  Ground based low frequency radio interferometers have been developed in the
last decade and are providing the scientific community with high quality
observations. Conversely, current radioastronomy instruments in space have a
poor angular resolution with single point observation systems. Improving the
observation capabilities of the low frequency range (a few kHz to 100 MHz)
requires to go to space and to set up a space based network of antenna that can
be used as an interferometer.
  We present the outcome of the NOIRE (Nanosatellites pour un Observatoire
Interf\'erom\'etrique Radio dans l'Espace / Nanosatellites for a Radio
Interferometer Observatory in Space) study which assessed, with help of CNES
PASO (Architecture Platform for Orbital Systems is CNES' cross-disciplinary
team in charge of early mission and concept studies), the feasibility of a
swarm of nanosatellites dedicated to a low frequency radio observatory. With
such a platform, space system engineering and instrument development must be
studied as a whole: each node is a sensor and all sensors must be used together
to obtain a measurement. The study was conducted on the following topics:
system principle and concept (swarm, node homogeneity); Space and time
management (ranging, clock synchronization); Orbitography (Moon orbit, Lagrange
point options); Telecommunication (between nodes and with ground) and
networking; Measurements and processing; Propulsion; Power; Electromagnetic
compatibility.
  No strong show-stopper was identified during the preliminary study, although
the concept is not yet ready. Several further studies and milestones are
identified. The NOIRE team will collaborate with international teams to try and
build this next generation of space systems.
