ESA Releases Lutetia Flyby Images

The European Space Agency has released images from yesterday's close approach of asteroid 21 Lutetia by the Rosetta probe. At its closest, the probe was a mere 3,162 km from the asteroid, passing at 15 km/s and snapping photos sharp enough to make out features as small as 60 meters. "Rosetta operated a full suite of sensors at the encounter, including remote sensing and in-situ measurements. Some of the payload of its Philae lander were also switched on. Together they looked for evidence of a highly tenuous atmosphere, magnetic effects, and studied the surface composition as well as the asteroid’s density. ... The flyby marks the attainment of one of Rosetta's main scientific objectives. The spacecraft will now continue to a 2014 rendezvous with its primary target, comet Churyumov-Gerasimenko. It will then accompany the comet for months, from near the orbit of Jupiter down to its closest approach to the Sun. In November 2014, Rosetta will release Philae to land on the comet nucleus." There is also a replay of the media event webcast on the ESA's website.

Comments

Re:Question for the rocket scientist(s)...

[Tablizer]

For one, at that close the instruments and/or craft must be coordinated to move in a way that keeps the target area in view of cameras and instruments. Features would pass by at a rather quick pace. Handling such adds to the complexity of the craft and mission.

This is similar to a key issue with the New Horizons (NH) Pluto/Kuiper-Belt mission. It's moving so fast that it doesn't have a long time at targets. The Voyager crafts had separate, semi-dedicated platforms for each instrument or instrument group. Thus, each could be aimed to work at its optimum pace.

However, that was deemed too expensive for NH, so instead they designed the *whole craft* to move via gyros and pressurized gas to aim each instrument. Many instruments thus have to take turns. It's not the ideal, but it cut costs. If you get too close, then there's no time for each instrument to get a look. You have to pick and choose. Maybe one instrument may get a good look, but the returns are diminishing.

For example, it may be cheaper to have a bigger telescopic lens rather than an independent camera platform and study the target from a medium distance.