Good beginning for Genesis

The arrays will catch just 10-20 micrograms of particles

The Genesis mission to grab particles from the solar wind and return them to Earth pulled off a crucial manoeuvre on Friday.

The spacecraft is in perfect health and we're ready to move into the next phase of its mission

Chet Sasaki, project manager

The spacecraft, which left this planet on 8 August, took up the position in space where it will begin its collection duties.

Engineers sent a final command to Genesis to begin operating its hydrazine thrusters for 268 seconds, to make the probe enter an orbit where the gravity of the Earth and the Sun are exactly balanced.

"The mission operations team did a great job - the orbit insertion went off exactly as planned, and we're in our 30-month science collection orbit," said project manager Chet Sasaki, of the American space agency's (Nasa) Jet Propulsion Laboratory in California.

"The spacecraft is in perfect health and we're ready to move into the next phase of its mission."

Helicopter catch

On 30 November, Genesis will deploy its collector arrays and begin to monitor and collect the solar wind ions flowing from the outer layer of the Sun. The samples of solar wind returned by the spacecraft will help scientists understand how the Solar System evolved.

The spacecraft has to get away from the Earth's magnetosphere

The probe carries three scientific instruments in addition to the bicycle-tyre-sized solar-wind collector arrays.

There is an ion monitor to record solar wind speed, density, temperature and composition; an electron monitor to measure similar details of the wind's electrons; and an ion concentrator to distinguish the wind's individual chemical elements, such as oxygen and nitrogen.

"The samples that Genesis returns will show us the composition of the original solar nebula that formed the planets, asteroids, comets and the Sun we know today," said Donald Burnett, the project's science leader.

These samples will come back to Earth in a special collection capsule that will parachute down towards the Utah desert to be retrieved mid-air by a helicopter.