OUT OF THIS WORLD
Keeping Halacha in space
By: Rav Yosef Fund, Posek for the Bais HaVaad,
A recent news article reported that Virgin
Galactic announced their first commercial spaceflight, planned for later this
year, establishing a precedent for other companies eager to send flights
outside of Earth’s orbit. This will no doubt have halachic ramifications and
here we will examine some of those.
One Giant Leap for… Shabbos
Shortly after Neil Armstrong took “one
small step for man” during the first manned lunar mission in 1969, halachic issues related to space travel were
already under discussion in the sefer HaAdam Al HaYareach (Man on the Moon), written by Rabbi Menachem Kasher. Years later, Rav Shlomo Zalman
Auerbach reviewed a halachic discussion regarding the observance of Shabbos in outer space, but
then advised not to print it since, in his words, those who travel to outer
space are not seeking halachic guidance.
However, all this changed in 2002,
when the Israeli astronaut Ilan Ramon asked Rabbi Zvi Konikov of Satellite
Beach, Florida, how —and when — to observe Shabbos in outer space.
All in a Day’s Work?
Whatever our plans, before we begin discussing
Shabbos observance in outer space, we must first attempt to define the halachic day. Indeed, this would be of
benefit for the overwhelming majority of my readers, who happen to reside along
with me on Planet Earth.
Is a day a period of 24 hours? As
such, do the rising and setting of the sun mark the boundaries of the day, but
not define it? Or, perhaps, do the rising and setting of the sun define a day? This
differentiation is relevant for an astronaut orbiting the earth; he may
experience 16 sunsets in a 24-hour period! Accordingly, does he pray the evening
prayers 16 times in 24 hours? The distinction is also important for someone in
the polar region where the sun may be visible for months at a time; is that
time period considered one long day?
Rabbi Eliezer Ashkenazi elaborates
on how to understand the days, as described in the Torah in the beginning of Bereishis. The Torah
describes the creation of the earth, including the first “day,” which transpired
prior to the creation of the sun. In the context of this discussion, Rabbi
Ashkenazi writes that one who finds himself in the polar region should observe
Shabbos after seven rotations of the earth, even though he did not experience
The Talmud in Maseches Chagigah quotes Rav Yehuda in the name of Rav, who said that one of the ten
things that were created on the first day of creation was the measure of day
and night. Rashi explains that
this is referring to the 24 hours between the two of them, meaning between day
and night. Divrei Yatziv writes that the words of Rashi
lend support to the opinion that in the polar region a day is defined as the
passage of 24 hours, even without a real day or night. However, Divrei Yatziv then writes that
this seems to be a subject of dispute between various Midrashim, raising the
question of whether days or years actually occur in the absence of movement of
heavenly bodies to delineate time.
Radal suggests that perhaps one who is in the polar region should not
count every 24 hours as a day, but that only an actual sunset marks a day. This
would mean that a “day” can continue for many months. As support for this
position, he cites the Midrash that the sun stood still for Yehoshua so
that he would not transgress the Shabbos. This implies that even though more
than 24 hours passed from the start of the sixth day, it was not considered
Shabbos since the sun did not actually set. Rabbi
points out that according to this reasoning, the passage of months could take
many years; this would have a profound effect on the observance of holidays in
So, Do We Call it a Day?
We are still left with the question
regarding an astronaut who is revolving around the earth and experiencing 16
sunsets in a 24-hour period. Does he count each sunset as the end of another
day, or only each period of 24 hours?
We find in the Talmud Shabbos  that Rav Huna said: One who
is traveling in the desert and does not know which day is Shabbos counts six
days and observes the seventh. In a further discussion, we are told that such a
person may only perform work that is necessary to maintain his life; this is
equally true of the six days as of the seventh, which he observes as his
Shabbos. His Shabbos is only distinct because that is when he recites Kiddush and Havdalah. Rashi comments that Kiddush and Havdalah on the seventh day are only recited as a remembrance— so that he
should not forget the concept of Shabbos.
Based on this passage in the Talmud,
Rav Yaakov Emden
writes that one who is in the Arctic or Antarctic region, where the polar day
or night lasts for many weeks, should count days of 24 hours from the time he
arrived there; he should then observe each seventh day as Shabbos. Similarly,
he writes that a traveler who circumscribes the globe should observe every
seventh day as Shabbos. Only
when returning to the original point of departure is one to cease his personal
count and to revert to observing Shabbos on the same day as the members of that
community. According to Rav Emden, there is an “individual” Shabbos, which each
person counts, and an absolute and universal Shabbos, which is in accord with
the day of Shabbos in Eretz Yisrael.
It would seem that according to Rav
Yaakov Emden’s position, the
Talmud’s instruction that a traveler should count six days and observe the
seventh is a true observance of Shabbos, while according to Rashi, it is only an observance to remind
one of Shabbos.
On a Wing and a Prayer:
This brings us to another question:
If every period of 24 hours constitutes a day for the purpose of the observance
of Shabbos — which is dependent on the passage of seven days — is this also
true regarding prayer? The daily prayers are ordered according to the times of
day; we have morning prayers, afternoon prayers, and evening prayers. One who
experiences a day without these phenomena (of morning, afternoon, and evening)
may not be obligated in these prayers. Nevertheless, he ought to observe these
as a remembrance, just
as a traveler is to recite Kiddush as a remembrance, as Rashi writes.
Zoning In and Out:
Rabbi Halperin argues that Torah
life is predicated on a day of approximately 24 hours; thus, he says that it is
not likely that halachah would require someone to pray the three daily prayers 16 times in
a 24-hour period, even if he experiences that many sunrises and sunsets within
that amount of time. Similarly, Rabbi Halperin rejects the idea that one who is
traveling in outer space should observe Shabbos according to the area he is
over at that time, since that would result in a “Shabbos day” that begins and
ends in a matter of minutes as he flies in, out of, and back into a “Shabbos
It is worth pointing out that this
last argument is not specific to one who is in outer space. Even one who is traveling
the globe on a super-fast train would be traveling in and out of Shabbos. It
would seem absurd to say that such a person need not observe Shabbos at the same time as
the stationary residents of the towns he is passing through. However, one may
still question whether one who is quite a distance from the earth is considered
as if he is located in the area of Planet Earth over which he finds himself.
According to Rabbi Halperin, the
entire concept of days and months does not apply in outer space. Thus, strictly
speaking, neither Shabbos nor tefillah would be obligatory in outer space. Nonetheless, he maintains that bound
observances would remain an obligation as a remembrance, just as they obligate
a desert traveler.
Back Down to Earth
these lines of argument are speculative; there seems to be no clear halachic
ruling regarding these matters. One thing is clear: Space travel should not be
undertaken for trivial reasons, especially when Shabbos is part of the schedule.
Maadanei Shlomo 2016 edition, p. 164-5
Kovetz Or Yisroel (Vol. 29) published Rabbi Konikov’s letter on the
topic, along with responsa from Rabbi Kenig, Rabbi Levi Yitzchok Halperin,
Rabbi Tzinner, and Rabbi Yitzchok Shechter. (Rabbi Halperin wrote a more
lengthy work on this topic published under the title Im Esak Shamayim. Rabbi
Shechter subsequently included a lengthier version of his response in his Shu”t
Yashiv Yitzchok (6:5).)
Maaseh Hashem, Maaseh Bereishis 3
O.C. 1: 108
in his commentary on Pirkei De’Rabbi Eliezer (52: fn 1)
Radal himself offers that we may distinguish between a case where the
entire world did not experience an advance of the sun, and one where only the
polar region did not observe a sunset.
Im Esak (fn 15)
Mor U’Ketziah 344
and not regard any dateline
Supports for the position of Rav Yaakov Emden
can be found in a response of the Radvaz (Shu”t Radvaz
1: 76) who wrote that the counting of days for
Shabbos is an individual count. This, he writes, is why the Talmud states that
a traveler makes his own count, and how it is that different parts of the globe
observe different days of Shabbos.
See Divrei Yatziv, who makes a similar point, and the words of Rabbi
Shechter in Ohr Yisroel (ibid p.41).
See the words of Rabbi Shechter in Ohr Yisroel (ibid p.56).
Should one argue in the negative, it would then be necessary to ascertain the
exact distance from Planet Earth that frees him from his earthly ties.