Asteroid 2010 TK7 is circled in green.
Image Credit: NASA / JPL-Caltech / UCLA
|Scientists using the Wide-field Infrared Survey Explorer (WISE) have discovered the first Trojan Asteroid in Earth orbit. Trojans orbit at a location in front of or behind a planet known as a Lagrange Point.
A video of the asteroid and its orbit at the Lagrange point can be found here.
Martin Connors of Athabasca University in Canada is the lead author of a new paper on the discovery in the July 28 issue of the journal Nature.
Connors notes that:
TK7 is roughly 300 meters in diameter and traces a complex motion around SEL-4 (Sun Earth Lagrange point 4). The asteroid’s orbit is stable for at least the next 100 years and is currently about 80 million kilometers from the Earth. In that time, it is expected to come no closer that 24 million kilometers.
The obvious question is whether this is the logical destination for NASA’s Flexible Path manned asteroid mission? The Lagrange 4 point (SEL-4) is a logical way station on the Solar System exploration highway. Other NEO asteroids that have been identified as possible targets are few and much more difficult to reach and return than an asteroid located directly at SEL-4 would be. An asteroid located there could well be the target of opportunity that opens manned exploration of the Solar System in an “easy” mode. Unfortunately, Asteroid 2010 TK7 would not serve as such a target because it travels in an eccentric orbit around SEL-4 so far above and below the plane of Earth’s orbit that it would require very large amounts of fuel to reach.
NEOWISE is the program for searching the WISE database for Near Earth Objects (NEO), as well as other asteroids in the Solar System.The NEOWISE project observed more than 155,000 asteroids in the main belt between Mars and Jupiter, and more than 500 NEOs, discovering 132 that were previously unknown.
Archive for July, 2011
PASADENA, Calif. – Astronomers studying observations taken by NASA’s Wide-field Infrared Survey Explorer (WISE) mission have discovered the first known “Trojan” asteroid orbiting the sun along with Earth.
Trojans are asteroids that share an orbit with a planet near stable points in front of or behind the planet. Because they constantly lead or follow in the same orbit as the planet, they never can collide with it. In our solar system, Trojans also share orbits with Neptune, Mars and Jupiter. Two of Saturn’s moons share orbits with Trojans.
Scientists had predicted Earth should have Trojans, but they have been difficult to find because they are relatively small and appear near the sun from Earth’s point of view.
“These asteroids dwell mostly in the daylight, making them very hard to see,” said Martin Connors of Athabasca University in Canada, lead author of a new paper on the discovery in the July 28 issue of the journal Nature. “But we finally found one, because the object has an unusual orbit that takes it farther away from the sun than what is typical for Trojans. WISE was a game-changer, giving us a point of view difficult to have at Earth’s surface.”
The WISE telescope scanned the entire sky in infrared light from January 2010 to February 2011. Connors and his team began their search for an Earth Trojan using data from NEOWISE, an addition to the WISE mission that focused in part on near-Earth objects, or NEOs, such as asteroids and comets. NEOs are bodies that pass within 28 million miles (45 million kilometers) of Earth’s path around the sun. The NEOWISE project observed more than 155,000 asteroids in the main belt between Mars and Jupiter, and more than 500 NEOs, discovering 132 that were previously unknown.
The team’s hunt resulted in two Trojan candidates. One called 2010 TK7 was confirmed as an Earth Trojan after follow-up observations with the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii.
The asteroid is roughly 1,000 feet (300 meters) in diameter. It has an unusual orbit that traces a complex motion near a stable point in the plane of Earth’s orbit, although the asteroid also moves above and below the plane. The object is about 50 million miles (80 million kilometers) from Earth. The asteroid’s orbit is well-defined and for at least the next 100 years, it will not come closer to Earth than 15 million miles (24 million kilometers).
“It’s as though Earth is playing follow the leader,” said Amy Mainzer, the principal investigator of NEOWISE at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Earth always is chasing this asteroid around.”
A handful of other asteroids also have orbits similar to Earth. Such objects could make excellent candidates for future robotic or human exploration. Asteroid 2010 TK7 is not a good target because it travels too far above and below the plane of Earth’s orbit, which would require large amounts of fuel to reach it.
“This observation illustrates why NASA’s NEO Observation program funded the mission enhancement to process data collected by WISE,” said Lindley Johnson, NEOWISE program executive at NASA Headquarters in Washington. “We believed there was great potential to find objects in near-Earth space that had not been seen before.”
NEOWISE data on orbits from the hundreds of thousands of asteroids and comets it observed are available through the NASA-funded International Astronomical Union’s Minor Planet Center at the Smithsonian Astrophysical Observatory in Cambridge, Mass.
JPL manages and operates WISE for NASA’s Science Mission Directorate in Washington. The principal investigator, Edward Wright, is a professor at the University of California, Los Angeles. The mission was selected under NASA’s Explorers Program, which is managed by the agency’s Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah.
The spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
For more WISE information visit: http://www.nasa.gov/wise.
by Howard Bloom
National Space Society Board of Governors
Recently The Economist magazine featured a piece inspired by the end of the Shuttle Era entitled, “The end of the Space Age. Inner space is useful. Outer space is history.”
The Economist is wrong. The space age is not ending. It is just beginning. And it is taking off fast. Its next giant leaps will change the nature of resources, energy, jobs, and the economy. The leap will make your grandkids lives so different from yours and mine that it will defy belief.
But this time, the future is not driven by NASA, it’s propelled by private enterprise. The players are small companies. But what they lack in fame, they more than make up for in spirit…and in smarts.
Below are five companies working diligently to bring humanity closer to the dream of permanent settlement in space.
1) Bigelow Aerospace (www.bigelowaerospace.com)
Robert Bigelow made his reputation, and his money, building Budget Suites of America. His thirteen year old company, Bigelow Aerospace, is putting hotels in space. Bigelow’s first 1/3 scale prototype inflatable habitat — complete with thirteen cameras and systems to maintain air pressure, oxygen content, and temperature (all systems powered by solar panels) — has been in orbit since 2006. It carries “guests” — Madagascar hissing cockroaches, and Mexican jumping beans from Bigelow Aerospace’s neighborhood in the desert of Nevada. It also carries an entire Gensat microsatellite from NASA. Bigelow’s second space hotel prototype went into orbit in 2007 with improved systems, 22 monitoring cameras, and more sophisticated guests — scorpions and an entire colony of seed-harvester ants. Bigelow’s plan is to offer far more living space than the International Space Station at a fraction of the cost.
Bigelow already has a list of seven countries waiting to occupy his space hotels. The pace of demand has increased to the point where the company is constructing its third habitat, the BA 330, ahead of schedule. It plans to have the BA 330 in orbit in 2014 or 2015.
2) SpaceX (www.spacex.com)
Space Exploration Technologies, or SpaceX, was founded in 2002 by PayPal co-founder Elon Musk. Musk defied all expectations by successfully building the Falcon 1 and Falcon 9 rockets. The Falcon 9 cost $400 million, which is a mere fraction of the cost of the Space Launch System — an overpriced rocket being pushed by Congress.
Musk has also built the Dragon capsule — which in December 2010 became the first spacecraft ever placed in orbit and recovered by a private company. The Dragon Capsule is capable of carrying seven passengers or a launch payload of 13,000 lbs. But on its maiden voyage, the Dragon Capsule carried a secret payload, later discovered to be a wheel of cheese — an homage to a Monty Python Cheese Sketch.
Upcoming is a super rocket called the Falcon Heavy, built on the base of the successful Falcon 9. It will use nine Merlin engines and carry 117,000 pounds to low earth orbit or 41,000 pounds to geosynchronous orbit. It will do something even more crucial: drastically reduce the cost of space access. In the Shuttle era, it cost us between $10,000 and $14,000 a pound to get humans and cargo into space. That’s much too much. If we can drive that cost down, the riches of space will open. Drive that cost down and we can deliver more solar energy from space than all the energy mankind has used to date. We can also mine space resources like platinum, lithium, and rare earth metals — the key materials for electric cars. And we can even build resorts in space. The Falcon Heavy is expected to drive the cost per pound to orbit down from $14,000 a pound to less than $1,000. This is something the traditional space industry experts said cannot be done.
And Musk is aiming to use the Falcon Heavy to send humans and supplies to the fourth planet from the sun. “We’re going all the way to Mars,” he said at the National Press Club on April 5th, 2011. “I think… best case 10 years, worst case 15 to 20 years.” The first demo flight of what will be the world’s most powerful rocket is expected in 2013.
3) XCOR (www.xcor.com)
XCOR was founded in 1999 by former members of Rotary Rocket — a company who wanted to combine a helicopter with a rocket. Jeff Greason, XCOR president, is also a visionary whose recent keynote speech at the International Space Development Conference is considered a major statement in space policy.
XCOR’s pride is the Lynx, capable of bringing people and science to the edge of space.
The Lynx is a two-seated, piloted space transport vehicle that will take humans and payloads on a half-hour suborbital flight to 100 km (330,000 feet) and then return safely to a landing at the takeoff runway. It takes off and lands like an aircraft, but runs like a rocket. And it will allow up to four flights per day.
Sales for the Lynx have surged. As of May, 2011, XCOR has sold approximately one hundred tickets costing $95,000 each.
But XCOR is also working with United Launch Alliance on building a new upper stage for the Atlas 5 and Delta 4 rockets. And, they are also working with the Planetary Science Institute to carry the Atsa Suborbital Observatory.
The Lynx Mark I is expected to begin test flights in 2012.
4) Sierra Nevada Corporation/SpaceDev
Many have claimed that the end of the shuttle means the end of Americans in space. But Sierra Nevada Corporation (SNC) proves them wrong. The company is one of four who received funding from NASA to carry cargo and crew to the International Space Station.
Their vehicle, the Dream Chaser, looks a lot like the shuttle because it was originally a NASA design. It will launch atop an Atlas V and return from space by gliding and landing at almost any aircraft runway in the world. It will be capable of holding a crew of seven people. Its missions will include delivering and returning crew and critical cargo to the International Space Station. Sierra Nevada’s current timetable calls for suborbital test flights starting in 2013 and orbital tests in 2014.
Blue Origin was started by Amazon founder, Jeff Bezos. The company’s motto, Gradatim Ferociter means, “Step by Step, Ferociously,” and might hint at Bezos’ plans. After all, Amazon has become more than just the world’s largest bookseller.
Blue Origin’s New Shepard is a rocket-propelled vehicle capable of carrying multiple astronauts into suborbital space. Along with providing spaceflight opportunities to the public, it will also allow researchers to fly experiments into space and a microgravity environment. It is based on the earlier Delta Clipper (DC-X).
The vehicle consists of a pressurized crew capsule (carrying the astronauts and experiments) which sits atop the propulsion module. Flights will take place from Blue Origin’s own launch site, which is already operating in West Texas. New Shepard will take-off vertically and the crew capsule will land softly under a parachute at the launch site. A scaled-down “Goddard” test vehicle has been flown.
The Economist is wrong because space is the next logical step for humanity. Exploring and settling new frontiers is what we’ve been doing for the past two million years. There’s no reason why we would now suddenly come to a screeching halt.
Edgar Mitchell, lunar module pilot of Apollo 14, sums it best:
The current period is of necessity, just a temporary lull in space activity. We must all get fully involved in due course. The eventual survival of our civilization depends upon becoming an extra-terrestrial universal civilization. In the most stark words it is “do or die.” So, let’s get the economy going again, get all the major nations involved, develop the necessary means for interplanetary and interstellar travel, and go for it.
Official landing times:
Mission Elapsed Times (MET):
Main Gear Touchdown: MET 12/18:27:56 - 9:57:00 am UTC
Nose Gear Touchdown: MET 12/18:28:16 - 9:57:20 am UTC
Wheel Stop: MET 12/18:28:50 - 9:57:54 am UTC
High resolution images of Atlantis are now on nasa.gov.
NASA’s Dawn spacecraft obtained this image of the protoplanet Vesta with its framing camera on July 18, 2011. It was taken from a distance of about 10,500 kilometers. The smallest detail visible is about 2.0 km.
In August, Dawn will begin sending images from its high resolution camera.
NASA’s Kennedy Space Center in Florida, the U.S. Office of Personnel Management (OPM) and Brevard Workforce are partnering to host a job fair with private sector companies and federal employers from across the country on July 26. The Space Coast Job Fair and Hands-on Training Event takes place at 11 a.m. EDT at the Radisson Resort at the Port, 8701 Astronaut Blvd., Cape Canaveral, Florida. More than 45 employers are expected to take part in the event.
NASA has been working with local, state and federal officials to provide future planning support and placement for non-civil servant contractors who work to support the Space Shuttle Program, which will end next month. In addition to this event, NASA’s Human Resources Office has hosted workshops, seminars and other events to help prepare employees for future opportunities. For more information about Kennedy’s work force support efforts, visit:
The National Space Society and Space Frontier Foundation also maintain directories of space companies. Visit these to find future job openings:
A new NASA publication is now available for free download from the NSS website: Psychology of Space Exploration — Contemporary Research in Historical Perspective, edited by Douglas Vakoch. The 267-page book is NASA Special Publication SP-4411 (2011).
As we stand poised on the verge of a new era of spaceflight, we must rethink every element, including the human dimension. This book explores some of the contributions of psychology to yesterday’s great space race, today’s orbiter and International Space Station missions, and tomorrow’s journeys beyond Earth’s orbit. Early missions into space were typically brief, and crews were small, often drawn from a single nation. As an intensely competitive space race has given way to international cooperation over the decades, the challenges of communicating across cultural boundaries and dealing with interpersonal conflicts have become increasingly important, requiring different coping skills and sensibilities from “the right stuff” of early astronauts.
As astronauts travel to asteroids or establish a permanent colony on the Moon, with the eventual goal of reaching Mars, the duration of expeditions will increase markedly, as will the psychosocial stresses. Away from their home planet for extended times, future spacefarers will need to be increasingly self-sufficient and autonomous while they simultaneously deal with the complexities of heterogeneous, multicultural crews. Psychology of Space Exploration: Contemporary Research in Historical Perspective provides an analysis of these and other challenges facing future space explorers while at the same time presenting new empirical research on topics ranging from simulation studies of commercial spaceflights to the psychological benefits of viewing Earth from space.
In addition to examining contemporary psychological research, each essay also explicitly addresses the history of the psychology of space exploration. Leading contributors to the field place the latest theories and empirical findings in historical context by examining changes in space missions over the past half century, as well as reviewing developments in psychological science during the same period. The essays are innovative in their approaches and conclusions, providing novel insights for behavioral researchers and historians alike.
The James Webb Telescope, successor to the Hubble Space Telescope, has been cut by the House Appropriations Committee. An amendment to the NASA budget to restore funding to the telescope was defeated July 14. The telescope has been plagued with large cost overruns.
However, it remains possible that funding could be restored in the Senate. Senator Barbara Mikulski (D-MD) plans to defend the telescope. Her home state includes the NASA Goddard Space Flight Center, which manages the project.
More about the James Webb Telescope.
NASA’s Dawn spacecraft will enter orbit around the second most massive (but third largest) asteroid in the asteroid belt at around 10 pm Pacific Daylight Time Friday July 15. It will stay in orbit around Vesta for about a year and then move on to orbit the largest asteroid, Ceres. This demanding mission profile is made possible by using ion propulsion.
Dimensions: About 578 by 560 by 458 kilometers (359 by 348 by 285 miles) - about the length of Arizona
Rotation: Once every 5 hours, 20 minutes
Size: 975 by 909 kilometers (606 by 565 miles)
Rotation: Once every 9 hours, 4.5 minutes
Composition: Believed to have large quantities of ice
According to National Space Society Director Al Globus, the development of thin-film solar cells may bring the reality of space solar power closer than ever.
Solar power originated roughly 50 years ago to power the satellites just beginning to orbit the Earth. From those roots it spawned a terrestrial-based power industry. Ironically, the same technology has, until recently, been prohibitively expensive for space based solar power. Thin-film solar cells are now changing the equation.
The terrestrial solar power industry relies upon a type of photovoltaics that uses a crystalline structure. Manufacturing costs of crystalline PV modules over the past few decades has decreased substantially. Combined with the ability to assemble each unit in a modular fashion, crystalline PV is now a viable source of power.
Space solar power using crystalline photovoltaics is expensive because the mass is high and launch costs tend to dominate. Industry people measure the effectiveness of a solar cell by its specific power, or output per weight. The unit of measurement is Watts per Kilogram (W/kg). The goal is to achieve 1000 W/kg. Recently, thin-film photovoltaics have exceeded this critical point. Very thin (10-25 micrometers) metallic substrates can achieve and exceed the required specific power targets.
According to Globus, this may bring space solar power within our grasp. Thin-film solar cells currently in use in space on the Ikaros solar sail achieve approximately 1,250 W/kg for power generation. However, this does not include the rest of the system (power beaming, ground receivers, etc.). Using current day technology, a thin-film based PowerSat could probably achieve around 275 W/kg. If we assume a reasonable R&D program to develop the basic technologies, it appears that 1,380 W/kg can be achieved in a reasonable time scale.
More on thin-film solar cells.