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November 29, 2022

The PI’s Perspective: Extended Mission 2 Begins!

NASA’s New Horizons spacecraft is exploring the outer reaches of the Kuiper Belt of small planets like Pluto and KBOs—ancient planetesimal building blocks of the outer planets. Only NASA’s Voyager mission is operating farther out from the Sun. (Credit: NASA/Johns Hopkins APL/Southwest Research Institute/Dan Durda)

New Horizons remains healthy from its position deep in the Kuiper Belt, even as it speeds farther from the Earth and Sun by about 300 million miles per year! The spacecraft, which began its second extended mission on Oct. 1, also continues its record-length hibernation that began June 1 and ends March 1. Hibernation, which takes place in spacecraft “spin mode,” saves fuel and wear and tear on the vehicle, as well as mission budget. But even in hibernation, New Horizons collects dust impact and plasma and charged particle measurements around the clock to better understand the environment of the Kuiper Belt and the Sun’s outer heliosphere.

Once New Horizons exits hibernation, our pace of activity will pick up dramatically. We’ll begin by downlinking the science data from hibernation and the final few gigabits of data from our encounter with the Kuiper Belt object Arrokoth.

Then, in the third week of April, the spacecraft will de-spin and begin 5 to 6 weeks of intensive planetary science, astrophysics and heliophysics observations using its onboard cameras. Among the investigations: studies of Uranus’ and Neptune’s energy balances; distant KBO observations; studies of both visible and ultraviolet cosmic background light; and mapping the “local” interstellar hydrogen gas. In addition, New Horizons will continue to make round-the-clock dust impact, plasma and charged particle spectrometer measurements, just as it did in hibernation.

Once we complete this intensive science period in May, New Horizons will resume its spin mode and begin a multi-month downlink of these new data, along with still more final Arrokoth science data. Then, in September, the spacecraft will again de-spin to collect more remote sensing observations for planetary science, astrophysics and heliophysics.

But there’s more news on the New Horizons project than science data collection and downlink plans! For one, our team of project scientists, which leads the mission’s science planning, has changed. Former long-time Project Scientist Hal Weaver, of the Johns Hopkins Applied Physics Laboratory (APL), has stepped down as he begins to ease into retirement; replacing Hal is Kelsi Singer, of the Southwest Research Institute (SwRI). Stepping in to Kelsi’s former role are Pontus Brandt, of APL, and Anne Verbiscer, of SwRI and the University of Virginia. John Spencer, of SwRI, will continue as deputy project scientist as well.

Our Ralph and Long Range Reconnaissance Imager (LORRI) camera teams have new leadership too. Carly Howett, of the Planetary Science Institute, and Silvia Protopapa, of SwRI, have taken on the Ralph instrument principal investigator (PI) and deputy PI roles, and Olivier Barnouin and Terik Daly, both of APL, are the new LORRI PI and deputy PI. I want to congratulate and thank all of these hard-working team members on their leadership roles in our second extended mission!


In 2015, New Horizons made the first exploration of Pluto and its system of moons. In 2022, space artist Don Davis used imagery from that exploration by New Horizons to create this gorgeous depiction of a sunrise over Pluto’s mountain ranges, replete with stunning renderings of the planet’s blue skies and high-altitude haze layers. (Credit: Don Davis)

Some other mission news worth sharing:

  • New projections by Mission Systems Engineer Chris Hersman at APL indicate that New Horizons will quite likely have enough power to take science data through the 2040s and even to 2050, when the spacecraft is more than 125 times as far from the Sun as Earth!
  • In October, a team of New Horizons scientists led a planetary science community workshop to solicit new ideas for scientific observations New Horizons can make from its distant perch.
  • Just this month, we began studying the possibilities for New Horizons to take a 21st-century version of the iconic NASA Voyager mission’s family portrait of the planets and the Earth as a “pale blue dot” – but from a far greater distance than Voyager did. No promises as to whether this is feasible, but I’ll report on the results of that study in my next PI Perspective.
  • And while all of this is taking place, we continue to publish scientific papers every month with discoveries about the Pluto system and Arrokoth, as well as other KBOs, dwarf planets and the Sun’s heliosphere.

As you can see, the New Horizons team has been hard at work planning for and making discoveries, using NASA’s only spacecraft in both the Kuiper Belt and the outer heliosphere.

A Pluto license plate recently spotted by colleague and Purdue University professor Steven Collicott. (Credit: Steven Collicott)

Well, that’s my latest update. I’ll write again early next year. In the meantime, I hope you’ll always keep exploring — just as we do!

–Alan Stern


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