The 1.6 tonne observatory was released into its transfer orbit from the rocket's Centaur upper stage about two hours after launch. It will take four months for the satellite to reach its final position, a unique vantage point, located 1.5 million kilometres from Earth, where the gravitational pull of the Earth and Sun are equal. From here, the Lagrange point, SOHO will have an unobstructed view of the Sun all year round.

SOHO's launch was delayed from 23 November because a flaw was discovered in a precision regulator, which throttles the power of the booster engine on the Atlas rocket. The system was replaced and retested before the launch.