Sol Alan Stern (born November 22, 1957) is an American engineer,
planetary scientist and
space tourist
Space tourism is human space travel for recreational purposes. There are several different types of space tourism, including orbital, suborbital and lunar space tourism. Tourists are motivated by the possibility of viewing Earth from space, ...
. He is the
principal investigator of the ''
New Horizons
''New Horizons'' is an Interplanetary spaceflight, interplanetary space probe launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institut ...
'' mission to
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ...
and the Chief Scientist at
Moon Express.
Stern has been involved in 24 suborbital, orbital, and planetary space missions, including eight for which he was the mission principal investigator. One of his projects was the Southwest Ultraviolet Imaging System, an instrument which flew on two space shuttle missions,
STS-85 in 1997 and
STS-93
STS-93 in 1999 marked the 95th launch of the Space Shuttle, the 26th launch of Space Shuttle Columbia, ''Columbia'', and the 21st night launch of a Space Shuttle. Eileen Collins became the first female shuttle Commander on this flight. Its prima ...
in 1999.
Stern has also developed eight scientific instruments for planetary and near-space research missions and has been a guest observer on numerous NASA satellite observatories, including the
International Ultraviolet Explorer, the
Hubble Space Telescope
The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...
, the International Infrared Observer and the Extreme Ultraviolet Observer. Stern was executive director of the
Southwest Research Institute's Space Science and Engineering Division until becoming Associate Administrator of
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
's
Science Mission Directorate in 2007. He resigned from that position after nearly a year.
His research has focused on studies of our solar system's
Kuiper belt
The Kuiper belt ( ) is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...
and
Oort cloud
The Oort cloud (pronounced or ), sometimes called the Öpik–Oort cloud, is scientific theory, theorized to be a cloud of billions of Volatile (astrogeology), icy planetesimals surrounding the Sun at distances ranging from 2,000 to 200,000 A ...
,
comet
A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...
s, the
satellite
A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
s of the
outer planet
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...
s,
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ...
, and the search for evidence of
planetary systems around other stars. He has also worked on
spacecraft rendezvous theory, terrestrial polar
mesospheric clouds, galactic astrophysics, and studies of tenuous satellite atmospheres, including
the atmosphere of the Moon.
Life and career
Stern was born in New Orleans, Louisiana to
Jewish
Jews (, , ), or the Jewish people, are an ethnoreligious group and nation, originating from the Israelites of History of ancient Israel and Judah, ancient Israel and Judah. They also traditionally adhere to Judaism. Jewish ethnicity, rel ...
parents Joel and Leonard Stern.
[ He graduated from St. Mark's School of Texas in 1975. He then attended the University of Texas, Austin, where he received his bachelor's degrees in physics & astronomy and his master's degrees in aerospace engineering and planetary atmospheres. He earned a doctorate in astrophysics and planetary science from the University of Colorado, Boulder.]
From 1983 to 1991, Stern held positions at the University of Colorado
The University of Colorado (CU) is a system of public universities in Colorado. It consists of four institutions: the University of Colorado Boulder, the University of Colorado Colorado Springs, the University of Colorado Denver, and the U ...
in the Center for Space and Geoscience Policy, the office of the vice president for Research, and the Center for Astrophysics and Space Astronomy. He received his doctorate in 1989. From 1991 to 1994 he was the leader of Southwest Research Institute's Astrophysical and Planetary Sciences group and was chair of NASA's Outer Planets Science Working Group. From 1994 to 1998 he was the leader of the Geophysical, Astrophysical, and Planetary Science section in Southwest Research Institute's Space Sciences Department, and from 1998 to 2005 he was the director of the Department of Space Studies at Southwest Research Institute. In 1995 he was selected to be a Space Shuttle
The Space Shuttle is a retired, partially reusable launch system, reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. ...
mission specialist finalist, and in 1996 he was a candidate Space Shuttle payload specialist but did not have the opportunity to fly on the Space Shuttle.
In 2007, Stern was listed among ''Time
Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...
'' magazine's 100 Most Influential People in The World.
On August 27, 2008, Stern was elected to the board of directors of the Challenger Center for Space Science Education.
In 2015, Stern was the recipient of ''Smithsonian Magazine
''Smithsonian'' is a magazine covering science, history, art, popular culture and innovation. The first issue was published in 1970.
History
The history of ''Smithsonian'' began when Edward K. Thompson, the retired editor of ''Life'' magazine ...
s American Ingenuity Award in the Physical Sciences category.
On October 7, 2016, Stern was inducted into the Colorado Space Hall of Fame.
Inspiration for Pluto/Kuiper belt mission
On June 14, 2007, in an address to the Smithsonian Institution for their "Exploring the Solar System Lecture Series", Stern commented on the New Horizons mission:
Private sector experience
After completing a master's degree in aerospace engineering Stern spent seven years as an aerospace systems engineer, concentrating on spacecraft and payload systems at the NASA Johnson Space Center, Martin Marietta Aerospace, and the Laboratory for Atmospheric and Space Physics at the University of Colorado.
Stern is currently active as a consultant for private sector space efforts and has stated:
On June 18, 2008, Stern joined Odyssey Moon Limited (Isle of Man), a private industry effort, as a part-time Science Mission Director/consultant in their efforts to launch a robotic mission to the Earth's Moon by participating in the $30 Million Google Lunar X-Prize competition.
In December 2008, Stern joined Blue Origin
Blue Origin Enterprises, L.P. is an American space technology company headquartered in Kent, Washington. The company operates the suborbital New Shepard rocket and the heavy-lift New Glenn rocket. In addition to producing engines for its own ...
, a company that was founded by Amazon.com's Jeff Bezos
Jeffrey Preston Bezos ( ;; and Robinson (2010), p. 7. ; born January 12, 1964) is an American businessman best known as the founder, executive chairman, and former president and CEO of Amazon, the world's largest e-commerce and clou ...
as an independent representative for research and education Missions. The company has stated that its objective is to develop a new vertical-take-off, vertical-landing vehicle known as New Shepard
New Shepard is a Reusable launch vehicle, fully reusable Sub-orbital spaceflight, sub-orbital launch vehicle developed for space tourism by Blue Origin. The vehicle is named after Alan Shepard, who became the List of space travelers by nationali ...
that is designed to take a small number of astronauts on a sub-orbital journey into space and reduce the cost of space transportation. The company is located in Kent, Washington
Kent is a city in King County, Washington, King County, Washington (state), Washington, United States. It is part of the Seattle metropolitan area, Seattle–Tacoma–Bellevue metropolitan area and had a population of 136,588 as of the 2020 Unit ...
and has flight tested some hardware.
In 2012, Stern co-founded Uwingu.
Space science mission
Stern has experience in instrument development, concentrating on ultraviolet technologies. Stern is a principal investigator (PI) in NASA's UV sounding rocket program, and was the project scientist on a Shuttle-deployable SPARTAN astronomical satellite. He was the PI of the advanced, miniaturized HIPPS Pluto breadboard camera/IR spectrometer/UV spectrometer payload for the NASA/Pluto-Kuiper Express mission, and he is the PI of the PERSI imager/spectrometer payload on NASA's ''New Horizons'' Pluto mission. Stern is also the PI of the ALI CE UV Spectrometer for the ESA/NASA '' Rosetta'' comet orbiter. He was a member of the New Millennium Deep Space 1 (DS1) mission science team, and is a Co-investigator on both the ESA SPICAM Mars UV spectrometer launched on Mars Express
''Mars Express'' is a space exploration mission by the European Space Agency, European Space Agency (ESA) exploring the planet Mars and its moons since 2003, and the first planetary mission attempted by ESA.
''Mars Express'' consisted of two ...
, and the Hubble Space Telescope Cosmic Origins Spectrograph (COS) installed in 2009. He is the PI of the SWUIS ultraviolet imager, which has flown two Shuttle missions, and the SWUIS-A airborne astronomical facility. In this capacity, Stern has flown numerous WB-57 and F-18 airborne research astronomy missions. Stern and his colleague, Dr. Daniel Durda, have been flying on the modified F/A-18 Hornet with a sophisticated camera system called the Southwest Ultraviolet Imaging System (SWUIS). They use the camera to search for a hypothetical group of asteroids ( Vulcanoids) between the orbit of Mercury and the Sun
The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...
that are so elusive and hard to see that scientists are not sure they exist.
NASA experience
Stern has served on various NASA committees, including the Lunar Exploration Science Working Group (LExSWG) and the Discovery Program Science Working Group (DPSWG), the Solar System Exploration Subcommittee (SSES), the New Millennium Science Working Group (NMSWG), and the Sounding Rocket Working Group (SRWG). He was Chair of NASA's Outer Planets Science Working Group (OPSWG) from 1991 to 1994 and served as a panel member for the National Research Council's 2003-2013 Decadal Survey on planetary science. Stern is a member of the AAAS, the AAS, and the AGU.
NASA Associate Administrator
Stern was appointed NASA's Associate Administrator for the Science Mission Directorate, essentially NASA's top-ranking official for science, in April 2007. In this position Stern directed a organization with 93 separate flight missions and a program of over 3,000 research grants. During his tenure a record 10 major new flight projects were started and deep reforms of the research and also the education and public outreach programs were put in place. Stern's style was characterised as "hard-charging" as he pursued a reform-minded agenda. He "made headlines for trying to keep agency missions on schedule and under budget" but faced "internal battles over funding". He was credited with making "significant changes that have helped restore the importance of science in NASA's mission".
On March 26, 2008, it was announced that Stern had resigned his position the previous day, effective April 11.[ ] He was replaced by Ed Weiler, who was to serve his second stint in the position. The resignation occurred on the same day that NASA Chief Michael D. Griffin overruled a decrease in funding for the Mars Exploration Rover
NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, ''Spirit (rover), Spirit'' and ''Opportunity (rover), Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rove ...
s and Mars Odyssey missions that was intended to free up funds needed for the upcoming Mars Science Laboratory
Mars Science Laboratory (MSL) is a robotic spacecraft, robotic space probe mission to Mars launched by NASA on November 26, 2011, which successfully landed ''Curiosity (rover), Curiosity'', a Mars rover, in Gale (crater), Gale Crater on Augus ...
. NASA officials would neither confirm nor deny a connection between the two events.
Stern left to avoid cutting healthy programs and basic research in order to cover cost overruns. He believed that cost overruns in the Mars program should be accommodated from within the Mars program, and not taken from other NASA programs. Michael D. Griffin became upset with Stern for making major decisions without consulting him, while Stern was frustrated by Griffin's refusal to allow him to cut or delay politically sensitive projects. Griffin favored cutting "less popular parts" of the budget, including basic research, and Stern's refusal to do so led to his resignation.
Casting doubt on the theory that Stern resigned due to conflict with former Administrator Griffin is his statement of March 25, 2009 at spacepolitics.com:
On November 23, 2008, in an op-ed
An op-ed, short for "opposite the editorial page," is a type of written prose commonly found in newspapers, magazines, and online publications. They usually represent a writer's strong and focused opinion on an issue of relevance to a targeted a ...
in ''The New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...
'', Stern criticized NASA's inability to keep its spending under control. Stern said that, during his own time at NASA, "when I articulated this problem... and consistently curtailed cost increases, I found myself eventually admonished and then neutered by still higher ups, precipitating my resignation earlier this year." While complimenting NASA Administrator Michael D. Griffin, Stern suggested that Griffin's decision to again bail out an over-budget mission was motivated by fear "that any move to cancel the Mars mission would be rebuffed by members of Congress protecting local jobs."
Since leaving NASA, Stern has made criticisms of the budgetary process and has advocated for revamping its public appeal.
Planetary classification
Stern has become involved in the debate surrounding the 2006 definition of planet by the IAU
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...
. After the IAU's decision was made he was quoted as saying "It's an awful definition; it's sloppy science and it would never pass peer review" and claimed that Earth, Mars, Jupiter and Neptune have not fully cleared their orbital zones and has stated in his capacity as PI of the New Horizons project that "The New Horizons project ..will not recognize the IAU's planet definition resolution of August 24, 2006."
A 2000 paper by Stern and Levison proposed a system of planet classification that included both the concepts of hydrostatic equilibrium
In fluid mechanics, hydrostatic equilibrium, also called hydrostatic balance and hydrostasy, is the condition of a fluid or plastic solid at rest, which occurs when external forces, such as gravity, are balanced by a pressure-gradient force. I ...
and clearing the neighbourhood used in the new definition, with a proposed classification scheme labeling all sub-stellar objects in hydrostatic equilibrium as "planets" and subclassifying them into "überplanets" and "unterplanets" based on a mathematical analysis of the planet's ability to scatter other objects out of its orbit over a long period of time. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune were classified as neighborhood-clearing "überplanets" and Pluto was classified as an "unterplanet".
Satellite planets and belt planets
Some large satellites are of similar size or larger than the planet Mercury, e.g. Jupiter's Galilean moons
The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter. They are, in descending-size order, Ganymede (moon), Ganymede, Callisto (moon), Callisto, Io (moon), Io, and Europa (moon), Europa. They are the most apparent m ...
and Titan
Titan most often refers to:
* Titan (moon), the largest moon of Saturn
* Titans, a race of deities in Greek mythology
Titan or Titans may also refer to:
Arts and entertainment
Fictional entities
Fictional locations
* Titan in fiction, fictiona ...
. Stern has argued that location should not matter and only geophysical attributes should be taken into account in the definition of a planet, and proposes the term '' satellite planet'' for a planet-sized object orbiting another planet. Likewise planet-sized objects in the asteroid belt
The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...
or Kuiper belt
The Kuiper belt ( ) is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...
should also be planets according to Stern. Others have used the neologism '' planemo'' (planetary-mass object) for the broad concept of "planet" advocated by Stern.[G. Basri & E.M. Brown, 2006. ''Annual Review of Earth and Planetary Sciences,'' 34: 193–216.]
Selected bibliography
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References
{{DEFAULTSORT:Stern, Alan
1957 births
American planetary scientists
Pluto's planethood
New Horizons
Jewish American scientists
Jewish engineers
St. Mark's School (Texas) alumni
Living people
Discoverers of trans-Neptunian objects
NASA people
University of Texas at Austin College of Natural Sciences alumni
University of Colorado Boulder alumni
Cockrell School of Engineering alumni