Sara Faggi Despite its moderate size (3 m), several features define the NASA/IRTF as a powerful facility for observing comets: 1. the ability to guide on sources during daytime, 2. The ability to observe at small solar elongation, and 3. the fact that 50% of the entire observing time is allocated for observations of Planetary System objects, and especially 4. the new near-IR high resolution immersion echelle spectrograph (iSHELL) that provides improved sensitivity and larger spectral coverage per setting compared with other available instruments. In April 2017, we acquired comprehensive high-resolution spectra of the newly-discovered Target-of-Opportunity comet C/2017 E4 (Lovejoy) as it approached perihelion, and just before its disintegration. The bright Oort cloud comet E4 Lovejoy combined with the new capabilities of iSHELL provided unique results. We detected many cometary emission lines across four customized instrument settings (L, L3, Lp1 and M1) in the (1.1 – 5.2) um range. The individual iSHELL settings cover very wide spectral ranges with very high accuracy, allowing simultaneous sampling of molecules and eliminating many sources of systematic errors when retrieving molecular abundances. The prompt response to ToO and DDT requests allows efficient sampling of a significant population of newly-discovered comets from the Oort cloud. This permits the comparison of cometary compositions to assess cometary delivery of organic compounds to the early Earth, in order to address the origin of water and organics on Earth.