms in two major San Antonio hotels, and covered a wealth of areas from “Adaptation (Film, TV, Literature & Electronic Gaming)” to “World War I & II.” In between were panels on such things as “Fat Studies,” “Grateful Dead,” the “Vampire in Literature,” and the perhaps more prosaic “Visual Arts in the West.” Our session fell into the “Collecting and Collectibles” area.

PCA began in the early 1970s as a reaction to what was perceived to be the elitism of the American Studies Association in favor of traditional American literature, and its disregard for new forms of expression such as material culture, popular music, movies, and comics. In 1979, the PCA began to partner with the American Culture Association and sponsored the first PCA/ACA Conference at Michigan State University. A number of people were involved in the formation of PCA/ACA, but Professors Ray Browne of Bowling Green State University and Russell Nye of Michigan State were the primary movers and shakers for the idea that popular culture deserved academic recognition as a topic of study. The PCA/ACA now has seven regional organizations, and is affiliated with four international popular culture organizations in Australia/New Zealand, East Asia, Canada, and Europe. Both organizations publish journals: The Journal of Popular Culture and The Journal of American Culture.

In museum circles, popular culture suffered the same fate as it did in academia. It was caught up in the “high culture” versus “low culture” debate, originated by literary critic Dwight Macdonald and others, in which high culture—classical art and literature, classical music, ballet, theater, etc.—was thought to be more worth considering than low culture—popular literature, movies, popular music, comics, etc. At the Smithsonian’s Museum of History and Technology (the predecessor of the Museum of American History), the story is told of how many curators were not in favor of collecting American political memorabilia because they considered it “junk.” I dare say this was true in other Smithsonian museums, including the National Air and Space Museum. Ironically, the Museum had been collecting “popular culture” for years, but calling it something else. In 1974, for example, the Museum accepted a donation from Paramount Pictures of the original Starship Enterprise model from the television program Star Trek. In the 1990s, the Museum did two major popular culture exhibitions, Star Trek (1992), and Star Wars: The Magic of Myth (1997), which were immensely well-liked and full of intellectual content, but looked on somewhat disapprovingly in some quarters of the Museum. But just as academic fashion changes over time, so did museum consideration of popular culture as a worthy topic of collecting, research, and exhibition. Now Margaret Weitekamp holds a curatorial title that indicates she is responsible for collecting social and cultural artifacts; i.e., popular culture.

 

Starship Enterprise Model

This 3.4 meter (11-foot) model of the fictional Starship "Enterprise" from the weekly television series "Star Trek" was donated to the National Air and Space Museum in 1974 by Paramount Pictures. To illustrate how popular culture can often impinge on real life, the National Aeronautics and Space Administration (NASA) was persuaded by a write-in campaign to change the name of the spaces shuttle full-scale test vehicle on display at the Steven F. Udvar-Hazy Center from "Constitution" to "Enterprise."

Although even the PCA/ACA disputes the definition of the term, preferring to create subject areas of academic interest, I do think there is some agreement that popular culture is influenced by industries that disseminate cultural material, for example, the film, television, and publishing industries, as well as the news media. It could even be described as not merely a cumulative product of those industries, but the result of a continuing interaction between them and the people of the society that consume the products. Popular culture is also a way to approach American consumer culture; i.e., the culture that surrounds American commerce, esp. advertising, marketing, merchandising, and the media, and its influence on American society. But even such definitions do not go far enough in my estimation.

However one wants to define it, there are a number of ways to rationalize collecting popular culture in a museum. In the case of the Stanley King Collection, the objects are a way of understanding the consumer tastes of Americans and to making sense of the idea of celebrity. The King Collection also tells us how dominant cultural images like aviation and personalities like Charles A. Lindbergh were used to sell all manner of goods. Lindbergh endorsed very few products, and those were related directly to aviation. Either he didn’t know or didn’t care that someone was making money from his celebrity. In our era, however, celebrities tend to keep a tight rein on their images or “brand,” and infringement is likely to prompt a lawsuit. Nevertheless, a good deal of popular culture merchandise that is unlicensed and unauthorized manages to find its way to the market place.

 

"Spirit of St. Louis" Toys

Four objects from the Stanley King Collection. Clockwise from bottom left: metal roll toy likeness of the "Spirit of St. Louis" with figure; windup metal toy "Spirit" with a New York-Paris map on wing; glass candy container in the shape of an airplane; puzzle game that depicts the flight paths of Lindbergh and his competitors for the Orteig Prize—Richard Byrd and Clarence Chamberlin.

The O’Harro Collection is somewhat different from the King Collection, even though it too consists of commercially-produced materials. Jules Verne’s De La Terra á la Lune (From the Earth to the Moon) is said to have stirred visionaries of modern rocketry like Tsiolkovski, Oberth, and Goddard. Similarly, space science fiction heroes of the 1930s, represented in the O’Harro Collection by Buck Rogers and Flash Gordon, stimulated American youth, and provided a glimpse at how space travel was imagined in the days before we had the technology to explore the Moon and distant planets. For a later era, the popular culture of the Star Trek television series (1966 to 1969) and the Star Wars trilogy (1977, 1980, 1983) indicates that space science fiction capitalized on the public interest in space travel prompted by the advent of the U.S. space program and the 1969 landing on the Moon.

 

Ray Guns

Four toy ray guns from the Museum's space popular culture collection illustrate how varied the colors, shapes, and designs of imagined space toys can be.

The Balloonomania Collection and the Mother Tusch Collection are rather different from the consumer-oriented popular culture of the King and O’Harro collections. The Balloonomania Collection of 18th century furniture and furnishings was in a sense both a popular and preindustrial commercial response to the advent of balloon flight, and the first glimpse of the Earth from above the planet. The Mother Tusch Collection represents the personal crusade of a woman who thought of herself as a mother image to hundreds of military aviators during and after World War I, and of the pilots’ response in giving her personal items in gratitude for her many kindnesses.

 

Mother Tusch

Mary E. “Mother” Tusch is shown here shortly before her collection was sent to Washington in 1947. She is surrounded by the aviation memorabilia that she avidly collected, especially the personal items given to her by the many military pilots who trained at the U.S. School of Military Aeronautics at the University of California at Berkeley campus during WWI. These objects, now in the Museum's collection, were meant to show the aviators’ gratitude for her maternal concern for them, hence the name “Mother” Tusch.

Further historical investigation of commercially-produced popular culture is necessary before we have a complete picture. Some questions to consider: who are the manufacturers of these products? Is there a relationship between the poplar objects of aviation and spaceflight and other collectibles that represent a dominant cultural image? Were these items advertised, if so, how were they advertised? What were the conditions of the workers who produced these items? Are these or similar types of materials being manufactured today?

The Museum does not have a collections fund to purchase items like these, which are likely to be found in the hands of collectors. Thus, subsequent acquisition of popular culture objects depends largely on the generosity of people like Michael O’Harro and Stanley King. Both curatorial divisions, however, have clearly-articulated collecting plans that specify what types of popular culture the Museum wishes to collect. The Aeronautics Division, for example, is especially interested in obtaining consumer items such as toys, games, household furnishings, apparel, and other collectibles that relate to aviation, especially for the interwar years, World War II, and the 1950s, and of more recent vintage, toys like action figures of pilots from the Vietnam War era to the present day, dolls or action figures that represent women in aviation, and electronic media like arcade games and flight simulation games for personal computers. The Space History Division is especially interested in acquiring scarce or rare items from early space science fiction, toys, games, lunch boxes, and other collectibles, electronic media like arcade games, computer games, and console games, and cultural objects from the early Project Mercury/Gemini/Apollo eras.

Dominick A. Pisano is a curator in the Aeronautics Division of the National Air and Space Museum

 

What Can You Really See From Space?

Most people know that satellites in orbit do useful things such as collect images of the Earth’s surface. At the National Air and Space Museum I use satellite images in my job to understand changes in the Earth’s land surface. Today millions of people are acquainted with satellite imagery on internet map services. People sometimes ask me if it’s possible to see even more detail from space. In this post I’ll explore what is really visible in different types of satellite data.

There are dozens of orbiting remote sensing satellites, and the level of detail they see depends on its precise mission. “Remote sensing” just means looking at something from a distance. In this case we’re talking about viewing the Earth from at least hundreds of miles above the atmosphere.

The images on internet map servers are provided by a recent generation of satellites that collect detailed images, including the GeoEye and WorldView satellites. Objects smaller than automobiles are visible in some of these images. In the past, only military and reconnaissance satellite were capable of this kind of detail.

IKONOS

Image from the IKONOS satellite showing downtown San Francisco. This type of image shows great detail over small areas.

Other satellites observe large areas and discern things the size of agricultural fields. These spacecraft, including the Landsat satellites, are useful for mapping cities or regional changes in land cover.

Landsat 7

Image from the Landsat 7 showing the metropolitan area of Mexico City in the upper left. On the right is the volcano Popocatepetl, which appears dark red in this false color infrared image. This image covers an area about 100 miles across.

Another class of satellites orbit thousands of miles out in space. These spacecraft, including the GOES satellites, are designed to observe changing weather over an entire hemisphere of the Earth. They cannot discern small details.

GOES

View from GOES satellite showing weather systems moving across the entire globe.

In the past, it was often incorrectly stated that the Great Wall of China was the only man-made thing visible from space. Although an astronaut would probably not be able to see it with unaided eyes, the Great Wall is visible using orbiting sensors. However, plenty of other things made by humans are also visible. It was sometimes even stated that the Great Wall is visible from the Moon, but that’s definitely not possible. If you stood on the Moon, the entire Earth would appear to be about the size of a quarter held at arm’s length.

In some Hollywood films, satellites provide moving images from space. The hero immediately targets a satellite to search for evildoers. While this type of real-time imagery looks very cool, it’s not really how satellites work. Orbiting satellites pass over a particular point only every couple of weeks, and they cannot be immediately moved or collect moving images.

There is a way to get imagery like that, but it’s from unmanned airplanes. Drone aircraft can provide real-time imagery and even be equipped with weapons to attack targets.

In reality, satellite imagery is used for “before” and “after” images. These can be used for research purposes and for responses to emergencies. Recently media outlets widely used imagery from the GeoEye-1 satellite to show tsunami devastation in Japan.

Sometimes a satellite passes overhead at just the right time to capture a rapid change. The Indian Ocean tsunami on December 26, 2004 was one of those times. The QuickBird satellite just happened to pass over Sri Lanka when the wave of water crashed ashore, providing an amazing (and scary) image. In 2005 the same satellite provided images of New Orleans immediately after Hurricane Katrina. I had an opportunity to closely examine those images at the time, and I remember making a sobering calculation of how much of the city remained submerged.

So the detail visible in a satellite image all depends on the mission of each satellite and the scale of its observations. A few non-military satellites can see objects down to about half the size of a car. Some military satellites can still see even smaller things. But that does not tell us the whole story. For most applications we need to see larger areas, which requires other satellites that observe at a different scale.

For each satellite imaging project, we need to choose between seeing small details or seeing a large area. You can’t usually have both. But  increased computing power has made it possible to combine highly detailed images to cover very large areas. The seemless imagery on internet map servers actually consists of many thousands of individual images that have been combined. Scientists use the same kind of approach to view fine scale vegetation changes across continents. Methods of combining small images will continue to be valuable for making detailed observations of the Earth in the future.

Andrew K. Johnston is a geographer in the Center for Earth and Planetary Studies at the National Air and Space Museum.

MESSENGER on Final Approach to Mercury

Today at 8:45 pm EDT (March 18, 2011, 12:45 am UTC), MESSENGER will become the first spacecraft ever to enter Mercury’s orbit. With MESSENGER on the last leg of its journey, I’m reminded how long it has taken to get there.  I watched the spacecraft launch in the early morning hours of August 3, 2004, almost six and a half years ago.  Now after one flyby of Earth, two flybys of Venus, and three flybys of Mercury, the spacecraft will catch up with Mercury again, but this time it will be captured by the planet.  You might think as one of our closest neighbors in the Solar System it would take a lot less time to get into Mercury orbit – but because Mercury is the closest planet to the Sun, at a distance where the influence of the Sun’s gravity is much greater, it is a challenge to reach and orbit.

MESSENGER

This artist's impression shows MESSENGER with its sunshade side. The sunshade shields the spacecraft from solar radiation, helping to keep the instruments from overheating. Image courtesy of Johns Hopkins University Applied Physics Laboratory.

In its three flybys of Mercury, MESSENGER imaged much of the planet’s surface. As great as the flyby images are, they vary greatly in resolution and in lighting geometry.  In orbit, MESSENGER will map the entire surface of Mercury at high resolution and with even lighting.  These first images obtained from orbit will revolutionize our understanding of Mercury.  I will be eagerly examining the new images for evidence of fault scarps, landforms created by the shrinking of Mercury’s crust causing it to break and from cliffs.  These cliffs tell us that Mercury’s interior has cooled and the entire planet has contracted.  With a new global view of Mercury, we can map all the fault scarps and estimate just how much the planet has contracted over time.  It’s an exciting time for the exploration of Mercury!

Mercury

This color image of Mercury was captured on September 29, 2009 during MESSENGER's third and final flyby. Image courtesy of NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

Tom Watters is senior scientist and geologist in the Center for Earth and Planetary Studies at the National Air and Space Museum.

Vintage Aircraft Tool Cataloging, Re-housing and Preservation Project

In the years following WWII the United States and her Allies conducted engineering and flight tests of many different types of captured or surrendered Axis aircraft, primarily from Germany and Japan. Many of these aircraft were acquired by Allied and US technical intelligence collection teams.  It was ordered that at least one of each type of enemy aircraft be captured and evaluated by these teams, and that each aircraft type be maintained in flyable condition for a minimum of one year. To make this possible all technical data and support materiel available (such as tool kits, parts, etc.) had to also be captured to meet this requirement.

fuselage

Fuselage of a captured German WWII FockeWulf Ta-152H-0 advanced fighter, currently stored at the Paul E. Garber Preservation, Restoration, and Storage Facility. This aircraft was surrendered to an RAF intelligence team and later transferred to the US for evaluation.

Several of these captured aircraft were donated to the National Air and Space Museum upon completion of US Air Force testing in the late 1940s and early 1950s, and much of the supporting parts and tools came along with them. At the time loose tools and toolkits were not seen as accessionable objects, merely as tools to be used for repair and possible future restoration purposes. They remained in storage for years. Today this collection of tools contains some of the very last examples of their kind to be found anywhere in the world. It is due to the historically important and unique nature of these objects that a Collections Care and Preservation Fund (CCPF) has enabled a project to catalog, re-house, and preserve these irreplaceable examples of tools and kits.

tools

One of several large crates filled with hundreds of loose tools of various types. Sorting these loose tools and beginning a comprehensive identification and inventory process has been the first priority of the 2010 CCPF Vintage Aircraft Tool project.

The  project began in July of 2010. The cataloging, condition assessment, and digital photography of this varied and unique collection was begun immediately so that a comprehensive inventory of this diverse collection could be created.

tools

Examples of sorted and inventoried tools. Upon identification it was discovered that these tools were highly specialized and potentially one-of-a-kind examples. The left tool was designed to cool large bearings with a cryogenic liquid to aid their removal during overhaul of a BMW 801 engine, like the one used to power the Focke Wulf FW-190. The right tool was designed to be used on the cylinder heads of several different types of Daimler-Benz engines, such as those used to power the He-219 Night Fighter currently being restored at the Paul E. Garber Preservation, Restoration, and Storage Facility.

One goal of the project is to create a curatorial and collections guideline for the proper and safe use of these tools, ensuring they remain in an accessible yet preserved condition. To ensure future access to restoration specialists and researchers, a series of protective storage cabinets will provide adequate space that maximizes accessibility yet minimizes unnecessary handling. This system of storage will also allow for easier transportation of the collection to the new Mary Baker Engen Restoration Hangar at the Steven F. Udvar-Hazy Center.

Additionally, it is necessary to prepare most of these tools for long-term, stable storage via thorough cleaning to remove old, soiled, or failing preservative coatings and service-related grime, and also treating areas of active surface corrosion. Once cleaned and treated each tool will then have a modern preservative coating reapplied, ensuring long-term stabilization and usability.

engines

Both engines above are from the He-219 Night Fighter being restored at the Paul E. Garber Preservation, Restoration, and Storage Facility. The left engine has already undergone restoration at the time this image was taken, while the right engine has yet to be restored. Being able to use or copy examples of purpose-built tools is important to restorers. If these necessary and unique tools are misplaced, damaged beyond usability or disappear, restoration is seriously hindered.

Copies of these tools have been made in the past to perform vital restoration work on some of the associated captured aircraft, and in some instances the tools themselves have been used. But once they are lost, then any similar restoration or stabilization work will be made much more difficult, if not impossible. This project will help ensure that these important objects are preserved.

Ray Barnett is a contractor working with the collections division of the National Air and Space Museum.

Learning to Capture the Sun

The Public Observatory Project is just over a year old now, and in that time we’ve been  experimenting with the telescope to discover what is visible in the daytime sky and devise ways that our visitors can have the best experience possible.  One of our goals is to use our equipment to take images of the Sun, so that we can share our star’s day-to-day activities with the visiting public as well as those who can’t make it to the Mall to look through our telescopes.  We wanted to capture true-to-life images of the Sun as it appears through our telescope and make interesting features clearer and more apparent.

It would be dangerous to use a normal telescope to look at the Sun because the Sun’s concentrated and unfiltered light would damage your eyes.  One of the tools we use to look at the Sun safely is our Lunt Solar Systems hydrogen-alpha telescope that filters out all but one wavelength of red light. This makes it safe for viewing a part of the Sun’s atmosphere, called the chromosphere.  To take images of the Sun, I started out with this telescope, as well as a Lumenera SKYnyx 2-0 Color camera that fits where the eyepiece usually goes. We also have a laptop with software to control the camera, called Lucam Recorder.  With these in hand, I set off to take some of my first images of the Sun.

sun

This image of two prominences was taken on June 8, 2010.

Through some experimentation, I found out that different exposure settings revealed very different details on the Sun. First I cranked up the exposure to capture the faint prominences coming off the edge of the Sun and took a series of images. Next, I turned down the exposure to what I thought was an appropriate level to capture details on the Sun’s surface before taking a second series of images. I used a processing program called the GIMP to merge the two images by selecting the disk detail and moving it on top of the prominence image.  But, something wasn’t quite right. This didn’t look much like what I was seeing with my own eyes. So, I turned to a local amateur solar imaging expert and friend of the National Air and Space Museum: Greg Piepol.

Greg’s solar imaging work, which you can check out on his website sungazer.net, has been praised for its beauty and attention to detail. My colleague at the Observatory and fellow Sun imager, Katie Moore, and I were thrilled that he agreed to come into the Museum and show us how he captures such stunning images.

Greg taught us several things that improved our imaging. The first and most important was that we had been drastically overexposing the disk of the Sun, which washed out the details we were trying to capture. Greg also taught us how to better use an image stacking program called Registax, which takes individual frames from a movie file and stacks them together, thereby removing a lot of noise caused by Earth’s turbulent atmosphere. Astronomers call this “seeing,” which is what makes the stars twinkle. He also showed us other image processing techniques in the GIMP, such as levels adjustment and color correcting that brought out details on the Sun.

sun

This image was taken on July 28, 2010, the day after Greg Piepol came to visit. The small dark Sunspot near the top of the disk is about the same size as the Earth!

This was most certainly closer to what we had seen in the telescope. But of course, as they say, practice makes perfect. Over the next few months I took pictures as often as I could. I learned the extreme importance of making fine adjustments to the filters inside the telescope to get exactly the right details. I learned the advantages of using a double-stacked filter on top of our telescope to help make the darker wispy absorptive lines in the solar atmosphere, called filaments, truly pop out.  I also learned the importance of careful processing to coax the most detail possible out of the raw data.  It is interesting to compare the final product to one of the raw, unprocessed images to see what a difference it makes.

This is a single frame from the raw video before the image is processed

This is a single frame from the raw video before the image is processed

sun

This final processed image of a Sunspot was taken on July 30, 2010

A large prominence on the Sun, taken on September 15, 2010

A large prominence on the Sun, taken on September 15, 2010

This mosaic of 2 images highlights a large Sunspot group, as well as a dark filament in the Sun’s chromosphere.

This mosaic of 2 images highlights a large Sunspot group, as well as a dark filament in the Sun’s chromosphere.

And so, the journey continues! The Sun is always changing, and there are always more techniques to be learned and perfected. If you get the chance, come see the Sun for yourself at the Public Observatory, which is open Thursday through Sunday, 11 am to 3pm for the month of October, weather permitting.  We are ordering an upgraded camera and some new software to better process these images, so be on the lookout for new images online!

Erin Braswell is an Astronomy Educator at the National Air and Space Museum.