Giotto spacecraft

Grigg-Skjellerup was visited by the Giotto spacecraft in 1989. NASA s demonstration spacecraft DS1 imaged the nucleus of Comet Borrelly in 2001. 

Image of comet Halley s nucleus, showing jets of dust and volatilized ices. This picture was taken by the Giotto spacecraft as it raced by in 1986. Image courtesy of ESA. 

Figure 2. Variation of the polarization in comet IP/Halley coma, as measured at 73 phase angle in the blue domain along the trajectory of Giotto spacecraft, for distances to the nucleus in the 1000-80000 km range. Local changes could be attributed to the crossing of swarms of particles with different scattering properties (from [11]).

Nearly all assured knowledge about the composition of comets comes from three sources (1) data collected from Comet Halley by the Soviet Union s two Vega spacecraft and the ESA s Giotto mission,... 

To date, there exists very little quantitative information concerning oxygen isotope compositions in major solar system reservoirs that is obtained by remote (spectroscopic) observation or spacecraft measurements. A measurement of water ice from comet P/Halley, made by the Giotto mission, yields = 12 75 %o (Balsiger et al. 1995 Eberhardt et al. 1995) but no measurement of is available. Precise data are obtained for the Moon, of course, from returned Apollo samples, and the oxygen isotope composition of Mars and the largest asteroid, Vesta, may be inferred from laboratory... 

Silver-cadmium batteries have been used in a number of space applications requiring nonmagnetic properties. One such battery provided the main power for the Giotto Halley Comet intercept spacecraft. 

Spacecraft missions like GIOTTO (see Fig. 5.3) (comet Halley) and Deep Space 1 (comet Borrelley) have shown that cometary nuclei are very dark (albedo less than 0.04). 

For components that require a high level of protection, the materials could be modeled as a scaled down version of comet probes such as Contour, Giotto, and Stardust. The selection of materials would also be based on the location of the component with the spacecraft If impacts could only occur at a direction perpendicular to the velocity vector of the spacecraft, then that component would receive a far lower fluence level compared to one that is exposed to impact from the front, in the direction of the spacecraft velocity vector. Preferential component location and orientation essentially shields the component from the particle flux and therefore reduces the scale of protection required... 

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