The Biosphere $2$ experiment was

Question $18$ options:

a successful attempt to grow crops hydroponically to see if space colonists could feed themselves with home$-$grown food

an experiment performed on Mars in the $1990\text{'}$s to see whether small$-$scale terraforming might be feasible

a prototype "space colony" in Low Earth Orbit that supported a crew of $6$ for nine months

a largely unsuccessful attempt to create a completely self$-$contained habitat on Earth