[meteorite-list] New Horizons: To Boldly Go On, In the Service of Exploration (2014 MU69)

[Ron Baalke]

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