Various halachic authorities have raised concerns about space travel in general

October 13, 2024, 7:25 a.m. Central Time, Boca Chica, Texas.

It’s just after sunrise, and the sky over southern Texas is almost completely clear. Suddenly, the deafening roar of 33 Raptor methane engines shatters the silence. Emitting a dense plume of fire and smoke, SpaceX’s Starship — 400 feet tall and weighing 5,500 tons — lifts off into the brightening morning sky.

The US aerospace company SpaceX, founded by tech billionaire Elon Musk — now head of the newly established Department of Government Efficiency — wrote a new chapter in the history of space travel.

After a brief flight over the Gulf of Mexico, the command was issued for the Super Heavy booster stage to return to the Starbase in Boca Chica instead of making its usual descent into the ocean after separating from the Starship capsule. From an altitude of over 40 miles and a speed of 3,100 miles per hour, the 233-foot booster was caught with millimeter precision by giant metal arms known as the “Chopsticks.”

Elon Musk celebrated this unprecedented achievement with a brief post on his social media platform X (formerly Twitter): “The tower has caught the rocket!!” The post included a video from the mission’s live broadcast.

This breakthrough is significant; the ability to reuse the booster stage could save millions in spaceflight costs. SpaceX’s official goal with the Starship is to transport people and cargo to the moon regularly and relatively affordably. However, Elon Musk’s ultimate vision — and by extension, SpaceX’s mission — is to reach and colonize Mars to secure humanity’s survival.

Interestingly, this is not the first time humanity has considered emigrating to another planet.

Rabbi Yehonasan Eybeschutz (1690–1764), in Tiferes Yehonasan (siman 8), asks the well-known question: What exactly was the generation of the Dor Haflagah trying to achieve with their plan to build a tower reaching the heavens? Did they truly believe it was possible to construct such a tall structure?

He offers a novel explanation: They intended to use “ships” to travel to the moon to escape the threat of another Mabul. Their biggest challenge was overcoming the Earth’s gravitational pull (as they lacked today’s advanced Raptor methane engines). They therefore devised the idea of building a tower so tall that at its peak, the lower gravity would allow them to launch their ships to the moon. (Rabbi Yehonasan Eybeschutz lived more than 100 years before Jules Verne, the French author hailed as a visionary of space travel for his novels From the Earth to the Moon and Around the Moon.)

The Dor Haflagah was punished because their intent was to rebel against Hashem by fleeing to the moon. This raises an interesting question: Are there halachic concerns with SpaceX’s current goals of traveling to the moon or Elon Musk’s vision of colonizing Mars?

The Ramban, in his commentary on the Chumash (Bereishis 1:28), explains the verse “u’milu es ha’aretz u’chivshuhah” as granting humanity permission to inhabit and cultivate the Earth. Rabbi Simcha Zissel Broide, longtime rosh yeshivah of Yeshivas Knesses Yisrael Chevron, notes (Sam Derech, parshas Kedoshim) that without this explicit Divine permission, it would have been prohibited to cultivate and settle the Earth.

He extrapolates from this that taking samples or cultivating land on the moon (or any other planet) would be similarly prohibited. It would be akin to working on someone else’s property without their consent, as the pasuk in Tehillim (115:16) states, “HaShamayim Shamayim l’Hashem, v’ha’aretz nasan l’bnei adam.”

Furthermore, various halachic authorities have raised concerns about space travel in general.

Rav Menashe Klein, in his responsa Mishneh Halachos (vol. 6, siman 259), writes that space is considered a makom sakanah, as the journey to space and stay in outer space involve significant risks. Therefore, space travel would be forbidden because halachah prohibits voluntarily entering dangerous situations. Though this teshuvah was written in 1971, and spaceflight has become much safer since then, with a current fatality rate of 1.3 percent, it remains inherently risky. For example, on February 1, 2003, the space shuttle Columbia (Mission STS-107) disintegrated upon reentry, resulting in the tragic deaths of all seven of its astronauts, including Israeli fighter pilot and astronaut Col. Ilan Ramon.

Another issue raised by halachic authorities pertains to the fulfillment of mitzvos in space. Representing the Jewish People in space, Col. Ilan Ramon, though from a secular background, sought to observe Shabbos in orbit. He consulted Rabbi Zvi Konikov of Chabad of Space and Treasure Coasts to determine how to observe Shabbos in space, where a full day-night cycle occurs every 90 minutes, making a week pass every 10.5 hours. This led to fundamental discussions among rabbinic authorities on how — or if — it is possible to fulfill time-bound mitzvos in space.

Rabbi Moshe Sternbuch (Teshuvos v’Hanhagos, Vol. 5, Siman 84), for instance, takes an extreme stance, arguing that the time dilation effects of gravity in space exempt one entirely from time-bound mitzvos. He concludes that it is strictly forbidden for a Jew to travel to space. Furthermore, he decries the allocation of billions of dollars to space exploration as a waste of resources, driven by national pride rather than necessity. In his opinion, the Jewish nation should generally stay away and not contribute in any way to this industry.

Even though halachah seems to forbid traveling into space, Jewish scholars have made significant contributions to astronomy and space exploration over the centuries. The Amora Shmuel states in Berachos (58b), “I am as familiar with the paths of the heavens as with the streets of Nehardea.”

Our sages drew their knowledge from the Torah, the blueprint of creation, and more than 3,000 years ago were already capable of making highly precise astronomical calculations for Kiddush Hachodesh. The duration of the lunar month as recorded in the Talmud differs from modern scientific calculations by only a few decimal places — an extraordinary level of accuracy, unimaginable given the scientific knowledge of their time. Recognizing this, the International Astronomical Union named four craters on the moon after Jewish astronomers and rabbis:

• Messala (Masha’allah ibn Atharī, c. 740–815 CE)
• Abenezra (Abraham ben Meir ibn Ezra, 1092–1167)
• Zagut (Rabbi Abraham Zacuto, 1452–1515)
• Rabbi Levi (Rabbi Levi ben Gershon, 1288–1344)

Thus, Jewish scholars have left their imprint on the lunar surface without ever setting foot there.

IN a shiur on gadlus ha’adam in 1969, Rav Shlomo Wolbe remarked that as humanity pursues groundbreaking discoveries in science and technology, it increasingly neglects the inner world of the human soul. In Rav Wolbe’s words, “Civilization magnifies the world and diminishes the individual’s inner world.” By focusing solely on external advancements, society risks losing touch with its ethical improvement.

True gadlus is focused entirely on the inner world of improving the middos and self-control. Non-Jews’ encounters with gedolei Yisrael left them in awe, from Alexander the Great meeting Shimon Hatzaddik to the Polish minister of education meeting the Chofetz Chaim.

“The secret of the greatness of Torah scholars is their absolute self-control, and the more a person merits to control himself, the more their neshamos’ powers are revealed.”

As the engines of the Super Heavy cool from the unprecedented achievement and SpaceX prepares for its next mission to expand the horizons of space exploration, we, on our part, continue striving to expand the horizons of the human neshamah.

(Originally featured in Mishpacha, Issue 1943)