"800 kilometers is a very popular orbit for remote Earth sensing and telecommunications satellites," said Vladimir Solovyov, head of the Russian segment of the International Space Station.
"There are a lot of communications satellites there, many of them still in operation. There are 66 Iridium series satellites alone on that orbit. The cloud [of debris] from the collision is a serious threat to them," he said
Tuesday's collision of a U.S. Iridium satellite and the defunct Russian Cosmos-2251 approximately 800 kilometers (500 miles) above Siberia was the first time such an incident has occurred.