Mark Kelly turns six decades old in 2026, having been born on February 21, 1964, while his identical twin brother Scott Kelly celebrates the same birthday later the same day as part of NASA’s legendary twin study. The brothers are retired NASA astronauts, decorated Navy captains, and public figures whose careers in space and subsequent policy work have drawn sustained media attention.
As both men approach their mid sixties, readers often compare their ages, careers, and ongoing influence in science, politics, and public service. This set of questions and reference points clarifies key details about Mark and Scott Kelly, how they compare, and what their timeline and achievements mean today.
| Name | Date of Birth | Age in 2026 | Known For |
|---|---|---|---|
| Mark Kelly | February 21, 1964 | 62 | NASA astronaut, U.S. Senator (D-AZ), Navy Captain, author |
| Scott Kelly | February 21, 1964 | 62 | NASA astronaut, retired Navy Captain, record-setting year in space, public speaker |
| Twin Status | Identical Twins | Same age | Only identical twin astronauts; key subjects in NASA Twin Study |
| Space Missions | Mark: STS‑108, STS‑121, STS‑124, STS‑134; Scott: Mir long-duration, ISS expeditions including one-year mission | Multiple flights | Mark commanded STS‑134; Scott accumulated 520 days in space |
Mark Kelly Early Career and Astronaut Background
Mark Kelly entered the U.S. Navy through the NROTC program, later trained as a pilot, and eventually became a test pilot before selection as an astronaut in 1996. His four Space Shuttle missions combined cutting edge science, Hubble servicing, and construction of the International Space Station, establishing a reputation for calm under pressure and technical excellence.
Key Flight Highlights
- STS‑108: Rendezvous and docking with the International Space Station
- STS‑121: Post Columbia Return to Flight testbed mission
- STS‑124: Primary payload delivery of the Japanese Experiment Module
- STS‑134: Final flight of Space Shuttle Endeavour and Hubble repair support
Scott Kelly Space Record and Year Long Mission
Scott Kelly’s extended stay aboard the International Space Station, which included a rare year long mission, provided NASA with unprecedented biomedical data about human adaptation to space. His identical twin Mark remained on Earth, enabling comparative studies that advanced understanding of genetics, epigenetics, and long duration flight risks.
Major Accomplishments
- Longest single spaceflight by an American at the time, 340 consecutive days
- Critical role in station maintenance and scientific research
- Extensive public outreach, including social media and books about the experience
- Subject of landmark twin study published in Science
Mark and Kelly Comparison in Careers and Health
Although they share the same birthday and DNA, the brothers’ career paths diverged into politics, public policy, and science communication, while both continued to advocate for STEM education and research funding.
| Category | Mark Kelly | Scott Kelly | Shared Notes |
|---|---|---|---|
| Political Role | U.S. Senator from Arizona (2020 present) | No elected office | Policy focus on science, veterans, and climate |
| Space Duration | ~50 days total across 4 shuttle flights | 520 days, including 340 days in one mission | Combined experience informs space policy decisions |
| Public Profile | Frequent media interviews, books on leadership | Speaker on endurance, health research advocate | Both leverage fame to promote STEM |
| Health Findings | Stable health, normal aging for age | Documented physiological changes from long mission, mostly reversible | Twin study highlights importance of monitoring astronauts long term |
Impact of Age on Space Readiness and Policy Work
At over sixty years old, both brothers remain active but have transitioned from frequent flight duty to roles that emphasize oversight, mentorship, and public advocacy. Age related considerations such as recovery time, cardiovascular fitness, and risk tolerance naturally influence how often they fly, yet both continue to contribute through strategic policy, education initiatives, and motivational speaking.
Current Focus Areas
- Promoting bipartisan support for science and technology funding
- Advising on long duration spaceflight health and safety
- Engaging students through outreach programs and media
- Sharing lessons on resilience, teamwork, and leadership
FAQ
Reader questions
How old are Mark Kelly and Scott Kelly in 2026?
Both Mark Kelly and Scott Kelly are 62 years old in 2026, having been born on February 21, 1964.
Have their ages affected their ability to serve in demanding roles?
They remain fully capable, with tailored schedules and support that accommodate normal aging while preserving the expertise and perspective they bring to space and policy work.
What health differences were observed in the NASA twin study between Mark and Scott Kelly?
The study highlighted temporary changes in Scott after his long mission, including shifts in gene expression and physiology, while Mark showed stable metrics, underscoring the value of longitudinal monitoring.
What are their primary contributions outside of flying in space?
Mark Kelly serves as a U.S. Senator shaping legislation on science and veterans, while Scott Kelly focuses on public education and advocacy around endurance, health research, and space exploration.