New Horizons Spacecraft
Introduction:
The mission of the New Horizons craft was developed to collect images and data of the dwarf planet Pluto, as well as add information so that we could understand the edge of the solar system. New Horizons would fist make a reconnaissance around Pluto and then enter into deeper space to explore the Kuiper Belt.
New Horizons was launch on January 19, 2006 with a targeted flyby of Pluto in July, 2006.
Prior to New Horizons, Pluto was at such as distance that even the best telescopes of the time could only offer a blurred grey image. Understanding Pluto was critical because we needed to know how it fit in with the other terrestrial and gas giant planets.
Pluto exists in the Kuiper Belt and the National Academy of Sciences has ranked exploration of the Kuiper Belt as a high priority. Pluto and Charon, its largest moon, are part of a third category of planets that are defined as “ice dwarfs.” These are dwarf planets that share the characteristic of having a solid surface with terrestrial planets, but a large portion of their mass is made up of icy material.
Thanks to the Hubble Space Telescope, the team for New Horizons discovered four additional moons of Pluto that were previously not known: Nix, Hydra, Styx, and Kerberos.
To understand how our solar system was formed we need to explore Pluto and the Kuiper Belt objects and see how these bodies have evolved.
The U.S. has been the first nation to reach and explore planets from Mercury to Neptune with probes. The mission of New Horizons completes the first solar system reconnaissance with the flyby of Pluto.
When a spacecraft is designed it has a specific lifecycle that is expected, in the same way that we know that eventually our cars and electronics will break. Spacecraft have some specific challenges that affect the lifetime including cosmic rays, solar particles and other phenomena that can mess up the electronics over time.
These conditions make it difficult to plan long missions such as New Horizons and require backup systems as well as a source of continual power that can keep it functioning far away from the sun’s energy.
Part of the plans for New Horizons was to make a quick visit to Jupiter for the purposes of using its gravity to boost it on its journey. New Horizons was to pass Jupiter at less than 1.4 million mi/2.4 million km and this would make it the first spacecraft since the Galileo probe to swing by Jupiter.
The first pictures that were sent back to Earth as New Horizons passed Jupiter were those of the volcanic activity of Jupiter’s moon, Io. The clearest images ever seen included the Tvashtar volcano.
An additional part of the mission found New Horizons flying through a stream of charged particles that were behind Jupiter. Examination of the particles found that they were large plasma bubbles that were charged.
Scientists said that this discovery would assist them in understanding the environment around “hot Jupiter” planets that have been found around other stars, as well as the large planets that are Jupiter-sized that have been located close to the orbit of their stars.
Conserving energy is a priority for a spacecraft on such a long mission and it also reduces the chances anything breaking. Controllers put New Horizons into hibernation mode and only woke it up for periodic system and navigation checks. It came out of hibernation mode in 2014 so that it could begin preparation for the encounter with Pluto.
When New Horizons finally achieved getting to Pluto it was so busy collecting the information and data that it didn’t send back communications to Earth during its closest approach to both Pluto and Charon, the dwarf planet’s moon. Controllers were concerned about the lack of contact but they finally celebrated when the little spacecraft “phoned home,” announcing that it would be sending the information.
The distance of New Horizons from the Earth when it was going to transmit the data about Pluto was around 3 billion mi/5 billion km. This had previously presented power challenges to the designers, especially because the rays of the sun are too weak at that distance to generate any power.
There are additional delays for communications and once New Horizons reached Pluto it would take 4.5 hours for a one-way message to get to New Horizons and another 4.5 hours for a return message to Earth.
The only thing that we knew about Pluto prior to New Horizons was that it looked like a fuzzy grey blob. The first pictures from New Horizons changed all that, showing that the surface of Pluto was relatively young, and that it had a mountain range that reached 11,000 ft/3,500 m high.
Scientists think that the mountain range is around 100 million years old and the fact that it exists leads them to believe that there was more recent surface geological activity.
This is important because researchers didn’t think there would be any geological activity on many of the icy worlds, and this discovery has required them to rethink what powers the activity on these planets.
Just north of the mountain range, New Horizons found that Pluto had a large plain that seemed to lack very many craters. This was another reason that scientists questioned geological activity that would have covered the evidence of craters. The area that they examined when the pictures were sent back was informally named Sputnik Planitia, and continues to be a focus of study.
When other telescopes located four new moons around Pluto that were previously unknown, those that were navigating New Horizons were concerned that there might be a problem. Thankfully, the moons weren’t in the trajectory path of the spacecraft.
Additional discoveries that New Horizons found during the journey was on Charon. There is significant evidence that there was a subsurface ocean on Charon in the past. New Horizons also found odd water-ice hills on Pluto that were floating in frozen nitrogen.
Scientists released a study in 2018 that suggested that Pluto may have an asphalt layer just under the surface. Other researchers are theorizing that Pluto might have a surface that has the ingredients for life, even though it is so far away from the sun.
New Horizons was well on its way to Pluto when, in 2006, the IAU (International Astronomical Union) had voted to reduce Pluto’s status to a dwarf planet. The decision to change Pluto’s classification was based on the discovery of several objects in the Kuiper Belt that were of similar size to Pluto.
Alan Stern, the principal investigator for the New Horizons team was not in favor of the decision, specifically because the Pluto flyby revealed that the little planet had more of a complex history of formation than anyone had previously thought.
A group of planetary scientists submitted a 2017 proposal to reclassify Pluto as a planet during the 48th Lunar and Planetary Science Conference in Woodlands, Texas.
The proposal redefined a “planet” as a round object that has never experience fusion (such as what happens in a star). The definition would include not just dwarf planets, but moons as well.
The 2016 NASA approval of extending the New Horizons mission so that it would take a look at the object 2014 MU69 in the Kuiper Belt, whose nickname is Ultima Thule. After a planned hibernation period of five months in 2017, the probe was awakened to plan for the extended mission.
New Horizons had previously taken some photos of objects in the Kuiper Belt including 2012 HZ84 and 2012 HE85, which had been the farthest distance that any spacecraft had taken photos.
(3.79 billion mi/6.12 billion km) The previous record for the farthest images was held by Voyager 1 when it took the famous “Pale Blue Dot” picture in 1990 from 3.75 billion mi/6 billion km from Earth.
New Horizons did a flyby of MU69 and it was so far away that the controllers didn’t know that it had accomplished the flyby until 10 hours later. New Horizons was 2,000 mi/3,540 km at its closest point to MU69.
The images sent back showed that MU69 was made up of two lobes and each one was almost spherical.
This was when NASA gave the nickname of Ultima to the larger lobe and Thule to the smaller lobe. The lobes are a reddish color and were at one time two separate objects that gradually became gravitationally attracted to each other over time.
The 2017 meeting of the OPAG (Outer Planets Assessment Group) in La Jolla, California brought about an announcement that the controllers of New Horizons thought that it had a “fighting chance” of encountering another object after the MU69 encounter. It depends on a number of variables including NASA approval of an extended mission.
No matter how long or short the mission, scientists, engineers, artists, and others are proposing to put a crowd-sourced message from Earth onto the hard-drive of New Horizons.
The Team:
Every spacecraft involves numerous individuals and companies that work as an integrated team. Each is responsible for the development and success of specific areas.
The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, designed, built, and operates the New Horizons spacecraft as well as responsible for management of the mission for NASA’s Science Mission Directorate.
The principal investigator is Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado. SwRI is responsible for data reduction and archiving, science payload operations, and participates as part of the science team.
The mission team also includes: KinetX, Inc. as part of the navigation team, Ball Aerospace Corporation, NASA Goddard Space Flight Center, the Boeing Company, Stanford University, NASA Jet Propulsion Laboratory, Lockheed Martin Corporation, the U.S. Department of Energy, University of Colorado, and NASA centers and university partners.
History:
New Horizons had a lofty mission to explore some of the objects that were the furthest out in the solar system than we had ever journeyed. On January, 19, 2006, New Horizons launched carrying an array of scientific and exploration technologies and devices.
New Horizons was going to take eight years to travel from Earth to Pluto. The original mission was only going to involve flybys and transmission of information regarding Pluto, however, NASA approved the extended mission so that once the Pluto portion was complete, the spacecraft could head into the farther areas of the Kuiper Belt to examine other old, and icy worlds that existed beyond the orbit of Neptune.
The journey of New Horizons was going to be a long one but scientists were hoping that the information sent back would help us to understand some of the basic questions that we have about the surface, geology, interior, and possible atmosphere of some of these objects in the Kuiper Belt region.
Calendar:
- Jan. 19, 2006: New Horizons launched.
- Feb. 2007: New Horizons swings by Jupiter for gravity boost, sending back the first images of Jupiter’s volcanic moon, Io including the first images ever taken of the volcanic fallout that was bigger than the state of Texas from the Tvashtar volcano.
- July 14, 2015: New Horizons has its closest approach to Pluto sending back data and images of the icy dwarf planet.
- Feb. 2019: New Horizons stretches its mission goal and does a close approach to point its cameras at 2014 MU69. Nicknamed Ultima Thule, this is the farthest object every viewed in the Kuiper Belt and the images that were sent back to Earth were obtained by the telephoto Long-Range Reconnaissance Imager LORRI).
- This was a particular success because to achieve the images it required that the team know exactly where both MU69 and New Horizons were at every moment. Examining the images of Ultima Thule has led the scientists to believe that it is the most primitive object ever encountered by a spacecraft.
- Mar. 2019: NASA creates a map of MU69 using the extensive data sent back by New Horizons. The map displays the complex geology including the various sized bumps and lumps on the object.
Facts about New Horizons Spacecraft:
- The most outrageous thing that New Horizons has done is to pass through a circular region of space that was only 300 km in diameter.
- New Horizons is so far, the fastest spacecraft that was launched, with a speed leaving Earth og nearing 16.26 km per second.
- So far, only four other spacecraft have travelled as far as New Horizons: Pioneer 10, Pioneer 11, Voyager 1, and Voyager 2.
- In addition to the intense amount of scientific equipment on New Horizons, it is also carrying a few artifacts including a US flag and an ounce of Clyde Tombaugh’s ashes. Tombaugh is the man that discovered Pluto in 1930.
- The power for New Horizons comes from a radioisotope thermal generator. This is a requirement since it is so far from the sun.
https://www.nasa.gov/mission_pages/newhorizons/main/index.html
https://www.nasa.gov/sites/default/files/atoms/files/nh-fact-sheet-2015_1.pdf
https://blogs.nasa.gov/pluto/2018/12/20/the-pis-perspective-on-final-approach-to-ultima/
https://www.space.com/18377-new-horizons.html
