A focal plane array of lens absorber coupled kinetic inductance detectors (KIDs) is proposed for future space-based far infrared astronomical observations. Designs at 6.98 THz and 12 THz are presented, and the design for 6.98 THz was fabricated as a hexagonal array of 25 detectors with a yield of 92%. Experimental results validated the expected 54% aperture efficiency of the lens absorbers averaged over two linear polarizations. The noise equivalent power of the KIDs was measured with limiting value of 8 × 10−20 W/√Hz at the bath and radiator temperatures of 130 mK and 2.7 K, respectively, under negligible optical loading.