Image above: The TDRS-K spacecraft
stands inside a processing hangar in Titusville, Fla., awaiting
packaging for launch into orbit 22,300 miles above Earth. Photo credit:
NASA/Jim Grossmann
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Image above: An artist concept of the
TDRS-K spacecraft in orbit with its assortment of antennas and a pair of
solar arrays to provide electricity. Credit: The Boeing Co.
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TDRS-K Offers Upgrade to Vital Communications Net
NASA's Tracking and Data Relay Satellite System, also known as the Space
Network, will get an upgrade this month when the agency launches the
first of a new generation of communications satellites to connect man of
NASA's spacecraft to their control centers and mission data centers.
A United Launch Alliance Atlas V 401 is due to loft the TDRS-K spacecraft Jan. 29 on a course to geosynchronous orbit where the spacecraft will have a wide view of Earth. From that position, the spacecraft will provide communications with NASA's fleet of Earth-orbiting science spacecraft, including the International Space Station and NASA's Hubble Space Telescope.
The advanced spacecraft, known as TDRS, is needed to ensure the communications network is able to provide critical services to user spacecraft in the next decade.
"We have some aging satellites, so we need new spacecraft to go in there and help carry more of the data," said Diana Calero, mission manager for NASA's Launch Services Program, or LSP, based at Kennedy Space Center in Florida.
The processing for this mission included the standard in-depth reviews but also took into account extra engineering sessions to investigate whether the underperformance of an upper stage engine during an earlier, non-NASA launch would occur during the TDRS ascent, said Tim Dunn, NASA launch director. The Centaur upper stage used by the Atlas V uses an engine similar to the one that underperformed during a Delta IV launch last year.
"Our engineers and analysts from the Launch Services Program, working alongside the United Launch Alliance engineers, we've been methodically reviewing data and working very closely on flight clearance for the TDRS-K mission, so that's been our biggest challenge to date," Dunn said.
The TDRS spacecraft is large and looked impressive as it stood with its large steerable antennas folded over top of each other inside a processing hangar at Astrotech in Titusville, Fla. The spacecraft, built by The Boeing Company in El Segundo, Calif., arrived in Florida on Dec. 18 on an Air Force C-17 transport plane. Following testing, fueling and launch preparations, it was positioned inside a two-part payload fairing and taken to Space Launch Complex 41 at Cape Canaveral Air Force Station.
Onboard thrusters will provide the final propulsion to reach geosynchronous orbit following separation from the Centaur upper stage.
"The antennas are furled and they have a certain amount of days that they can stay furled," Calero said. "If they pass that, then the antennas, when they're deployed, they can actually degrade in space and so we have to play close attention to how long they stay furled. So it was really challenging trying to schedule the shipping of the spacecraft with the moving launch date. We're still watching it very closely."
TDRS-K will be the 11th TDRS launched by NASA since it began building the space-borne network in 1983. The most recent spacecraft launched in 2002 on an Atlas IIA.
Orbiting about 22,300 miles above Earth, positioned roughly over Hawaii, TDRS-K will use its antennas to receive and transmit signals from a wide range of spacecraft to Earth in several frequency bands.
Even rockets carrying spacecraft carry TDRS-compatible communications gear and transmit telemetry during ascent through the orbiting network instead of ground stations, an advancement that saves money by not having to field specialized aircraft and ships or maintain a string of remote stations to monitor a launch.
The number of TDRS satellites required to serve NASA's orbiting fleet of scientific spacecraft has grown from the original architecture of two to six to service the requirements of a diverse set of users.
"All the Hubble images come through TDRS, all the video that we see from the space station and the astronauts and the video we saw from the shuttle, it all comes through TDRS, and then we have all the Earth-orbiting satellites, all that data comes through TDRS," said Paul Buchanan, deputy project manager for TDRS.
The communications constellation replaced the ground stations positioned on Earth so NASA could communicate with astronauts in orbit. That system allowed contact only when the spacecraft passed within range of the antennas, however. With TDRS satellites in place, controllers have near-constant contact with spacecraft.
"If you roll back in history maybe 30, 40 years, back in Mercury days and Apollo there were no TDRS satellites for communication so you had outages between the ground stations," Buchanan said. "We didn't want the outages, we wanted continuous (communications), so that's what motivated the desire for the Space Network."
"We've had to decommission two spacecraft in the last few years due to the electronics degradation after 20, 25 years," Buchanan said. "We're launching now for an immediate need and replenishment schedule."
When their service life is up, the TDRS satellites are boosted about 250 miles higher into what's called a disposal orbit. Steven Siceloff,
NASA's John F. Kennedy Space CenterA United Launch Alliance Atlas V 401 is due to loft the TDRS-K spacecraft Jan. 29 on a course to geosynchronous orbit where the spacecraft will have a wide view of Earth. From that position, the spacecraft will provide communications with NASA's fleet of Earth-orbiting science spacecraft, including the International Space Station and NASA's Hubble Space Telescope.
The advanced spacecraft, known as TDRS, is needed to ensure the communications network is able to provide critical services to user spacecraft in the next decade.
"We have some aging satellites, so we need new spacecraft to go in there and help carry more of the data," said Diana Calero, mission manager for NASA's Launch Services Program, or LSP, based at Kennedy Space Center in Florida.
The processing for this mission included the standard in-depth reviews but also took into account extra engineering sessions to investigate whether the underperformance of an upper stage engine during an earlier, non-NASA launch would occur during the TDRS ascent, said Tim Dunn, NASA launch director. The Centaur upper stage used by the Atlas V uses an engine similar to the one that underperformed during a Delta IV launch last year.
"Our engineers and analysts from the Launch Services Program, working alongside the United Launch Alliance engineers, we've been methodically reviewing data and working very closely on flight clearance for the TDRS-K mission, so that's been our biggest challenge to date," Dunn said.
The TDRS spacecraft is large and looked impressive as it stood with its large steerable antennas folded over top of each other inside a processing hangar at Astrotech in Titusville, Fla. The spacecraft, built by The Boeing Company in El Segundo, Calif., arrived in Florida on Dec. 18 on an Air Force C-17 transport plane. Following testing, fueling and launch preparations, it was positioned inside a two-part payload fairing and taken to Space Launch Complex 41 at Cape Canaveral Air Force Station.
Onboard thrusters will provide the final propulsion to reach geosynchronous orbit following separation from the Centaur upper stage.
"The antennas are furled and they have a certain amount of days that they can stay furled," Calero said. "If they pass that, then the antennas, when they're deployed, they can actually degrade in space and so we have to play close attention to how long they stay furled. So it was really challenging trying to schedule the shipping of the spacecraft with the moving launch date. We're still watching it very closely."
TDRS-K will be the 11th TDRS launched by NASA since it began building the space-borne network in 1983. The most recent spacecraft launched in 2002 on an Atlas IIA.
Orbiting about 22,300 miles above Earth, positioned roughly over Hawaii, TDRS-K will use its antennas to receive and transmit signals from a wide range of spacecraft to Earth in several frequency bands.
Even rockets carrying spacecraft carry TDRS-compatible communications gear and transmit telemetry during ascent through the orbiting network instead of ground stations, an advancement that saves money by not having to field specialized aircraft and ships or maintain a string of remote stations to monitor a launch.
The number of TDRS satellites required to serve NASA's orbiting fleet of scientific spacecraft has grown from the original architecture of two to six to service the requirements of a diverse set of users.
"All the Hubble images come through TDRS, all the video that we see from the space station and the astronauts and the video we saw from the shuttle, it all comes through TDRS, and then we have all the Earth-orbiting satellites, all that data comes through TDRS," said Paul Buchanan, deputy project manager for TDRS.
The communications constellation replaced the ground stations positioned on Earth so NASA could communicate with astronauts in orbit. That system allowed contact only when the spacecraft passed within range of the antennas, however. With TDRS satellites in place, controllers have near-constant contact with spacecraft.
"If you roll back in history maybe 30, 40 years, back in Mercury days and Apollo there were no TDRS satellites for communication so you had outages between the ground stations," Buchanan said. "We didn't want the outages, we wanted continuous (communications), so that's what motivated the desire for the Space Network."
"We've had to decommission two spacecraft in the last few years due to the electronics degradation after 20, 25 years," Buchanan said. "We're launching now for an immediate need and replenishment schedule."
When their service life is up, the TDRS satellites are boosted about 250 miles higher into what's called a disposal orbit. Steven Siceloff,
NASA Joins ESA's 'Dark Universe' Mission
WASHINGTON
-- NASA has joined the European Space Agency's (ESA's) Euclid mission, a
space telescope designed to investigate the cosmological mysteries of
dark matter and dark energy.
Euclid will launch in 2020 and spend six years mapping the locations and measuring the shapes of as many as 2 billion galaxies spread over more than one-third of the sky. It will study the evolution of our universe, and the dark matter and dark energy that influence its evolution in ways that still are poorly understood.
The telescope will launch to an orbit around the sun-Earth Lagrange point L2. The Lagrange point is a location where the gravitational pull of two large masses, the sun and Earth in this case, precisely equals the force required for a small object, such as the Euclid spacecraft, to maintain a relatively stationary position behind Earth as seen from the sun.
"NASA is very proud to contribute to ESA's mission to understand one of the greatest science mysteries of our time," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate at the agency's Headquarters in Washington.
NASA and ESA recently signed an agreement outlining NASA's role in the project. NASA will contribute 16 state-of-the-art infrared detectors and four spare detectors for one of two science instruments planned for Euclid.
"ESA’s Euclid mission is designed to probe one of the most fundamental questions in modern cosmology, and we welcome NASA’s contribution to this important endeavor, the most recent in a long history of cooperation in space science between our two agencies," said Alvaro Giménez, ESA’s Director of Science and Robotic Exploration.
In addition, NASA has nominated three U.S. science teams totaling 40 new members for the Euclid Consortium. This is in addition to 14 U.S. scientists already supporting the mission. The Euclid Consortium is an international body of 1,000 members who will oversee development of the instruments, manage science operations, and analyze data.
Euclid will map the dark matter in the universe. Matter as we know it -- the atoms that make up the human body, for example -- is a fraction of the total matter in the universe. The rest, about 85 percent, is dark matter consisting of particles of an unknown type. Dark matter first was postulated in 1932, but still has not been detected directly. It is called dark matter because it does not interact with light. Dark matter interacts with ordinary matter through gravity and binds galaxies together like an invisible glue.
While dark matter pulls matter together, dark energy pushes the universe apart at ever-increasing speeds. In terms of the total mass-energy content of the universe, dark energy dominates. Even less is known about dark energy than dark matter.
Euclid will use two techniques to study the dark universe, both involving precise measurements of galaxies billions of light-years away. The observations will yield the best measurements yet of how the acceleration of the universe has changed over time, providing new clues about the evolution and fate of the cosmos.
Euclid is an ESA mission with science instruments provided by a consortia of European institutes and with important participation from NASA. NASA's Euclid Project Office is based at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. JPL will contribute the infrared flight detectors for the Euclid science instrument. NASA's Goddard Space Flight Center in Greenbelt, Md., will test the infrared flight detectors prior to delivery. Three U.S. science teams will contribute to science planning and data analysis.
For more information about NASA, visit:
Euclid will launch in 2020 and spend six years mapping the locations and measuring the shapes of as many as 2 billion galaxies spread over more than one-third of the sky. It will study the evolution of our universe, and the dark matter and dark energy that influence its evolution in ways that still are poorly understood.
The telescope will launch to an orbit around the sun-Earth Lagrange point L2. The Lagrange point is a location where the gravitational pull of two large masses, the sun and Earth in this case, precisely equals the force required for a small object, such as the Euclid spacecraft, to maintain a relatively stationary position behind Earth as seen from the sun.
"NASA is very proud to contribute to ESA's mission to understand one of the greatest science mysteries of our time," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate at the agency's Headquarters in Washington.
NASA and ESA recently signed an agreement outlining NASA's role in the project. NASA will contribute 16 state-of-the-art infrared detectors and four spare detectors for one of two science instruments planned for Euclid.
"ESA’s Euclid mission is designed to probe one of the most fundamental questions in modern cosmology, and we welcome NASA’s contribution to this important endeavor, the most recent in a long history of cooperation in space science between our two agencies," said Alvaro Giménez, ESA’s Director of Science and Robotic Exploration.
In addition, NASA has nominated three U.S. science teams totaling 40 new members for the Euclid Consortium. This is in addition to 14 U.S. scientists already supporting the mission. The Euclid Consortium is an international body of 1,000 members who will oversee development of the instruments, manage science operations, and analyze data.
Euclid will map the dark matter in the universe. Matter as we know it -- the atoms that make up the human body, for example -- is a fraction of the total matter in the universe. The rest, about 85 percent, is dark matter consisting of particles of an unknown type. Dark matter first was postulated in 1932, but still has not been detected directly. It is called dark matter because it does not interact with light. Dark matter interacts with ordinary matter through gravity and binds galaxies together like an invisible glue.
While dark matter pulls matter together, dark energy pushes the universe apart at ever-increasing speeds. In terms of the total mass-energy content of the universe, dark energy dominates. Even less is known about dark energy than dark matter.
Euclid will use two techniques to study the dark universe, both involving precise measurements of galaxies billions of light-years away. The observations will yield the best measurements yet of how the acceleration of the universe has changed over time, providing new clues about the evolution and fate of the cosmos.
Euclid is an ESA mission with science instruments provided by a consortia of European institutes and with important participation from NASA. NASA's Euclid Project Office is based at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. JPL will contribute the infrared flight detectors for the Euclid science instrument. NASA's Goddard Space Flight Center in Greenbelt, Md., will test the infrared flight detectors prior to delivery. Three U.S. science teams will contribute to science planning and data analysis.
For more information about NASA, visit:
NASA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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