The moon’s surface is more complex than previously thought and was bombarded by two distinct populations of asteroids or comets in its youth, according to three new papers in the Sept. 17 issue of Science that describe data from NASA’s Lunar Reconnaissance Orbiter.

Two of the papers describe data from LRO’s Diviner Lunar Radiometer Experiment instrument that reveal the complex geologic processes that forged the lunar surface. The data showed previously unseen compositional differences in the crustal highlands, and confirmed the presence of anomalously silica-rich material in five distinct regions.

All minerals and rocks absorb and emit energy with unique signatures that reveal their identity and formation mechanisms. For the first time, the Diviner instrument is providing scientists with global, high-resolution infrared maps of the moon, enabling them to make a definitive identification of silicate minerals commonly found within its crust. “Diviner is literally viewing the moon in a whole new light,” said Benjamin Greenhagen of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., lead author of one of the Diviner papers.

Lunar geology can be roughly broken down into two categories – the anorthositic highlands, rich in calcium and aluminium, and the basaltic “maria,” giant impact basins filled with solidified lava flows that are abundant in iron and magnesium. Both of these crustal rocks are considered the direct result of crystallization from lunar mantle material, the partially molten layer beneath the crust.

Diviner’s observations have confirmed that most lunar terrains have signatures consistent with compositions in these two broad categories. But they have also revealed lunar soil compositions with more sodium than that of typical anorthosite crust. The widespread nature of these soils reveals that there may have been variations in the chemistry and cooling rate of the magma ocean that formed the early lunar crust, or they could be the result of secondary processing of the early lunar crust.

Most impressively, in several locations around the moon, Diviner has detected highly silicic minerals such as quartz, potassium-rich and sodium-rich feldspar — minerals that are only associated with highly evolved lithologies, or rocks that have undergone extensive magmatic processing. Detection of silicic minerals at these locations is significant, as they occur in areas previously shown to exhibit anomalously high abundances of the element thorium, another proxy for highly evolved lithologies.

“The silicic features we’ve found on the moon are fundamentally different from the more typical basaltic mare and anorthositic highlands,” said Timothy Glotch of Stony Brook University, N.Y., lead author of the second Diviner paper. “The fact that we see this composition in multiple geologic settings suggests that there may have been multiple processes producing these rocks.”

One thing not apparent in the data is evidence for pristine lunar mantle material, which previous studies have suggested may be exposed at some places on the lunar surface. Even in the South Pole Aitken basin, also known as SPA, the largest, oldest, and deepest impact crater on the moon — deep enough to have penetrated through the crust and into the mantle — there is no evidence of mantle material.

The implications of this are as yet unknown. Perhaps there are no such exposures of mantle material, or maybe they occur in areas too small for Diviner to detect. But it’s likely that if the impact that formed this crater did excavate any mantle material, it has since been mixed with crustal material from later impacts inside and outside the basin.

“The new Diviner data will help in selecting the appropriate landing sites for potential future robotic missions to return samples from SPA,” Greenhagen said. “We want to use these samples to date the SPA-forming impact and potentially study the lunar mantle, so it’s important to use Diviner data to identify areas with minimal mixing.”

In the other paper, lead author James Head of Brown University in Providence, R.I., describes an analysis of a detailed global topographic map of the moon created using LRO’s Lunar Orbiter Laser Altimeter. This new dataset shows that the older highland impactor population can be clearly distinguished from the younger population in the lunar maria. The highlands have a greater density of large craters, implying that the earlier population of impactors had a proportionally greater number of large fragments than the population characterizing later lunar history, Head said.

Head said details about impactor populations on the moon have implications for the earliest history of all the planets in the inner solar system, including Earth. “Like the Rosetta stone, the lunar record can be used to translate the ‘hieroglyphics’ of the poorly preserved impact record on Earth,” he said.

NASA’s Goddard Space Flight Center in Greenbelt, Md., built and manages the Lunar Reconnaissance Orbiter, a NASA mission with international participation from the Institute for Space Research in Moscow. JPL designed, built and operates the Diviner instrument. The University of California, Los Angeles is the home institution of Diviner’s principal investigator, David Paige. LOLA was built by Goddard.

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The moon is the Earth’s nearest celestial neighbor and a geologic wonderland. There are mountains that are many miles high, lava flows several hundred miles long and enormous lava tubes and craters of every size. It is the brightest object in the night sky and has profoundly influenced the course of human civilization.

For early humans, the moon provided lighting for hunting and defined when crops should be planted and harvested. Markings of lunar phases appear in cave paintings in France and defined the arrangement of Stonehenge.

The 2010 International “Observe the Moon Night” is happening on Saturday, Sept. 18. On Thursday, Sept. 16, at 3:00 p.m. EDT, Dr. Rob Suggs of NASA’s Marshall Space Flight Center in Huntsville, Ala., will answer your questions about the moon and National Observe the Moon Night. Joining the chat is easy. Simply return to this page a few minutes before the chat time on Thursday. The chat module will appear at the bottom of this page. After you log in, wait for the chat module to be activated at 3:00, then ask your questions!

About Chat Expert Dr. Rob Suggs

Dr. Rob Suggs is the Space Environments Team Lead in the Engineering Directorate of NASA’s Marshall Space Flight Center. For the past 4 years he has managed the NASA Lunar Impact Monitoring Project which has recorded over 200 meteoroid impacts on the Moon using telescopes at 2 observatories. He has a Ph.D. in Astronomy from New Mexico State University (NMSU) and was part of the NMSU team which attempted to record the LCROSS spacecraft impact on the Moon last October.

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When astronauts venture outside of a spaceship or the International Space Station, they must wear protective space suits to keep them safe from the harsh environment of space. While inside these pressurized suits, it’s essential that they remain in constant communication with the rest of the crew in space as well as Mission Control Center on Earth.

While wearing the current space suits, astronauts wear a Communications Carrier Assembly (CCA), or “Snoopy Cap” — a fabric hat fitted with microphones in the ear area for listening and boom microphones in front of the mouth for speaking. These caps are worn under the helmet and visor that surround an astronaut’s head.

NASA is in the process of completely redesigning their space suits, with the goal of creating a brand new space suit to be used starting in 2020. Redesigned and reinvented communications equipment will be an important facet of the new suit.

Integrated Audio

NASA’s Glenn Research Center in Cleveland is working on different parts of the new space suit, including communications equipment. The Exploration Technology Development Program (ETDP) is involved with testing various proposed solutions to the communications requirements within the suit.

The Communications Carrier Assembly (CCA), while effective, has some logistical drawbacks. Multiple cap sizes must be available due to the difference in astronauts’ head sizes. The caps cannot be adjusted once the visor of the helmet is in place and the astronaut is in space, which means that if the microphones shift, communication quality can decrease. The boom microphones can also interfere with feeding and drinking mechanisms during long-duration spacewalks. An additional problem is that astronaut sweat can negatively interfere with the performance of the electrical and mechanical parts in the CCA.

For several years, Glenn has performed research and development on a variety of communications technologies. About six years ago, teams at Glenn began working on integrated audio solutions to support extravehicular activities, like space walks. In 2008, Glenn signed a Small Business Innovation Research (SBIR) agreement with WeVoice Inc. of Bridgewater, N.J. Together, they began developing and testing an integrated audio system that is built directly into a space helmet.

“The integrated audio system is where the microphones and earphones are removed from the Communications Carrier Assembly and integrated into the structure of the space suit itself,” says Obed “Scott” Sands, an electronics engineer at Glenn, lead for Configuration II Audio under Constellation and lead for integrated audio development for the Exploration Technology Development Program (ETDP).

The new integrated audio system solves many of the issues the CCA presents. As the integrated audio system is part of the actual space suit, there are no additional parts to worry about maintaining. The microphones and earphones are built into the suit, which means there are no moving parts to disrupt an astronaut’s movements or become dislodged during activity. And the integrated audio system is a universal size — no separate caps are needed for individual crew members.

Rather than one boom microphone, the new integrated audio system uses an array of microphones — currently four, but the number could increase — that are located in front of where an astronaut’s mouth is while inside the helmet. The integrated audio system features cutting-edge digital signal processing which helps the microphones overcome loss of fidelity on the outbound (speaking) part of the system.

The microphone array and associated signal processing are needed in the integrated audio system to overcome decreased sound quality. Sound quality can be negatively impacted because the microphones of the integrated audio system are positioned on the inside of the helmet — farther from an astronaut’s mouth. This makes the microphones more susceptible to interference from noise created inside of the suit as well as noise from vibrations of the spacesuit structure.

The current technology development approach to solving these problems involves processing signals from each element in the array, known as Multi-Channel Noise Reduction. This new filtering approach features technology adapted from video teleconferencing systems. Advanced filters are used for each of the array’s channels, and additional noise reduction is used to isolate the sound of speech.

Several speakers are installed in the helmet, which are designed to focus the sound towards the astronaut’s ears. These speakers also isolate other sounds so that crew members can effectively hear. This solves the issue of occasional unclear inbound communications (listening).

“This new system will provide the crew member with more freedom and increased reliability,” says Terry O’Malley, an aerospace engineer and the EVA lead at Glenn. “It also provides the system designers with increased flexibility in designing the system.”

Testing with a Torso

In order to assess the effectiveness of the new system, the conditions inside a space suit must be replicated. Then the integrated audio is tested by using a specialized piece of equipment that creates human speech. This equipment, shaped like a human torso, is called HATSMAN — Head and Torso Simulator. It is manufactured by Brüel & Kjær, a company based in Denmark.

“It listens like a person and talks like a person,” Sands says. “It’s got microphones in its ears and a speaker in its mouth, and the radiation patterns conform to international standards for mannequins that emulate human speech and hearing.”

The testing involves taking advanced measurements of the noise produced by HATMSAN and received by the integrated audio system and vice versa. This anthropometric measuring helps Glenn researchers refine their design, using data created by machines that accurately represent the needs of the humans who will eventually use the completed system.

The HATMSAN at Glenn is installed in a testing tank that is carefully designed to mimic the environment inside a space suit. It is lined with acoustic absorbing foam that isolates extra noise that the tank itself might create. Then a noise source simulates the sound created by space suits, which is generated from a recording taken inside an actual space suit. Special microphones that do not create their own static pressure are installed, which take measurements without affecting the readings.

“The biggest reason we’re in the tank is that we can create a static pressure environment that simulates the inside of the actual suit,” says Dave Pleva (DB Consulting Group, Inc.), an IT Project Analyst at Glenn who supports audio development work for ETDP.

The tank recreates the pressure inside of the suit, not the pressure of the entirety of space — because the integrated audio system is made for use inside a helmet. The positive pressure inside a space suit is about 4.3 PSI (equivalent to about 35,000 feet altitude) so the team tests with this as its base. They also explore other variations in barometric pressure. The test rig also includes an acrylic dome to simulate the helmet. The team explores how speech and sound bounce off of the surface of the helmet.

A specialized device, called Digital Speech Level Analyzer (DSLA), provides vocal tracks for use in testing. Various utterances comprise the test speech to make it phonetically balanced — including all of the patterns and pairs that, statistically speaking, would show up in the English language. Both male and female voices are used.

“We generate a signal, it goes through an amplifier that powers the speaker in the HATSMAN, and then the array picks up the speech. The array then processes the speech and sends out the process signal to the DSLA. The DSLA then does a comparison of what it sent and what it receives,” Pleva says.

The primary performance concern is speech intelligibility. Although quality of sound is also important, the main interest is that as many words as possible be successfully transmitted both ways. This can be effectively measured using the equipment in place.

“The next step would be to build an even higher fidelity version of this integrated audio system. Then we’ll do another round of these tests. Eventually, we’ll have a human being tested inside a pressure chamber,” says Dave Irimies, a computer engineer and ETDP lead at Glenn.

Advancing Technology

The ongoing research, development and testing of this integrated audio system is part of the Space Audio Development and Evaluation Laboratory at Glenn.

“Our direction is replacing the current suit on the space station and shuttle. The current certification runs out in ten years, in 2020, so… this is an opportunity to use even more advanced technology,” Irimies says. “This work is pressing forward.”

The team hopes that the integrated audio system can commence testing on the space station in 2016. The technology may also be useful for communicating inside the station as well as during space walks. There may also be the potential that the technology can help on Earth. WeVoice Inc. is currently working with the University of Pittsburg on one potential spin-off: developing a teleconferencing system using microphone arrays for operating rooms in hospitals.

The team looks forward to working together to continue testing and evolving their integrated audio system, with the goal of significantly influencing how the next generation space suit will work.

“We all challenge each other in different ways, all the time,” Sands says. “It’s a lot of fun, getting new concepts infused into space systems. That’s what NASA is all about.”

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Saturn’s moon Titan ripples with mountains, and scientists have been trying to figure out how they form. The best explanation, it turns out, is that Titan is shrinking as it cools, wrinkling up the moon’s surface like a raisin.

A new model developed by scientists working with radar data obtained by NASA’s Cassini spacecraft shows that differing densities in the outermost layers of Titan can account for the unusual surface behavior. Titan is slowly cooling because it is releasing heat from its original formation and radioactive isotopes are decaying in the interior. As this happens, parts of Titan’s subsurface ocean freeze over, the outermost ice crust thickens and folds, and the moon shrivels up. The model is described in an article now online in the Journal of Geophysical Research.

“Titan is the only icy body we know of in the solar system that behaves like this,” said Giuseppe Mitri, the lead author of the paper and a Cassini radar associate based at the California Institute of Technology in Pasadena. “But it gives us insight into how our solar system came to be.”

An example of this kind of process can also be found on Earth, where the crumpling of the outermost layer of the surface, known as the lithosphere, created the Zagros Mountains in Iran, Mitri said.

Titan’s highest peaks rise up to about two kilometers (6,600 feet), comparable to the tallest summits in the Appalachian Mountains. Cassini was the first to spot Titan’s mountains in radar images in 2005. Several mountain chains on Titan exist near the equator and are generally oriented west-east. The concentration of these ranges near the equator suggests a common history.

While several other icy moons in the outer solar system have peaks that reach heights similar to Titan’s mountain chains, their topography comes from extensional tectonics — forces stretching the ice shell — or other geological processes. Until now, scientists had little evidence of contractional tectonics — forces shortening and thickening the ice shell. Titan is the only icy satellite where the shortening and thickening are dominant.

Mitri and colleagues fed data from Cassini’s radar instrument into computer models of Titan developed to describe the moon’s tectonic processes and to study the interior structure and evolution of icy satellites. They also made the assumption that the moon’s interior was only partially separated into a mixture of rock and ice, as suggested by data from Cassini’s radio science team.

Scientists tweaked the model until they were able to build mountains on the surface similar to those Cassini had seen. They found the conditions were met when they assumed the deep interior was surrounded by a very dense layer of high-pressure water ice, then a subsurface liquid-water-and-ammonia ocean and an outer water-ice shell. So the model, Mitri explained, also supports the existence of a subsurface ocean.

Each successive layer of Titan’s interior is colder than the one just inside it, with the outermost surface averaging a chilly 94 Kelvin (minus 290 degrees Fahrenheit). So cooling of the moon causes a partial freezing of the subsurface liquid ocean and thickening of the outer water ice shell. It also thickens the high-pressure ice. Because the ice on the crust is less dense than the liquid ocean and the liquid ocean is less dense than the high-pressure ice, the cooling means the interior layers lose volume and the top “skin” of ice puckers and folds.

Since the formation of Titan, which scientists believe occurred around four billion years ago, the moon’s interior has cooled significantly. But the moon is still releasing hundreds of gigawatts of power, some of which may be available for geologic activity. The result, according to the model, was a shortening of the radius of the moon by about seven kilometers (four miles) and a decrease in volume of about one percent.

“These results suggest that Titan’s geologic history has been different from that of its Jovian cousins, thanks, perhaps, to an interior ocean of water and ammonia,” said Jonathan Lunine, a Cassini interdisciplinary scientist for Titan and co-author on the new paper. Lunine is currently based at the University of Rome, Tor Vergata, Italy. “As Cassini continues to map Titan, we will learn more about the extent and height of mountains across its diverse surface.”

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the Cassini-Huygens mission for NASA’s Science Mission Directorate. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. JPL is a division of the California Institute of Technology in Pasadena.

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Schrödinger impact basin (centered -75.0˚, 132.4˚ E), located on the lunar far side within South Pole-Aitken Basin, is not visible from the Earth. Crater counts suggest that the basin is less than one billion years old, making it the second youngest impact basin on the Moon (the youngest being Orientale).LOLA data reveal that the basin has approximately 3.3 km of relief from rim to floor. The basin’s inner ring is clearly visible, as are lunar rilles, smaller impact craters, and a volcanic cone (see arrow).

The cone is believed to be pyroclastic in nature, largely due to the dark halo that can be seen surrounding it in visible light images. The LRO narrow angle camera has also captured a view of the cone (http://lroc.sese.asu.edu/news/index.php?/archives/215-Craters-on-the-Schrodinger-pyroclastic-cone.html). Additional evidence for volcanic activity comes in the form of rilles and the relatively flat and smooth basin floor, which is most likely the result of infill by lava flows.

Schrödinger basin is named for Erwin Schrödinger (1887-1961), a theoretical physicist who received the Nobel Prize in Physics in 1933 for the development of the Schrödinger equation and it contributions to quantum mechanics.

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The South Pole-Aitken (SPA) basin is the largest and oldest recognized impact basin on the Moon. It’s diameter is roughly 2,500 km or 1,550 miles. The Moon’s circumference is just under 11,000 km, meaning the basin stretches across nearly a quarter of the Moon. In the LROC WAC mosaic below, which is centered on the middle of the basin, you can see SPA as an area of relatively low reflectance extending from the crater Aitken in the north and all the way down to the South Pole. Topographic data from LOLA can also help to give a sense of the enormous effect the SPA impact had on the Moon – the basin is more than 8 km (5 miles) deep.

Stratigraphic relationships show that SPA is the oldest impact basin on the Moon, but scientists are intensely interested in just how old it is. Lunar samples suggest that most of the major basins on the Moon formed around 3.9 billion years ago in a period called the late heavy bombardment. By this time most of the large debris within the solar system should have already accreted to form the planets, so such a large number of big impacts occurring at nearly the same time may have been due to unusual gravitational dynamics in the early Solar System. Was the impact that caused the SPA basin also a part of some cataclysmic event that occurred 3.9 billion years ago? If so, that impact is strong evidence for an extreme event that would have affected all of the terrestrial planets, including Earth at a time when life was just beginning. If the basin is much older, that may suggest that instead of a spike in the impact rate at 3.9 billion years, the number of impacts simply trailed off from a peak earlier on.

How can we find out just how old the SPA impact basin is? The best way would be to sample materials from the interior of the basin and use radiometric age-dating techniques to determine when they were last molten, as heat from the impact would have melted a large volume of material, resetting radiometric clocks. But the basin is so old that its surface has been cratered many times over, meaning that some of the rocks would have had their radiometric ages reset by these subsequent impacts. So it may be difficult to find rocks with ages that truly reflect the SPA event without careful consideration of the local geology. The Constellation region of interest, highlighted in the NAC detail above and outlined in the WAC mosaic below, was selected because it is in a deep portion of the basin, where a large volume of melt would be expected. Some of this melt would remain as a significant component of the soil, and an analysis of a carefully selected suite of samples from this region would reveal the age of the oldest lunar impact basin.

One final note – imagine the view of the Moon from the Earth when the SPA impact occurred. What would it have looked like? How much ejecta would have landed on the Earth? How long would it take for ejecta to reach the Earth? Surely this impact profoundly affected the young Earth.

Where would the best sample site be? Browse the full-resolution NAC image and WAC mosaic and decide for yourself!

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In a new analysis of a lunar model collected by Apollo 17, researchers have detected and dated carbon on the moon in the form of graphite — the sooty stuff of pencil lead which survived from around 3.8 billion years ago, when the moon was greatly bombarded by meteorites. Up to now, scientists thought the trace amounts of carbon formerly detected on the surface of the moon came from the solar wind.

Goddard Crater is located along the Moon’s eastern limb (14.8 N, 89.0 E). LOLA data show the floor of the 90 km diameter crater to be relatively flat and smooth. The crater is named after pioneering rocket scientist Robert H. Goddard (1882-1945). Considered to be to be the father of modern rocketry, Goddard built the world’s first liquid-fueled rocket. Incidentally, the LOLA instrument was built at the one NASA Center named for Robert H. Goddard, Goddard Space Flight Center  in Greenbelt, MD. The Lunar Reconnaissance Orbiter on which LOLA flies was also built at Goddard Space Flight Center.

To learn more about Robert H. Goddard, visit Dr. Robert H. Goddard, American Rocketry Pioneer

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The Orion crew exploration vehicle took shape as the two halves of the crew module were fused together at NASA’s Michoud Assembly Facility in New Orleans, La. The Lockheed Martin Orion team welded the forward cone assembly to the aft barrel assembly using the next generation friction stir weld process. The 445-inch long weld is the longest such weld of its kind and will ensure optimal structural integrity for the harsh environments of space flight.

“The completion of the final welds on the Orion crew module ground test article is another important milestone,” said Mark Geyer NASA’s Orion project manager. “The team’s dedication, hard work and ingenuity kept us on schedule for the assembly, integration and further testing of the vehicle. We now have the ability to see how the crew module will respond to space environments and can validate production processes that are critical to the safety of the crew.”

Prior to flight testing, this crew module will be tested on the ground in flight-like environments, including static vibration, acoustic and water landing tests. Results will be used to correlate sizing models for all subsystems on the vehicle.

Orion weld operations take place on a Universal Weld System II (UWS II) that includes a 22-foot diameter turntable, a self-reacting friction stir weld head and a modular t-grid floor. The system affords virtually unlimited five-axis welding on fixture-mounted hardware. The UWS II is part of the National Center for Advanced Manufacturing, managed by the University of New Orleans Foundation in partnership with NASA and the State of Louisiana.

The friction stir welding process advances the state-of-the-art for circumferential welds, yielding higher strength and higher quality welds at a lower cost. The latest state-of-the-art manufacturing technologies, efficient processes and new materials, such as the ultra-light weight Aluminum-Lithium alloy, are all being employed on Orion to produce the lightest possible vehicle for space flight.

“The combination of material and manufacturing advancements in technology are key reasons why the spacecraft is more lightweight and damage resistant than many industry experts thought possible,” said Larry Price, Lockheed Martin Orion deputy program manager. “The balance of manufacturing methods and varied materials such as composites and advanced alloys that have been applied to Orion resulted in vehicle optimizations across the board – lowest cost, lightest weight, and improved structural integrity, which is critical to crew safety.”

Lockheed Martin is the prime contractor to NASA for the Orion crew exploration vehicle, which is managed at NASA’s Johnson Space Center. The Orion spacecraft is comprised of a crew module for crew and cargo transport; a service module for propulsion, electrical power and fluids storage; a spacecraft adapter for securing it to the launch vehicle, and a launch abort system that will significantly improve crew safety.

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Space shuttle Atlantis thundered away from NASA’s Kennedy Space Center on May 5, 2010 at 2:20 p.m. The on-time liftoff under a picturesque Florida sky was a perfect beginning to Atlantis’ last scheduled mission, STS-132. The Final Planned Flight of Atlantis Delivers New ‘Dawn’

shuttle carried a six-person crew on a journey to deliver a new Russian module and several critical spare parts to the International Space Station.

“There are thousands of folks out there that have taken care of this bird for a long time,” Commander Ken Ham said after Atlantis was cleared for launch. “We’re going to take her on her 32nd flight, and if you don’t mind, we’ll take her out of the barn and make a few more laps around the planet.”

Tucked into the shuttle’s payload bay was the Russian-built Mini Research Module-1 known as “Rassvet,” meaning “dawn.” Nearly 20 feet long and weighing more than 17,700 pounds including its cargo, the module features eight workstations designed for a variety of science experiments and educational research.

The ambitious tasks ahead would be taken on by a crew of experienced space fliers. Ham was joined by Pilot Tony Antonelli, Mission Specialists Garrett Reisman, Michael Good, Steve Bowen and Piers Sellers.

During the astronauts’ first full day in orbit, the standard inspection of the orbiter’s protective thermal coverings was completed using a backup camera system when a snagged cable temporarily prevented use of the intended laser and digital cameras. Both the primary and backup systems are part of the orbiter boom sensor system that attaches to the shuttle’s robotic arm.

Atlantis docked with the International Space Station on May 16, two days after liftoff. Ham guided the orbiter through a graceful backflip known as a “rendezvous pitch maneuver,” giving station crew members the chance to take nearly 400 photos of the shuttle. Finally, the two spacecraft linked up at 10:28 a.m. EDT as the pair sailed 220 miles above the South Pacific Ocean.

The hatches between shuttle and station were opened at 12:18 p.m. and the six STS-132 astronauts were welcomed aboard by the station’s six residents: cosmonauts Oleg Kotov, Expedition 23 commander, Alexander Skvortsov and Mikhail Kornienko, Japan Aerospace Exploration Agency astronaut Soichi Noguchi, and U.S. astronauts T.J. Creamer and Tracy Caldwell Dyson.

“We’ve been here before, but it’s bigger than we remember — and, speaking for myself, better than I remember,” Ham said as docked operations officially began. “I love this place!”

The combined crew got right to work, using the station’s Canadarm2 robotic arm to remove a cargo carrier from Atlantis’ open payload bay to the station’s mobile transporter. Mounted on the carrier were important new equipment and spares to be installed during the mission’s three spacewalks, including a backup space-to-ground antenna and six 375-pound batteries.

The first of the mission’s three spacewalks started the next morning at 7:54 a.m. when Reisman and Bowen switched their spacesuits to battery power and floated out of the station’s Quest airlock. Riding the station’s robotic arm, Reisman carried the boom for the new antenna from the cargo pallet up to the Z1 truss and returned to the cargo pallet to grab the six-foot-wide

The pair then installed the antenna on the waiting boom, where it will help provide two-way data, voice and video communications for station residents. Reisman and Bowen added a spare-parts platform to the station’s Dextre robotic arm and loosened the bolts holding the new batteries to the cargo carrier before wrapping up the 7-hour, 25-minute outing.

Installation of the Rassvet research module was the crew’s next assignment. Ham and Antonelli used Atlantis’ robotic arm to lift the nearly-20-foot-long component from the shuttle’s payload bay, then handed it off to the station’s robotic arm. Reisman guided the new module into the Earth-facing port on the Zarya module, achieving a flawless docking with one millimeter of clearance on either side of Rassvet’s docking probe.

“Looks like a pretty good docking,” Sellers reported to Mission Control. “Straight down the middle, got capture and contact.”

Good joined Bowen for the second spacewalk, which got off to a head start at 6:38 a.m. May 19. First, Bowen fixed the snagged cable that had interfered with the early inspection of Atlantis’ heat shield. After adjusting the cable and using a plastic tie to keep it in place, Mission Control announced the fix was successful.

Next, the astronauts installed four of six new batteries on the station’s port 6 truss, the station’s backbone, transferring the old batteries to the cargo carrier for the return trip to Earth. Good and Bowen tightened the bolts on the new space-to-ground antenna before coming back inside as the 7-hour, 9-minute spacewalk ended.

Hatches between the station and Rassvet were opened the following day, as Atlantis and crew finished the mission’s first week and enjoyed a few hours of off-duty time.

The final two port 6 truss batteries were installed during the mission’s third and final spacewalk. Good and Reisman swapped out the remaining batteries and installed a backup ammonia coolant line between the port 4 and port 5 truss segments. They also left a new power and data grapple fixture inside the Quest airlock. The fixture will be installed by the station crew on the exterior of the Zarya module this summer.

With all the mission’s major tasks accomplished, Good and Reisman headed back to the airlock after working outside the station for 6 hours and 46 minutes.

The astronauts finished transferring equipment and supplies from Atlantis to the space station as the docked portion of the STS-132 mission drew to a close.

“Thank you, Ken, and thank you to the whole crew,” said station Commander Kotov as the Atlantis and station crews prepared to part ways. “Thank you for an excellent job, for your patience, for your work — for everything.”

Ham answered, “Through our entire docked timeframe here, we were a 12-person crew that operated together, and that was the only way we got everything done. …We’ve had a great time together.”

Atlantis undocked from the station May 23 at 11:22 a.m. after a weeklong stay at the orbiting complex. The shuttle circled the station at a distance of 400 to 600 feet and finally pulled away with a separation burn an hour and 15 minutes later.

The late inspection of Atlantis’ protective skin went off without a hitch, and the shuttle was cleared to land.

Atlantis touched down at 8:48 a.m. May 26, gliding smoothly along Kennedy’s Runway 33 after 186 orbits and nearly 12 full days in space. With Ham and Antonelli at the controls, the orbiter returned to its home port for what was planned to be the last time. During its 25 years of spaceflight, Atlantis completed 32 missions and traveled more than 120 million miles.

“We’ve all flown on Atlantis now, and some of us have flown on her a couple of times. She’s a great ship,” Antonelli said hours after landing, adding that it was a “real honor” to be on what may be its last flight. “We’re happy to bring her back home to you here in Florida.”

Anna C. Heiney
NASA’s John F. Kennedy Space Center

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