From Newsgroup: sci.space.news

http://pluto.jhuapl.edu/News-Center/PI-Perspectives.php?page=piPerspective_04_14_2016

April 14, 2016

The PI's Perspective: To Boldly Go On, In the Service of Exploration

New Horizons is healthy and has just last month completed the halfway
point in its long download of 50-plus gigabits of Pluto system data that
we collected last summer. We expect the download to continue through October or November of this year, with more data coming to the ground virtually
every week until then. And in July we'll conduct a final Pluto flyby calibration of all seven scientific instruments aboard New Horizons.

Our most recent scientific publications appeared in Science magazine last month - a series of five massive scientific reports detailing discoveries
made about Pluto system geology, surface compositions, atmospheres, plasma science, and Pluto's small moons. This was the third time the flight
of New Horizons has made the cover of Science!

This week, though, we completed and turned in our proposal to NASA to
continue the exploration by New Horizons. The proposed effort covers another almost two billion miles of space, lasting until 2021, and includes another close flyby, in 2019.

NASA will carefully evaluate this proposal for funding and let us know
the outcome by June or July. I'm so excited about what we proposed that
I thought I'd write about that "extended mission" in this installment
of the New Horizons PI Perspective, so you can learn our plans too.

Extending the Voyage

We call this mission to explore the Kuiper Belt (KB) "KEM" for
KB Extended Mission.

The centerpiece of the KEM is the close flyby of an ancient Kuiper Belt
object (KBO) called 2014 MU69 on Jan 1, 2019 - yep, on New Year's
Day! The planned flyby will approach MU69 to about 1,900 miles (3,000 kilometers), which is about four times closer than we flew past Pluto. Consequently, imaging and compositional mapping spectroscopy resolutions
are all expected to be even better than what we achieved at the Pluto
system!

We discovered 2014 MU69 (or MU69, for short) in a dedicated search for possible extended mission flyby targets that we conducted in 2014, using
the Hubble Space Telescope. MU69 is about 21 to 40 kilometers across,
which makes it about 1,000 times more massive than comet 67P that Rosetta
is orbiting but about 500,000 times less massive than Pluto. This places
it in a key intermediate size regime to better understand planetary accretion. And given its 4-plus-billion-year existence in cold storage so far from
the sun, MU69 will be the most pristine object ever visited by any space mission. With NASA's concurrence, we fired the engines on New Horizons
late last year to target this flyby before it cost too much fuel - which
would have happened had we waited.

In late 2015, with NASA's concurrence, New Horizons was targeted to
make a flyby of an ancient Kuiper Belt object a billion miles beyond Pluto, with closest approach planned for Jan. 1, 2019.

New Horizons will use all seven of its scientific instruments to explore
MU69. The encounter will include detailed global and high-resolution mapping, including color mapping. It will also include compositional mapping, searches for moons of MU69, studies of its surface properties, and searches for
an atmosphere. If KEM is approved, flyby operations would begin about
100 days out, in late September 2018 (just 2 years from now!) and continue through the first week of 2019, after closest approach. MU69 data downlink will take 20 months, until late 2020.


Some of the attributes of our flyby target (2104 MU69) and our preliminary flyby plans are summarized here.
[Table]

If I do say so myself, the flyby of MU69 would be a landmark event, shattering all distance records for deep space exploration, and yielding an impressive scientific bounty.

However, the New Horizons extended mission we proposed to NASA is much
more than just a close flyby of MU69. It also aggressively exploits New Horizons as an observation platform in the Kuiper Belt, capable of studying many other KBOs and the space environment in which they orbit. KEM's
other scientific objectives are to:

.* Make distant flyby observations of about 20 other KBOs during 2016-2020, determining their shapes, satellite populations and surface properties - something
no other mission or ground-based telescope can.
.* Make sensitive searches for rings around a wide variety of KBOs during 2016-2020.
.* Conduct a heliospheric transect of the Kuiper Belt - making nearly continuous plasma, dust and neutral gas observations from 2016 to 2021,
when the spacecraft reaches 50 astronomical units (AU) from the sun.
.* Potentially conduct astrophysical cruise science in 2020 and 2021,
after the MU69 flyby, if NASA desires.

A summary of distant KBO and Centaur observations in KEM. In the timeline (upper left), blue vertical bars indicate targeted periods when observations are possible. Object diameters, in kilometers, assume an albedo of 0.1
for smaller objects where the true albedo is not known. Object classes
are as follows: CC=cold classical; HC=hot classical; CN=Centaur; PT=Plutino; SC=Scattered; DP=dwarf planet. Diamonds show geometry and expected observation signal-to-noise ratios (SNRs). Satellite search limits assume satellite albedos of 0.10 and 3 detection thresholds.

The Kuiper Belt is a rich scientific frontier. Its exploration has important implications for better understanding comets, the origin of small planets,
the solar system as a whole, the solar nebula, and dusty Kuiper Belt-like disks around other stars, as well as for studying primitive material from
our own solar system's planet formation era. The exploration of the
Kuiper Belt and KBOs like MU69 by New Horizons would transform Kuiper
Belt and KBO science from a purely astronomical pursuit, as it is today,
to a geological and geophysical pursuit.

Strong science community support for the exploration of the Kuiper Belt
by New Horizons has been expressed by both NASA's own Outer Planets
Assessment Group (OPAG) and Small Bodies Assessment Group (SBAG). In April 2014, these two advisory committees stated that SBAG and OPAG are united
in affirmation of the tremendous scientific value of exploring a primitive
KBO in situ, where it remains essentially unaltered since the time of planetesimal formation, and that "The scientific bounty of a spacecraft encounter with a primitive KBO is realizable in our lifetimes, but only
with New Horizons - No other mission currently in flight, in build,
or in design will reach the Kuiper Belt."

With New Horizons so healthy, so capable of carrying out KEM, and so successful

at Pluto, we are optimistic about our proposal, which NASA will soon have
peer reviewed. If KEM is approved, we will begin both KEM science observations and MU69 flyby planning this fall. If the proposal fails, we will have
to turn the spacecraft off in December for a lack of funds to continue.

In the meantime, while we await word, we continue to download and analyze
data from the Pluto system, creating new science every day as we make discoveries. The flyby of Pluto may be nine months in our past, but the
data it has provided is truly a gift that keeps on giving.

That's it for now, and I'll write again soon. Until then, I hope you'll
keep exploring - just as we do!

-Alan Stern

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