Donald Roy Pettit (born April 20, 1955) is an American
astronaut
An astronaut (from the Ancient Greek (), meaning 'star', and (), meaning 'sailor') is a person trained, equipped, and deployed by a List of human spaceflight programs, human spaceflight program to serve as a commander or crew member of a spa ...
and
chemical engineer
A chemical engineer is a professional equipped with the knowledge of chemistry and other basic sciences who works principally in the chemical industry to convert basic raw materials into a variety of Product (chemistry), products and deals with ...
best known for his orbital astrophotography and in-space inventions such as the
Zero G Cup, which received the first ever patent for an object invented in space.
He is a veteran of three long-duration stays aboard the
International Space Station
The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...
, one Space Shuttle mission, and a six-week expedition to find
meteorite
A meteorite is a rock (geology), rock that originated in outer space and has fallen to the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical ...
s in
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
. As of 2025, at age 70, he is NASA's oldest active astronaut and the third oldest person to reach orbit, behind
John Glenn
John Herschel Glenn Jr. (July 18, 1921 – December 8, 2016) was an American Marine Corps aviator, astronaut, businessman, and politician. He was the third American in space and the first to orbit the Earth, circling it three times in 1 ...
and
Larry Connor. He has accumulated 590 days in space, behind only
Peggy Whitson and
Suni Williams.
Early life and education
Pettit was born and raised in
Silverton, Oregon. He is an
Eagle Scout.
Pettit graduated from
Oregon State University
Oregon State University (OSU) is a Public university, public Land-grant university, land-grant research university in Corvallis, Oregon, United States. OSU offers more than 200 undergraduate degree programs and a variety of graduate and doctor ...
in 1978 with a
Bachelor of Science
A Bachelor of Science (BS, BSc, B.S., B.Sc., SB, or ScB; from the Latin ') is a bachelor's degree that is awarded for programs that generally last three to five years.
The first university to admit a student to the degree of Bachelor of Scienc ...
in chemical engineering. He then did graduate study in chemical engineering at the
University of Arizona
The University of Arizona (Arizona, U of A, UArizona, or UA) is a Public university, public Land-grant university, land-grant research university in Tucson, Arizona, United States. Founded in 1885 by the 13th Arizona Territorial Legislature, it ...
, receiving a
Ph.D. in 1983.
NASA career

Pettit worked as a scientist at the
Los Alamos National Laboratory
Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development Laboratory, laboratories of the United States Department of Energy National Laboratories, United States Department of Energy ...
from 1984 until 1996, when
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 ...
selected him as an astronaut candidate. He was a junior advisor to the Synthesis Committee of the
Space Exploration Initiative on its May 1991 report "America at the Threshold", recommending plans for a
human mission to Mars
The idea of sending humans to Mars has been the subject of aerospace engineering and scientific studies since the late 1940s as part of the broader exploration of Mars. Long-term proposals have included sending settlers and terraforming the p ...
.
An
astrophotographer, Pettit has captured thousands of unique star trails and photographic data sets, which he regularly shares online. One, titled 'Lightning Bugs', went viral on the internet.
Spaceflight experience
Expedition 6

Pettit's first journey to space was as a flight engineer on
Expedition 6
Expedition 6 was the sixth expedition to the International Space Station (25 November 2002 – 3 May 2003). It was the last three-man crew to reside on the station until the arrival of STS-121 in 2006, delivering the final astronaut of Expedi ...
, a long-duration mission aboard the International Space Station (ISS). Originally the backup for NASA astronaut
Donald Thomas, Pettit was assigned to the mission just weeks before launch after Thomas was grounded due to medical concerns. The crew lifted off on November 24, 2002, aboard on mission
STS-113
STS-113 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle ''Space Shuttle Endeavour, Endeavour''. During the 14-day mission in late 2002, ''Endeavour'' and its crew extended the ISS backbone with the Int ...
.
During his time on the ISS, Pettit conducted two
extravehicular activities (EVAs) to install external scientific equipment. He was not initially scheduled for a spacewalk but stepped in for
Nikolai Budarin, who was removed from the task days before due to a medical issue. In his free time on ISS, Pettit created and filmed "Saturday Morning Science", a series of demonstrations exploring fluid behavior in microgravity.
The Expedition 6 mission was extended by about two months after the
Space Shuttle ''Columbia'' disaster on February 1, 2003, which led to the grounding of the shuttle fleet. Instead of returning on a shuttle as planned, the crew returned in the Russian
Soyuz TMA-1 capsule on May 4, 2003, the first time NASA astronauts had landed in a Soyuz spacecraft.
Pettit's first Soyuz landing proved challenging. Concerned about potential radiation damage to his scientific film before a shuttle could retrieve it, he secured the materials in a pack strapped to his chest. While a typical Soyuz descent subjects astronauts to 3
G's, guidance system failure during the
Soyuz TMA's inaugural reentry caused a ballistic reentry, exposing the crew to over 8 G's. This intensified the pack’s weight to approximately , leaving Pettit exhausted and reportedly causing a shoulder dislocation. However, space agencies downplayed the incident, stating the astronauts were in good condition.
STS-126
Pettit was a mission specialist on the
STS-126, a short-duration mission on Space Shuttle ''Endeavour'' to deliver equipment and supplies to the ISS.
In his free time on ISS, Pettit performed experiments related to the clumping of solid particles in
microgravity
Weightlessness is the complete or near-complete absence of the sensation of weight, i.e., zero apparent weight. It is also termed zero g-force, or zero-g (named after the g-force) or, incorrectly, zero gravity.
Weight is a measurement of the fo ...
. The experiments showed that particles of various materials which varied in size between 1 micrometer and 6 millimeters naturally clumped together in microgravity when confined to a volume of 4 liters that included a few grams of the materials. The cause was theorized to be electrostatic. This presents a plausible mechanism for the initial stages of planetary formation, since particles of this size do not have sufficient gravity to cause this phenomenon.
Expedition 30/31
Pettit again launched to the International Space Station on December 21, 2011, as part of the
Expedition 30/
31 crew. He and fellow crew members
Oleg Kononenko and
André Kuipers arrived at the ISS on December 23.
Among his off-duty video demonstrations on the space station has been on water as
thin film
A thin film is a layer of materials ranging from fractions of a nanometer ( monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many ...
and the
Marangoni convection. On May 25, 2012, Pettit operated the
Canadarm2
The Mobile Servicing System (MSS) is a robotic system on board the International Space Station (ISS). Launched to the ISS in 2001, it plays a key role in station assembly and maintenance; it moves equipment and supplies around the station, suppo ...
to grapple the first
SpaceX Dragon 1 and berth it to the
''Harmony'' module. During the capture, he was quoted saying, "Houston, Station, we've got us a dragon by the tail."
This marked the first time a private spacecraft had ever rendezvoused with the ISS. The Dragon capsule was carrying supplies for the ISS, and the successful capture demonstrated the feasibility of using privately developed spacecraft to resupply the station. Pettit was the first to enter the uncrewed supply ship on May 26, making him the first astronaut in the history of space exploration to successfully enter a commercially-built and operated spacecraft in orbit.
= Angry Birds Space Demos
=

During Expedition 30, on behalf of NASA in cooperation with
Finland
Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...
-based
Rovio Entertainment, creator of the
Angry Birds franchise, Pettit also made another video by using an Angry Birds character to explain how physics works in space, including demonstrating
trajectories in microgravity by catapulting a Red Bird through the space station.
NASA states that such collaboration may share the excitement of space with the game community, educate users on NASA's programs, and create interactive educational experiences for the public.
The footage was released by NASA both on its official site and
YouTube
YouTube is an American social media and online video sharing platform owned by Google. YouTube was founded on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim who were three former employees of PayPal. Headquartered in ...
along with another commercial version by Rovio on March 8, 2012, to announce the launch of new game
Angry Birds Space on March 22, 2012.
Expedition 71/72
On September 11, 2024, Pettit launched aboard
Soyuz MS-26 alongside Russian cosmonauts
Aleksey Ovchinin and
Ivan Vagner. The trio joined the crews of
Expedition 71 and later
Expedition 72 for a mission aboard the ISS lasting 220 days. During their mission, the crew orbited Earth 3,520 times, traveling approximately 93.3 million miles. Pettit conducted scientific investigations on behalf of NASA, including studies on water purification technology, plant growth in microgravity, and fire behavior in space. He also continued to share his astrophotography work to acclaim on social media.
The mission concluded on April 20, 2025 with the safe landing of Soyuz MS-26 on the
Kazakh Steppe
The Kazakh Steppe ( ), also known as the Great Steppe or Great Betpak-Dala, Dala ( ), is a vast region of open grassland in Central Asia, covering areas in northern Kazakhstan and adjacent areas of Russia. It lies east of the Pontic–Caspian step ...
on Pettit's 70th birthday, making him NASA’s oldest active-duty astronaut to return from space. As recovery teams assisted the crew from the capsule, Pettit appeared disoriented, a sensation he had anticipated due to prior experiences with readjustment to gravity. NASA said after the landing that Pettit was doing well and was flown to NASA’s Johnson Space Center in Houston for normal post-flight evaluation and rehabilitation.
Innovations and inventions

During Expedition 6, Pettit used spare parts found throughout the Station to construct a
barn door tracker; the device compensates for the movement of the ISS relative to the Earth's surface, permitting sharper high resolution images of city lights at night from the orbiting space station.
In November 2008, Pettit invented the
zero-g coffee cup, which used the
wetting angle to carry fluid along a crease to permit drinking and avoid the necessity of a straw. This zero-g cup was featured in the May 2009 issue of ''
National Geographic
''National Geographic'' (formerly ''The National Geographic Magazine'', sometimes branded as ''Nat Geo'') is an American monthly magazine published by National Geographic Partners. The magazine was founded in 1888 as a scholarly journal, nine ...
'' magazine, along with his notes on the relation of the internal cup angle to the contact wetting angle for various construction materials. The cup received the first ever patent for an object invented in space.
Antarctica
From November 2006 through January 2007, Pettit joined the
Antarctic Search for Meteorites (ANSMET), spending six weeks in the Antarctic summer collecting meteorite samples,
including a lunar meteorite. During the expedition, he was called on to perform emergency electrical repairs to a snowmobile and emergency dental surgery. Periods of tent-confining inclement weather were spent continuing his Saturday Morning Science series—"on Ice"—with photographic surveys of crystal sizes of glacial ice samples and collections of magnetic
micrometeorites from ice melt used for cooking water. He estimated Antarctic glacial ice to contain roughly 1 micrometeorite per
liter
The litre ( Commonwealth spelling) or liter ( American spelling) (SI symbols L and l, other symbol used: ℓ) is a metric unit of volume. It is equal to 1 cubic decimetre (dm3), 1000 cubic centimetres (cm3) or 0.001 cubic metres (m3). A cu ...
.
References
External links
*
NASA BiographyDon Pettit's Space Chronicles on Ice*
{{DEFAULTSORT:Pettit, Donald
1955 births
Living people
American astronauts
Oregon State University alumni
University of Arizona alumni
People from Silverton, Oregon
Crew members of the International Space Station
Los Alamos National Laboratory personnel
Space Shuttle program astronauts
Spacewalkers