Astronauts and other spaceflight participants have observed their religions while in space; sometimes publicly, sometimes privately. Religious adherence in outer space may pose unique challenges and opportunities for practitioners. Space travellers have reported changes in the way they view their faith related to the overview effect, some said that their faith grew stronger. Conversely, some secularist groups have criticized the use of government spacecraft for religious activities by astronauts.

Christianity

Apollo 8 Genesis Reading

On Christmas Eve, 1968, astronauts Bill Anders, Jim Lovell, and Frank Borman read from the Book of Genesis as Apollo 8 orbited the Moon. A lawsuit by American Atheists founder Madalyn Murray O'Hair alleged that the observance amounted to a government endorsement of religion in violation of the First Amendment, but the case was dismissed.

Protestantism Apollo 11 astronaut Buzz Aldrin, an ordained Presbyterian ruling elder, celebrated the sacrament of communion in a small service for himself using a kit provided by his church. Aldrin had told flight director Chris Kraft of his plans and intended to broadcast the service back to Earth but opted not to at the request of Deke Slayton, due to the continuing controversy over Apollo 8's reading.

A microfilm Bible brought to the surface of the Moon by Apollo 14 astronaut Ed Mitchell was auctioned off in 2011. It was a King James Version created after three astronauts lost their lives in the Apollo 1 fire. Ed White, one of the astronauts who perished, had wanted to take a Bible to the Moon.

On the 2009 STS-128 flight to the International Space Station, astronaut Patrick Forrester brought a fragment of a Missionary Aviation Fellowship aircraft that had been used by the Operation Auca martyrs in Ecuador in 1956.

Several members of the crew of the Space Shuttle Challenger tragedy mission STS-51-L were people of faith. Among them were Commander Dick Scobee and Pilot Michael J. Smith. Scobee was a Baptist who met his wife June at a church social event. After the tragedy, she would go on to write an article in Guidepost Magazine about how their faith helped her through the tragic time. Smith and his family attended a non-denominational Christian church in a community close to their home near Houston's NASA JSC Space Centre. Similarly, mission specialist Ronald McNair was a devout Christian.

Rick Husband, the Commander of the ill-fated STS-107 Columbia tragedy mission, was also a devout Christian. On the last-request forms that astronauts fill out before every flight, he left his pastor a personal note: "Tell them about Jesus; he's real to me." Later his wife Evelyn wrote a book about their life with him as an astronaut and the importance of their Christian faith entitled High Calling: The Courageous Life and Faith of Space Shuttle Columbia Commander Rick Husband. Likewise, his STS-107 crewmate Michael P. Anderson was also a devout Christian and when not on a mission for NASA, was an active member of the Grace Community Church choir.

Catholicism A signed message from Pope Paul VI was included among statements from dozens of other world leaders left on the Moon on a silicon disk during the Apollo 11 mission. Following the mission, William Donald Borders, Bishop of the Roman Catholic Diocese of Orlando, told the Pope that the 1917 Code of Canon Law placed the Moon within his diocese, as the first explorers had departed from Cape Kennedy which was under his jurisdiction. The claim was neither confirmed nor denied by the Pope, and the Moon is not recognized as part of the diocese in any official capacity.

Following Buzz Aldrin's communion on the Moon, other astronauts have done the same in Earth orbit. Three Catholic astronauts on Space Shuttle mission STS-59 received Holy Communion on 17 April 1994. NASA astronaut Michael S. Hopkins took a supply of six consecrated hosts to the International Space Station in September 2013, allowing him to receive the Eucharist weekly during his 24-week mission.

In May 2011, Pope Benedict XVI of the Catholic Church talked to the crew of the Space Shuttle Endeavour while it was in Earth orbit.

Russian Orthodox In Russia, spaceflight crews are blessed by Russian Orthodox priests before launch, and their Soyuz rockets are also blessed on the launch pad. Cosmonaut Aleksandr Viktorenko initiated the crew blessing tradition when he requested one for the launch of Soyuz TM-20 in 1994.

Russian Orthodox Christmas was celebrated on the International Space Station, on January 7, 2011. Cosmonauts had the day off, but one of the other crew posted on Twitter, "Merry Christmas to all Russia." The whole crew also celebrated on December 25, two weeks prior.

Cosmonauts sometimes at the request of the Russian Orthodox Church, carry religious icons to space, which upon return to Earth are distributed to churches.

Islam Islamic Jurisprudence of Space (Fiqh al-Fada)

Islamic law as it applies to space is called fiqh of space in Islam. Islamic scholars, space agencies, and religious councils have developed specific guidelines and fatwas to help Muslim astronauts navigate their religious obligations while in outer space. Muslims in space adapt to fulfil religious obligations, such as praying in a zero-gravity environment. The issue was first opened to debate with the flight of Saudi prince Sultan bin Salman Al Saud on STS-51-G and with Anousheh Ansari participating as a tourist on the International Space Station.

Religious Practices in Space (Fiqh al-Ibadah) Space travel poses unique logistical challenges to fundamental Islamic rituals, particularly the five daily prayers (Salat) and fasting (Sawm) during Ramadan, which are tied to the sun's position and Earth's geography. For instance, a spacecraft like the International Space Station (ISS) orbits the Earth at 27,600 km/h, meaning an astronaut witnesses a sunrise and sunset approximately 16 times every 24 hours, and the direction from the station to Mecca changes significantly within seconds.

After a meeting of over 150 religious scholars and scientists, the Department of Islamic Development Malaysia, which follows the Shafi'i school of Islamic jurisprudence, presented the guidelines as an 18-page fatwa. These guidelines were translated into multiple languages and now serve as a guide for Muslim astronauts in space. Diyanet, the Presidency of Religious Affairs of Turkey, which follows the Hanafi school of Islamic jurisprudence, also set guidelines for Muslim astronauts. The diyanet also posted job listings for astronomers and astronauts, possibly as advisors. Islamic scholars from Egypt and Guinea have also issued fatwas on how to perform prayers in space.

Prayer

Qibla The Malaysian Council wrote that when determining the Qibla in space, one should base it on "whatever is possible". They proposed four options and deemed it appropriate to move to the next option if the preceding one is not possible:

The Kaaba The position directly above the Kaaba at the altitude of the astronaut's orbit Planet Earth "Wherever possible" The Turkish Diyanet ruled that simply turning towards Earth is sufficient.

Planet Earth Whatever is possible

In line with the fatwa council, other Muslim scholars argue for the importance of flexibility and adapting the qibla requirement to what an astronaut is capable of fulfilling. Khaleel Muhammad of San Diego State University opined "God does not take a person to task for that which is beyond his/her ability to work with." Kamal Abdali argued that concentration during a prayer is more important than the exact orientation, and he suggested keeping the qibla direction at the start of a prayer instead of "worrying about possible changes in position".

Ablution, bowing, and prostration Scholars said that using a "wet wipe" would be sufficient for ablution (wudu) instead of washing completely. If this is also not possible, it was decided that symbolically "rubbing hands on a clean wall" (tayammum) would suffice. Diyanet also agreed that tayammum would suffice. The Malaysian fatwa stated that prayers can be shortened or combined if necessary, and prayer times can be determined according to the last place the astronaut set foot on Earth, or all Muslim astronauts could pray at the same time. Mecca has also been suggested as an alternative. Diyanet suggested that one could "estimate" prayer times by dividing a standard 24-hour day into five segments. Regarding prayer movements, if it is not possible to physically perform them, scholars deemed it appropriate to perform bowing (ruku) and prostration (sujud) by "moving the chin up and down", and if that is not possible, by "looking up and down with the eyes". If none of these are possible, they ruled that simply "imagining the movements" would be sufficient.

Malaysian astronaut Sheikh Muszaphar Shukor spoke about his experience praying in space. He shared footage of himself praying in space, noting that the sun rises and sets every 45 minutes. He said that he read the Quran even more frequently after going to space and stated that he felt "spiritually closer to Allah". Furthermore, he also said that he heard the sound of the adhan (call to prayer) in space, calling it a miracle and attributing it to what he called "the majesty of Allah".

Ramadan Muslim astronauts in space celebrate Ramadan and Eid al-Fitr. Sheikh Muszaphar Shukor threw a party for the entire crew during Eid, handing out cookies and kebab.

Fasting Islamic scholars ruled that since astronauts hold the status of travellers and fasting could harm their mission, it is not mandatory for them to fast, and the days can be made up upon returning to Earth. It was stated that Muslims who insist on fasting can do so according to Greenwich Mean Time. Furthermore, Muslims in space were permitted to eat food to satisfy their hunger even if they are not certain that it is halal. Some astronauts chose to fast regardless. Saudi astronaut Sultan bin Salman Al Saud, whose mission was during Ramadan, fasted, despite religious authorities telling him he did not have to.

Death in space Islamic guidelines also stipulate protocols for the death of a Muslim in space. Ideally, the deceased's body should be brought back to Earth for a normal Islamic funeral. If returning the body is not possible, it is permissible to perform a simplified funeral ceremony and bury the body in space.

Islamic Views on Space Exploration

The Malaysian fatwa states that space travel is encouraged and Muslims should travel to space to "maintain a relationship with God, preserve the space environment, and maintain peaceful relations with others". Since Islam emphasizes the concepts of Tawhid (the oneness of God) and Khilafah (human stewardship of creation), Islamic thinkers emphasized space exploration must be conducted "equitably, sustainably, and responsibly". Space activities that promote monopolistic commercialization, extreme militarization, or the unchecked accumulation of space debris are seen as contrary to Islam. In modern Quranic exegesis, some scholars have interpreted specific verses as affirming human spaceflight. For example, in his translation The Majestic Quran, Sunni Islamic scholar Musharraf Hussain interprets verses 33 to 35 of Surah Ar-Rahman as a direct allusion to space travel. Hussain suggests that the "authority" or "power" (sultanin) required to pass beyond the regions of heaven and earth refers to the technological power of a space rocket, and notes that the verses' description of lashing flames and smoke resembles a rocket hurtling through the stratosphere.