CONTOUR

CONTOUR

The "CO"met "N"ucleus "TOUR" (CONTOUR) was a NASA Discovery-class space probe that failed shortly after launch. It had as its primary objective close flybys of two comet nuclei with the possibility of a flyby of a third known comet or an as-yet-undiscovered comet. The two comets scheduled to be visited were Encke and Schwassmann-Wachmann-3, and the third target was d'Arrest. It was hoped that a new comet would have been discovered that would have been in the inner solar system between 2006 and 2008, in which case the spacecraft trajectory would have been changed if possible to rendezvous with the new comet. Scientific objectives included imaging the nuclei at resolutions of 4 m, performing spectral mapping of the nuclei at resolutions of 100-200 m, and obtaining detailed compositional data on gas and dust in the near-nucleus environment, with the goal of improving our knowledge of the characteristics of comet nuclei.

After ignition on 15 August 2002 of the solid rocket motor intended to inject the spacecraft into solar orbit, contact with the probe could not be re-established. Ground-based telescopes later found three objects along the course of the satellite, leading to the speculation that it had been destroyed. Attempts to contact the probe were ended on 20 December 2002. The probe accomplished none of its objectives.

Spacecraft design

The "CONTOUR" spacecraft had a total fueled mass of 775 kg, including 70 kg of hydrazine fuel and a Star 30BP booster with a mass of 377 kg. Power was provided by a body-mounted solar array designed for operation at distances between 0.75 and 1.5 AU from the Sun. It was three-axis stabilized for encounters and spin-stabilized during cruise mode between encounters. COUNTOUR's Command/Data-handling and Guidance/Control computers each used the Mongoose-V microprocessor. Communications were through a fixed 0.45 m diameter high-gain antenna to support data rates greater than 100 kbit/s at encounters. Data and images were stored on two 3.3 Gbit solid-state recorders with a capacity of 600 images. The spacecraft was equipped with four primary science instruments, the Contour Remote Imager/Spectrograph (CRISP), the Contour Aft Imager (CAI), the Dust Analyzer (CIDA), and the Neutral Gas Ion Mass Spectrometer (NGIMS).

Mission

CONTOUR launched on a Delta 7425 (a Delta II Lite launch vehicle with four strap-on solid-rocket boosters and a Star 27 third stage) on July 3, 2002 at 6:47:41 UT (2:47:41 a.m. EDT) into a high-apogee Earth orbit with a period of 5.5 days from Cape Canaveral Air Force Station. Following a series of phasing orbits, the Star 30 solid rocket motor was used to perform an injection maneuver on August 15, 2002 to put CONTOUR in the proper trajectory for an Earth flyby in August 2003 followed by an encounter with comet Encke on 12 November 2003 at a distance of 100 to 160 km and a flyby speed of 28.2 km/s, 1.07 AU from the Sun and 0.27 AU from Earth. During the maneuver the probe was lost. Three more Earth flybys would have followed, in August 2004, February 2005, and February 2006. On 18 June 2006 CONTOUR would have encountered comet Schwassmann-Wachmann-3 at 14 km/s, 0.95 AU from the Sun and 0.33 AU from Earth. Two more Earth flybys were scheduled in February 2007 and 2008, and a flyby of comet d'Arrest might have occurred on 16 August 2008 at a relative velocity of 11.8 km/s, 1.35 AU from the Sun and 0.36 AU from Earth. All flybys would have had a closest encounter distance of about 100 km and would have occurred near the period of maximum activity for each comet. After the comet Encke encounter, CONTOUR might have been retargeted towards a new comet if one is discovered with the desired characteristics (e.g. active, brighter than absolute magnitude 10, perihelion within 1.5 AU).

External links

* cite web
url = http://discovery.nasa.gov/contour.html
title = CONTOUR
work = NASA Discovery Program
accessmonthday = December 27
accessyear = 2007

* [http://solarsystem.nasa.gov/missions/profile.cfm?MCode=CONTOUR CONTOUR Mission Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]

* cite web
url = http://spaceflightnow.com/delta/d292/020628contour.html
title = The CONTOUR spacecraft

* cite web
last = Bradley, Jr.
first = Theron
coauthors = Gay, Charles; Martin, Patrick; Stepheson, David; Tooley, Craig
date = MAY 31, 2003
url = http://www.nasa.gov/pdf/52352main_contour.pdf
title = Contour Comet Nucleus Tour Mishap Investigation Board Report
format = PDF
publisher = NASA
accessmonthday = December 27
accessyear = 2007


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  • contour — [ kɔ̃tur ] n. m. • v. 1200 « enceinte »; de contourner, avec infl. de l it. contorno 1 ♦ (1651) Limite extérieure d un objet, d un corps. ⇒ bord, bordure, délinéament, limite, périmètre, périphérie, 3. tour. Le contour d une table, d un tapis.… …   Encyclopédie Universelle

  • Contour — may refer to: an outline or silhouette a contour line on a contour map, or the corresponding line on the ground or sea bed Contour (linguistics), a phonetic sound Pitch contour (music), a melody shape Contour (camera system), a 3D digital camera… …   Wikipedia

  • CONTOUR — antes del lanzamiento Organización NASA Estado Perdido en el espacio …   Wikipedia Español

  • contour — [kän′to͞or΄] n. [Fr < It contorno < LL contornare, to go around < L com , intens. + tornare, to turn in a lathe: see TURN] 1. the outline of a figure, mass, land, etc. 2. the representation of such an outline vt. 1. to make a contour or… …   English World dictionary

  • contour — CONTOUR. subs. masc. Terme de Peinture et de Sculpture. Ce qui termine une figure, ou les parties d une figure. Un beau contour. Le contour de cette figure est admirable. De beaux contours. Des contours hardis, bien entendus. Des contours élégans …   Dictionnaire de l'Académie Française 1798

  • Contour — Con*tour , n. [F. contour, fr. contourner to mark the outlines; con + tourner to turn. See {Turn}.] 1. The outline of a figure or body, or the line or lines representing such an outline; the line that bounds; periphery. [1913 Webster] Titian s… …   The Collaborative International Dictionary of English

  • contour — 1660s, a term in painting and sculpture, from Fr. contour circumference, outline, from It. and M.L. contornare to go around, from L. com , intensive prefix (see COM (Cf. com )), + tornare to turn on a lathe, from tornus lathe (see TURN (Cf.… …   Etymology dictionary

  • contour — Contour. s. m. Terme de Peinture & de Sculpture. Ce qui termine une figure, & les parties d une figure, & leur donne le tour qu elles doivent avoir. Un beau contour. le contour de cette figure est admirable. de beaux contours. des contours hardis …   Dictionnaire de l'Académie française

  • Contour — Contour, der Abriß oder Umriß von Bildern, Gebäuden oder andern Dingen, die durch ihre Gestalt in die Augen fallen. Bildlich wendet man es auch z. B. auf Wissenschaften an; und der Contour einer solchen müßte ihren Umfang und Inhalt so darstellen …   Damen Conversations Lexikon

  • contour — ► NOUN 1) an outline, especially one representing or bounding the shape or form of something. 2) (also contour line) a line on a map joining points of equal height above or below sea level. ► VERB 1) mould into a specific shape. 2) (contoured)… …   English terms dictionary

  • Contour — (fr., spr. Kongtuhr, ital. Contorno), Umriß, Linien, durch welche bei Zeichnungen die äußeren Umrisse der Figuren u. Gegenstände bestimmt werden; davon Contonriren, die Umrisse der Figuren zeichnen. Von der Richtigkeit der C. hängt im Allgemeinen …   Pierer's Universal-Lexikon

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