At 4.4 kilometers in elevation, California's Mt. Whitney is the highest point in the continental United States. Image credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team
[/caption]NASA and Japan recently announced a new and improved digital topographic map of Earth, which was produced with detailed measurements from NASA’s Terra spacecraft.
The new data covers over 99 percent of Earth’s landmass and spans from 83 degrees north latitude to 83 degrees south. Each elevation measurement point in the data is only 30 meters apart.
How were scientists able to improve on previous generations of detailed topographic maps?
The new model, known as a global digital elevation model, was created from images collected by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, instrument aboard NASA’s Terra spacecraft. To create a “stereo pair” image,scientists can take two slightly offset images and combine them to create a three-dimensional effect of depth.
The previous version of the global digital elevation model was released in June of 2009 by NASA and Japan’s Ministry of Economy, Trade and Industry.
“The ASTER global digital elevation model was already the most complete, consistent global topographic map in the world,” said ASTER program scientist Woody Turner, “With these enhancements, its resolution is in many respects comparable to the U.S. data from NASA’s Shuttle Radar Topography Mission, while covering more of the globe.”
The ASTER team added 260,000 stereo-pair images to improve the previous model, which improved spatial resolution, increased horizontal and vertical accuracy, and provided the ability to identify lakes as small as 1 kilometer in diameter.
“This updated version of the ASTER global digital elevation model provides civilian users with the highest-resolution global topography data available,” said ASTER science team lead Mike Abrams. “These data can be used for a broad range of applications, from planning highways and protecting lands with cultural or environmental significance, to searching for natural resources.”
Arguably one of America's most magnificent national parks is the Grand Canyon in northern Arizona. Image credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team
Joining together in a collaborative effort, NASA and METI are contributing data for the ASTER topographic map to the Group on Earth Observations, for use in the group’s Global Earth Observation System of Systems. No, the previous statement wasn’t a typo – the “system of systems” is an international effort, which uses shared Earth observation data to help monitor and forecast global environmental changes.
One of five instruments launched on Terra in 1999, ASTER acquires images from visible to thermal infrared wavelengths, with spatial resolutions ranging from about 15 to 90 meters. ASTER’s science team is a joint effort between the United States and Japan.
The ASTER data was validated by NASA, METI, Japan’s Earth Remote Sensing Data Analysis Center (ERSDAC), and the U.S. Geological Survey, with additional support from the U.S. National Geospatial-Intelligence Agency and other collaborators. NASA’s Land Processes Distributed Active Archive Center is handling the distribution of the new ASTER global digital elevation model.
If you’d like to download the ASTER global digital elevation model to study at no cost, you can do so at: https://lpdaac.usgs.gov/ or http://www.ersdac.or.jp/GDEM/E/4.html
To learn more about ASTER, or NASA’s Terra mission, visit: http://asterweb.jpl.nasa.gov/ and http://www.nasa.gov/terra
Southern Hemisphere of Vesta; Rheasilvia and Older Basin. Colorized shaded-relief map showing identification of older 375-kilometer-wide impact basin beneath and overlapping with the more recent Rheasilvia impact structure at asteroid Vesta’s South Pole. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
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Scientists leading NASA’sDawn mission have discovered a 2nd giant impact basin at the south pole of the giant asteroid Vesta, which has been unveiled as a surprisingly “dichotomous” and alien world. Furthermore, the cosmic collisions that produced these two basins shuddered through the interior and created vast Vestan troughs, a Dawn scientist told Universe Today.
The newly discovered impact basin, nicknamed ‘Older Basin’, is actually significantly older in age compared to the initially discovered South Pole basin feature named ‘Rheasilvia’ – perhaps by more than a billion years. And that is just one of the many unexplained mysteries yet to be reconciled by the team as they begin to sift through the millions of bits of new data streaming back daily to Earth.
Scientists speculate that ‘Older Basin’ is on the order of 3.8 Billion years old, whereas ‘Rheasilvia’ might be as young as about 2.5 Billion years, but those are just tentative estimates at this time and subject to change. Measurements so far indicate Rheasilvia is composed of basaltic material.
Shaded-relief topographic map of Vesta southern hemisphere showing two large impact basins - Rheasilvia and Older Basin.
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
“We found many surprising things at Vesta, which is quite unique and the results have exceeded our expectations”, said Dr. Carol Raymond, Dawn deputy principal investigator, of NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
Researchers presented the latest findings from Dawn’s initial science mapping orbit at a news briefing at the annual meeting of the Geological Society of America in Minneapolis, Minn., on Oct. 13.
The team considers Vesta to be the smallest terrestrial planet.
Since achieving orbit in July, Dawn’s Framing Cameras (FC) have imaged most of Vesta at about 250 meter resolution and the Visible and Infrared mapping spectrometer(VIR) at about 700 meter resolution. The measurements were collected at the survey orbit altitude of 2700 km. Before Dawn, Vesta was just a fuzzy blob in humankind’s most powerful telescopes.
Vesta from Hubble (top) as a fuzzy blob and from Dawn in orbit (bottom) in crystal clear high resolution.
Credit: NASA/JPL-Caltech/ UCLA/MPS/DLR/IDA
“There is a global dichotomy on Vesta and a fundamental difference between the northern and southern hemispheres”, said Raymond. “The northern hemisphere is older and heavily cratered in contrast to the brighter southern hemisphere where the texture is more smooth and there are lots of sets of grooves. There is a massive mountain at the South Pole. One of the more surprising aspects is the set of deep equatorial troughs.”
“There is also a tremendous and surprising diversity of surface color and morphology. The south is consistent with basaltic lithology and the north with impacts. We are trying to make sense of the data and will integrate that with the high resolution observations we are now collecting.”
Indeed Vesta’s completely unique and striking dichotomy can be directly traced back to the basins which were formed by ancient cataclysmic impacts resulting in shockwaves that fundamentally altered the surface and caused the formation of the long troughs that ring Vesta at numerous latitudes.
“The troughs extend across 240 degrees of longitude,” said Debra Buczkowski, Dawn participating scientist, of the Applied Physics Laboratory at Johns Hopkins University, Laurel, Md. “Their formation can be tied back to the two basins at the South Pole.”
Asteroid Vesta and Equatorial Grooves
This full view of the giant asteroid Vesta was taken by NASA’s Dawn spacecraft, as part of a rotation characterization sequence on July 24, 2011, at a distance of 3,200 miles (5,200 kilometers). A rotation characterization sequence helps the scientists and engineers by giving an initial overview of the character of the surface as Vesta rotated underneath the spacecraft. This view of Vesta shows impact craters of various sizes and grooves parallel to the equator. The resolution of this image is about 500 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
In an exclusive follow up interview with Universe Today, Raymond said “We believe that the troughs formed as a direct result of the impacts,” said “The two sets of troughs are associated with the two large basins [Rheasilvia and Older Basin].”
“The key piece of evidence presented was that the set of troughs in the northern hemisphere, that look older (more degraded) are circumferential to the older impact basin,” Raymond told me.
“The equatorial set are circumferential to Rheasilvia. That Rheasilvia’s age appears in places to be much younger is at odds with the age of the equatorial troughs. An explanation for that could be resurfacing by younger mass wasting features (landslides, slumps). We will be working on clarifying all these relationships in the coming months with the higher resolution HAMO (High Altitude Mapping Orbit) data.”
Dawn has gradually spiraled down closer to Vesta using her exotic ion thrusters and began the HAMO mapping campaign on Sept. 29.
Surface features are dated by crater counting methodology.
“Preliminary crater counting age dates for the equatorial trough region yields a very old age (3.8 Billion years). So there is a discrepancy between the apparent younger age for the Rheasilvia basin and the old age for the troughs. These could be reconciled if Rheasilvia is also 3.8 Billion years old but the surface has been modified by slumping or other processes,” Raymond elaborated.
Time will tell as further data is analyzed.
Dawn launch on September 27, 2007 by a Delta II Heavy rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer
“Vesta is full of surprises, no more so than at the South Pole,” said Paul Schenk at the GSA briefing. Schenk is a Dawn participating scientist of the Lunar and Planetary Institute, Houston, Texas.
The ‘Rheasilvia’ basin was initially discovered in images of Vesta taken a decade ago by the Hubble Space Telescope which revealed it as a gaping hole in the southern hemisphere. But it wasn’t until Dawn entered orbit on July 16, 2011 after a nearly four year interplanetary journey that Earthlings got their first close up look at the mysterious polar feature and can now scrutinize it in detail to elucidate its true nature.
“The South Pole [Rheasilvia] basin is a roughly circular, impact structure and a deep depression dominated by a large central mound,” said Schenk. “It shows sharp scarps, smooth areas, landslide deposits, debris flows. It’s about 475 km in diameter and one of the deepest (ca. 20 -25 km) impact craters in the solar system.”
The central peak is an enormous mountain, about 22 km high and 180 km across- one of the biggest in the solar system. “It’s comparable in some ways to Olympus Mons on Mars,” Schenk stated.
“We were quite surprised to see a second basin in the mapping data outside of Rheasilvia. This was unexpected. It’s called ‘Older Basin’ for now.”
‘Older Basin’ is about 375 km in diameter. They overlap at the place where Rheasilvia has a missing rim.
“These basins are interesting because we believe Vesta is the source of a large number of meteorites, the HED meteorites that have a spread of ages,” Schenk explained.
Images showing key components of Rheasilvia impact basin on Vesta in high resolution ,referred to Shaded-relief topographic map. Credit: NASA/JPL-Caltech/ UCLA/MPS/DLR/IDA
Multiple large impacts over time may explain the source of the HED (Howardite, Eucrite and Diogenite) meteorites.
“We did expect large impacts on Vesta, likely associated with the late heavy bombardment recognized in the lunar impact record,” Raymond told Universe Today. “The surprising element is that the two apparently largest impacts – keeping in mind that other larger impact basins may be lurking under the regolith – are overlapping.”
Dawn’s VIR spectrometer has detected pyroxene bands covering Vesta’s surface, which is indicative of typical basaltic material, said Federico Tosi, a VIR team member of the Italian Space Agency, Rome. “Vesta has diverse rock types on its surface.”
“VIR measured surface temperatures from 220K to 270 K at the 5 micron wavelength. The illuminated areas are warmer.”
So far there is no clear indication of olivine which would be a marker for seeing Vesta’s mantle, Tossi elaborated.
The VIR spectrometer combines images, spectral information and temperature that will allow researchers to evaluate the nature, composition and evolutionary forces that shaped Vesta’s surface.
The team is absolutely thrilled to see a complicated geologic record that’s been preserved for study with lots of apparent surface layering and surprisingly strong and complex structural features with a large range of color and brightness.
Stay tuned for a year of Vestan delights !
Asteroid Vesta from Dawn
South Pole Rheasilvia basin is at lower right. NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011 from a distance of about 3,200 miles (5,200 kilometers). Dawn entered orbit around Vesta on July 16, and will spend a year orbiting the body.
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Artist's rendering of a vacuum tube, one of the main components of an atomic clock. Credit: NASA
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When people think of space technologies, many think of solar panels, propulsion systems and guidance systems. One important piece of technology in spaceflight is an accurate timing device.
Many satellites and spacecraft require accurate timing signals to ensure the proper operation of scientific instruments. In the case of GPS satellites, accurate timing is essential, otherwise anything relying on GPS signals to navigate could be misdirected.
The third technology demonstration planned by NASA’s Jet Propulsion Laboratory is the Deep Space Atomic Clock. The DSAC team plans to develop a small, low-mass atomic clock based on mercury-ion trap technology and demonstrate it in space.
What benefits will a new atomic clock design offer NASA and other players in near-Earth orbit and the rest of our solar system?
The Deep Space Atomic Clock demonstration mission will fly and validate an atomic clock that is 10-times more accurate than today’s systems. The project will demonstrate ultra-precision timing in space as well as the benefits said timing offers.
The DSAC will fly on an Iridium spacecraft and make use of GPS signals to demonstrate precision orbit determination and confirm the clock’s performance. As mentioned previously, precise timing and navigation are critical to the performance of many aspects of deep space and near-Earth exploration missions.
The DSAC team believes the demonstration will offer enhancements and cost savings for new missions, which include:
Increase Data Quantity: A factor of 2 to 3 increase in navigation and radio science data quantity by allowing coherent tracking to extend over the full view period of Earth stations.
Improve Data Quality: Up to 10 times more accurate navigation, gravity science, and occultation science at remote solar system bodies by using one-way radiometric links.
Enabling New Missions: Shift towards a more flexible and extensible one-way radio navigation architecture enabling development of capable in-situ satellite navigation systems and autonomous deep space radio navigation.
Reduce Proposed Mission Costs: Reduce mission costs for using the Deep Space Network (DSN) through aperture sharing and one-way downlink only time.
Benefits to GPS: Improve clock stability of the next GPS system by 100 times.
One example use for the DSAC is for a future mission that is a follow-up to the Mars Reconnaissance Orbiter (MRO). A spacecraft equipped with the DSAC could avoid reliance on two-way communications using NASA’s Deep Space Network to perform orbital determination.
One of the benefits of avoiding said reliance on two-way communications would allow the mission to only require the DSN for one-way communication to transmit scientific data to Earth. Reducing the reliance on two-way communications would provide an additional benefit of cost savings.
In the previous example, the DSAC team estimates an $11 million dollar reduction in network operational costs, as well as a 100% increase in the amount of usable science and navigation data that could be received. Overview of Deep Space Atomic Clock (DASC) mission. Image Credit: NASA
The Space Communications and Navigation (SCaN) office in the Human Exploration and Operations Mission Directorate is collaborating with the NASA Office of the Chief Technologist in sponsoring this technology demonstration.
If successful the DSAC flight demonstration mission will bring the improved atomic clock technology to a technological readiness level that will allow it to be used in a wide variety of future space missions.
Read our earlier articles about the other technology demonstrations planned:
The Atlas Spaceflight Operations Center or ASOC is where the Atlas V launch vehicle, in this case the one which will launch the Mars Science Laboratory (MSL) rover on its mission Nov. 25 at 10:21 a.m. EDT. Photo Credit: United Launch Alliance
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CAPE CANAVERAL, Fla – United Launch Alliance (ULA) uses a structure that incorporates several launch and support operations into one centralized facility. Known as the Atlas Spaceflight Operations Center (ASOC) is about 9,290 square-meters (100,000 square-foot) in size. The ASOC provides all of the required elements – command, control and communication with the Atlas V. It is from the ASOC that the mission is managed as well as monitoring and evaluating launch operations.
The ASOC is actually two separate buildings that were combined into one. More accurately an existing structure had modern sections added to it. The first section was originally built back in the early 60s as part of the Titan III Program. The ASOC was built for the Titan II Chemical Systems Division Solid Rocket Motors. During this period, it was referred to as the Motor Inert Storage (MIS).
The ASOC is actually two buildings in one. The original structure was built in the 60s for the Titan Program. Later elements allowed for spacecraft processing as well as launch operations to be conducted all under one roof. Photo Credit: Alan Walters/awaltersphoto.com
Later, after the awarding of the Evolved Expendable Launch Vehicle (EELV) contract to Lockheed Martin in Oct. of 1998, they added three additional stories to the MIS. Part of this was the addition of the ASOC’s Launch Control Center (LCC).
The blockbuster film, Transformers 3, Dark of the Moon, had a few scenes filmed at the ASOC. Josh Duhamel, who played Lt. Colonel William Lennox, stood in the center of the LCC while battling the Decepticons. The filming took place back in October of 2010.
Key scenes of the blockbuster fiml "Transformers 3: Dark of the Moon" were shot within the ASOC. Image Credit: Paramount Pictures
The different manners in which the various rockets supported by the Denver, Colorado-based ULA are produced are in large part determined by the history of the rockets themselves.
“Launch vehicles are processed in various ways due to the design of the rocket, the backgrounds of the engineers, designing the rocket and how the rocket evolved all played their part,” said United Launch Alliance’s Mike Woolley. “The facilities available to the designers of the launch vehicle’s systems, the topography and geography of the installation as well as the rules, regulations, restrictions of the area played there part in how each of the individual launch systems are processed.”
The Atlas V launch vehicle is one of the two primary launch systems that is supported by the United Launch Alliance (the other being the Delta IV). Image Credit: Lockheed Martin
The ASOC is one part of the overall launch flow for the Atlas V launch vehicle. The other elements (excluding Space Launch Complex 41) are the Horizontal Integration Facility (HIF) and Vertical Integration Facility (VIF).
with a rooms looking down into it, The ASOC a Mission Directors Center, the Spacecraft Operations Center, the Engineering Support Facility, engineering support room which has been dubbed the “Gator Room” as well as an executive conference room.
Inside of the ASOC is the Atlas Launch Control Center or LCC. This allows for rockets to be prepard for flight as well as the launches themselves - to be managed from one building. Photo Credit: United Launch Alliance
The ASOC also has a hospitality room as well as a viewing room on the third floor (the roof is also made available for viewing launches). Lockheed Martin chose to cut back the number of support structures and decided to just build on to the existing MIS building. By doing this, Atlas engineers and technicians as well as the Atlas launch control center are close to the High ay where the Atlas V launch vehicle is processed for flight. This not only reduces the amount of time to process the Atlas booster, but it reduces costs as well.
The last Atlas V that was in the High Bay of the ASOC was the one that will be utilized to send the Mars Science Laboratory (MSL) rover, dubbed Curiosity. The Atlas V 541 (AV-028) recently underwent what is known as a Wet Dress Rehearsal (WDR) where the rocket is taken all the way up to launch. This is done to test out the rocket’s key systems before the payload is attached to the launch vehicle. Currently, MSL is set to launch from Space Launch Complex-41 (SLC-41) on Nov. 25 at 10:21 a.m. EDT.
The next mission that will be launched on the Atlas V Evolved Expendable Launch Vehicle is JPL's Mars Science Laboratory (MSL) rover. Photo Credit: Alan Walters/awaltersphoto.com
The X-37, versions of which have flown twice into space already, is now being proposed as a potential means of transportation for crews to the International Space Station. Photo Credit: Boeing
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As reported online at Space.com, the Boeing Company is already working on the CST-100 space taxi as a means of transportation to and from the International Space Station (ISS). But the aerospace firm is not content with just this simple space capsule and is looking into whether-or-not another of Boeing’s current offerings – the X-37B space plane could be modified to one day ferry crew to and from the orbiting laboratory as well.
proposed variant of the spacecraft, dubbed the X-37C, is being considered for a role that has some similarities to the cancelled X-38 Crew Return Vehicle (CRV). The announcement was made at a conference hosted by the American Institute of Aeronautics and Astronautics (AIAA) and reported on Space.com.
The USAF has already launched two of the X-37B Orbital Text Vehicles (OTV) from Cape Canaveral Air Force Station in Florida. Photo Credit: ULA/Pat Corkery
The X-37B or Orbital Test Vehicle (OTV) has so far been launched twice by the U.S. Air Force from Cape Canaveral Air Force Station in Florida. One of the military space planes completed the craft’s inaugural mission, USA-212, on Apr. 22, 2010. The mini space plane reentered Earth’s atmosphere and conducted an autonomous landing at Vandenberg Air Force on Dec. 3, 2010.
The U.S. Air Force then went on to launch the second of the space planes on mission USA-226 on Mar. 5, 2011. With these two successful launches, the longest-duration stay on orbit by a reusable vehicle and a landing under its belt, some of the vehicle’s primary systems (guidance, navigation, thermal protection and aerodynamics among others) are now viewed as having been validated. The vehicle has performed better than expected with the turnaround time being less than predicted.
If the X-37C is produced, it will be roughly twice the size of its predecessor. The X-37B is about 29 feet long; this new version of the mini shuttle would be approximately 48 feet in length. The X-37C is estimated at being approximately 165-180 percent larger than the X-37B. This increase in the size requires a larger launch vehicle.
This larger size also highlights plans to have the spacecraft carry 5 or 6 astronauts – with room for an additional crew member that is immobilized on a stretcher. The X-38, manufactured by Scaled Composites, was designed, built and tested to serve as a lifeboat for the ISS. In case of an emergency, crew members on the ISS would have entered the CRV and returned to Earth – a role that now could possibly be filled by the X-37C. The key difference being that the CRV only reached the point of atmospheric drop tests – the X-37B has flown into space twice.
Certain elements of the X-37C proposal highlight mission aspects of the cancelled X-38 Crew Return Vehicle. Photo Credit: NASA.gov
The crewed variant of the X-37 space plane would contain a pressurized compartment where the payload is normally stored, it would have a hatch that would allow for astronauts to enter and depart the spacecraft. Another hatch would be located on the main body of the mini shuttle so as to allow access to the vehicle on the ground. The X-37C, like its smaller cousin, would be able to rendezvous, dock, reenter the atmosphere and land remotely, without the need of a pilot. Acknowledging the need for pilots to control their own craft however, the X-37C would be capable of accomplishing these space flight requirements under manual control as well.
As mentioned in the Space.com article, one of the other selling points for the X-37C is its modular nature. Different variants could be used for crewed flights or unmanned missions that could return delicate cargo from the ISS. Neither the Russian Soyuz spacecraft, nor commercially-developed capsules are considered as appropriate means of returning biological or crystal experiments to Earth due to the high rate of acceleration that these vehicles incur upon atmospheric reentry. By comparison the X-37B experiences just 1.5 “g” upon reentry.
The launch vehicle that would send the proposed X-37C to orbit would be the United Launch Alliance Atlas V rocket. In provided images the X-37C is shown utilizing a larger version of the Atlas booster and without the protective fairing that covered the two X-37B space planes that were launched.
<>. Mission Poster for the Russian Phobos-Grunt soil sample return spacecraft set to launch to Mars and its moon Phobos in November 2011. Phobos-Grunt consistes Credit: Roskosmos - Russian Federal Space Agency
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Russia is marking the upcoming blastoff of their dauntingly complex Phobos-Grunt sample return mission to the Martian moon Phobos with the release of a quite cool looking mission poster – see above. Phobos-Grunt translates as Phobos-Soil and is due to liftoff on or about November 7, 2011 from the Baikonur Cosmodrome atop a Zenit rocket.
The holy grail of Mars exploration has long been a sample return mission. But with severe cutbacks to NASA’s budget that goal is realistically more than a decade away. That’s why Phobos- Grunt is so exciting from a scientific standpoint.
Phobos-Grunt Orbiter/Lander
Russia's Phobos-Grunt is designed to land on Mars' moon Phobos, collect soil samples and return them to Earth for study. The lander will also carry scientific instrumetns to study Phobos and its environment. It will travel to Mars together with Yinghuo-1, China's first mission to the Red Planet. Credit: NPO Lavochkin
Phobos-Grunt Robotic sampling arm. Credit: Roskosmos
If successful, this audacious probe will retrieve about 200 grams of soil from the diminutive moon Phobos and accomplish the round trip in three years time by August 2014. Scientists speculate that martian dust may coat portions of Phobos and could possibly be mixed in with any returned samples.
Included here are more photos and graphics of the Phobos-Grunt spacecraft which is equipped with two robotic arms and a sampling device to transfer regolith and rocks to the Earth return vehicle and an on board array of some 15 science instruments, including lasers, spectrometers, cameras and a microscope. Readers please feel free to help with Russian translations.
Phobos-Grunt Model
This is a full-scale mockup of Russia's Phobos-Grunt. The spacecraft will collect samples of soil on Mar's moon Phobos and to bring the samples back to Earth for detailed study. Credit: CNES
Phobos-Grunt is the first of Earth’s two missions launching to the Red Planet in 2011. NASA’s Curiosity Mars Science Laboratory is due to lift off on Nov. 25, 2011 from Cape Canaveral, Florida.
The Solar Sail demonstration mission. Credit: NASA
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Solar sails, much like anti-matter and ion engines appear at first glance to only exist in science fiction. Many technologies from science fiction however, become science fact.
In the example of solar sails, perfecting the technology would allow spacecraft to travel through our solar system using very little fuel.
NASA has been making strides with solar sail technology. Using the NanoSail-D mission, NASA continues to gather valuable data on how well solar sails perform in space. The Planetary Society will also be testing solar sail technology with their LightSail-1 project sometime next year.
How will NASA (and others) test solar sail technology, and develop it into a common, reliable technology?
The second of three recently announced technology demonstrations, The Solar Sail Demonstration, will test the deployment of a solar sail in space along with testing attitude control. The solar sail will also execute a navigation sequence with mission-capable accuracy.
In order to make science fiction into reality, NASA engineers are testing solar sails that could one day provide the propulsion for deep space missions. Spacecraft using solar sails would travel in our solar system in a similar manner to a sailboat through water, except spacecraft using solar sails would rely on sunlight instead of wind. A spacecraft propelled by a solar sail would use the sail to capture photons emitted from the Sun. Over time, the buildup of the solar photons provides enough thrust for a small spacecraft to travel in space.
NASA’s solar sail demonstration mission will deploy and operate a sail area 7 times larger than ever flown in space. The technology used in the demonstration will be applicable to many future space missions, including use in space weather warning systems to provide timely and accurate warnings of solar flare activity. The solar sail demonstration is a collaborative effort between The National Oceanic and Atmospheric Administration (NOAA), NASA and contractor L’Garde Inc.
NASA lists several capabilities solar sails have to offer, such as:
Orbital Debris: Orbital debris can be captured and removed from orbit over a period of years using the small solar-sail thrust.
De-orbit of spent satellites: Solar sails can be integrated into satellite payloads so that the satellite can be de-orbited at the end of its mission.
Station keeping: Using the low propellantless thrust of a solar sail to provide station keeping for unstable in-space locations.
Deep space propulsion: Payloads free of the Earth’s pull can be continuously and efficiently accelerated to the other planets, or out of the solar system, such as proposed in Project Encounter.
As an example, the GeoStorm project considers locating solar storm warning satellites at pseudo Lagrange points three times further from the Earth by using the solar sail to cancel some solar gravitational pull, thus increasing warning time from ~15 minutes to ~45 minutes.
Providing a satellite with a persistent view of northern or southern latitudes, i.e., a “pole-sitter” project. This allows the observational advantages of today’s geosynchronous satellites for orbits with view angles of the northern and southern high-latitudes.
A solar sail system, measuring 66 feet on each side was tested in 2005 in the world's largest vacuum chamber. Image Credit: NASA
If you’d like to learn more about solar sails, Caltech has a nice “Solar Sailing 101” page at: http://www.ugcs.caltech.edu/~diedrich/solarsails/intro/intro.html
Sierra Nevada Corporation is set to conduct a high-altitude free-flight test of the company's dream Chaser space plane as early as this summer. Image Credit: SNC
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It looks as though the efforts to get commercial space taxis off the ground – is succeeding. Sierra Nevada Corporation’s (SNC) “Dream Chaser” space plane is slated to conduct its first test flight as early as next summer. SNC is one of four companies that have had proposals selected by NASA under the Commercial Crew Development Program – 02 (CCDev2).
The test flight, what is known as a high-altitude free-flight test or “drop-test” will see Dream Chaser lifted high into the air, where the craft will then be released from its carrier aircraft and attempt an unmanned landing. During the course of this flight test program SNC will test out the space plane’s autoland and other capabilities.
The Dream Chaser space plane is derived from the HL-20 lifting body developed by NASA. Photo Credit: SNC
“Sierra Nevada Space Systems is honored to be awarded an additional $25.6 million by NASA as part of the second round of the Commercial Crew Development Program (CCDev2), bringing the total award to $105.6 million for this round of the competition,” said Mark Sirangelo, head of Sierra Nevada Space Systems. “As part of CCDev2, the Program has already completed four of the planned milestones, on time and on budget. The now thirteen CCDev2 milestones will culminate in a high-altitude free-flight test of our vehicle in the summer of 2012. ”
With NASA’s fleet of orbiters retired and being prepared to go on display in museums, NASA is dependent on the Russian Soyuz for access to the International Space Station (ISS). NASA currently pays Russia $63 million per seat for trips to the orbiting laboratory.
If all goes according to plan, the Dream Chaser could be one of many 'space-taxis' that would supply transportation services to the International Space Station. Image Credit: SNC
Many within both NewSpace and established space companies have stated their intent on reducing the amount of time that the U.S. is in such a position. NASA also has worked to assist companies that are working on CCDev2 to either meet or exceed their deadlines.
NASA is hopeful that these developments will allow the space agency to turn over transportation to the ISS to commercial firms by 2016.
In the case of SNC, NASA increased what the company was paid by an added $25.6 million. SNC had already been awarded $80 million as their part of the CCDev2 contract. After this boost in funding, SNC announced that the drop test would be held next summer.
The Dream Chaser design is based primarily off of the HL-20 lifting body design and is capable of carrying seven astronauts to orbit. Dream Chaser is designed to launch from Cape Canaveral Air Force Station located in Florida atop a United Launch Alliance (ULA) Atlas V 402.
Sierra Nevada Corporation is working steadily to test out and prove the Dream Chaser's various systems. Photo Credit: SNC
If everything goes according to how it is currently planned, the test flight will take place at either Edwards Air Force Base, located in California or White Sands Missile Range in New Mexico. Virgin Galactic’s WhiteKnightTwo will carry the Dream Chaser space plane aloft for the test. Virgin Galactic, another NewSpace firm, is based in the U.S. and owned by Sir Richard Branson.
The ISS is viewed by the U.S, and the 15 other nations involved with the project as a crucial investment and having only one way to send crew to and from the ISS as being unacceptable. Sierra Nevada’s Dream Chaser is joined by Space Exploration Technologies’ (SpaceX) Dragon spacecraft, Boeing’s CST-100 and Blue Origin’s as-yet unnamed spacecraft in the CCDev2 contract.
The Dream Chaser space plane atop a United Launch Alliance Atlas V rocket. Image Credit: SNC
Conceptual image of The Laser Communications Relay Demonstration. Credit: NASA
[/caption]Quite often, communication rates with remote spacecraft have been a limiting factor when exploring our solar system. For example, it can take up to 90 minutes to transfer one high-resolution image from the Mars Reconnaissance Orbiter to scientists on Earth.
Improving data communication rates would allow scientists to collect additional data from future missions to Mars, Titan or other destinations in our solar system.
How does NASA plan to overcome the current limitations in communication with spacecraft outside Earth orbit?
One of three recently announced technology demonstrations, The Laser Communications Relay Demonstration, will help demonstrate and validate laser-based communications. One of many goals for the LCRD is to provide spacecraft in Earth orbit ( and beyond ) a faster and reliable method of communication than standard radio communications currently in use.
A laser-based communication will allow NASA and other government agencies to perform missions that require higher data rates. In the cases where less data is required, the laser-based systems would consume less power, mass and precious volume inside a spacecraft. Given roughly equal mass, power, and volume, the laser-based communications system offers much higher data rates than a radio-based communications system.
NASA’s goals for the LCRD are to:
Enable reliable, capable, and cost effective optical communications technologies for near earth applications and provide the next steps required toward optical communications for deep space missions
Demonstrate high data rate optical communications technology necessary for:
Near-Earth spacecraft (bi-directional links supporting hundreds of Mbps to Gbps)
Deep Space missions (tens to hundreds of Mbps from distances such as Mars and Jupiter)
Develop, validate and characterize operational models for practical optical communications
Identify and develop requirements and standards for future operational optical communication systems
Establish a strong partnership with multiple government agencies to facilitate crosscutting infusion of optical communications technologies
Develop the industrial base and transfer technology for future space optical communications systems
High-rate communications 10-100 times more capable than current radio systems will also allow for greatly improved connectivity and enable new generations of remote missions that are far more capable than today’s missions. NASA’s LCRD will also provide the satellite communication industry with technology not available today. Laser-based space communications will enable missions to use high-definition video and and pave the way for a possible “virtual presence” on a remote planet or other bodies in the solar system.
While the laser-based communications technology featured in the LCRD will allow more data to be sent from spacecraft to scientists on Earth, the communication delays (a few seconds for the Moon, and over twenty minutes for Mars) will still require careful mission planning.
Diagram of LCRD mission. Image Credit: NASA
The Laser Communications Relay Demonstration (LCRD) is led by the NASA Goddard Space Flight Center. Space Communications and Navigation (SCaN) office in the Human Exploration and Operations Mission Directorate is collaborating with the NASA Office of the Chief Technologist in sponsoring this technology demonstration.
Kennedy Space Center Director Bob Cabana introduces NASA Administrator Charles Bolden in front of the Mobile Launch Platform at Kennedy Space Center in Florida. Photo Credit: Suresh Atapattu
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CAPE CANAVERAL, Fla – NASA Administrator Charles Bolden stopped by Kennedy Space Center in Florida to tour NASA’s Mobile Launch Platform. Bolden was joined by fellow former shuttle astronaut and current Kennedy Space Center Director Robert Cabana. The duo toured the 355-foot-tall structure Tuesday, Oct. 11 at 11 a.m. EDT.
The Mobile Launcher’s future was in doubt after the Constellation Program was cancelled. Although nothing definite was stated – everything from scrapping the structure, using it as a platform for tourists at the Kennedy Space Center Visitor Center to just keeping it in reserve was suggested. The space agency now plans to use the structure to launch the Space Launch System or SLS rocket.
NASA Kennedy Space Center Director Bob Cabana (far left) gestures while discussing how the MLP will be used in upcoming missions. To his left is NASA Administrator Charles Bolden and they are surrounded by members of the local media. Photo Credit: Suresh Atapattu
The NASA administrator’s visit was designed to help promote NASA’s recently-unveiled SLS heavy-lift rocket. The launch vehicle somewhat resembles a cross between the cancelled Ares V and the Saturn V moon rockets that launched Apollo astronauts to the moon. It is slated to begin conducting flights by 2017. SLS is comprised primarily of so-called “legacy hardware” – proven technology derived from the space shuttle and Saturn systems.
Bolden spent some time chatting with reporters and working to reassure Kennedy Space Center’s remaining workforce, as well as several hundred Space Coast community and business leaders and elected officials that the area’s future was bright. Bolden used the visit to state that this was a sign that things were improving in the region. He highlighted the fact that new capabilities, such as the placement of the Commercial Crew program office at Kennedy, will help to maintain aerospace skills and capabilities. NASA Administrator Charles Bolden descends the steps of the MLP during his visit to Kennedy Space Center on Oct. 11, 2011. Photo Credit: Suresh Atapattu
“As our nation looks for ways to compete and win in the 21st century, NASA continues to be an engine of job growth and economic opportunity,” Bolden said. “From California to Florida, the space industry is strong and growing. The next generation of explorers will
not fly a space shuttle, but they may be able to walk on Mars. And those journeys are starting at the Kennedy Space Center today.”
The shuttle elements of SLS include the RS-25 engines (Space Shuttle Main Engines) along with modified versions of the Solid Rocket Boosters that were employed on the space shuttle. The Saturn elements (descendent) are the J-2X engines, which are simpler variants of the J-2 engines employed during the Apollo era.
A few up the massive Mobile Launch Platform and Mobile Launch Tower (the combined structure is generally called the Mobile Launcher). Photo Credit: Julian Leek/Blue Sawtooth Studios
NASA made its plans for the SLS public in September, just one day after Alliant Techsystems (ATK) and NASA announced that an unfunded Space Act Agreement deal to study the viability of using the Liberty rocket to ferry astronauts to orbit. If all goes according to plan, SLS will eventually be utilized to launch the Orion Multi-Purpose Crew Vehicle. It is hoped that the introduction of SLS and other space systems will help to stem the flow of highly-trained and experienced workers from the space agency.
