- Shortcut URL Euclid will be carried into a direct transfer
orbit by a Soyuz ST 2-1b launch vehicle departing from Europe's
Spaceport in French Guiana. The transfer phase to the target
orbit around the second Sun-Earth Lagrange point, L2, will last
approximately 30 days. A correction manoeuvre will be performed
about two days into the flight, once sufficient tracking data
have been acquired to evaluate the radial velocity error, which
arises due to uncertainties in the conditions during launch.
Commissioning of the spacecraft and instruments will start
during the transfer phase. No insertion manoeuvre is needed to
reach the chosen orbit. To cope with the unprecedented science
data volume generated by Euclid in L2, K-band (25.5-27 GHz)
communications will be used, which offer a transfer rate of 55
Mbit/s. As a consequence of the large variations in the Sun-
spacecraft-Earth angle, a two-degrees-of-freedom mechanism for
the antenna is needed to maintain the science telemetry link to
Earth. The selected orbit is