1976–1995 KH-11 Crystal Kennan Res: 0.15 m Mirror: 2.3 m First known digital imaging spy satellite. Thought possibly to be similar in size and overall layout to the Hubble Space Telescope. 1990―? KH-12 Ikon Improved Crystal Res: 0.15 to 0.10? m Mirror: 2.4 to 4? m Digital imaging; probably incorporates low light level visible and 3 to 5 micrometre infrared imaging capabilities; possible "live" intelligence gathering. 1999―? KH-13 8X? EIS? Res: 0.10? to 0.04? m (*) Mirror: 4? m Very little known; possibly includes radar imaging or maybe stealth technology.[citation needed]