MOSCOW , Russia ( CNN ) -- Two satellites , one Russian and one American , have collided some 800 kilometers ( 500 miles ) above Siberia , the Russian and U.S. space agencies , said Thursday . Debris from the collision poses no threat to the International Space Station . The collision on Tuesday produced two large debris clouds , NASA said . The satellites collided at 10 kilometers ( 6 miles ) per second , producing 500-600 new pieces of space debris , the U.S. Strategic Command said . That debris is not believed to pose a threat to the International Space Station as long as the clouds continue moving in a lower orbit , according to NASA and the Russian federal space agency , Roscosmos . `` There is some elevated risk , but it is considered to be very small to the ISS and to the other satellites that NASA has in orbit , '' NASA spokeswoman Beth Dickey told CNN . She said experts were still assessing the effects of the debris . Mikhail Martirosov , from Russian mission control center , told Interfax news agency that the real threat from the debris will become obvious next week , once experts can calculate the trajectory of the fragments ' descent . `` We have not received a warning of the possible danger to the ISS . The fragments may descend to the ISS orbit in several years , although I do not rule out that some fragments may go down within several days , '' Martirosov said . The Russian satellite was launched in 1993 and had been out of service at the time of the collision , Roscosmos said . The U.S. satellite was part of the Iridium global mobile communications system and is owned by a consortium headed by Motorola , the space agency said . It was launched in 1997 . Iridium said in a statement Wednesday it `` expects to implement a network solution by Friday , '' and will `` move one of its in-orbit spare satellites into the network constellation to permanently replace the lost satellite '' within the next 30 days . CNN is `` one of the larger non-government users '' of Iridium , said Arnie Christianson , operations manager for CNN Satellites and Transmission . `` We do rely on it for communication in high-risk areas like Iraq , Afghanistan , and other remote locations , '' he said . `` Because of this collision , there may be a slightly longer hole in the coverage from one satellite to the next , but only in a very small area and for a very small amount of time . This is a collision , not an internal failure of the satellite or the system . '' The satellite crash may result in `` brief , occasional outages '' that may slightly disrupt service , Iridium said in the statement , adding `` this event is not the result of a failure on the part of Iridium or its technology . '' Christianson questioned how U.S. government , which tracks all space junk larger than a football , did n't see this coming . But he said the system will continue to work without any noticeable problems . A representative of Iridium could not immediately be reached for comment . NASA 's Dickey said a collision like this one is very rare . `` This is the first impact between two intact satellites traveling at hypervelocity , '' she said . `` There have been some other occasions when things have accidentally collided in space , but they have been parts of rockets or parts of satellites and ( produced ) a very small cloud . '' Major Regina Winchester , of the U.S. Strategic Command , said : `` Space is getting pretty crowded . The fact that this has n't happened before -- maybe we were getting a little bit lucky . '' Winchester said Strategic Command tracks more than 18,000 pieces of manmade objects in space every day . `` Any time there 's an event that creates more debris , it 's a concern , '' she said . `` All countries who have assets in space are going to be concerned simply because when there 's more debris , there 's a higher chance it 's going to hit something . '' CNN 's Yuri Pushkin in Moscow and Melissa Gray in London contributed to this report .
One Russian and one U.S. satellite collide at 10 km per second . Score: 7 NASA spokesman quoted as saying crash produced massive debris cloud . Wreckage from collision expected to burn up in the Earth 's atmosphere .