Sentinel-2 is an ESA programme of earth observation satellites. Among others, it provides worldwide 10 m resolution colour imagery.
EU law grants free access to Copernicus Sentinel Data and Service Information for the purpose of the following use in so far as it is lawful:
- (a) reproduction;
- (b) distribution;
- (c) communication to the public;
- (d) adaptation, modification and combination with other data and information;
- (e) any combination of points (a) to (d).
Sentinel data is already listed as availlable to OSM, at: https://wiki.openstreetmap.org/wiki/Contributors#EU_Copernicus_.28GMES.29_data
Also it's under development a JOSM plugin for Sentinel Hub: https://josm.openstreetmap.de/ticket/14921#comment:26
- Worldwide coverage in 10 m resolution and full colour
- Very recent, imagery updated between every month to every two weeks and available just a few days after sensing date
- Published data needs to be processed into usable background imagery by the end user
- Tiles may be cloud covered, check the thumbnails before processing
- Resolution only sufficient to trace major roads and landuse features.
- For use with JOSM activate the EOx cloudless Sentinel-2 2018 layer.
- If you need the maximum possible resolution or more recent imagery, you can download unprocessed data directly from ESA and convert it to a background layer. User:Ff5722/Using Sentinel-2 imagery
- A plugin to use Sentinel-hub backgrounds directly with JOSM is proposed. 
The following links are for preview only and are not licenced for OSM use.