Current hyperspectral imagers are either bulky with good performance, or compact with only moderate performance. This paper presents a new hyperspectral technology which overcomes this drawback, and makes it possible to integrate extremely compact and high performance push-broom hyperspectral imagers for Unmanned Aerial Vehicles (UAV) and other demanding applications. Hyperspectral imagers in VIS/NIR, SWIR, MWIR and LWIR spectral ranges have been implemented. This paper presents the measured performance attributes for a VIS/NIR imager which covers 350 to 1000 nm with spectral resolution of 3 nm. The key innovation is a new imaging spectrograph design which employs both transmissive and reflective optics in order to achieve high light throughput and large spatial image size in an extremely compact format. High light throughput is created by numerical aperture of F/2.4 and high diffraction efficiency. Image distortions are negligible, keystone being <2 um and smile 0.13 nm across the full focal plane image size of 24 mm (spatially) x 6 m (spectrally). The spectrograph is integrated with an advanced camera which provides 1300 spatial pixels and image rate of 160 Hz. A higher resolution version with 2000 spatial pixels will produce up to 100 images/s. The camera achieves, with spectral binning, an outstanding signal-to-noise ratio of 800:1, orders of magnitude higher than any current compact VIS/NIR imager. The imager weighs only 1.4 kg, including fore optics, imaging spectrograph with shutter and camera, in a format optimized for installation in small payload compartments and gimbals. In addition to laboratory characterization, results from a flight test mission are presented.