deep space
noun
: space well outside the earth's atmosphere and especially that part lying beyond the earth-moon system
Examples of deep space in a Sentence
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No human has ventured into deep space since the final Apollo mission in 1972, but that is about to change.
—
The Week, TheWeek, 7 Jan. 2026
Flying aboard the Orion spacecraft atop the Space Launch System (SLS) megarocket, Artemis 2 will test life-support systems, navigation and communications in deep space ahead of future lunar landings.
—Samantha Mathewson, Space.com, 1 Jan. 2026
The mission will send four astronauts on a roughly 10-day journey around the moon to evaluate how the Orion spacecraft’s various systems and hardware function in a deep space environment.
—Marlene Lenthang, NBC news, 1 Jan. 2026
But returning to deep space after a more than five-decade hiatus is not without its challenges.
—Jackie Wattles, CNN Money, 31 Dec. 2025
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The Week, TheWeek, 7 Jan. 2026
Flying aboard the Orion spacecraft atop the Space Launch System (SLS) megarocket, Artemis 2 will test life-support systems, navigation and communications in deep space ahead of future lunar landings.
—Samantha Mathewson, Space.com, 1 Jan. 2026
The mission will send four astronauts on a roughly 10-day journey around the moon to evaluate how the Orion spacecraft’s various systems and hardware function in a deep space environment.
—Marlene Lenthang, NBC news, 1 Jan. 2026
But returning to deep space after a more than five-decade hiatus is not without its challenges.
—Jackie Wattles, CNN Money, 31 Dec. 2025
See All Example Sentences for deep space
Cite this Entry
“Deep space.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/deep%20space. Accessed 16 Jan. 2026.
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