Pluto
Hubble's Faint Object Camera images Pluto through much of a rotation, enabling an image-based map of most of its surface.
Historical biography archive · Updated 2026-11-03
Alan Stern Biography and Timeline
Follow Alan Stern through 43 dated historical records for United States of America.
Alan Stern, historical timeline
A chronological timeline drawn from matching World History Database records.
43Distinct records
1 of 2Page
1994–2018Years on this page
1994
1996
Pluto
Hubble observations indicate Pluto's surface patterns are strongly influenced by migrating nitrogen and methane frosts.
Pluto
Hubble results produce the first image-based surface map of Pluto, revealing about a dozen major bright and dark regions.
2001
New Horizons
NASA approves the New Horizons mission to conduct the first close reconnaissance of Pluto, Charon and the Kuiper Belt.
2005
New Horizons
The New Horizons spacecraft arrives in Florida for final testing and launch preparations for its journey to Pluto.
2006
New Horizons
Mission controllers receive New Horizons' first post-launch radio signals, confirming the Pluto-bound spacecraft is healthy.
New Horizons
New Horizons launches aboard an Atlas V rocket, beginning the first spacecraft journey to Pluto.
2007
New Horizons
New Horizons uses Jupiter for a gravity assist that shortens its flight time to Pluto.
Jupiter Ring Clumps
New Horizons images clumpy structures in Jupiter's faint rings and improves understanding of ring dynamics.
Role range: 1957-
Little Red Spot Close-Up
New Horizons obtains close views of the developing Little Red Spot and measures storm dynamics.
Role range: 1957-
New Horizons Jupiter Flyby
New Horizons uses Jupiter for a gravity assist and conducts a broad scientific survey of the system.
Role range: 1957-
Polar Lightning on Jupiter
New Horizons detects lightning at high Jovian latitudes, extending known lightning activity toward the poles.
Role range: 1957-
New Horizons
New Horizons enters its first long hibernation period during the cruise from Jupiter toward Pluto.
Jupiter Magnetotail Traverse
New Horizons follows Jupiter's magnetotail for roughly one hundred million miles after the flyby.
Role range: 1957-
2008
New Horizons
New Horizons begins another scheduled hibernation cycle while continuing its multi-year cruise toward Pluto.
2009
New Horizons
New Horizons begins a further hibernation cycle as mission controllers conserve spacecraft resources during the Pluto cruise.
2010
New Horizons
New Horizons passes the halfway point in travel time between its 2006 launch and the 2015 Pluto encounter.
2014
New Horizons
New Horizons begins its fourth major hibernation cycle before the final approach to Pluto.
New Horizons
Controllers wake New Horizons from hibernation for the final time before its active Pluto encounter.
2015
New Horizons
New Horizons begins its formal approach phase toward Pluto after nearly nine years of interplanetary flight.
New Horizons
A 93-second thruster burn adjusts New Horizons' trajectory for the forthcoming Pluto encounter.
New Horizons
New Horizons becomes closer to Pluto than Earth is to the Sun, marking a major approach milestone.
Pluto
Approach images begin showing distinct surface features on Pluto with steadily improving detail.
New Horizons
A final 23-second engine burn fine-tunes New Horizons' trajectory toward its Pluto flyby.
New Horizons
After a detailed hazard search, the mission team keeps New Horizons on its planned Pluto flyby trajectory.
New Horizons
New Horizons enters safe mode because of a spacecraft command-sequence timing problem days before the Pluto encounter.
New Horizons
New Horizons returns to normal science operations after recovery from the July 4 safe-mode event.
Pluto
New Horizons measurements determine Pluto is about 2,370 kilometres in diameter, larger than many pre-encounter estimates.
Pluto
New Horizons returns its last and most detailed full-disk image of Pluto before closest approach.
New Horizons
New Horizons completes humanity's first close flyby of Pluto and its system of moons.
Pluto
The New Horizons team reports more than fifty Pluto-system discoveries four months after the flyby as stored data continue reaching Earth.
Arrokoth Selected as Flyby Target
The New Horizons team selects 2014 MU69 as the preferred Kuiper Belt object for the spacecraft's post-Pluto flyby.
Arrokoth Trajectory Corrections
New Horizons performs a sequence of course corrections that redirects the spacecraft toward the selected Kuiper Belt object 2014 MU69.
2016
New Horizons
The final stored data from the 2015 Pluto encounter finish downloading to Earth after more than fifteen months.
New Horizons Extended Mission
NASA approves the New Horizons extended mission to explore the Kuiper Belt and conduct a close flyby of 2014 MU69.
Pluto
New Horizons results strengthen evidence that Pluto may retain a subsurface water-ice ocean beneath its crust.
2017
Halfway to Arrokoth
New Horizons reaches the halfway point in distance between Pluto and its next Kuiper Belt target, 2014 MU69.
Record-Distance KBO Imaging
New Horizons photographs Kuiper Belt objects 2012 HZ84 and 2012 HE85 from farther from Earth than any previous spacecraft image location.
2018
Kuiper Belt Image Record Announced
NASA announces New Horizons images of 2012 HZ84 and 2012 HE85 as record-setting distant spacecraft observations of Kuiper Belt objects.
Arrokoth Navigation Detection
New Horizons detects its Kuiper Belt flyby target in long-range navigation images months before closest approach.
Records, sources and methodology
These dates and descriptions come from the historical_events database. Exact duplicate records have been collapsed. Names are grouped by the country, Name 2 and Name 1 fields; records with missing Name 2 cannot be reliably assigned to an individual biography. Check the underlying sources before formal citation.