Q. Can the mitzvot be observed in space?
The view of Rabbi Benzion Firrer is that the mitzvot only apply in our territorial habitat and therefore man is exempt from the mitzvot in places which are not on the earth.
Rabbi Shlomo Goren, on the other hand, says that in space, human life is still dependent on elements transported from earth, therefore we are governed by the laws operative on earth and must keep the mitzvot.
Rabbi Firrer disagrees and says that once such materials come into contact with the moon, they have the same status as lunar material.
The Talmud states (Gittin 7b): The bodies of water in Eretz Yisrael are not part of the land of Israel; therefore a ship in the lakes and rivers of Eretz Yisrael, as long as it does not scrape the bottom, is considered to be outside the borders of Israel.
When the vessel touches the bottom, its cargo and passengers are considered to be within Eretz Yisrael.
The ship acquires the halachic status of the underlying river bed by coming into physical contact with it.
Similarly, a space craft landing on the moon becomes part of the moon.
Rabbi Menahem Kasher rules that the mitzvot are obligatory on Jews wherever they are, even on the planets (JD Bleich, “Contemporary Halachic Problems”, vol.1).
Issues that require attention include the following:
1. Shabbat (which is dependent upon time): do we accept times as in Jerusalem? Or observe Shabbat for the period of one orbit after every 6 orbits?
2. Festivals (dependent upon specific dates determined by earthly perception): do we follow dates as in Jerusalem? Or suspend all such mitzvot?
3. Prayers, tallit, tefillin, etc.: do we say with Rabbi Menahem Kasher: “The situation on the moon [or Mars] is equivalent to the north and south poles; therefore posit a 24-hour day, with alternating periods of 12 hours day and 12 hours night regardless of the presence or absence of light from the sun”.
4. Kashrut – does edible material necessarily retain its status quo in space?
5. Ethical laws, e.g. “Love your neighbour as yourself” (Lev. 19:19): who is my “neighbour” in space, and how do I love him/her?