Nobody is still currently trapped in space as of now although Suni Williams and Butch Wilmore were stuck in space for 268 days on the International Space Station but returned to earth.
More than one astronaut has been stranded in space but they eventually returned to earth.
Astronauts get stuck in space all the time for a variety of reasons which include trouble with the spacecraft, weather and geopolitics, which have stranded astronauts since at least the 1970s.
Suni Williams and Butch Wilmore spent 286 days on the International Space Station after technical issues bedeviled their weeklong mission.
Russian cosmonaut Valery Polyakov spent 14 ½ months stranded in space aboard the Mir space station in the mid-1990s.
He volunteered for it.
As a physician, he wanted to observe the changes in the human body and mind after a prolonged period of weightlessness.
His 437-day spaceflight remains a world record.
Butch Wilmore and Suni Williams were stuck in space due to issues with the original return vehicle being the Boeing's Starliner.
Wilmore and Williams were part of the first crewed flight of Boeing's Starliner, which encountered problems during it's journey to the ISS, which included propulsion and helium leak issues.
And due to safety concerns, NASA decided to not return the astronauts on the Starliner.
SpaceX offered to send a Crew Dragon capsule to retrieve the astronauts, which was a proposal that was initially rejected by the Biden administration.
Although NASA ultimately accepted the offer and the Crew-9 mission was modified to include room for Williams and Wilmore on their return trip to earth.
The SpaceX Crew Dragon capsule, carrying both the replacement astronauts and Wilmore and Williams, successfully docked with the ISS and ultimately returned the two stranded astronauts to earth.
The two American astronauts returned to earth and home on March 18th 2025, splashing down at 5:57 P.M. EDT off of Florida's Gulf coast after spending more than 9 months orbiting Earth.
Suni Williams and Butch Wilmore emerged from the SpaceX Dragon capsule which carried them home, waving and giving thumbs up and smiling.
No one has gone missing in space or even been lost in space as in being stranded and unable to return.
Although astronauts have faced dangerous situations and even near disasters, they've always managed to return to earth on their spacecraft.
Although there have been some deaths during re-entry and when traveling to space when spaceships have exploded and crashed.
Astronauts have floated away in space, although no astronaut has ever been fully lost in space or floated away in space where they were not able to be retrieved.
Astronauts have experienced some close calls and have also been untethered from their spacecraft, they have always been safely recovered.
Bruce McCandless II famously floated 320 feet away from the space shuttle using a Manned Maneuvering Unit.
An astronaut named Bruce McCandless II has floated away although no astronaut as fully ever floated away and been lost in space.
Bruce McCandless II died in December of 2017 at the age of 80.
Bruce McCandless II was the astronaut who first floated in space untethered and was famously photographed floating away from the Space Shuttle Challenger in 1984 by using a Manned Maneuvering Unit.
A Soviet cosmonaut named Sergei Krikalev was also abandoned in space for 311 days.
Sergei Krikalev, spent 311 days in space during the collapse of the Soviet Union, which exceeded his planned mission duration.
Initially Sergei Krikalev was scheduled for a 5 month stay in space, but he was stranded unexpectedly when the Soviet Union dissolved, and a new crew couldn't be sent to replace him.
The extended stay in space was from May 1991 to March 1992 which earned him the nickname of "the last Soviet" and also highlighted the political upheaval of the time.
And the two abandoned astronauts in space were Wilmore and Sunita "Suni" Willians and Barry "Butch" who both remained on the ISS or international space station for 286 days.
They were both stranded on the International Space Station for 9 months as a result of issues with their Boeing Starliner Spacecraft.
Eventually though they were returned to Earth on a SpaceX Dragon Capsule.
Both Suni Williams and Butch Wilmore were sent to the ISS or international space station on a test flight of Boeing's Starliner.
Then technical problems with the Starliners, most particularly with it's thrusters, prevented them from returning to earth as planned.
And instead of returning to earth on the Starliner which was deemed to be unsafe, they were incorporated into the regular Crew-9 rotation and remained on the ISS or international space station for 286 days.
Eventually though they were able to return to earth via a SpaceX Dragon Capsule, landing off the coast of Florida.
And despite their extended and unplanned stay, both Williams and Wilmore expressed their positive sentiments about the Starliner and their overall experience, highlighting the capabilities of the spacecraft and the dedication of the teams involved.
They have also since emerged from recovery and are also actively involved in the support of Boeing and NASA programs.