CONTOUR

File:CONTOUR pre-launch.jpg in May 2002, being prepared for launch.]]

The CONTOUR spacecraft was constructed in-house at the Johns Hopkins University Applied Physics Laboratory. CONTOUR was shaped as an octagonal prism, measuring at {{convert|2.1|m|ft}} tall and {{convert|1.8|m|ft}} long, had a total fueled mass of {{cvt|398|kg|lb}} at launch, not including the {{cvt|377|kg|lb}} mass of the Star 30 booster it was attached to, during the launch phase of the mission. The spacecraft was fitted with a {{cvt|25|cm|in}} whipple shield, similar to the one used on Stardust, on its leading face, designed with four layers of nextel fabric and seven layers of kevlar.{{r|sfn-spacecraft|Ulivi_2012}} The shield was built to allow the spacecraft to withstand the respective 28.2 and 14 km/s velocity flybys of comets Encke and Schwassmann-Wachmann-3, where the spacecraft would be subjected to numerous particles ejecting from the nuclei of the comets. Although mission scientists predicted that the spacecraft would take no significant damage during the Encke and Schwassmann-Wachmann-3 encounters, the shield and its prototypes were tested vigorously during the construction of the spacecraft, including one where a shield prototype was shot at with surrogate nylon particles from a two stage light-gas gun. The results of the earlier tests allowed mission planners to determine a safe distance from which the CONTOUR would pass by comets targeted on the mission. Three of the four scientific instruments aboard the spacecraft were embedded within this shield.

Power for CONTOUR derives from solar cells, which are mounted onto the spacecraft, decorating the sides and rear and generating up to 670 watts of power. A nickel–cadmium battery designed to last up to nine ampere hours was also installed aboard the spacecraft in the event that the solar cell system fails, or does not provide enough power for the spacecraft or its instruments to function.

Unlike many interplanetary missions, CONTOUR was not designed to be propelled beyond Earth orbit by the rocket that launched it, instead it exited Earth orbit using a STAR-30 solid rocket booster built into the spacecraft. This STAR-30 engine provided 1,922 meters per second of delta-v. The firing of this engine is the reason the CONTOUR spacecraft was destroyed. In addition, there were 16 hydrazine thrusters for normal propulsion and course corrections. These thrusters were divided into four clusters of four.

• CIDA

:The Comet Impact Dust Analyzer (CIDA)

• CRISP

:The CONTOUR Remote Imager/Spectrograph (CRISP)

• CAI

:The CONTOUR Aft Imager (CAI), also known as the CONTOUR Forward Imager (CFI)

• NGIMS

:Neutral Gas Ion Mass Spectrometer (NGIMS)

File:CONTOUR Launch (19083178100).jpg on July 3, 2002.]]

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) from Cape Canaveral Air Force Station. It was launched into a high-apogee Earth orbit with a period of 5.5 days. 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 on August 15, 2003, followed by an encounter with comet Encke on November 12, 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 August 2002 injection maneuver, the probe was lost.

Three more Earth flybys would have followed, on August 14, 2004, February 10, 2005, and February 10, 2006. On June 18, 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 was discovered with the desired characteristics (e.g. active, brighter than absolute magnitude 10, perihelion within 1.5 AU).

{{clear}}

According to NASA: "An investigation board concluded that the most likely cause of the mishap was structural failure of the spacecraft due to plume heating during the solid-rocket motor burn. Alternate possible but less likely causes determined were catastrophic failure of the solid rocket motor, collision with space debris, and loss of dynamic control of the spacecraft."{{r|nasa1|nasa2|nasa3}}

After the loss of CONTOUR, a replacement spacecraft – CONTOUR 2 – was proposed, scheduled for launch in 2006. However, the replacement did not ultimately materialize.{{Citation needed|date=August 2020}}

• List of missions to comets

{{Reflist|refs=

{{cite conference

| author1= C. C. DeBoy

| author2= C. B. Haskins

| author3= T. A. Brown

| author4= R. C. Schulze

| author5= M. A. Bernacik

| author6= J. R. Jensen

| author7= W. Millard

| author8= D. Duven

| author9= S. Hill

| display-authors=5

| conference= 2004 IEEE Aerospace Conference Proceedings

| id= IEEE Cat. No.04TH8720

| title= The RF telecommunications system for the New Horizons mission to Pluto

| pages= 1463–1478

| volume= 3

| location= Big Sky, Montana, USA

| doi= 10.1109/AERO.2004.1367922

| isbn= 978-0-780-38155-1

| year= 2004

| s2cid= 1979067 }}

{{cite web

| title= CONTOUR – NASA Science

| url= https://science.nasa.gov/mission/contour/

| website= science.nasa.gov

| publisher= NASA

| access-date= 19 January 2012 }}

{{cite report

| author1= T. Bradley, Jr

| author2= C. Gay

| author3= P. Martin

| author4= D. Stepheson

| author5= C. Tooley

| url= https://spacese.spacegrant.org/Failure%20Reports/ContourFailureReport.pdf

| title= Comet Nucleus Tour (CONTOUR) Mishap Investigation

| publisher= NASA

| date= 31 May 2003

| access-date= 19 January 2012 }}

{{cite web

| title= Lessons Learned #1385

| url= https://llis.nasa.gov/lesson/1385

| website= llis.nasa.gov

| publisher= NASA

| access-date= 19 January 2012 }}

{{cite web

| author1= David R. Williams

| title= CONTOUR

| url= https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2002-034A

| website= nssdc.gsfc.nasa.gov

| publisher= NASA

| date= 2002

| access-date= 23 January 2016 }}

{{cite journal

| author1= R. Osegueda

| author2= C. Carrasco

| author3= M. Orozco

| author4= J. Eftis

| author5= E. Reynolds

| author6= T. Sholar

| title= CONTOUR Dust Shield Performance

| journal= Journal of Aerospace Engineering

| date= 1 October 2001

| volume= 14

| issue= 4

| pages= 147–157

| doi= 10.1061/(ASCE)0893-1321(2001)14:4(147)

| issn= 0893-1321 }}

{{cite web

| title= The CONTOUR spacecraft

| url= https://spaceflightnow.com/delta/d292/020628contour.html

| website= Spaceflight Now

| date= 28 June 2002

| access-date= 24 January 2016 }}

{{cite book

| author1= P. Ulivi

| author2= D. Harland

| title= Robotic Exploration of the Solar System (Part III): Wows and Woes, 1997-2003

| date= 14 August 2012

| publisher= Springer

| isbn= 978-0-387-09627-8

| pages= 250–254

| url= https://books.google.com/books?id=Ndjt1DkCFvoC&pg=PR1

| access-date= 23 January 2016 }}

}}

{{Portal|Spaceflight}}

• {{cite web

|url = http://discovery.nasa.gov/contour.html

|title = CONTOUR

|work = NASA Discovery Program

|access-date = December 27, 2007

|url-status = dead

|archive-url = https://web.archive.org/web/20100425080955/http://discovery.nasa.gov/contour.html

|archive-date = April 25, 2010

}}

• [https://web.archive.org/web/20070610161342/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=CONTOUR CONTOUR Mission Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]

{{Planetary Missions Program Office|Discovery=y}}

{{Comet spacecraft}}

{{Orbital launches in 2002}}

{{Use American English|date=January 2014}}

{{DEFAULTSORT:Contour}}

Category:Missions to comets

Category:NASA space probes

Category:Discovery Program

Category:Satellite launch failures

Category:Space probes launched in 2002

Category:Derelict satellites in heliocentric orbit

Category:Spacecraft launched by Delta II rockets

Category:Destroyed space probes

Category:Spacecraft launched in 2002

Category:Space accidents and incidents in the United States