The head of Russia’s space agency, Roscosmos, is again threatening to end service to the International Space Station, saying Russia will stop supplying rocket engines to the United States and may curtail cooperation on the station in retaliation for Western sanctions against Russia for the invasion of Ukraine. NASA says operations on the orbiting observatory are normal.   In an interview with Russian state television Thursday, Roscosmos chief Dmitry Rogozin said, considering the situation, “We can’t supply the United States with our world’s best rocket engines. Let them fly on …

The U.N. children’s agency says it is procuring nearly seven million doses of polio vaccine to inoculate children in Malawi. The action follows a confirmed polio case last month in Malawi’s capital, the first reported in Africa in five years and the first in Malawi in decades.   Malawi had last reported a polio case in 1992. The country was declared polio-free in 2005 — 15 years before the African continent as a whole was declared polio-free.   But health experts said the polio strain which paralyzed a three-year-old child …

Even before Russian forces shelled the Zaporizhzhia nuclear power plant, sparking a fire in a nearby building early Friday, Ukraine’s main nuclear regulatory agency had sought “immediate assistance” from the international nuclear agency. International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi said Wednesday he had received a letter from the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU) asking for “immediate assistance to ensure the safety of the Chernobyl Nuclear Power Plant and other nuclear facilities in the country.” Grossi said the IAEA had begun consultations on the request. …