Check the listing for details. U.S. Space Exploration - Mint condition United States postage stamps. Condition: New. Listed at 4.50 USD. For sale is a quality, mint condition, post office fresh group of 5 Space Exploration related US postage stamps. These stamps commemorate significant milestones and events in the United States space program. These stamps will be a fine addition to your Space Exploration collection or make a perfect gift for that 'hard to shop for' friend. They will also provide standout detail to any mail addressed to 'special' friends or Space Program historians. Originally issued on May 14, 1974, February 28 and April 4, 1975, July 20, 1978 and November 18, 1999, all of these stamps can still be used as valid United States Postal Service postage today. Multiple lots of these stamps may be purchased and will be sent with no additional postage charges. Your stamps will be enclosed in a protective glassine envelope and sent USPS First Class.