This material has been adapted from the New Horizons web site.


Mission Overview
================
The primary science goals of the NEW HORIZONS mission are to
characterize the global geology and morphology of Pluto and Charon, to
map the surface composition of Pluto and Charon, and to characterize
the neutral atmosphere of Pluto and its escape rate (NASA AO, 2001
[NASAAO2001]; Stern & Spencer, 2004 [STERN&SPENCER2004A]).


Mission Design
==============
The New Horizons spacecraft trajectory was designed to have as early
an arrival time at Pluto as practicable.

There are two reasons why the New Horizons science team wanted to
reach Pluto and Charon quickly. The first has to do with the Pluto
atmosphere: Since 1989, Pluto has been moving farther from the Sun,
getting less heat every year [LUNINEETAL1995]. As Pluto gets colder
scientists expect its atmosphere will freeze out, so the team wanted
to arrive while there is a chance to see a thicker atmosphere.

The second reason is to map as much of Pluto and Charon as possible.
As New Horizons approaches and flies by the Pluto system, parts of
Pluto or Charon will be in constant darkness, and, the later the
flyby, the more of Pluto and Charon that will be unlit.

In addition, the trajectory was designed to enable all of the science
goals, including Solar and Earth occultations by Pluto and Charon.


Prime Opportunity: Jupiter
---------------------------
By launching in January 2006, New Horizons took advantage of a
gravity assist from Jupiter. In February 2007, New Horizons passed
through the Jupiter system at about 80,000 kmph, ending up on a path
that gets it to Pluto on July 14, 2015.

Science Opportunities at Jupiter included meteorology, aurora
studies, magnetospheric sampling, and dust sampling and ultraviolet
mapping of the torus around Io. Surface mapping, compositional
mapping and atmospheric studies of the Jovian moons were possible,
as was a close encounter with a small Jovian satellite.


Cruise from Jupiter to Pluto
----------------------------
During the PLUTOCRUISE mission phase from Jupiter to Pluto, the
mission team monitored the health of the spacecraft while planning
and practicing for the encounter with Pluto and Charon. At the same
time, observers used telescopes on Earth and in Earth orbit to
search for Kuiper Belt Objects (KBOs) the spacecraft can fly by
after Pluto and Charon (as part of an extended mission). The KBOs
are ancient, icy bodies that orbit beyond Neptune.


Closing In: Pluto
------------------
The cameras on New Horizons started taking data on Pluto and Charon
months before the spacecraft arrived. Pluto and Charon will first
appear as unresolved bright dots, but the planet and its moon appear
larger as the encounter date approaches. About three months from the
closest approach - when Pluto and Charon are about 105 million
kilometers away - the cameras on the spacecraft can make the first
maps. For those three months, the mission team took pictures and
spectral measurements.

Pluto and Charon each rotate once every 6.4 Earth days. For the last
three Pluto days before encounter (21 Earth days), the team compiled
maps and gathered spectral measurements of Pluto and Charon every
half-day. The team then compared these maps to look for changes over
a Pluto day, at a scale of about 48 kilometers.


The Encounter
-------------
The busiest part of the Pluto-Charon flyby lasted a full Earth day,
from a half-day before closest approach to a half-day after. On the
way in, the spacecraft looked for ultraviolet emission from the
Pluto atmosphere and made the best global maps of Pluto and Charon
in green, blue, red and a special wavelength detector that is
sensitive to methane frost on the surface. It also made spectral
maps in the near infrared, telling the science team about the Pluto
and Charon surface compositions and locations and temperatures of
these materials.

In current mission designs, the spacecraft comes as close as about
9,600 kilometers from Pluto and about 27,000 kilometers from Charon.
During the half-hour when the spacecraft is closest to Pluto or its
largest moon, it will take close-up pictures in both visible and
near-infrared wavelengths. The best pictures of Pluto depict surface
features as small as about 60 meters across.

Even after the spacecraft passed Pluto and its moons, its work is
far from done. Looking back at the mostly dark side of Pluto or
Charon is the best way to spot haze in the atmosphere, to look for
rings, and to figure out whether their surfaces are smooth or rough.
Also, the spacecraft flew through the shadows cast by Pluto and
Charon. It looked back at the Sun and Earth, and watched the light
from the Sun or the radio waves from transmitters on Earth. A unique
time to measure the atmosphere occurs as the spacecraft watches the
Sun and Earth set behind Pluto and Charon.


Launch: January 19, 2006

Launch Vehicle: Atlas V 551 first stage; Centaur second stage;
STAR 48B solid rocket third stage

Location: Cape Canaveral Air Force Station, Florida

Trajectory: To Pluto via Jupiter Gravity Assist


Mission Phases
==============

Summary of mission phases
-------------------------
Mission phases provide convenient handles and approximate time
boundaries to

1) partition the data into very broad categories of mission activity

2) provide approximate time boundaries for PDS archive data sets

The mission is continuous, so the boundaries are very soft i.e. in
an operational sense they do not exist in a noticeable way.

That being the case, the user should not expect the actual range of
times covered by data in this data set to exactly agree with the
boundaries of the corresponding mission phase described below; the
data set time range may be far less or it may overlap the
boundaries. This is intentional and will not be changed.

For example, during the New Horizons mission it was decided to
deliver data sets for the first three years of the 7.5-year Pluto
Cruise mission phase before that mission phase was complete. As
such, the time range of those data sets was from 2007 until mid- to
late-2010, while the mission phase described below extends through
the end of 2014. The intention was to deliver the balance of the
Pluto Cruise at a later date. Once all Pluto Cruise data are
delivered this paragraph will become obsolete; nonetheless this
paragraph may be left in place as an example of the intentional
flexibility of the boundaries between the mission phases defined in
the dates below.


Full MISSION_PHASE_NAME,
Short name Start(1,3) Stop(2,3) plus optional Description
---------- ---------- --------- -------------------------

LAUNCH 2006-01-19 2006-12-31 POST-LAUNCH CHECKOUT

JUPITER 2007-01-01 2007-06-26 JUPITER ENCOUNTER

PLUTOCRUISE 2007-06-27 2014-12-31 PLUTO CRUISE,
Jupiter-Pluto/Charon
Interplanetary Cruise

PLUTO_CHARON 2015-01-01 2016-04-30 PLUTO ENCOUNTER,
Pluto/Charon approach,
flyby, post-encounter

KBO1CRUISE 2016-05-01 TBD KBO1 CRUISE,
Pluto-KBO1 Cruise (4)

KBO1 TBD TBD KBO1 ENCOUNTER
KBO1 approach, flyby,
post-encounter (4)

KBO2CRUISE TBD TBD KBO2 CRUISE,
KBO1-KBO2 Cruise (4)


KBO2 TBD TBD KBO2 ENCOUNTER
KBO2 approach, flyby,
post-encounter (4)
Notes:

1 Start at 00:00:00 UTC on the spacecraft that day
2 End before 00:00:00 UTC on the spacecraft next day
3 Start and end dates are not exact and identical for all
instruments; some instruments take single observations over several
days which span these mission phase boundaries.
4 All mission phases after PLUTO ENCOUNTER assume an extended
mission for NH; as of early 2016, no extension to the mission has
been approved.


The Voyage
----------
Post-Launch Checkout:

Short phase name (in DATA_SET_ID; DSID): LAUNCH
Formal mission phase name: POST-LAUNCH CHECKOUT
Mission Phase Start Time - 2006-01-19
Mission Phase Stop Time - 2006-12-31

The first 13 months include spacecraft and instrument checkouts,
instrument calibrations, trajectory correction maneuvers, and
rehearsals for the Jupiter encounter.


Jupiter Encounter:

Short phase name (in DSID): JUPITER
Formal mission phase name: JUPITER ENCOUNTER
Mission Phase Start Time - 2007-01-01
Mission Phase Stop Time - 2007-06-26

Closest approach occurred on Feb. 28, 2007. Moving about 21
kilometers per second, New Horizons flew 3 to 4 times closer to
Jupiter than the Cassini spacecraft, coming within 32 Jupiter
radii of Jupiter.


Pluto Cruise:

Short phase name (in DSID): PLUTOCRUISE
Formal mission phase name: PLUTO CRUISE
Mission Phase Start Time - 2007-06-27
Mission Phase Stop Time - 2015-01-15

Activities during the approximately 8-year PLUTOCRUISE mission
phase to Pluto include annual spacecraft and instrument checkouts
(ACOs), trajectory corrections, instrument calibrations and Pluto
encounter rehearsals.


Pluto-Charon Encounter
----------------------
Short phase name (in DSID): PLUTO_CHARON
Formal mission phase name: PLUTO ENCOUNTER
Mission Phase Start Time - 2015-01-15
Mission Phase Stop Time - 2016-04-30

This phase will be broken down into three sub-phases:

Approach:

Mission Sub-phase Start Time - 2015-01-15
Mission Sub-phase Stop Time - 2015-07-14

Ten weeks before encounter, image resolution will exceed that of
the best Hubble Space Telescope images. Four weeks before
encounter, daily studies will begin. New Horizon will acquire
maps and spectra throughout this period.


Near Encounter Phase (NEP, or Flyby):

Mission Sub-phase Start Time - 2015-07-14
Mission Sub-phase Stop Time - 2015-07-14

Activities include taking the highest resolution visible and
spectral imaging at closest approach to Pluto and Charon. The
time near occultations (Pluto/Sun, Pluto/Earth, Charon/Sun and
Charon/Earth) will be used for atmospheric studies.


Departure (Post-Encounter):

Mission Sub-phase Start Time - 2015-07-14
Mission Sub-phase Stop Time - 2016-04-30

Four weeks of post-encounter studies and nine months of
downloading data.


KBO 1 Cruise:

Short phase name (in DSID): KBO1CRUISE
Formal mission phase name: KBO1 CRUISE
Mission Phase Start Time - 2016-05-01
Mission Phase Stop Time - TBD

Activities during the KBO1CRUISE mission phase to the first KBO
encounter will be similar to those for Pluto Cruise phase.


KBO 1 Encounter

Short phase name (in DSID): KBO1
Formal mission phase name: KBO1 ENCOUNTER
Mission Phase Start Time - TBD
Mission Phase Stop Time - TBD

Activities during this encounter are TBD, but will be similar to
the Pluto Encounter phases.


KBO 2 Cruise:

Short phase name (in DSID): KBO2CRUISE
Formal mission phase name: KBO2 CRUISE
Mission Phase Start Time - TBD
Mission Phase Stop Time - TBD

Activities during the KBO2CRUISE mission phase to the first KBO
encounter will be similar to those for Pluto and KBO 1 Cruise
phases.


KBO 2 Encounter

Short phase name (in DSID): KBO2
Formal mission phase name: KBO2 ENCOUNTER
Mission Phase Start Time - TBD
Mission Phase Stop Time - TBD

Activities during this encounter are TBD, but will be similar to
the Pluto and KBO Encounter phases.

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