The HelioSwarm mission was selected as a MIDEX mission by NASA in February 2022 for launchin 2029 with a nominal duration of 15 months. Its main objectives are to reveal the 3D spatialstructure and dynamics of turbulence in a weakly collisional plasma and to investigate the mutualimpact of turbulence near boundaries (e. g., Earth’s bow shock and magnetopause) and large-scalestructures evolving in the solar wind (e. g., coronal mass ejection, corotating interaction region).The HelioSwarm mission will also contribute to the space weather science and to a betterunderstanding of the Sun-Earth relationship. It consists of a platform (Hub) and eight smallersatellites (nodes) evolving along an elliptical orbit with an apogee ~ 60 and a perigee ~15 Earthradii. These 9 satellites, three-axis stabilised, will provide 36 pair combinations and 126 tetrahedralconfigurations covering the scales from 50~km (subion scale) to 3000 km (MHD scale). It will bethe first mission able to investigate the physical processes related to cross-scale couplings betweenion and MHD scales by measuring, simultaneously at these two scales, the magnetic field, iondensity and velocity variations. Thus each satellite is equipped with the same instrument suite. Afluxgate magnetometer (MAG from Imperial College, UK) and a search-coil magnetometer (SCM)provide the 3D measurements of the magnetic field fluctuations whereas a Faraday cup (FC, SAO,USA) performs the ion density and velocity measurements. In addition, the ion distribution functionis measured at a single point onboard the Hub by the iESA instrument, allowing to investigate theion heating in particular. The SCM for HelioSwarm provided by LPP and LPC2E is stronglyinherited of the SCM designed for the ESA JUICE mission. It will be mounted at the tip of a 3mboom and will cover the frequency range associated with the ion and subion scales in the near-Earthenvironment [0.1-16Hz] with the following sensitivities [15pT/√Hz at 1 Hz and 1.5 pT/√Hz at 10Hz]. The iESA, developped by IRAP and LAB, is inherited from the PAS instrument operating onthe ESA Solar Orbiter mission. It will provide the ion distribution function at high time and angularresolutions, respectively 0.150 s and 3°. Furthermore the energy range will be ~200 eV to 20 keVwith 8% energy resolution. Status of the development of SCM and iESA prototypes will bepresented.< Réduire