To Pluto and beyond By Henry M. Holden
ANOTHER EXCITING, pioneering journey began on July 14, 2015, as NASA’s New Horizons spacecraft made its successful flight through the Pluto system. It is heading ever deeper into space to a distant and largely unknown area on the edge of our solar system.
The New Horizons spacecraft was originally designed to fly beyond the Pluto system and explore additional Kuiper Belt objects (KBO). The spacecraft carries extra hydrazine fuel for a KBO flyby; its communications system is designed to work from far beyond Pluto; its power system is designed to operate for many years, and its scientific instruments were designed to operate in light levels much lower than it will experience.
NASA’s Hubble Space Telescope selected a potential next destination for the New Horizons mission. The destination is a small Kuiper Belt object known as “2014 MU69” that orbits nearly a billion miles beyond Pluto.
This is an artist’s rendering of the New Horizons spacecraft encountering a Kuiper Belt object — a city-sized icy relic left over from the birth of our solar system. The sun, more than 4,1 billion miles (6,7 billion kilometres) away, shines as a bright star embedded in the glow of the zodiacal dust cloud. Jupiter and Neptune are visible as orange and blue “stars” to the right of the sun. (Image: JHUAPL/SwRI)
The Kuiper Belt is a vast debris field of icy bodies left over from the solar system’s formation 4,6 billion years ago. A KBO has never been seen up close because the belt is so far from the sun, stretching out to a distance of five-billion miles into a neverbefore- visited frontier of the solar system. “Even as the New Horizon’s spacecraft speeds away from Pluto out into the Kuiper Belt, and the data from the exciting encounter with this new world is being streamed back to Earth, we are looking outward to the next destination for this intrepid explorer,” said John Grunsfeld, astronaut and chief of the NASA Science Mission Directorate at the agency headquarters in Washington.
“While discussions whether to approve this extended mission will take place in the larger context of the planetary science portfolio, we expect it to be much less expensive than the prime mission while still providing new and exciting science.”
Early target selection was important; the team needs to direct New Horizons toward the object this year in order to perform any extended mission with healthy fuel margins.
New Horizons performed a series of four manoeuvres in late October and early this month to set its course toward 2014 MU69 – nicknamed “PT1” (for “Potential Target 1”) – which it expects to reach on January 1, 2019. Any delay would cost precious fuel and add mission risk.
Unlike asteroids, KBOs have not been heated by the Sun, and are thought to represent a pristine, well preserved, deepfreeze sample of what the outer solar system was like following its birth 4,6- billion years ago. The KBOs found in the Hubble data are thought to be the building blocks of dwarf planets such as Pluto.
In early September, the team identified one KBO that is “definitely reachable” and two other potentially accessible KBOs that will require more tracking over several months to know whether they, too, are accessible by the New Horizons spacecraft (see Pages 52 - 56 – A Heartful of Stars).................................... For the FULL ARTICLE please subscribe to our digital edition.