[meteorite-list] NASA's New Horizons Team Selects Potential Kuiper Belt Flyby Target (2014 MU69)

[Ron Baalke]

http://www.nasa.gov/feature/nasa-s-new-horizons-team-selects-potential-kuiper-belt-flyby-target

NASA's New Horizons Team Selects Potential Kuiper Belt Flyby Target
August 28, 2015

NASA has selected the potential next destination for the New Horizons 
mission to visit after its historic July 14 flyby of the Pluto system. 
The destination is a small Kuiper Belt object (KBO) known as 2014 MU69 
that orbits nearly a billion miles beyond Pluto.
New Horizons flyby

This remote KBO was one of two identified as potential destinations and 
the one recommended to NASA by the New Horizons team.  Although NASA has 
selected 2014 MU69 as the target, as part of its normal review process 
the agency will conduct a detailed assessment before officially approving 
the mission extension to conduct additional science.
 
"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."
 
Like all NASA missions that have finished their main objective but seek 
to do more exploration, the New Horizons team must write a proposal to 
the agency to fund a KBO mission. That proposal - due in 2016 - will 
be evaluated by an independent team of experts before NASA can decide 
about the go-ahead.
 
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 will perform a series of four maneuvers 
in late October and early November to set its course toward 2014 MU69 
- nicknamed "PT1" (for "Potential Target 1") - which it expects 
to reach on January 1, 2019. Any delays from those dates would cost precious 
fuel and add mission risk.

"2014 MU69 is a great choice because it is just the kind of ancient 
KBO, formed where it orbits now, that the Decadal Survey desired us to 
fly by," said New Horizons Principal Investigator Alan Stern, of the 
Southwest Research Institute (SwRI) in Boulder, Colorado. "Moreover, 
this KBO costs less fuel to reach [than other candidate targets], leaving 
more fuel for the flyby, for ancillary science, and greater fuel reserves 
to protect against the unforeseen."

New Horizons was originally designed to fly beyond the Pluto system and 
explore additional Kuiper Belt objects. 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 more 
years; and its scientific instruments were designed to operate in light 
levels much lower than it will experience during the 2014 MU69 flyby.

The 2003 National Academy of Sciences' Planetary Decadal Survey ("New 
Frontiers in the Solar System") strongly recommended that the first 
mission to the Kuiper Belt include flybys of Pluto and small KBOs, in 
order to sample the diversity of objects in that previously unexplored 
region of the solar system. The identification of PT1, which is in a completely 
different class of KBO than Pluto, potentially allows New Horizons to 
satisfy those goals.

But finding a suitable KBO flyby target was no easy task. Starting a search 
in 2011 using some of the largest ground-based telescopes on Earth, the 
New Horizons team found several dozen KBOs, but none were reachable within 
the fuel supply available aboard the spacecraft.

The powerful Hubble Space Telescope came to the rescue in summer 2014, 
discovering five objects, since narrowed to two, within New Horizons'
flight path. Scientists estimate that PT1 is just under 30 miles (about 
45 kilometers) across; that's more than 10 times larger and 1,000 times 
more massive than typical comets, like the one the Rosetta mission is 
now orbiting, but only about 0.5 to 1 percent of the size (and about 1/10,000th 
the mass) of Pluto. As such, PT1 is thought to be like the building blocks 
of Kuiper Belt planets such as Pluto.
New Horizons Path

Unlike asteroids, KBOs have been heated only slightly by the Sun, and 
are thought to represent a well preserved, deep-freeze sample of what 
the outer solar system was like following its birth 4.6 billion years 
ago.

"There's so much that we can learn from close-up spacecraft observations 
that we'll never learn from Earth, as the Pluto flyby demonstrated so 
spectacularly," said New Horizons science team member John Spencer, 
also of SwRI. "The detailed images and other data that New Horizons 
could obtain from a KBO flyby will revolutionize our understanding of 
the Kuiper Belt and KBOs."

The New Horizons spacecraft - currently 3 billion miles [4.9 billion 
kilometers] from Earth - is just starting to transmit the bulk of the 
images and other data, stored on its digital recorders, from its historic 
July encounter with the Pluto system. The spacecraft is healthy and operating 
normally.
 
New Horizons is part of NASA's New Frontiers Program, managed by the 
agency's Marshall Space Flight Center in Huntsville, Ala. The Johns 
Hopkins University Applied Physics Laboratory in Laurel, Md., designed, 
built, and operates the New Horizons spacecraft and manages the mission 
for NASA's Science Mission Directorate. SwRI leads the science mission, 
payload operations, and encounter science planning.