Tag Archives: Pluto

Introducing the New Horizons Instrument Menagerie

Reposted from https://blogs.nasa.gov/mission-ames/2013/07/23/introducing-the-new-horizons-instrument-menagerie/.

During the first day of the Pluto Science Conference, being held July 22-26, 2013, in Laurel, MD, the conference participants listened to a series of talks describing the rich instrument suite aboard the New Horizons Spacecraft. This entry is just a very brief synopsis of the instruments.

Ralph, Alice, MVIC, LEISA, LORRI, REX, SWAP, PEPSSI, SDC. Those are instrument names and acronyms of the New Horizons science instruments.

New Horizons Instrument Suite at a Glance

LORRI (Long Range Reconnaissance Imager), among many things, “Enables Far-Out Encounter Science. ” That is, at 10 weeks from closest approach, LORRI can observe the Pluto system with spatial resolution better than Hubble. It is a visible camera, equipped with a 1024 x 1024 pixel CCD, with a 0.29 x 0.29 degree field of view (5 microradian pixel iFOV). LORRI also will be used, on approach, for optical navigation. The LORRI Instrument Principal Investigator and Instrument Scientist is Andy Cheng (JHU/APL) and Hal Weaver (JHU/APL), respectively.

Ralph & Alice form New Horizons’  “Remote Science Suite.” Ralph is both a color-imager (MVIC) and an infrared mapping spectrometer (LEISA). Alice is a ultraviolet spectrometer.

Ralph’s MVIC (Multi-Spectral Visible Imaging Camera) consists of seven independent CCD arrays. Four channels are filtered to map blue (400-550 nm), red (540-700 nm), near infrared (780-975 nm) and a narrow methane absorption band (860-910 nm). Six of the MVIC arrays (including all the filter channels) have a 5.7 x 0.037 degree field of view (20 microradian pixel iFOV). LEISA (Linear Etalon Imaging Spectral Array) is a grating spectrometer covering 1.25 to 2.5 microns wavelength range at a resolving power of R~240. A second segment covers 2.1 to 2.25 micron range with a resolving power of R~560. The Ralph Instrument Principal Investigator and Instrument Scientist is Alan Stern (SwRI) and Dennis Reuter (NASA Goddard), respectively.

Alice is an ultraviolet imaging spectrometer. It has two entrance apertures, a large airglow channel and a small SOCC aperture for solar occultation measurements. The entrance slit has two sections, a “box” with a 2.0 x 2.0 degree field of view, and a “stem” with a 0.1 x 4.0 degree field of view. The wavelength coverage spans from 520 to 1870 Angstroms, with a resolution of 3.6 Angstroms.  The Alice Instrument Principal Investigator and Instrument Scientist is Alan Stern (SwRI) and Maarten Versteeg (SwRI, San Antonio), respectively.

REX, New Horizons’ Radio Science Experiment, is enabled by adding a small amount of signal processing hardware to the existing communication hardware on New Horizons’ main antenna. It will be used, among other observations of Pluto, to showcase a “Different Kind of Radioscience” via 20kW uplink experiments from the DSN during the Pluto and Charon occulations at flyby. The REX Principal Investigator and Instrument Scientist are G.L. Tyler and Ivan Linscott (Stanford University), respectively.

PEPSSI (Pluto Energetic Particle Spectrometer Science Investigation) & SWAP (Solar Wind Around Pluto) are modern particle instruments designed to capture Pluto’s interaction with the solar wind. PEPSSI can measure ions and electrons from 10s of keV to 1 MeV over a 160 x 12 degree fan-shapped beam. SWAP can measure particles with energies 35 eV to 7.5 keV over a 276 x 10 degree field of view. PEPSSI’s Principal Investigator and Instrument Scientist are Ralph McNutt (JHU/APL) and Matthew Hill (JHU/APL). SWAP’s Principal Investigator and Instrument Scientist are David McComas (SwRI, San Antonio) and Heather Elliott (SwRI, San Antonio).

SDC, the Student Dust Counter, designed and built by students at the University of Colorado, Boulder, is “The First Student Experiment on a Deep-Space Probe.” The Principal Investigator is Mihaly Horanyi (University of Colorado). There have been numerous Instrument Scientists, all students at Univ. of Colorado. The current Instrument Scientist is Jamey Szalay. Students continue to be active in supporting data analysis as SDC collects dust rates on its voyage through the solar system. More information about the SDC and the students behind it at http://lasp.colorado.edu/sdc/.

More details about each of the instrument descriptions and performance can be found at http://pluto.jhuapl.edu/Mission/Spacecraft/Payload.php.

Locations of the science instruments on the New Horizons Spacecraft


The Architecture of New Horizons’ Pluto Fly-By Sequence

Reposted from https://blogs.nasa.gov/mission-ames/2013/07/22/the-architecture-of-the-pluto-fly-by-sequence/.

In her presentation at the Pluto Science Conference, Dr. Leslie Young (SwRI), deputy Project Scientist and chief architect of the Pluto Encounter Sequence, stepped us through the New Horizons’ Science Objectives and the types of observations that will be pre-programmed aboard the craft for the entire year of 2015. Unique science is not just around Pluto Closest Approach on Tues, Jul 14, 2015, but many months prior and post the encounter. Although most of the “Group 1” (see below for description) science objectives for the mission will be met by measurements made in the -2hr to +3hr from closest approach. Closest approach is on July 14, 2015.

Leslie Young (deputy Project Scientist) describes the overview of the science highlights for the year 2015. Also shown in the slide is a mapping of the Science Objectives per each phase.

Science space missions typically have a set of “science requirements,” specific measurements to address specific questions, set forth to be met by the mission design. The main science questions that the New Horizons mission is designed to answer were asked in the proposal call (AO 01-OSS-01) that NASA put out in early 2001, the competition which the New Horizons team won. The proposed series of measurements that New Horizons will do with its instrument suite provide measurements to answer Group 1, Group 2 or Group 3 objectives. Group 1 are measurements that must be done and define baseline science mission success. Group 2 are highly desired measurements and Group 3 are desired measurements. To obtain data that meets Group 1, 2 & 3 measurements is full-science success.

That single slide that Leslie showed (above) is the sum of many, many, many months of work with the New Horizons Science Team, along with support from the project’s Mission Design team, to identify which measurements of which body at which time (or times), as an ensemble meet the Group objectives. She specifically calls out the Group 1 by showing those categories in Bold Italics.

As the New Horizons Science Fly-By mission is a temporal series of measurements, the mission has been constructed to compartmentalize the measurements as a function of day from the closest approach. Hundreds of unique measurements are scheduled in rapid-formation within the day prior and after closest approach, called the NEP or Near Encounter Period.

Some Pluto Encounter Design Temporal Terminology:
AP= Approach Phase, NEP=Near Encounter Period, DP=Departure Phase
AP1: Jan 6-Apr 4, 2015, P-180 to P-100 days to Closest Approach
AP2: Apr 4-Jun 23, 2015, P-100 to P-21 days to Closest Approach
AP3: Jun 23-Jul 13, 2015, P-21 to P-1 days to Closest Approach
NEP: Jul 13-15, 2015, P-1 to P+1 day from Closest Approach
DP1: Jul 15-Aug 4, 2015, P+1 to P+21 days from Closest Approach
DP2: Aug 5-Oct 22, 2015, P+21 to P+100 days from Closest Approach
DP3: Oct 22, 2015-Jan 1, 2016, P+100 to P+180 days from Closest Approach

Leslie Young describes the mission science measurements on a timeline near closest-approach. The instruments are color-coded in this representation of the distance to Pluto (y axis) vs. distance from Earth/Sun (x axis) with respect to the closest approach (nominal July 14, 2015 11:50 UTC).

A larger version of that slide is shown below. The x-axis spans 5 hrs of time.


Below is a summary of the best spatial resolution measurements anticipated from New Horizons’ Remote Sensing Suite within a few hours of closest approach. Panchromatic (LORRI camera), Color (Ralph MVIC), and Infrared (Ralph LEISA) resolutions are shown against each target body for the closest-distance to those target bodies in the nominal sequence. The science requirement for the equivalent Group 1 objective is shown in italicized text.

Best_ResWith our current best resolution of Pluto spanning 100 km/pixels taken with the Hubble Space Telescope, the New Horizons mission with its up-close-and-person will rewrite the textbooks on this elusive system with more than 2 orders of magnitude resolution improvement, plus spectral, radioscience, and plasma unique measurements.

Our best on Pluto from Hubble can be found form these links for observations taken in 1994 & 2010:
http://hubblesite.org/newscenter/archive/releases/1996/09/image/a/format/web_print/ and http://hubblesite.org/newscenter/archive/releases/solar-system/pluto/2010/06/, respectively.

Calling for proposals to observe the Pluto System from Earth and Earth satellite-assets! “As planetary astronomers, we love phases” as Rick Binzel (MIT) describes “Earth-Based Observing Campaign for the New Horizons Encounter.” We’re going to need to make a link to connect decades of earth-based observations of the Pluto system before the fly-by and continue it for decades after the New Horizons fly-by. There is a website set up for information on how to participate and get more information. Specifically observations are needed in 2014, 2015 (encounter year), and 2016.


The website will be based at http://www.boulder.swri.edu/nh-support-obs/ . Check back later since they are actively working the content, but you can always email nhobs “at” boulder.swri.edu for information.

Rick Binzel also introduced the campaign to get a Lego set made of the New Horizons Spacecraft. It needs to vote to get it approved for production. Note: this requires you to register for free-account to log in to vote. https://ideas.lego.com/projects/107933.

New Horizons LEGOSumming up the first session of an exciting beginning to the Pluto Science Conference,  per Alan Stern, the Principal Investigator for NASA’s New Horizons’ Mission: “The most exciting discoveries will likely be the ones we don’t anticipate” and  “Revolution in Knowledge is in Store.”

Initial Reconnaissance of the Solar System’s Third Zone

Reposted from https://blogs.nasa.gov/mission-ames/2013/07/22/initial-reconnaissance-of-the-solar-systems-third-zone/.

This is part of a blog series on the Pluto Science Conference, “The Pluto System on the Eve of Exploration by New Horizons: Perspectives and Predictions,” held July 22-26, 2013 in Laurel, MD.

alan_stern_nh_overviewNew Horizons’ Principal Investigator (lead scientist) is Dr Alan Stern (SwRI/Southwest Research Institute). In his presentation, he gave an overview of the mission concept, the science objectives and mission status. The scientific suite is sophisticated and carries the first student-built deep space instrument. The cruise period spans two Presidential administrations (8 years). New Horizons launched on January 19, 2006, and will fly by the Pluto system with closest approach July 14, 2015.

For more information about the mission, do check out the New Horizons Mission Websites: http://pluto.jhuapl.edu/ (JHU APL site) and http://www.nasa.gov/mission_pages/newhorizons/main/index.html. (NASA site).

At a glance, the New Horizons Mission to Pluto and Beyond. Key milestone dates and the spacecraft trajectory (in red).

Measurement-wise, New Horizons’ Pluto fly-by of July 2015 is comparable to Voyager 2’s fly-by of Neptune’s moon Triton in 1989. However, Voyager 2 did not have an infrared mapping nor ultraviolet imaging spectrometer, something New Horizons will have. Also, New Horizons will be flying three times closer to Pluto than Voyager 2 did at Triton.  A snapshot of the comparison highlights from Alan’s talk is below.

Comparison of Voyager 2 data from its fly-by of Neptune’s moon Triton in August 1989, with a “visualization” of what New Horizons’ best resolution at Pluto might reveal during its fly-by of Pluto in July 2015.

The New Horizons’ unique science encounter involves more than 6 months of active science operations, starting in mid-April 2015 when the on-board instrument suite achieves resolution better than Hubble.

A more in depth discussion about “When will New Horizons have better views of Pluto than Hubble does?” can be found in this blog entry on the Planetary Society’s blog site at http://www.planetary.org/blogs/emily-lakdawalla/2013/0218-new-horizons-pluto-better-hubble.html .

For more in-depth information about the New Horizons mission check out a series of a papers published in Space Science Reviews.  Link: http://www.boulder.swri.edu/pkb/

To end this posting, a few fun factoids about New Horizon’s Speedy Performance since Launch.

New Horizons’ Speed Record. Launched on an Atlas V-551 on January 19, 2006 at 14:00 EST, the ~400 kg spacecraft, about the size of a grand-piano, needs to travel 5 billion km (5x10e9 km) from Earth before it can execute the observations for its prime science mission. Launching with a speed of  58,000 km/hr (36,000 mph) and benefiting from a gravity-assist from Jupiter in February 2007 (which boosted the spacecraft speed), New Horizons will reach its destination, Pluto, after ~9.5 years of space flight.

New Horizons Speed Facts:
Launched at 36,000 mph
Passed Moon’s orbit in 9 hours
Passed orbits of:
Mars on 4/7/2006
Jupiter on 2/28/2007
Saturn on 6/8/2008
Uranus on 3/18/2011
To cross orbit of:
Neptune on 8/24/2014
With closest Approach Pluto-Charon on 7/14/2015

New Horizons, a mission for the patient (and persistent)

Reposted from https://blogs.nasa.gov/mission-ames/2013/07/22/new-horizons-a-mission-for-the-patient-and-persistent/.

New Horizons is a Mission for the Patient (and Persistent). It is a labor of love, dedication, fortitude, with compelling science, top-notch engineering, and tight management. This is an entry part of a blog series covering the Pluto Science Conference, held July 22-26, 2013 in Laurel, MD.

Tom Krimigis (JHU/APL) started off our excited Pluto crowd with an overview of the steps that enabled the New Horizons mission to become reality. Any science mission starts with its science objectives. Successful science mission concepts that make it to launch rely on thorough reviews of its science, engineering, and investment (i.e. cost & feasibility).  New Horizons, owes its existence to both initial scientific grounding work by the scientists in the 1970s and equally also to the persistence of those scientists and supporters at NASA and Congress over the subsequent decades to make it get to flight. New Horizons was selected in November 2001 from a competition and launched in January 2006. It will reach its destination, the Pluto-Charon system in 2015.

A rose by any other name is still a rose. A mission to Pluto has had many names over these past decades and with concepts “varying on a theme.” It was called Mariner-Jupiter-Pluto (MJP), mini Voyager-Pluto Fast Flyby (PFF), Pluto Express-Pluto-Kuiper Express, and now New Horizons, among many mission names.

For more reading about the saga, science, and significance of Pluto exploration, check out Andrew Lawler, Science 295, 32-36, Jan 4, 2002. “Planetary Science’s Defining Moment.” at http://www.sciencemag.org/content/295/5552/32.full.pdf  (requires login access) or find it here from the author’s website.


Pluto Not Yet Explored (lower right) from USPS Stamp Series (1991)

Introducing the Pluto Science Conference July 22-26, 2013

Reposted from  https://blogs.nasa.gov/mission-ames/2013/07/22/introducing-the-pluto-science-conference-jul-22-26-2013/.

The mind of a scientist understands, embraces, and executes the scientific method, the process by which an idea is created, then tested by experiment or model, validated or refuted, and then, when validated, culminates in the description of the results to the larger community through a publication. The cycle begins again, sometimes building on previously published work, or in some cases, the birth of new ideas to the scene, most likely inspired by previous knowledge.

A key component to a scientist’s work is the attendance and interaction with colleagues at scientific conferences. At such gatherings we can see examples of the scientific method in a multitude of stages: the birth of a new idea, the suggestion of methods to carry-out the experiment or computation, a presentation that disproves an approach requiring the scientist to start anew, through the description of the results of the recent experiment or computation.

~150 people are to gather this week at the Johns Hopkins University Applied Physics Laboratory in Laurel, MD to share ideas, debate hypotheses, and explain experiments related to the emissary from our Solar System’s Third Zone, the dwarf planet Pluto and its moons. The timing is crucial to have these conversations because in two years from now, in July 2015, NASA’s New Horizons Spacecraft will do a close fly-by of the Pluto system, a system never before visited by another spacecraft. The forum provides an update of the mission and its measurement capabilities and encourages healthy dialog among theorists who have predictions, laboratory spectroscopists who can build examples of chemistry happening on these icy bodies, and observers who have been monitoring and documenting the changing nature of Pluto and its environment.

Details about the Pluto Science Conference, “The Pluto System on the Eve of Exploration by New Horizons: Perspectives and Predictions,” can be found here at http://pluto.jhuapl.edu/News-Center/events/2013-PlutoScienceConference/.

You can follow the New Horizons mission status at any time by visiting the New Horizons Mission Website at http://pluto.jhuapl.edu/ and http://www.nasa.gov/mission_pages/newhorizons/main/index.html.

I’ll be providing summaries of the meeting content and discussions through a series of blog posts this week. For now, I’ll leave you with some things we do know about Pluto and its largest moon Charon.

The diameters of Pluto & Charon shown with respect to the USA for scale.

What do we know about Pluto so far?

  • Highly elliptical (e = 0.25), Highly inclined (i = 17 deg), 248 year orbit
  •  Rotational period of 6.387230 days
  •  Small (diameter = 2328 ± 42 km), Rock/Ice object (“Icy Dwarf”)
  •  Density is 2.03 ± 0.06 g cm-3, Mass = 0.0022 MEarth
  •  Bright surface frosts of N2, CH4, CO, and C2H6  produce albedo of ~55%
  •  Highly variegated surface (bright and dark regions)
  •  Reddish in color, probably due to surface organics
  •  Tenuous, variable atmosphere (mostly N2; 2-10 µbars at the surface & going up)

What do we know about Charon?

  • Discovered, by accident, in July 1978 by James Christy (USNO)
  •  In circular orbit ~19,573 km from Pluto, with a 6.3872273 day period
  •  Tidally-locked spin period (i.e., spin-orbit synchronous)
  •  Diameter is 1212 ± 3 km (about half of Pluto’s Diameter: “Binary Planet”)
  •  Density is 1.66 ± 0.06 g cm-3 (vs 2.03 ± 0.06 g cm-3 for Pluto)
  •  Surface has crystalline H2O-ice and NH3-hydrate (recent?)
  •  Average albedo ~35%, neutral color (variegation change over time?)
  •  Average T ~ 50 K, low thermal inertia (high porosity)
  •  No atmosphere detected yet (~10-300x lower pressure than Pluto’s)
(left) Charon Discovery Image July 1978; (right) New Horizons’ LORRI instrument spots Charon July 2013 from 6AU away.

To Pluto and beyond!