A Russian cargo spacecraft undocked from the International Space Station Tuesday for a weeklong test of its engines in the ionosphere, officials said.

Following the tests in the ionosphere, which reaches from 50 to 250 miles above Earth, the Progress M-19M spacecraft will be deorbited June 19, they said, and "buried" in the Pacific Ocean, RIA Novosti reported.

The unmanned cargo craft arrived at the space station April 26 with more than 2.5 tons of cargo, including food, water and oxygen for the station crew.

Its departure from the station freed up a docking port so the European ATV-4 cargo craft, which launched from the Kourou space center in French Guiana June 5, can join with the ISS June 15.

The next Russian cargo spacecraft, Progress M-20M, is scheduled to launch July 28 from the Baikonur space center in Kazakhstan, sources in the Russian space industry told RIA Novosti.