1 Sputnik 1, the first artificial satellite to go into orbit, launched 4 October 1957. 2  Sputnik 2, the first spacecraft to carry a living animal (the dog Laika), launched 3 November 1957.  Sputnik 3, a research satellite launched 15 May 1958.
By population the 3 largest cities in Spain are Madrid 2.9 million, Barcelona 1.5 million, and Valencia 741,000. They include: the capital Madrid, Barcelona and Valencia. Onlyâ¦ two  of Spain's cities, the national capital Madrid and Barcelona, have  populations of more than one million.
Historically part of Castile, Madrid today is its own autonomous region, and the most densely populated area in Spain. The Spanish metropolitan area is home to about 6 million people, and is a bustling and prosperous area, with a strong serviced-based economy. The area has seen massive development in the past decades.