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Showing posts with label Satellite. Show all posts
Showing posts with label Satellite. Show all posts

Friday, 23 September 2011

North America Safe From NASA's Doomed 6.5-Ton Satellite

A dead NASA satellite will plummet to Earth will on Friday (Sept. 23), and while the U.S. space agency doesn't know exactly where pieces of the massive spacecraft will hit, one thing is certain: North America is in the clear.


NASA's Upper Atmosphere Research Satellite, or UARS, is set to make an uncontrolled re-entry into Earth's atmosphere on Friday. However, it is still too early to tell exactly where the 6.5-ton spacecraft will fall. Scientists will likely have a much better idea of where the debris will land about two hours before the impact, NASA officials said.


But, NASA was able to rule out North America as being in the potential debris drop zone. 


Track NASA's falling satellite in our exclusive online tracker in real-time.


"Re-entry is expected sometime during the afternoon of Sept. 23, Eastern Daylight Time," agency officials said in a statement. "The satellite will not be passing over North America during that time period. It is still too early to predict the time and location of re-entry with any more certainty, but predictions will become more refined in the next 24 to 48 hours."


In the meantime, NASA and the U.S. Air Force will be closely monitoring the satellite and its decaying orbit.


"With re-entry we're always interested in day-by-day and hour-by-hour details," Mark Matney, a scientist with NASA's Orbital Debris Program Office, told SPACE.com. "It's very difficult to predict how it's going to happen. With our models, we try to figure out what parts of the spacecraft — what materials — will interact with the atmosphere in terms of temperature and melting, and determine which of those will survive. But it's a very dynamic environment, the force is very intense." [Photos of NASA's Huge Falling Satellite UARS]


 


Wide range of possibilities


Current predictions of the potential impact zone cover a giant swath of the planet — anywhere between the latitudes of northern Canada and southern South America. Scientists will be able to refine these projections as the spacecraft makes its fiery journey through the atmosphere.


"It's partly a matter of not knowing enough," said Ray Williamson, executive director of the Secure World Foundation, an organization dedicated to the peaceful use of outer space. "The shape of the structure is not perfectly spherical, so when it heats up and starts to break up, it will break into odd pieces. Once it begins to break up, then they can get a better sense of where this is roughly going to hit."


Scientists at NASA's Orbital Debris Program Office estimate that at least 26 large pieces of the bus-size satellite will endure the scorching heat of re-entry. Approximately 1,170 pounds (532 kilograms) of material are expected to reach the ground, NASA officials said.


These pieces of debris will likely be scattered over a 500-mile (804-kilometer) long path. But agency officials have been quick to stress that there is very little chance that satellite chunks will smash intotowns or cities. [Amateur Astronomer Photographs Doomed Satellite]


Instead, it's much more likely that the debris will fall over water or remote, uninhabited areas, NASA officials said.


"There's always a concern," Matney said. "But, populated areas are a small fraction of the Earth's surface. Much of the Earth's surface has either no people or very few people. We believe that the risk is very modest."


Odds of human injury very low


For comparison, when NASA's space shuttle Columbia tragically broke apart during re-entry in 2003, debris from the 100-ton spacecraft was scattered across Texas, but did not damage any structures or injure any people.


"When [Columbia] came back, as the shuttle heated up, it broke into pieces — some of them very large, and some very small," Williamson said. "Even then, there was difficulty in trying to find the pieces that were spread over such a large area. It was such an unpopulated area that it was very difficult to locate all the pieces, even though they knew from videos pretty much precisely the track that it followed across the atmosphere."


 


NASA has calculated the odds of anyone anywhere in the world being hit by a piece of the UARS satellite at 1in3,200. But, the chance that you personally will get hit is much more remote, on the order of 1inseveral trillion, Williamson said.


Still, if anyone happens to stumble upon a piece of the defunct satellite on the ground, agency officials stress that for safety and legal reasons, it is best to leave the material where it is, and alert the authorities.


"If you find something you think may be a piece of UARS, do not touch it," NASA officials said. "Contact a local law enforcement official for assistance."


- Photos: Space Debris Images & Cleanup Concepts


- Video: Crashing Satellite's Debris Region Predicted: 500 Miles of Possibilities


- Worst Space Debris Events of All Time


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Tuesday, 20 September 2011

Secret Cold War Spy Satellite Program Declassified, Finally Revealed

CHANTILLY, Va. –  Twenty-five years after their top-secret, Cold War-era missions ended, two clandestine American satellite programs were declassified Saturday (Sept. 17) with the unveiling of three of the United States' most closely guarded assets: the KH-7 GAMBIT, the KH-8 GAMBIT 3 and the KH-9 HEXAGON spy satellites.


The vintage National Reconnaissance Office satellites were displayed to the public Saturday in a one-day-only exhibit at the Smithsonian National Air and Space Museum's Udvar-Hazy Center at Dulles Airport, Va. The three spacecraft were the centerpiece of the NRO's invitation-only, 50th Anniversary Gala celebration held at the center last evening.


Saturday's spysat unveiling was attended by a number of jubilant NRO veterans who developed and refined the classified spacecraft and its components for decades in secret, finally able to show their wives and families what they actually did 'at the office' for so many years. Both of the newly declassified satellite systems, GAMBIT and HEXAGON, followed the U.S. military's frontrunner spy satellite system CORONA, which was declassified in 1995. [See photos of the declassified U.S. spy satellites]


Big spy satellites revealed


The KH-9 HEXAGON, often referred to by its popular nickname "Big Bird," lived up to its legendary expectations. As large as a school bus, the KH-9 HEXAGON carried 60 miles of high resolution photographic film for space surveillance missions. 


Military space historian Dwayne A. Day was exuberant after his first look at the KH-9 HEXAGON.


"This was some bad-ass technology," Day told SPACE.com. "The Russians didn't have anything like it."


Day, co-editor of "Eye in the Sky: The Story of the CoronaSpy Satellites," noted that "it took the Soviets on average five to 10 years to catch up during the Cold War, and in many cases they never really matched American capabilities."


Phil Presser, designer of the HEXAGON's panoramic 'optical bar' imaging cameras, agreed with Day's assessment.


"This is still the most complicated system we've ever put into orbit …Period."


The HEXAGON's twin optical bar panoramic mirror cameras rotated as the swept back and forth as the satellite flew over Earth, a process that intelligence officials referred to as "mowing the lawn."


Each 6-inch wide frame of HEXAGON film capturing a wide swath of terrain covering 370 nautical miles — the distance from Cincinnati to Washington — on each pass over the former Soviet Union and China. The satellites had a resolution of about 2 to 3 feet (0.6 to nearly 1 meter), according to the NRO. [10 Ways the Government Watches You]


According to documents released by the NRO, each HEXAGON satellite mission lasted about 124 days, with the satellite launching four film return capsules that could send its photos back to Earth. An aircraft would catch the return capsule in mid-air by snagging its parachute following the canister's re-entry.


In a fascinating footnote, the film bucket from the first KH-9 HEXAGON sank to the bottom of the Pacific Ocean in spring 1972 after Air Force recovery aircraft failed to snag the bucket's parachute.


The film inside the protective bucket reported contained high resolution photographs of the Soviet Union's submarine bases and missile silos. In a daredevil feat of clandestine ingenuity, the U.S. Navy's Deep Submergence Vehicle Trieste II succeeded in grasping the bucket from a depth of 3 miles below the ocean.


Hubble vs. HEXAGON


Former International Space Station flight controller Rob Landis, now technical manager in the advanced projects office at NASA's Wallops Flight Facility in Virginia, drove more than three hours to see the veil lifted from these legendary spacecraft.


Landis, who also worked on NASA's Hubble Space Telescope program, noticed some distinct similarities between Hubble and the huge KH-9 HEXAGON reconnaissance satellite.


"I see a lot of Hubble heritage in this spacecraft, most notably in terms of spacecraft size," Landis said. "Once the space shuttle design was settled upon, the design of Hubble — at the time it was called the Large Space Telescope — was set upon. I can imagine that there may have been a convergence or confluence of the designs. The Hubble’s primary mirror is 2.4 meters [7.9 feet] in diameter and the spacecraft is 14 feet in diameter. Both vehicles (KH-9 and Hubble) would fit into the shuttle's cargo bay lengthwise, the KH-9 being longer than Hubble [60 feet]; both would also fit on a Titan-class launch vehicle."


The 'convergence or confluence' theory was confirmed later in the day by a former spacecraft designer, who declined to be named but is familiar with both programs, who confided unequivocally: "The space shuttle's payload bay was sized to accommodate the KH-9."  [Infographic: NASA's Space Shuttle from Top to Bottom]


The NRO launched 20 KH-9 HEXAGON satellites from California's Vandenberg AFB from June 1971 to April 1986.


The HEXAGON's final launch in April 1986 — just months after the space shuttle Challenger explosion — also met with disaster as the spy satellite's Titan 34D booster erupted into a massive fireball just seconds after liftoff, crippling the NRO's orbital reconnaissance capabilities for many months.


The spy satellite GAMBIT


Before the first HEXAGON spy satellite systems ever launched, the NRO's GAMBIT series of reconnaissance craft flew several space missions aimed at providing surveillance over specific targets around the world.


The  satellite program's initial system, GAMBIT 1, first launched in 1963 carrying a KH-7 camera system that included a "77-inch focal length camera for providing specific information on scientific and technical capabilities that threatened the nation," according to an NRO description. A second GAMBIT satellite system, which first launched aboard GAMBIT 3 in 1966, included a175-inch focal length camera. [Related: Anatomy of a Spy Satellite]


The GAMBIT 1 series satellite has a resolution similar to the HEXAGON series, about 2 to 3 feet, but the follow-up GAMBIT 3 system had an improved resolution of better than 2 feet, NRO documents reveal.


The GAMBIT satellite program was active from July 1963 to April 1984. Both satellites were huge and launched out of Vandenberg Air Force Base.


The satellite series' initial version was 15 feet (4.5 m) long and 5 feet (1.5 m) wide, and weighed about 1,154 pounds (523 kilograms). The GAMBIT 3 satellite was the same width but longer, stretching nearly 29 feet (9 m) long, not counting its Agena D rocket upper stage. It weighed about 4,130 pounds (1,873 kg).


Unlike the follow-up HEXAGON satellites, the GAMBIT series were designed for extremely short missions.


The GAMBIT 1 craft had an average mission life of about 6 1/2 days. A total of 38 missions were launched, though 10 of them were deemed failures, according to NRO documents.


The GAMBIT 3 series satellites had missions that averaged about 31 days. In all, 54 of the satellites were launched, with four failures recorded.


Like the CORONA and HEXAGON programs, the GAMBIT series of satellites returned their film to Earth in re-entry capsules that were then snatched up by recovery aircraft. GAMBIT 1 carried about 3,000 feet (914 meters) of film, while GAMBIT 3 was packed with 12,241 feet (3,731 meters) of film, NRO records show.


The behemoth HEXAGON was launched with 60 miles (320,000 feet) of film!


HEXAGON and GAMBIT 3 team up


During a media briefing, NRO officials confirmed to SPACE.com that the KH-8 GAMBIT 3 and KH-9 HEXAGON were later operated in tandem, teaming-up to photograph areas of military significance in both the former Soviet Union and China.


The KH-9 would image a wide swath of terrain, later scrutinized by imagery analysts on the ground for so-called ‘targets of opportunity.' Once these potential targets were identified, a KH-8 would then be maneuvered to photograph the location in much higher resolution.


"During the era of these satellites — the GAMBIT and the HEXAGON — there was a Director of Central Intelligence committee known as the 'Committee on Imagery Requirements and Exploitation' that was responsible for that type of planning," confirmed the NRO's Robert McDonald, Director of the Center for the Study of National Reconnaissance.


NASA's Rob Landis was both blunt and philosophical in his emotions over the declassification of the GAMBIT and HEXAGON programs.


"You have to give credit to leaders like President Eisenhower who had the vision to initiate reconnaissance spacecraft, beginning with the CORONA and Discoverer programs," Landis said. "He was of the generation who wanted no more surprises, no more Pearl Harbors." 


"Frankly, I think that GAMBIT and HEXAGON helped prevent World War III."


  *   Gallery: Declassified US Spy Satellite Photos & Designs
  *   7 Sci-Fi Weapons of Tomorrow Here Today 
  *   Top 10 Space Weapons


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6.5-Ton Defunct Satellite Falling to Earth Faster Than Expected, NASA Says

NASA space junk experts have refined the forecast for the anticipated death plunge of a giant satellite, with the U.S. space agency now predicting the 6 1/2-ton climate probe will plummet to Earth around Sept. 23, a day earlier than previously reported.


The defunct bus-size spacecraft is NASA's Upper Atmospheric Research Satellite (UARS), which launched in 1991 and was shut down in 2005 after completing its mission. The satellite was expected to fall to Earth sometime this year, with experts initially pegging a weeks-long window between late September and early October, then narrowing it to the last week of this month.


That window, NASA now says, has been trimmed to just three days.


"Re-entry is expected Sept. 23, plus or minus a day. The re-entry of UARS is advancing because of a sharp increase in solar activity since the beginning of this week," NASA officials wrote in a status update today (Sept. 16). The projection is a day earlier than a previous forecast released by NASA yesterday.


NASA spokeswoman Beth Dickey confirmed with SPACE.com earlier today that the reason UARS is expected to fall early in its re-entry window is because of the sharp uptick in solar activity. Solar effects from the sun can create an extra drag on satellites in space because they can heat the Earth's atmosphere, causing it to expand, agency officials have said. [Photos: Space Debris & Cleanup Concepts]


Where will UARS fall?


But exactly where the UARS spacecraft will fall is still unknown.


NASA expects at least 26 large pieces of the massive satellite to survive the scorching temperatures of re-entry and reach Earth's surface. Titanium pieces and onboard tanks could be among that debris, but the UARS satellite carries no toxic propellant (NASA used up all the fuel in 2005).


The debris is expected to fall over a swath of Earth about 500 miles (804 kilometers) long, NASA officials said. [Video: Where Could UARS Satellite Debris Fall?]


There is a 1-in-3,200 chance of satellite debris hitting a person on the ground, odds that NASA says are extremely remote. Outside experts agree.


"Look at how much of Earth is covered with water," Victoria Samson, the Washington Office Director of the Secure World Foundation, an organization dedicated to the peaceful use of outer space, told SPACE.com this week. "There's a really good chance it's going to go straight into the ocean."


Constant satellite watch


NASA officials expect the UARS satellite to fall over a region somewhere between the latitudes of northern Canada and southern South America, which leaves a vast swath of the world open as a possible re-entry point. About 75 percent of the Earth's surface is covered in water, which makes an ocean splashdown likely, NASA and experts have said.


NASA and the Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base, Calif., are keeping a close watch on the falling satellite, but will only be able to pinpoint its actual crash zone to within about 6,000 miles (10,000 km) about two hours before re-entry.


As of Thursday, the UARS satellite was flying in an orbit of between 143 and 158 miles (230 to 255 km) above Earth. That orbit is dropping lower each day, NASA officials said. [Infographic: NASA's Falling UARS Satellite Explained]


NASA has advised the public not to touch any debris that may reach the surface, should it be discovered. Instead, the space agency says that anyone who finds satellite debris should contact their local law enforcement agency.


The $750 million UARS mission was designed to measure ozone and other chemical compounds found in Earth's ozone layer in order to better understand how the upper atmosphere affects our planet. It also recorded wind speeds and temperatures in the stratosphere, as well as the energy Earth received from the sun.


To follow NASA's UARS satellite updates, click here.


  *   Worst Space Debris Events of All Time
  *   Fear of Ozone Loss Launched UARS Satellite
  *   Falling Space Junk: The Facts About NASA's Doomed UARS Satellite


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