A contour, or piecewise smooth arc, is an arc consisting of a finite number of smooth arcs joined end to end. Hence if z(t) represents a contour, z(t) is continuous, and its derivative, z'(t), is piecewise continuous.

CONTOUR, standing for Comet Nucleus Tour, is a NASA spacecraft intended to make several close approaches to the nuclei of comets. The 970 kg craft, costing a relatively low $159 million, and run by Johns Hopkins University, was launched from Cape Canaveral on 3 July 2002.

Only twice before have cometary nuclei been imaged up close: by the European Space Agency's Giotto approach to Halley's Comet in 1986, and by NASA's Deep Space 1 visiting Comet Borrelly in 2001.

Sadly, it appears that CONTOUR has failed to survive the rocket firing needed to boost it out of Earth orbit. It orbited the Earth until 15 August, when its solid fuel rocket should have fired while it was at a low 225 km over the Indian Ocean, out of tracking range, at 08.49 a.m. UTC (04.49 EDT).

The Deep Space Network (DSN) trackers ought to have picked it up again at about 09.35 a.m. UTC, but no signal has been received. An on-board instruction to move its antennae has, if it happened, not made any difference. CONTOUR is programmed to begin a test transmission cycling through all four of its antennae 96 h after it fails to hear from its mission control. But an Arizona telescope has detected two parallel trails roughly where CONTOUR should be, suggesting it has broken up.

Its two scheduled targets were the short-period Comet Encke in November 2003, and Comet Schwassmann-Wachmann 3 in June 2006, to a distance of about 100 km, though some flexibility was built in to enable it to be diverted to new comets of interest.

Main website at www.contour2000.org. This has news updates but at time of noding they had not mentioned the sighting of the parallel trails. It's always sad when we lose a spacecraft.

Con*tour" (?), n. [F. contour, fr. contourner to mark the outlines; con- + tourner to turn. See Turn.]


The outline of a figure or body, or the line or lines representing such an outline; the line that bounds; periphery.

Titian's coloring and contours. A. Drummond.

2. Mil.

The outline of a horizontal section of the ground, or of works of fortification.

Contour feathers Zool., those feathers that form the general covering of a bird. -- Contour of ground Surv., the outline of the surface of ground with respect to its undulation, etc. -- Contour line Topographical Suv., the line in which a horizontal plane intersects a portion of ground, or the corresponding line in a map or chart.


© Webster 1913.

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