As of 29 February 2016, 124 countries were contributing a total of 105,314 personnel in Peacekeeping Operations, with Ethiopia leading the tally (8,324), followed by India (7,695) and Bangladesh (7,525). In June 2013. Pakistan contributed the highest number overall with 8,186 personnel, followed by India (7,878), Bangladesh (7,799), Ethiopia (6,502), Rwanda (4,686), Nigeria (4,684), Nepal (4,495), Jordan (3,374), Ghana (2,859), and Egypt (2,750). As of 28 February 2015, 120 countries were contributing a total of 104,928 personnel in Peacekeeping Operations, with Bangladesh leading the tally (9446). As of March 2008, in addition to military and police personnel, 5,187 international civilian personnel, 2,031 UN Volunteers and 12,036 local civilian personnel worked in UN peacekeeping missions.
The Soviet Union suffered greatly in the war, losing around 27 million people. Approximately 2.8 million Soviet POWs died of starvation, mistreatment, or executions in just eight months of 1941 -- 42. During the war, the Soviet Union together with the United States, the United Kingdom and China were considered as the Big Four of Allied powers in World War II and later became the Four Policemen which was the foundation of the United Nations Security Council. It emerged as a superpower in the post-war period. Once denied diplomatic recognition by the Western world, the Soviet Union had official relations with practically every nation by the late 1940s. A member of the United Nations at its foundation in 1945, the Soviet Union became one of the five permanent members of the United Nations Security Council, which gave it the right to veto any of its resolutions.
During the Middle Ages, the Eritrea region was known as Medri Bahri ("sea-land"). The name Eritrea is derived from the ancient Greek name for Red Sea (Ἐρυθρὰ Θάλασσα Erythra Thalassa, based on the adjective ἐρυθρός erythros "red"). It was first formally adopted in 1890, with the formation of Italian Eritrea (Colonia Eritrea). The territory became the Eritrea Governorate within Italian East Africa in 1936. Eritrea was annexed by Ethiopia in 1953 (nominally within a federation until 1962) and an Eritrean Liberation Front formed in 1960. Eritrea gained independence following the 1993 referendum, and the name of the new state was defined as State of Eritrea in the 1997 constitution.[citation needed]
Sputnik 1 (/ ˈspʊtnɪk / or / ˈspʌtnɪk /; ``Satellite - 1 '', or`` PS - 1'', Простейший Спутник - 1 or Prosteyshiy Sputnik - 1, ``Elementary Satellite 1 '') was the first artificial Earth satellite. The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957, orbiting for three weeks before its batteries died, then silently for two more months before falling back into the atmosphere. It was a 58 cm (23 in) diameter polished metal sphere, with four external radio antennas to broadcast radio pulses. Its radio signal was easily detectable even by radio amateurs, and the 65 ° inclination and duration of its orbit made its flight path cover virtually the entire inhabited Earth. This surprise success precipitated the American Sputnik crisis and triggered the Space Race, a part of the Cold War. The launch ushered in new political, military, technological, and scientific developments.

Question: The us and country building the first satellite to orbit earth became important members in an organization. When was Eritrea annexed by the country being the largest troop contributor to this organization's peace keeping mission?
Answer: 1953