Scope and Content
Arrangement of the Alvin Seiff Papers
Title: Alvin Seiff Papers
Date (inclusive): 1955-2000
Collection Number: PP05.22-AS
Number of containers: 9
Volume: 3.15 cubic feet
Ames Research Center,
Ames History Office
Moffett Field, California 94035
Abstract: The Alvin Seiff Papers include instrument descriptions, design reviews, testing reports, progress reports, meeting notes,
project proposals, correspondence, publications, photographs, and overheads documenting Seiff's contributions to atmospheric
structure experiments in Viking, Cassini-Huygens, Galileo, and other projects during his career as a scientist and research
associate at the NASA Ames Research Center.
Collection is open for research.
Copyright does not apply to United States government records. For non-government
material, researcher must contact the original creator.
NASA Ames History Office, NASA Ames Research Center. Moffett Field, California. PP05.22-AS, Alvin Seiff Papers 1955-2000,
[Container number] : [Folder number]. [Identification of item]. [Date, if available].
Removed or Separated Material
One folder has been removed from the collection and placed into the Archives Reference Collection (AFS1070.8A): Aeroassist
Flight Experiment Science Review. Monterey, CA, May 16-20, 1988. 1985-1990.
Donated by Charles Sobeck on October 24,2005
Alvin Seiff (called "Al" by his colleagues) made important contributions to the space exploration community during his career
at NASA's Ames Research Center. He is thought by many to be the chief creator of the idea of employing entry probes to determine
a planet's atmospheric structure.
Seiff was born in Kansas City, Missouri. When he was twenty years old, he obtained a Bachelor of Science degree from the University
of Missouri in chemical engineering. Soon after, Seiff joined the Manhattan Project and worked on resolving the uranium separation
problem. Before joining the Ames Research Center in 1948, Seiff lectured at the University of Tennessee teaching physics.
In his career at Ames Research Center, Seiff undertook many roles and tasks, impressing his colleagues with his knowledge,
skills, and leadership ability in each position he held. For his first ten years (1948-1957) at NASA (at that time it was
called NACA, the National Advisory Committee for Aeronautics), Seiff was as a research scientist. From 1952 until 1963 Seiff
also became the Chief of the Supersonic Free Flight Research Branch at Ames. Subsequently, he became the Chief of the Vehicle
Environment Division from 1963 until 1972. During that period, Ames became one of the chief centers for reentry studies. For
instance, it was Seiff's team that planned out and conducted the Planetary Atmosphere Experiments Test (PAET) in 1971 that
proved reliable data (such as chemical composition and changes in density, temperature, and pressure) could be retrieved from
probes entering a planetary atmosphere. The experience and knowledge NASA gained from the PAET Project was used to create
the foundation upon which all subsequent entry and descent experiments were based, including the Pioneer Venus Mission, the
Viking Mission to Mars, the Galileo Mission to Jupiter, the Cassini-Huygens Atmospheric Entry Probe into Titan, and the Mars
Pathfinder. For a majority of these missions (the Pioneer Probe Mission to Venus, the Viking Mission to Mars, the Galileo
Probe Mission to Jupiter, and the Mars Pathfinder) Seiff was the Principal Investigator for the Atmospheric Structure Instruments.
For the Cassini-Huygens Probe, Seiff, in conjunction with several European Space Agency colleagues, was a Co-Investigator
for the Huygens Atmospheric Structure Instrument.
In 1972, Seiff became a Senior Staff Scientist in the Space Science Division until he retired 1986. However, even after retirement,
Seiff remained active in space exploration studies at NASA Ames as a research associate. During the Mars Pathfinder Mission
development, he was the Chairman of the Atmospheric Science Advisory Team. Once Pathfinder was launched, Seiff joined the
team of scientists in charge of the Atmospheric Structure Investigation/Meteorology Package Experiment on the probe. During
the Cassini-Huygens Project development, he became very active in coordinating with European Space Agency scientists as a
Co-Investigator for the Huygens Probe Atmospheric Structure Instrument. He did not live to see the spacecraft arrive at Titan
in 2005. After a three-month struggle with brain cancer, Seiff passed away on December 16, 2000.
The following terms may be used to index this collection.
Ames Research Center
European Space Agency
Planetary science: atmospheres
Atmospheric Structure Instrument
Viking Mars Program (U.S.)
Viking lander 1
Viking lander 2
Space station modules
Moffett Field (Calif.)
Scope and Content
The Alvin Seiff Papers (3.15 cubic feet) include technical documents, reports, conference and meeting documentation, publications,
overheads, correspondence, and photographs detailing Seiff's contributions to the Viking, Cassini-Huygens, and Galileo projects.
Also included are general correspondence (such as future mission announcements and a book review) and brief records of his
involvement as an advisor to the Committee on Uses of Shuttle External Tanks.
The first series, the Viking Project, contains Seiff's documentation of various pressure and temperature sensor tests during
the development phase of the Viking Project. It contains documents, test reports, mechanical descriptions and plans, and photographs.
The primary objectives of the Viking Project were to photograph the surface of Mars, determine the structure and components
of the Martian atmosphere and surface, and look for any signs of life. The mission consisted of two spacecraft, each consisting
of an orbiter and a lander. Viking 1 left Earth on August 20, 1975 and arrived at Mars on June 19, 1976. The spacecraft spent
four weeks taking images of the surface in order to find appropriate landing sites for both landers. On July 20, 1976 the
Viking 1 Lander separated from the orbiter and touched down at Chryse Planitia (a smooth rounded basin, probably an ancient
impact site, in the northern equatorial area of Mars). The second spacecraft, Viking 2, was launched on September 9, 1975
and arrived at Mars on August 7, 1976. A month later, the Viking 2 Lander touched down at Utopia Planitia (a part of the vast
plains that covers most of the northern Martian hemisphere) on September 3, 1976. After several years of operation (which
included conducting soil and atmosphere experiments and sending back a combined total of over 1400 pictures) both landers
lost power. First, the Viking 2 Lander ended communications on April 11, 1980, and later the Viking 1 Lander stopped functioning
on November 13, 1982.
Seiff was the Principal Investigator on the Atmospheric Structure Instrument. The instrument contained sensors such as accelerometers,
radar altimeters, thermometers, and pressure sensors. The results, taken from below an altitude of 132 km, provided Seiff
and his colleagues with information detailing pressure, temperature, wind speed, lander acceleration, and other important
information from varying altitude levels. From this data, the team was able to determine how the Martian atmosphere is structured.
The second series, the Cassini-Huygens Project, details Seiff's involvement in the joint NASA-ESA (European Space Agency)-ASI
(Italian Space Agency) mission to Saturn and Titan (one of Saturn's moons). It contains records of Seiff's correspondence
with his ESA counterparts, tests of instruments, instrument descriptions, meeting reports, studies, proposals, and publications.
The primary objective of the mission was to study the Saturn planetary system and Titan itself. Cassini-Huygens launched on
October 17, 1997. Its trajectory took it past Venus (twice), back to Earth, and on to Jupiter where it was able to briefly
join the Galileo spacecraft (then still in orbit) on December 30, 2000. On June 11th, 2004, Cassini entered the Saturn system.
In December of that year, the Huygens Probe was detached and, after coasting towards the planet for twenty days, entered Titan's
atmosphere on January 14, 2005. The probe collected over two and a half hours of data about the atmosphere while descending
and approximately one and a half hours of data on the surface. As of April 2007, the Cassini spacecraft itself is still operational
and continues to send back readings and photographs from the Saturn system.
Seiff's contributions to the Cassini-Huygens Project dealt primarily with the Huygens Atmospheric Structure Instrument (HASI).
The purpose for this instrument was to determine the physical and electrical structure of Titan's atmosphere by using accelerometers,
temperature and pressure sensors, and the Permittivity and Electromagnetic Wave Analyzer (which measures the conductivity
of the atmosphere). As a Co-Investigator for the HASI, Seiff was able to use his knowledge and years of experience with entry
probes to help his ESA counterparts in developing a working ASI for the Huygens Probe.
The third series, the Galileo Project, contains documentation that covers only a small part of Seiff's involvement with the
project including a draft of a Galileo Mission history, a final ASI technical report, and results of the retrieved ASI data.
The primary objective of the project was to determine atmospheric structure of Jupiter and conduct studies of the Jupiter
system. On October 18, 1989, the Galileo spacecraft left Earth in the cargo bay of the Atlantis Space Shuttle. Soon after,
the shuttle crewmembers sent Galileo on its way. The spacecraft did not have enough power to make it to Jupiter on its own.
Instead, NASA planned a trajectory that would slingshot Galileo past Venus and twice past Earth to gain enough momentum to
reach Jupiter. On the way there, the spacecraft was able to take our first images of asteroids and even was able to capture
the first pictures of the comet Shoemaker-Levy 9 smashing into Jupiter. Before the spacecraft arrived at Jupiter, on July
13, 1995, the probe was detached and sent ahead on a trajectory to enter Jupiter's atmosphere. The probe arrived at Jupiter
on December 7, 1995. The spacecraft itself continued on to achieve its two-year mission observing the Jupiter planetary system.
Later, due to its success, its mission was extended and lasted until September 21, 2003. At this time, the decision was made
to destroy the probe by sending it into Jupiter's atmosphere. In its nine years spent at Jupiter, Galileo had returned over
30 gigabytes of data, including 14,000 pictures.
As before, Seiff was the Principle Investigator for the Atmospheric Structure Instrument on the probe. The probe's purpose
was to determine the temperature, pressure, and density of the atmosphere and how they vary as it descended. The probe was
able to record information from an attitude of 20 km above the atmosphere to -140 km. The results provided NASA with enough
information to keep analysts busy for years to come.
Proposed Space Shuttle External Tank Usage
The fourth series, Proposed Space Shuttle External Tank Usage, contains a few documents Seiff maintained from his time as
an advisor to the Committee on Uses of Shuttle External Tanks. The committee's job was to figure out if there was a way to
turn the external tanks of the space shuttles into part of a space station as a storage, manufacturing, or other type of unit.
The fifth series, General Correspondence, contains correspondence from various times during Seiff's career, future mission
notifications, and an evaluation of chapter 3 of the book Atmosphere of Freedom by Glenn Bugos.
Arrangement of the Alvin Seiff Papers
The papers are arranged into 5 series:
- I. Viking Project.
- II. Cassini-Huyens Project.
- III. Galileo Project.
- IV. Proposed Space Shuttle External Tank Usage.
- V. General Correspondance.