A Delta II 7326  successfully launched Genesis from Cape Canaveral, SLC-17A, at 1613:40 UTC (9:13:40 a.m. PDT) on August 8.

The Genesis spacecraft will collect samples of the solar wind. The mission is designed to measure the composition of isotopes in solar matter, to improve knowledge about the differing amounts of elements, and to obtain separate samples of different types of solar wind. By studying the composition of the solar wind, scientists hope to find clues to the formation of the solar system. The Solar wind does not strike the Earth directly, but is deflected by the Earth's magnetosphere, requiring the spacecraft to be placed into orbit around L1, a point between Earth and the sun where the gravity of both bodies is balanced. Once in orbit, Genesis will deploy its collectors and begin collecting particles of the solar wind that will imbed themselves in specially designed high purity wafers. After two years, the sample collectors will be re-stowed and returned to Earth for a mid-air recovery of the sample return capsule.

The Lockheed Martin built spacecraft will cost US$216 million, including the rocket that launches it into space and all communications systems. The spacecraft’s launch mass is 636 kg (1400 lbm), having an on-orbit mass of 494 kg (1089 lbm). The satellite maximum power is 0.254 kW. The satellite will communicate using S-band telemetry at 15 kilobits per second during the halo orbit phase, and 120 bits per second during the cruise and return phases.

The Genesis spacecraft will be placed into orbit around L1, a point between Earth and the sun where the gravity of both bodies is balanced. Once in the L1 orbit, Genesis will deploy its collector arrays and begin collecting particles of the solar wind that will imbed themselves in specially designed high purity wafers. After two years, the sample collectors will be re-stowed for return to Earth and a mid-air recovery of the sample return capsule. The samples will be stored and cataloged under ultra-pure cleanroom conditions and made available to the world scientific community for study.

The Genesis spacecraft is spin stabilized with fixed solar arrays and antenna and passive thermal control, powered by a hydrazine monopropellant thruster. It consists of a sample return capsule containing a cannister holding a concentrator and three collector arrays. The collector arrays are flat discs made of ultra-pure silicon wafers which are exposed to the solar wind and into which isotopes of helium, oxygen, nitrogen, neon, radon, and other elements are implanted. The concentrator is an electrostatic mirror which concentrates elements up to neon by a factor of approximately 20. Each collector array is to be deployed for a different solar wind regime. The spacecraft is also equipped with ion and electron electrostatic monitors to determine which solar wind regime is being encountered and to help set the appropriate collector voltage. Spacecraft subsystems and monitors are mounted beneath the sample return capsule.

The sample return capsule (SRC) is mounted on the top deck of the Genesis spacecraft, which will face the sun during most of the mission. The SRC contains the science equipment for the Genesis mission. When the spacecraft is at L1 and ready to collect solar wind, an external hinge will open the top of the SRC, exposing the science canister. The canister cover will then open to reveal a stacked set of collectors, or arrays. Each collector is made up of many hexagonal wafers of ultra-pure silicon, held in place by a framework of clips. The stack will rise up out of the canister and turn outward, exposing a solar wind concentrator underneath. Two solar wind monitors will control the collection of samples. The solar wind will constantly strike the topmost collector. The ions and particles that make up the solar wind will embed themselves and be trapped in small hexagonal plates on the circular blades. The three collectors underneath can be swung out independently. Each will be uncovered during certain types of solar wind conditions, collecting specific samples.

To prepare for the return journey, the collectors will be re-stowed inside the science canister and the lid closed securely to prevent contamination. Then the cover of the SRC will be closed tightly over the canister. Prior to entry into the Earth’s atmosphere, the SRC will separate from the spacecraft using push-off springs. The heat shield will protect the SRC during the peak heating period of reentry. A drogue and a main parachute will then be released to further slow its reentry. Helicopters will snag the descending capsule‘s parachute lines so the silicon wafers with the embedded solar wind particles will not be damaged on landing. The samples will be stored and cataloged under ultra-pure cleanroom conditions and made available to the world scientific community for study.