Ten Years & Three Billion Miles

Well, hi there. So here goes… This is my first EVER blog post! Contact light. Shutdown. Okay engine stop. Mode control, auto. Descent engine command override off. Engine arm, off… Blogging world, I have landed.

Let me start by taking us back; back to 2006 when Pluto left our Solar System (purely in a ‘reclassified’ sense) and like that, we went from 9 to 8 Planets. But we hadn’t truly said Goodbye.

Back to the present day, now that the majority of NASA’s New Horizons data has been downloaded back here on Earth, it seems only fitting to reflect on the ten years and three billion mile journey that took New Horizons to arguably the furthest frontier of our solar system.

New Horizons is one part of NASA’s New Frontiers program of space exploration missions with the purpose of researching several of the Solar System bodies, including Pluto, and was developed and advocated by NASA and its approval was granted by Congress and it received it’s funding in 2002. NASA then worked around the clock to deliver New Horizons to the launchpad in time for the earliest possible launch window and therefore guaranteeing the shortest flight time to Pluto, 10 years.

The New Horizons spacecraft arrived at John F. Kennedy Space Center/Cape Canaveral Air Force Station in September 2005, where various tests were run to demonstrate readiness for launch. Passing the Mission Readiness Review on 13th of December 2005, and New Horizons launched on the 19th of January 2006.

A Lockheed Martin Atlas V rocket carrying the New Horizons spacecraft lifts off from Launch Complex 41 at Cape Canaveral in Florida, Thursday, January 19, 2006. The New Horizons spacecraft is bound for the planet Pluto to map surface composition and temperatures, and examine Pluto's atmosphere. It will take 9 years for the spacecraft to reach the planet Pluto. (Photo by Red Huber/Orlando Sentinel/MCT via Getty Images)

Lockheed Martin Atlas V rocket carrying the New Horizons spacecraft lifts off from Launch Complex 41 at Cape Canaveral in Florida, Thursday, January 19, 2006. The New Horizons spacecraft is bound for the planet Pluto to map surface composition and temperatures, and examine Pluto’s atmosphere. It will take 9 years for the spacecraft to reach the planet Pluto.

Image credit: Photo by Red Huber/Orlando Sentinel/MCT via Getty Images)

Settling comfortably into it’s long journey, New Horizons opened the aperture on it’s LOng Range Reconnaissance Imager (LORRI) on the 29th August 2006, and its first images of a star cluster looked great.

060901_new_horizons_02

On Aug. 29, 2006, the New Horizons Long Range Reconnaissance Imager (LORRI) opened its launch cover door and took its first image in space, of Messier 7, a star cluster in our Milky Way galaxy. The image shows the center of Messier 7, which was catalogued by Charles Messier in 1764, and described by Ptolemy around 130 A.D. Stars to at least 12th magnitude are clearly visible, meaning LORRI’s sensitivity and noise levels in space are consistent with its pre-launch calibrations on the ground. Directionally, north is at the top of the images, east is to the left.

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

But in early September, the New Horizons team announced that LORRI had accidentally been pointed at the Sun! As anybody who has worked with telescopes knows; focusing sunlight on a sensitive detector/sensor can overheat and destroy the detector, it is the same reason you’re told as a child to never look directly at the Sun. Fortunately, the Sun was only briefly exposed to the LORRI sensor, and LORRI survived without any degradation, thank goodness. And on New Horizons went, flying by Jupiter for a gravity assist that saved a whole three years of flight time!

For most of the eight-year cruise from Jupiter to Pluto, the craft spun slowly in a state of peaceful hibernation, signalling once a week to assure that it was indeed ‘sleeping peacefully.’ But for about 50 days each year, it was awakened to conduct an intensive set of mechanical and instrument checks as well as navigational measurements to verify that New Horizons still on course for Pluto.

Nine years after launch; In December 2014 the spacecraft was awakened from its final planned hibernation 2.9 billion miles from Earth, and only 162 million miles from Pluto.

“This is the turning of a page. This is changing from a mission in cruise to a mission at its destination,”

Alan Stern, of the Southwest Research Institute in Boulder, Colorado

pluto-charon-orbit-new-horizons

This photo of Pluto (centre) and its largest moon Charon was captured by NASA’s New Horizons spacecraft in July 2014 and released on Aug. 7. New Horizons took this image and others from a range of 267 million to 262 million miles (429 million to 422 million kilometers).

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

On the 14th of July 2015 New Horizons made its closest approach to Pluto passing within 7,800 miles from the surface. And I cried. Before that date, back in 1994, the Hubble Telescope had offered us the only image that was representative of the highest resolution that could be achieved from Earth of what Pluto actually looked like.

pluto

The Pluto image to the right was taken by New Horizons just 16 hours before closest approach in July 2015. This LORRI image is the raw, compressed version seen by New Horizons scientists shortly after midnight on July 13, but it still clearly demonstrates the dramatic increase in science content available from a flyby mission.

Image credit: NASA/ESA/A. Stern and M. Buie (left image); NASA/JHUAPL/SWRI (right image)

The Pluto encounter in July 2015 was the highlight of the New Horizons mission, and the World gasped at the image of the iconic “heart” of Pluto and the diversity of the terrain surrounding it. Meanwhile, whilst LORRI was taking its photographs the onboard Particle Instrument used to measure the properties of the solar wind around Pluto (SWAP) and the Particle Detection Instrument used to detect molecules and atoms escaping from Pluto’s atmosphere and whilst it also searched for dust, which inferred meteoroid collision rates and would determine if Pluto had any invisible rings (PEPSSI) were working overtime measuring and recording its findings and sending its data back to Earth. The Radio Experiment (REX) performed active and passive radio science so that the communications dish on Earth measured the disappearance and reappearance of the radio occultation signal as the probe flew by behind Pluto. The results resolved Pluto’s diameter (by their timing) and atmospheric density and composition (by their weakening and strengthening pattern). (The ultraviolet Imaging Spectrometer ALICE can performed similar occultations, using sunlight instead of radio beacons). Pluto’s mass and mass distribution were evaluated by the gravitational tug on the spacecraft. As the spacecraft sped up and slowed down, the radio signal exhibited a Doppler shift. The Doppler shift was measured by comparison with the ultrastable oscillator in the communications electronics. Reflected sunlight from Pluto’s moon Charon allowed for some imaging observations of the nightside as backlighting by the Sun gave an opportunity for REX to highlight if Pluto had any rings or atmospheric haze that PEPSSI didn’t record with its particle detection instrument. Then almost as soon as it had arrived on the 25th of October 2016, the last of the recorded data from the Pluto flyby was received from New Horizons.

Mission accomplished!

mission-pathtopluto-missiontimeline-tenyears

With news that a New Horizons mission extension proposal has been granted, in January 2019 New Horizons will encounter the Kuiper Belt, specifically object 2014 MU69, which might be the most primitive body ever visited by a spacecraft. So we must say so long and good luck to New Horizons, and the spell you cast over us as we followed your  journey to distances that are truly incomprehensible, and a heartfelt thank you for offering the best images of Pluto anyone has ever seen! I can only hope New Horizons fares just as well on its way into the Kuiper Belt, survives, and advances our knowledge of the outer Solar System even farther.

So for now, Godspeed New Horizons. Speak to you soon.

Title image credit: ESA

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