Alan Stern Biography

Hubble's Faint Object Camera images Pluto through much of a rotation, enabling an image-based map of most of its surface.

Hubble results produce the first image-based surface map of Pluto, revealing about a dozen major bright and dark regions.

Hubble observations indicate Pluto's surface patterns are strongly influenced by migrating nitrogen and methane frosts.

NASA approves the New Horizons mission to conduct the first close reconnaissance of Pluto, Charon and the Kuiper Belt.

The New Horizons spacecraft arrives in Florida for final testing and launch preparations for its journey to Pluto.

New Horizons launches aboard an Atlas V rocket, beginning the first spacecraft journey to Pluto.

Mission controllers receive New Horizons' first post-launch radio signals, confirming the Pluto-bound spacecraft is healthy.

New Horizons follows Jupiter's magnetotail for roughly one hundred million miles after the flyby.

New Horizons images clumpy structures in Jupiter's faint rings and improves understanding of ring dynamics.

New Horizons obtains close views of the developing Little Red Spot and measures storm dynamics.

New Horizons uses Jupiter for a gravity assist that shortens its flight time to Pluto.

New Horizons uses Jupiter for a gravity assist and conducts a broad scientific survey of the system.

New Horizons detects lightning at high Jovian latitudes, extending known lightning activity toward the poles.

New Horizons enters its first long hibernation period during the cruise from Jupiter toward Pluto.

New Horizons begins another scheduled hibernation cycle while continuing its multi-year cruise toward Pluto.

New Horizons begins a further hibernation cycle as mission controllers conserve spacecraft resources during the Pluto cruise.

New Horizons passes the halfway point in travel time between its 2006 launch and the 2015 Pluto encounter.

New Horizons begins its fourth major hibernation cycle before the final approach to Pluto.

Controllers wake New Horizons from hibernation for the final time before its active Pluto encounter.

The New Horizons team selects 2014 MU69 as the preferred Kuiper Belt object for the spacecraft's post-Pluto flyby.

New Horizons performs a sequence of course corrections that redirects the spacecraft toward the selected Kuiper Belt object 2014 MU69.

New Horizons begins its formal approach phase toward Pluto after nearly nine years of interplanetary flight.

A 93-second thruster burn adjusts New Horizons' trajectory for the forthcoming Pluto encounter.

New Horizons becomes closer to Pluto than Earth is to the Sun, marking a major approach milestone.

Approach images begin showing distinct surface features on Pluto with steadily improving detail.

A final 23-second engine burn fine-tunes New Horizons' trajectory toward its Pluto flyby.

After a detailed hazard search, the mission team keeps New Horizons on its planned Pluto flyby trajectory.

New Horizons enters safe mode because of a spacecraft command-sequence timing problem days before the Pluto encounter.

New Horizons returns to normal science operations after recovery from the July 4 safe-mode event.

New Horizons measurements determine Pluto is about 2,370 kilometres in diameter, larger than many pre-encounter estimates.

New Horizons returns its last and most detailed full-disk image of Pluto before closest approach.

New Horizons completes humanity's first close flyby of Pluto and its system of moons.

The New Horizons team reports more than fifty Pluto-system discoveries four months after the flyby as stored data continue reaching Earth.

NASA approves the New Horizons extended mission to explore the Kuiper Belt and conduct a close flyby of 2014 MU69.

New Horizons results strengthen evidence that Pluto may retain a subsurface water-ice ocean beneath its crust.

The final stored data from the 2015 Pluto encounter finish downloading to Earth after more than fifteen months.

New Horizons reaches the halfway point in distance between Pluto and its next Kuiper Belt target, 2014 MU69.

New Horizons photographs Kuiper Belt objects 2012 HZ84 and 2012 HE85 from farther from Earth than any previous spacecraft image location.

New Horizons detects its Kuiper Belt flyby target in long-range navigation images months before closest approach.

NASA announces New Horizons images of 2012 HZ84 and 2012 HE85 as record-setting distant spacecraft observations of Kuiper Belt objects.

New Horizons flies past Arrokoth, completing the most distant close reconnaissance of a Solar System object ever attempted.

The Kuiper Belt object 2014 MU69 receives the official name Arrokoth following the New Horizons flyby.

New analysis finds evidence that liquid nitrogen has recently risen through cracks to wet parts of northern Sputnik Planitia.