This paper presents the scientific objectives and technical aspects of the balloon-borne Experiment for Large Infrared Survey Astronomy (ELISA). The emphasis is put upon the synergies existing between the ELISA project and future space missions, both with respect to scientific and technical aspects. ELISA is a small balloon project for an experiment dedicated to measure the Far-Infrared to Sub-millimeter continuum emission of Galactic dust over a large fraction of the sky, with unprecedented sensitivity and angular resolution. The primary mirror of the telescope, similar to the one used for the Top-Hat mission, will have a diameter of 1 m, ensuring an angular resolution of about 3.5'. Bolometer arrays will be used in four photometric bands centered at 170, 240, 400, and 650 μm and providing a 22' × 45' instantaneous field of view per channel. A liquid He cryostat will host the cold optics, including the secondary mirror of the telescope, as well as the detectors, which will be cooled to 0.3 K using an 3He close-cycle fridge. Mapping of the sky will be accomplished by rotating the gondola over a large azimuth range (up to 60° amplitude). The pointing of the experiment will be maintained to a constant elevation during the azimuth scans through a feed back loop using the signal from a large format, fast stellar sensor, operating day and night. The scientific goal of the experiment is to map the diffuse Sub-millimeter emission along a large fraction of the Milky Way. The astronomical data obtained will be used to derive the emission properties of the dust grains in the Interstellar Medium (ISM), such as their temperature and emissivity. It will also allow to systematically measure the polarization of the dust emission. It should also lead to the detection of a few thousand point sources such as newly formed stars and distant galaxies. In addition to these goals, the ELISA project will serve as a test bed for the detector technology that will be used for the HERSCHEL space mission to be launched in 2007. The ELISA data will be made available to help calibrate the observations of HERSCHEL and PLANCK and to plan the large-scale surveys to be undertaken with HERSCHEL. Owing to these objectives, 3 flights of the ELISA experiment, are foreseen in the period from 2004 to 2006. The ELISA project is carried out by an international collaboration including France (CESR, IAS, CEA, CNES), The Netherlands (SSD/ESTEC), Denmark (DSRI), UK (Cardiff Univ.).