A NEW HORIZON FOR PLUTO: A MISSION TO UNDERSTAND THE OUTER SOLAR SYSTEM
John A. Jaksich
New Horizons Instrumentation Packages
Among Solar System objects, the Pluto/Charon system is among the least understood. The ignorance of the Pluto/Charon system is due in part to its distance from Earth, and as well as its size and eccentricity of its orbit around about the Sun. Understanding the outer solar system is important because this part of the solar system most resembles the early stages of the solar system’s development.
Trajectory of New Horizons probe
When the New Horizons spacecraft encounters the Pluto/Charon system in 2015, it will have traveled approximately 33 AU in the shortest time of all the spacecraft to date. The probe will spend approximately 150 earth-days characterizing and measuring the Pluto/Charon system to a much higher level of accuracy than possible from even Hubble. Its science suite consists of seven instrument packages:
The objectives of the New Horizons mission may be summed in one sentence: characterize and understand the aspects of the early Solar System. The methods which New Horizons will use consist of:
- Understand Global geology & morphology of the Pluto/Charon system
- Map the Pluto/Charon system
- Attempt to identify Pluto’s atmosphere.
After numerous Keck and Hubble images, it was determined that Pluto contains a wispy atmosphere that will wax and wane proportionate to its eccentricity and distance from the Sun.
At this point, let’s speak more of the instrumentation packages:
RALPH is a single telescope with two separate image collectors—Visible and infrared
- Multispectral visible imaging camera (MVIC) will produce visible color images of the Pluto/Charon system.
- Linear Etalon Imaging Spectral Array (LEISA) is an infrared imager designed to measure the distribution of Methane, molecular Nitrogen, Carbon Monoxide and Water.
Alice is a UV spectrometer—it will measure Ultraviolet light absorption of Pluto in two modes:
- Sun/star occultation
- “’Airglow mode’”- no star occultation
REX is a Radio experiment that has two purposes:
- Through the bending of the radio waves through interplanetary space—it is designed to characterize the average molecular weight of Pluto’s atmosphere
- REX is also designed to measure weak radio emissions from the Pluto’s surface—namely, it will derive an accurate temperature of the night-side temperature.
LORRI enables investigators to map Pluto down to 100 meter resolution in the visible light with an effective 8 inch aperture.
PEPSSI is a low-resolution plasma detection device designed to roughly count the escape of atoms from Pluto.
SWAP will measure the amount of solar wind near Pluto—and in effect determines Pluto’s magnetosphere.
Finally, a public outreach experiment—the Student Dust Counter (SDC) is built and managed by students at the University of Colorado, Boulder. The main objective of SDC is to count and measure the size of interplanetary dust particles.
When the New Horizons probe completes its Solar System trek—we may muse that it was just a small step in a long journey past the Pluto/Charon system. We might—if luck prevails—have a better understanding of our Solar System’s origins as a result from New Horizons, as well as, by future probes.