Aerial means existing, happening, or operating in the air. I am wondering if there any word that has the same definition but in space?
Referring to the context you pose, I would suggest "cosmic" or "extraterrestrial" as describing the specific "space" that you refer to in the question.
In comments you clarify,
I was looking for a word for Unmanned Aerial Vehicle but in space. Not sure Unmanned Spatial Vehicle will fit the context or not.
Unmanned space vehicle would certainly be clear and to the point.
You might also call it an unmanned spacecraft or unmanned space ship.
In science fiction, writers have often mentioned things such as space probes or drones with a similar meaning.
In some cases, the name we use for the vehicle might make it clear that it travels in space, without having to use an extra word to say so. For example, NASA calls its unmanned space vehicles, unmanned satellites (if they remain in Earth orbit) or unmanned missions. Wikipedia has a List of unmanned NASA missions that might provide other ideas for nomenclature.
Space is accepted and is self-defining. Why not use Unmanned Space Vehicle?
From Oxford English Dictionary:
The expanse in which celestial objects are situated; the physical universe (excluding celestial objects) beyond the earth's atmosphere, consisting of near vacuum with small amounts of gas and dust.
As in: article
This United States Air Force unmanned space vehicle explores reusable vehicle technologies that support long-term space ...
You said in a comment under your question:
Thanks, I was looking for a word for
Unmanned Aerial Vehiclebut in space. Not sure
Unmanned Spatial Vehiclewill fit the context or not. (Also this is the first time I see this word)
Aerial and aeronautical are adjectives for things in the atmosphere.
Analogously, the adjective for things in space is astronautical. (Spatial, while also analogous, doesn't really work in this case.)
From the noun astronautics:
: the science of the construction and operation of vehicles for travel in space beyond the earth's atmosphere
As per another answer, unmanned space vehicle sounds more natural than unmanned astronautical vehicle.
However, when you talk about things manufactured for space in general, you are talking about things that are of an astronautical nature, not things that are of a space nature.