NEW HORIZONS

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NEW HORIZONS
NASAs Pluto-Kuiper Belt Mission The First
Mission to the Last Planet
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Toward New Frontiers
New Horizons is Demonstrating That Exciting,
Lower Cost Outer Planet Missions Are Indeed
Feasible.
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Pluto A Little Background
Pluto was discovered in January-February 1930, by
Clyde Tombaugh at Lowell Observatory, Arizona.

• Pluto is a Small, Distant World
• lt1 Marss Max Apparent Diameter (0.1 arcsec)
• And 50,000 times fainter than Mars (V14)

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Pluto Some Basic Properties

• Rotation Period 6.4 days (retrograde)
• Axial Tilt (obliquity) 118 deg
• Mass 0.2 Earths (1.5x1025 gm)
• Diameter 18 Earths (1180 km)
• Reflectivity 50 (due to its icy surface)

The Best Hubble Images of Pluto Are Still Crude
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Pluto A Misfit?

• Distance from the Sun varies from 30 to 50 AU
• Orbital Period 248 years
• Eccentricity 0.25
• Inclination 16 deg

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1976 Discovery of Methane On Plutos Surface

• N2 and CO ices were later discovered.
• The CH4, N2, CO distribution is patchy.
• But N2 dominates almost 101

True Color Map
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1988 Discovery of Plutos Atmosphere

• Pluto has an atmosphere it was definitively
  detected in 1988 by a refractive signature seen
  in a stellar occultation.
• It is composed of N2, CO, and CH4, plus trace
  species there is evidence for hazes.
• The atmosphere is thought to be escaping to
  space hydrodynamically.
• An occultation in 2003
• revealed distinct structural and pressure changes.

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1978 Discovery of Plutos Moon Charon

• Charon was discovered, by accident, in July 1978
  by Jim Christy
• of the U.S. Naval Observatory.
• Charon is in synchronous orbit 19,400 km from
  Pluto, and spin-spin-orbit locked with a 6.4 day
  period.

0.9 arc-sec
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2005 The Discovery of Two New Moons
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And Do Not Judge This Book By Its Cover
From the Densities of Pluto and Charon, One Can
Derive Crude Interior Models.
Pluto is a primarily rocky, not icy body!
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Pluto A Clear Outlier Among The Giant Planets
A Dwarf Planet and A True Binary World

• Charons radius is 50 of Plutos.
• Charons mass is about 10 of Plutos.

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But the 1990s Clearly Revealed Plutos Context
The Kuiper Belt
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The Discovery Of the Kuiper Belt

• 1992 Jewitt Luu found a 100 km sized object in
  a near-circular orbit, well beyond Pluto.
• 1993 4 more KBOs found.
• 1994 10 KBOs found.
• 2005 Over 1000 KBOs are now known.

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The Kuiper Belt

• Over 140,000 KBOs predicted with diameters gt100
  km, orbits 30-50 AU (assuming 4 reflectivity).
• Billions of smaller comets are also predicted to
  exist there.
• The largest KBOs are well over
• 2000 km in diameter.
• Three Orbit Types
• Plutinos Neptune resonant, alt50 AU
• Classical Non-resonant, alt50 AU
• Scattered Distant (agt50 AU), Neptune ejected

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Large KBOs Abound

• The large KBOs are planetary embryos.
• These objects reached the mid-stage of planetary
  accretion.
• They are dwarf planets.

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As Do KBO Satellites

• Pluto/Charon was only the first binary object
  (1978).
• Next up 1998 WW31 (2001).
• 16 KBO binaries discovered so far (late 2004).
• Implication gt20 of all KBOs have satellites.

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A Historic Journey
The Initial Reconnaissance of The Solar Systems
Third Zone
Pluto-Charon July 2015
KBOs 2016-2020
Jupiter System March 2007
Launch Jan 2006
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Project Philosophy
Offer early and highly-leveraged science. Do so
on time, within budget, and at low risk. Provide
Intensive Public Outreach Keep It Simple
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Launch Vehicle Atlas V 551 With A STAR-48 Upper
Stage
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Instrument Payload
REX
LORRI
ALICE
PEPSSI
RALPH

• CORE
• REX radio science radiometry
• RALPH VIS/IR imaging spectroscopy
• ALICE UV imaging spectroscopy
• Supplemental
• LORRI High-resolution imager
• SWAP plasma spectrometer
• PEPSSI energetic particle spectrometer
• SDC EPO Student Dust Counter

SWAP
Student Dust Counter
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The Student Dust Counter A New Kind of EPO

• EPO Goal Give students a chance to design,
  build, operate, study data from a planetary
  flight experiment.
• Science Goal Make the first dust density
  size spectrum observations beyond 18 AU.
• Students have the primary responsibility for the
  design and development of the SDC over 35 first
  generation students were involved at CU, with
  dozens more participating across the U.S.
• Four Generations of Students To Be Involved.

SDC Student Team Leaders
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Launch Windows Overview

• 2006 Primary
• Jan 11-Feb 14 Jan 06
• Window 34 days
• C3 164 km2/s2
• Earliest Arrival 2015
• 2007 Backup
• 0215 Feb 07
• Window 14 days
• C3 166 km2/s2
• Earliest Arrival 2019
• Requires KBO Fuel Removal

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Jupiter Flyby Science
Jupiter science will include studies of Jovian
meteorology, satellite geology and
composition, Auroral phenomena, and
magnetospheric physics.
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Pluto-Charon Encounter Highlights

• Six months of encounter science.
• Exceed Hubble resolution for months.
• Map all of Pluto and all of Charon.
• Make global composition maps of Pluto and
  Charon.
• Map their surface temperature fields.
• Directly measure Plutos escape rate and assay
  its atmospheric structure and composition.
• Improve interior models and determine if either
  Pluto or Charon differentiated.
• Locate additional Pluto-system satellites lt1 km
  in diameter.

The most exciting discoveries will likely be the
ones we Dont anticipate.
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New Horizons Will Yield Dramatic Results at
Pluto-Charon
Triton from Voyager
Triton and Pluto at Best HST Resolution
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New Horizons at the Cape
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Atlas V-010 in Denver
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Mission Status Summary
Project Element Status
Spacecraft GO
Payload GO
RTG GO
Atlas V GO
STAR-48 GO
PI Science GO