How old is this article? Says 2021/2023, but: "The on-again off-again trip to Mars, originally scheduled for the 1970s, will very likely be too expensive for e

How old is this article? Says 2021/2023, but: "The on-again off-again trip to Mars, originally scheduled for the 1970s, will very likely be too expensive for either the United States or the Soviet Union to undertake alone."