The objective of this activity is to develop radiation tolerant platform technologies and semi-autonomous orbit transfer capabilityfor small satellite platforms. An experimental small satellite will be designed, manufactured and launched. The satellite will feature the platform technologies developed as well as a simple telecommunication payload allowing experiments during orbit raising to GEO as well as in GSO. Targeted Improvements: Enabling self-transfer capability of small satellites to GEO to unlock potential commercial applications not yet exploited. Description: There is a significant challenge in reaching Geostationary Earth Orbit (GEO) withsmall satellites. Only few launch opportunities exist reaching GEO directly and the delivery cost to GEO is significant. An alternative mission concept is to place the spacecraft in Low Earth Orbit (LEO) or Geo Transfer Orbit (GTO) and then raise its orbit to GEOwith the help of a propulsive stage. Current propulsion technologies for small satellites favour electric propulsion, which resultsin transit times of 6-12 months. During this time, the satellite crosses the Van Allen belts and is exposed to a significant dosageof radiation. However, current small satellite platforms are not designed for this level of radiation exposure. Another aspect is guidance, navigation and control (GNC) of the satellite during the orbit transfer. Today, manoeuvres are performed with involvement of ground operational teams that receive GNSS measurements, compute the manoeuvres, upload the manoeuvre profile, assess the performances and decide if more manoeuvres are needed. This GNC concept used today is not compatible with the targeted mission costs for commercial smallsat missions. Hence, this activity will develop and test radiation tolerant platform technologies and a semi-autonomous GNC concept for orbit transfer. The activity will design a robust and scalable (up to 200 kg) small satellite platform with a wetof mass of up to 30 kg using a clean sheet approach. The activity will develop the following technologies for small satellites not availabletoday:- a radiation tolerant Electrical Power System (EPS) for an Electric Propulsion (EP) thruster (the thruster is not part of this development),- a low mass radiation shielding concept and solution,- a reconfigurable GNC subsystem integrating (a) Fault Detection Isolation and Recovery (FDIR) techniques as well as (b) semi-autonomous on-board guidance during the orbit transfer.In addition to the platform, a small experimental payload will be developed. Baseline is a low power Ka-band or Ku-band transparenttransponder. However, the final selection of the experiment payload will consider alternatives such as a spectrum surveyor experimental payload, a GNSS signal monitor experiment or a technology evaluation of satellite subsystems such as a digital sun-sensor, startracker, radiation monitor etc. In-orbit experiments will be carried out to test and evaluate the self-transfer capability of the scalable small satellite platform. With the help of the FDIR, the platform will be assessed for reliability in a high-radiation environment. The destination orbit for the experiment will be a super-synchronous GEO. Footnote: On Delegation Request activities will only be initiated on the explicit request of at least one National Delegation.