This paper presents current status of lossless compression of ultraspectral sounder data. The lossless compression results from the transform-based (e.g. JPEG2000, 3D SPIHT, and Lossless PCA), prediction-based (e.g. JPEG-LS, CALIC, and linear prediction using OOMP), and clustering-based (e.g. PVQ, DPVQ, PPVQ and FPVQ) methods are presented. The ultraspectral sounder data features strong correlations in disjoint spectral regions affected by the same type of absorbing gases. Some robust data preprocessing scheme (e.g. BAR) is also demonstrated to improve compression gains of existing state-of-the-art compression methods such as JPEG2000, 3D SPIHT, JPEG-LS, and CALIC.