American astronaut and engineer (born 1964)
Factsheet
Born Scott Joseph Kelly
(1964-02-21) February 21, 1964 (age 61)
Orange, New Jersey, U.S.
(1964-02-21) February 21, 1964 (age 61)
Orange, New Jersey, U.S.
Education University of Maryland, Baltimore County
State University of New York Maritime College (BEng)
University of Tennessee, Knoxville (MS)
State University of New York Maritime College (BEng)
University of Tennessee, Knoxville (MS)
Spouses Leslie Yandell
(m. 1992; div. 2009)
Amiko Kauderer (m. 2018)
(m. 1992; div. 2009)
Amiko Kauderer (m. 2018)
Born Scott Joseph Kelly
(1964-02-21) February 21, 1964 (age 61)
Orange, New Jersey, U.S.
(1964-02-21) February 21, 1964 (age 61)
Orange, New Jersey, U.S.
Education University of Maryland, Baltimore County
State University of New York Maritime College (BEng)
University of Tennessee, Knoxville (MS)
State University of New York Maritime College (BEng)
University of Tennessee, Knoxville (MS)
Spouses Leslie Yandell
(m. 1992; div. 2009)
Amiko Kauderer (m. 2018)
(m. 1992; div. 2009)
Amiko Kauderer (m. 2018)
Wikipedia
en.wikipedia.org › wiki › Scott_Kelly_(astronaut)
Scott Kelly (astronaut) - Wikipedia
1 week ago - Kelly retired from NASA on April 1, 2016. His identical twin brother, Mark Kelly, is also a retired astronaut, and the senior U.S.
NASA
nasa.gov › humans-in-space › twins-study
Twins Study - NASA
July 10, 2025 - The landmark Twins Study brought ... accomplished by comparing retired astronaut Scott Kelly while he was in space, to his identical twin brother, retired astronaut Mark Kelly, who remained on Earth....
Videos
04:19
Twin Brothers Mark & Scott Kelly Reflect on Being Astronauts Together ...
04:33
Kelly astronaut twins to participate in year-long NASA experiments ...
- YouTube
13:45
Does Space Travel Affect Genetics? | Scott and Mark Kelly Research ...
02:11
A Year in Space | Space Twins | Episode 1 | PBS
Former astronaut twin brothers Mark and Scott Kelly on NASA cuts and challenges of being on ISS
“We always want to retain the best people. That's critical to any program across government, but also in the private sector," the senator said. "Often projects and programs and agencies have to undergo some change. I think this is a time with some change right now, but NASA is a resilient and innovative agency." Expected more from Mark Kelly. Hopefully once I watch the interview he says more than this. Because the complete handicapping of NASA is being undersold greatly by this comment. More on reddit.com
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July 31, 2025TIL Senator Mark Kelly (former astronaut) has an identical twin who confusingly also was an astronaut
I mean it's not that confusing. they were part of a twin study at NASA. More on reddit.com
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March 28, 2024In 2015, NASA did a one of its kind "Twins Study" when it send astronaut Scott Kelly to International Space Station for an entire year while his retired twin astronaut Mark Kelly was observed on Earth for comparison.
And for that reason the age difference between them changed slightly. More on reddit.com
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July 23, 2024Scott Kelly and his twin brother Senator Mark Kelly in the office together.
Both are astronauts, correct? More on reddit.com
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January 4, 2023What are Mark Kelly’s achievements in politics?
Mark Kelly won a U.S. Senate seat in Arizona in a special election in 2020 and was re-elected in 2022. His background as an astronaut and Arizona’s changing demographics contributed to his ability to win a seat that had been held by Republicans, including Barry Goldwater and John McCain, for more than 50 years. He was on Kamala Harris’s short list for vice president in 2024.
britannica.com
britannica.com › politics, law & government › world leaders › senators
Mark Kelly | Astronaut, Gabby Giffords, U.S. Senator, 2024 election, ...
What is notable about Mark Kelly’s early life and education?
Mark Kelly was born in Orange, New Jersey, and has a twin brother, Scott Kelly. He graduated from the United States Merchant Marine Academy and earned a master’s degree in aeronautical engineering from the U.S. Naval Postgraduate School. Both he and his brother went on to become astronauts.
britannica.com
britannica.com › politics, law & government › world leaders › senators
Mark Kelly | Astronaut, Gabby Giffords, U.S. Senator, 2024 election, ...
What were Mark Kelly’s accomplishments as an astronaut?
Mark Kelly flew four space shuttle missions, including as pilot of Endeavour and Discovery, and as mission commander. He was involved in a landmark study comparing the effects of space on his twin brother Scott, who was in space, and himself on Earth.
britannica.com
britannica.com › politics, law & government › world leaders › senators
Mark Kelly | Astronaut, Gabby Giffords, U.S. Senator, 2024 election, ...
Space Center Houston
spacecenter.org › home › twins study research reveals effects of space
Twins Study research reveals effects of space - Space Center Houston
May 13, 2019 - The research used Kelly and his twin brother, retired astronaut Mark Kelly, to study the effects of long duration spaceflight on the human body.
Reddit
reddit.com › r/nasa › former astronaut twin brothers mark and scott kelly on nasa cuts and challenges of being on iss
r/nasa on Reddit: Former astronaut twin brothers Mark and Scott Kelly on NASA cuts and challenges of being on ISS
July 31, 2025 - TIL Senator Mark Kelly (former astronaut) has an identical twin who confusingly also was an astronaut
Time
time.com › meet-the-twins-unlocking-the-secrets-of-space
NASA's One-Year Mission with Mark and Scott Kelly
December 18, 2014 - NASA will track how identical twins Mark and Scott Kelly change as one brother heads into orbit for a record-long year mission.
Wikipedia
en.wikipedia.org › wiki › Mark_Kelly
Mark Kelly - Wikipedia
1 day ago - Mark Kelly was born on February 21, 1964, in Orange, New Jersey, and raised in West Orange, New Jersey. He and his identical twin brother, Scott Kelly, are sons of Richard and Patricia (née McAvoy) Kelly, two retired police officers. Kelly ...
Stanford Medicine
med.stanford.edu › gbsc › pages › nasa-twins.html
NASA Twins | Genetics Bioinformatics Service Center | Stanford Medicine
November 10, 2016 - Twins Study is ten separate investigations coordinating together and sharing all data and analysis as one large, integrated research team. NASA has selected 10 investigations to conduct with identical twin astronauts Scott and Mark Kelly.
Encyclopedia Britannica
britannica.com › politics, law & government › world leaders › senators
Mark Kelly | Astronaut, Gabby Giffords, U.S. Senator, 2024 election, Donald Trump & Biography | Britannica
1 week ago - Mark Kelly flew four space shuttle missions, including as pilot of Endeavour and Discovery, and as mission commander. He was involved in a landmark study comparing the effects of space on his twin brother Scott, who was in space, and himself ...
United States Merchant Marine Academy
usmma.edu › about › communications › usmma-alumnus-captain-mark-kelly-reunites-twin-captain-scott-kelly-following
USMMA Alumnus Captain Mark Kelly To Reunite With Twin, Captain Scott Kelly, Following His Year In Space | U.S. Merchant Marine Academy
KINGS POINT, N.Y., MARCH 1, 2016 – Tomorrow, Capt. Mark Kelly, United States Merchant Marine Academy (USMMA) Class of ’86 will be reunited with his twin brother, State University Maritime College (SUNY) Maritime Alumnus, Capt. Scott Kelly, Class of ’87, after being apart for almost an ...
Encyclopedia Britannica
britannica.com › world history › military leaders
Scott Kelly | Astronaut, Year in Space, & Biography | Britannica
November 19, 2025 - Scott Kelly (born February 21, 1964, Orange, New Jersey, U.S.) is an American astronaut who made four spaceflights, the longest of which lasted 340 days. He is the twin brother of American astronaut and senator Mark Kelly.
PubMed Central
pmc.ncbi.nlm.nih.gov › articles › PMC11336052
Exploring the Twin Paradox: From Einstein’s Theory to NASA’s Twin Astronauts - PMC
The time dilation Scott Kelly experienced during his 1-year space journey, relative to his twin brother Mark Kelly on Earth, can be estimated.
U.S. Senate
kelly.senate.gov › home › about mark
About Mark - Senator Mark Kelly
July 22, 2025 - That’s why I am working to ensure every Arizonan gets a chance to achieve their own dreams. In 1996, he was selected as an astronaut in the same NASA class as his identical twin brother Scott.
NASA
nasa.gov › humans-in-space › nasas-twins-study-results-published-in-science-journal
NASA’s Twins Study Results Published - NASA
October 12, 2023 - The landmark Twins Study brought ... accomplished by comparing retired astronaut Scott Kelly while he was in space, to his identical twin brother, retired astronaut Mark Kelly, who remained on Earth....
The Economic Times
economictimes.indiatimes.com › business news › magazines
Mark and Scott Kelly - UK's 95-Year-Old Tipton Twins, And Other Prominent Identical Twins In The World | The Economic Times
... Mark and Scott Kelly were astronauts who became famous after NASA conducted a study comparing their physiology and psychology, which enabled researchers to comprehend the impact of space travel on the body’s molecular level.
NASA
nasa.gov › humans-in-space › twins-study › twins-study-about
Twins Study | About - NASA
September 28, 2023 - The landmark Twins Study helped scientists better understand the impacts of spaceflight on a human body through the study of identical twins. Retired astronaut Scott Kelly spent one year in low-Earth orbit aboard the International Space Station ...
Facebook
facebook.com › CaptMarkKelly › posts › please-watch-this-video-from-senator-mark-kelly-and-his-twin-brother-scott-kelly › 1179874460174152
Please watch this video from Senator Mark Kelly and his ...
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AZPM
news.azpm.org › p › spacenews › 2016 › 2 › 26 › 106575-kelly-twins-what-does-a-year-in-space-do-to-body-mind
Kelly Twins: What Does a Year in Space Do to Body, Mind? - AZPM
NASA astronaut Scott Kelly will return to Earth Tuesday night after spending 340 days in space. He and his identical twin brother, Tucsonan Mark Kelly, are participating in a study to determine the effects of long-duration space travel on the ...
BBC
bbc.co.uk › newsround › 47908169
Nasa twin study: What happens to the body in space? - BBC Newsround
April 12, 2019 - Well, that's what happened to identical twin astronauts Scott and Mark Kelly.
Hindustan Times
hindustantimes.com › news › world news › us news
Who are Scott and Mark Kelly, and what was NASA's Twins Study on the astronauts? | Hindustan Times
March 19, 2025 - Scott Kelly and Mark Kelly are American astronauts and identical twin brothers. They participated in NASA's Twins Study, conducted between 2015 and 2018.
LADbible
ladbible.com › news › science
NASA stunned after comparing health of astronaut who spent 340 days in space to identical twin brother on Earth
March 21, 2025 - What happened to NASA astronaut Scott Kelly after spending almost one year in space while twin brother Mark, also an astronaut, remained at home?