New Horizons Journey of a Decade

Planetary Pioneers Mercury – Mariner 10, Mar. 29, 1974 Venus – Mariner 2, Dec. 14, 1962 Mars – Mariner 4, Jul. 15, 1965 Jupiter – Pioneer 10, Dec. 3, 1973 Saturn – Pioneer 11, Sep. 1, 1979 Uranus – Voyager 2, Jan. 24, 1986 Neptune – Voyager 2, Aug. 25, 1989

Mission Profile 35 day launch window starting Jan. 11, 2006 Jupiter assist if launched before Jan. 29, 2006 Atlas V 551 launch vehicle Slated to arrive at Pluto between 2015 – 2020 Hopefully look at Jupiter along the way Examine more KBOs after Pluto

Mission Timing with Jupiter Assist

What New Horizons Looks Like

Who is Involved First project within the New Frontiers Program Program Managed by NASA./Marshall SFC John Hopkins University Applied Physics Laboratory – mission development and operations lead Southwest Research Institute – science team and payload lead NASA/KSC – launch services

Launch Vehicle 5 SRB – 102 klb thrust each Common core booster – 860 klb thrust Centar (upper stage) Payload Fairing 17.7 ft diameter, 68.0 ft long Watch the Launch

Enjoying the Trip Launched – Jan. 19, 2006 Moon crossing – 8 hr mi/s Mars crossing – Apr. 7, Jupiter gravity assist – Feb, 28, 2007, +2.4 mi/s Saturn crossing – Jun. 8, 2008 Uranus crossing – Mar. 18, 2011 Neptune crossing – Aug. 25, 2014 Arrive at Pluto – Jul. 14, 2015

Meet Pluto Discovered in 1930 by Clyde Tombaugh 5 known moons – Charon – 1978 – Nix and Hydra – 2005 – Styx – 2011 – Kerberos – 2012 Charon and Pluto are tidally locked Declassified in 2006 by the IAU 50,000 times fainter than Mars

Meet Pluto – Orbital Properties Orbital period of 248 years Average orbital distance 40.7 AU Halfway to the heliosheath Closest than Neptune from Feb. 7, 1979 until Feb. 11, 1999 Same sides of Charon and Pluto face each other all the time. Charon and Pluto orbit each other in 6.4 days Rotational tilt of 118 degrees

Meet Pluto – Physical Properties Diameter of about 1500 miles Surface composition includes Nitrogen, Carbon Monoxide, Methane and Ethane Extreme seasonal changes Surface gravity about 6% of the Earth’s Surface temperature -223C (-387F) More surface contrast than any other planet Atmospheric pressure about 1/50,000 of the Earth’s or about 1/300 of Mars’

Meet Charon Diameter of about 745 miles Largest satellite relative to the planet it orbits Surface mostly water ice with some ammoniated hydrates No detectable atmosphere from Earth Density is about twice that of water

Meet the Other Moons Hydra – Radius 25 by 35 miles, period of 38.2 days Nix – Radius of 22 by 26 miles, period of 24.8 days Styx – Radius 6 to 16 miles, period of 20.2 days Kerberos – Radius of 10 miles, period of 32.2 days

Required Science Objectives Map the surface – Resolution of 1 km/pixel – Best Hubble can do is 500 km/pixel Determine the geological composition and morphology of the surface Determine the structure and escape rate of Pluto’s atmosphere (hydrodynamic escape)

Instruments

Heat Control Designed like a thermos bottle Heat from the electronics maintain a 10C to 30C temperature range The radioisotope thermoelectric generator supplies about 200 Watts of power 18 layers of Dacron mesh sandwiched between layers of Mylar and Kapton film used as thermal blanketing

Alice UV imaging Spectrometer 50nm to 180nm Search for ionosphere around Pluto Search for atmosphere around Charon Measure the density of Pluto’s atmosphere Measure the temperature of Pluto’s atmosphere

Ralph Study geology and morphology Map maker 3 panchromatic and 4 color imagers Infrared compositional mapping spectrometer Resolution better than 10 times the human eye

REX Radio Science Experiment Miniaturized printed circuit board integrated into New Horizons’ telecommunication system NASA’s DSN antennas will beam radio signals to the spacecraft as it passes behind Pluto The radio waves will bend according to the temperature and density of the gas in the atmosphere.

LORRI Long Range Reconnaissance Imager Study geology Provide high resolution approach images Provide highest resolution encounter images 8.2 inch telescope with CCD imager Map surface features as small as 240 ft across Map the far side of Pluto 3 days before closest approach

SWAP Solar Wind At Pluto Measure the interaction between Pluto’s atmosphere and the stream of charged particles radiating out of the Sun Measure where the solar wind is blocked by Pluto’s atmosphere Determine the escape rate of material from Pluto

PEPSSI Pluto Energetic Particle Spectrometer Science Investigation Study the density and composition of energetic particles and plasmas resulting from the escape of Pluto’s atmosphere Detect neutral molecules that are broken up by the Sun’s UV light

SDC Venetia Burney Student Dust Counter Measure concentration of dust particles across the outer Solar System Designed by students at UC Boulder Detects microscopic dust grains generated from collisions among asteroids, comets, and KBOs No dust detector has flown beyond 18AU

Encounter Pluto March 10 th, 4:20pm – Crosses the 1AU limit April 9 th – Ralph takes its first color image of Pluto – Distance to Pluto about 71 million miles

April 12 th to April 18 th – LORRI detects possible polar cap – Composition is suggested as frozen nitrogen

April 25 th to May 1 st – All 5 of Pluto’s detected for the first time – Processed picture removing background stars – Taken via LORRI at about 55 million miles

July 1 st to July 3 rd – Last images taken before safe mode

May 28 th – First hazard search completed July 4 th – New Horizons encounters a glitch – Puts itself in “safe mode” – Communications with Earth were lost July 7 th – Normal operations resume – Glitch was caused by a sequencing error – Glitch was not caused by software or hardware

July 7 th – First color map released – Images taken June 27 th to July 3 rd by LORRI

July 8 th – Distance of 3.7 million miles – Bright features around edge of Pluto are the result of image processing – Bright silver bow below the whale is observable in the unprocessed image – Intensity information from LORRI – Ralph provided the color information

July 11 th – Pluto at 1 million miles – The dark spots are only fond on the side facing Charon

July 11 th – Charon at 1 million miles – Impact craters, dark polar region, and chasms on Charon

July 13 th – 476,000 miles – The heart is about 1000 miles across

July 13 th – False color image produced by Ralph using 3 filters – Differences in surface material and features are easy to spot

July 14 – Region of the Tombaugh Regio from 47,800 miles – 1.5 hours before closest approach – Resolution of just less than 1 mile – Mountains estimated at 11,000 feet high

The flyby in a nutshell

What we have learned #1: Diameter of Pluto is 2370 ±4 km –1473 ±2.5 miles –Larger than Eris – 2326 ±12 km –Density 1.9 g/cm 3 –Eris is smaller but denser at 2.5 g/cm 3. #2: Hydra Revealed –Looks like a rubber ducky –Able to detect details as small at 0.7 miles

#3: Charon has a strange mountain on a moat – There is a mountain coming out of a depressed area – Waiting for a better image to be downlinked #4: Charon’s strange features – Some cliffs extend 600 miles across the surface – A 4 to 6 mile deep canyon – A darkened pole dubbed “Mordor” – The pole seems to be a deposite because craters in the region are white

#5: Charon doesn’t have an atmosphere – Alice solar occultation light curves drop off suddenly – Pluto’s light curve during occultation falls off much more gradually indicating the presence of an atmosphere – Once all the data is downlinked, we may find out that Charon has a tenuous atmosphere #6: Pluto has an ion tail – About 500 tons/hour is being stripped away – If this has been happening for the last 4.6 billion years, Pluto has lost 9000 feet of nitrogen

#7: Pluto’s atmosphere has layers of haze – Actually visible with the naked CCD (eye) – Much higher in the atmosphere than previously predicted – The haze particles interact with the light from the Sun to produce tholins

#8: Pluto’s atmosphere may be undergoing its first stages of collapse – Since 1988, occultations have provided data – From 1988 to 2013 the data seems to say the pressure was increasing – New Horizons measured only half the atmosphere that was measured in 2013 – This may be due to Pluto receding to aphelion

– Heart of ices that flow – Mountains over 2 miles high – Craterless plains full of ices – Some surfaces seems to be no older than 100 million years – only 2.2% of the age of the Solar System #9:Pluto is geologically active

#10 Pluto’s surface variation is pretty constant from the equator to the poles except for the Tombaugh Regio – May be due to the tilt of the axis which causes the equator to be constantly baked – May also have to do with the 30AU to 50AU orbit

The Plan Intensive downlinking began September 5 th Typical downlink rate is 1 to 4 kbps depending on how the information is sent and which DSN antenna is receiving it