{"id":16645,"date":"2015-01-22T17:39:53","date_gmt":"2015-01-22T09:39:53","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/did-two-more-iridium-satellites-collide-with-space-debris\/"},"modified":"2015-01-22T17:39:53","modified_gmt":"2015-01-22T09:39:53","slug":"did-two-more-iridium-satellites-collide-with-space-debris","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/did-two-more-iridium-satellites-collide-with-space-debris\/","title":{"rendered":"Did two more Iridium satellites collide with space debris?"},"content":{"rendered":"
\"Credit:
An Iridium satellite on display at the Smithsonian Institution\u2019s National Air and Space Museum in Washington, D.C. Credit: Image by Eric Long, National Air and Space Museum, Smithsonian Institution<\/figcaption><\/figure>\n

Two mystifying incidents last year involving separate Iridium communications satellites have experts wondering whether the spacecraft collided with tiny fragments of space junk.<\/p>\n

Both satellites kept operating after inexplicably shedding debris, puzzling engineers who are concerned about the population of small objects in orbit that cannot be tracked by the U.S. Air Force\u2019s network of sensitive radars and cameras.<\/p>\n

Both events \u201cillustrate how mysterious many of the debris phenomena in Earth orbit still remain,\u201d according to an article in a quarterly report published by NASA\u2019s Orbital Debris Program Office at the Johnson Space Center in Houston.<\/p>\n

The U.S. Joint Space Operations Center detected 10 pieces of debris from the Iridium 47 satellite June 7, 2014. Some of the objects flew away from Iridium 47 at up to 80 meters per second \u2014 nearly 180 mph \u2014 into orbits almost 200 miles above the satellite, suggesting an explosion or collision triggered their creation.<\/p>\n

Another Iridium spacecraft \u2014 Iridium 91 \u2014 produced four debris fragments Nov. 30, according to U.S. military tracking data.<\/p>\n

\u201cIn contrast to the previous Iridium breakup, however, these pieces were produced with minimal delta velocity and remained in the vicinity to the parent spacecraft for some time,\u201d NASA officials wrote.<\/p>\n

In both cases, the satellites showed no signs of a breakup and remain operational, according to Iridium Communications, a Virginia-based company that uses a fleet of spacecraft nearly 500 miles above Earth for mobile voice and data services.<\/p>\n

\"Artist's
Artist\u2019s concept of the distribution of space debris in Earth orbit based on actual density data. The sizes of each object are exaggerated to make them visible. Credit: European Space Agency<\/figcaption><\/figure>\n

NASA\u2019s orbital debris experts said strikes from small bits of space junk could have caused either or both incidents. It is possible that Iridium 91, which generated less debris at slower speeds \u2014 may have cast off chunks of thermal insulation, according to the orbital debris report.<\/p>\n

\u201cThe Iridium 47 event, however, clearly was due to some sort of high-energy event,\u201d NASA experts wrote. \u201cIn the absence of evidence of an explosion on board the spacecraft, a collision with a piece of untracked debris is the most likely culprit.\u201d<\/p>\n

At orbital speeds, an impact with a sizable piece of space junk can be catastrophic.<\/p>\n

If something hit one of the satellites, it would not be the first time an Iridium spacecraft had a run-in with space junk.<\/p>\n

The Iridium 33 spacecraft collided with a dead Russian military satellite in February 2009, destroying both craft and polluting busy space traffic lanes with thousands of new pieces of debris in low Earth orbit.<\/p>\n

The Iridium constellation is located at the same altitude as much of the debris left over from the 2009 crash and a Chinese anti-satellite weapons test that littered Earth orbit with another set of satellite shards in 2007.<\/p>\n

Iridium operates the largest network of commercial satellites in orbit, with 66 interconnected spacecraft to beam global phone calls and data transfers between the company\u2019s customers, which include military troops, ships at sea, media organizations, and transport companies.<\/p>\n

\"A
A diagram of Iridium\u2019s global satellite constellation. Credit: Iridium<\/figcaption><\/figure>\n

Since the 2009 collision, the Air Force has disseminated warnings of possible satellite conjunctions \u2014 or close flybys \u2014 with commercial and international satellite operators, providing the owners a chance to maneuver operational spacecraft out of the way and avoid another collision.<\/p>\n

The U.S. military\u2019s radars and optical sensors can see anything larger than a basketball, or about 23,000 objects in orbit, less than 5 percent of the total number of tiny junk fragments believed to be circling Earth.<\/p>\n

The holes in coverage mean small bits of space debris roam undetected.<\/p>\n

The Air Force and Lockheed Martin are working on a modernized tracking system called the Space Fence, which will detect objects as small as a softball at an altitude of 1,200 miles, giving officials the ability to monitor more than 200,000 satellites, derelict rockets, and other manmade debris.<\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/i><\/b><\/p>\n","protected":false},"excerpt":{"rendered":"

An Iridium satellite on display at the Smithsonian Institution\u2019s National Air and Space Museum in Washington, D.C. Credit: Image by Eric Long, National Air and Space Museum, Smithsonian Institution Two mystifying incidents last year involving separate Iridium communications satellites have experts wondering whether the spacecraft collided with tiny fragments of space junk. Both satellites kept […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[530,2681,79,4180],"class_list":["post-16645","post","type-post","status-publish","format-standard","hentry","category-news","tag-iridium","tag-jspoc","tag-space-debris","tag-space-junk"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16645"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=16645"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16645\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=16645"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=16645"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=16645"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}