In the history of space exploration, the first animal to be sent into space by humans aboard a rocket was which of the following?

Introduction / Context:
Before humans were sent into space, scientists conducted experiments with animals to understand the effects of microgravity, radiation, and launch stresses on living organisms. These early missions laid the foundation for human spaceflight. This question asks which animal was the first to be sent into space aboard a rocket, a key milestone in space exploration history.

Given Data / Assumptions:

• The focus is on the very first animal sent into space, not the first to orbit Earth.
• The context is early rocket experiments carried out after the Second World War.
• The options include a dog (Laika), fruit flies, a monkey (Albert II), a mouse, and a cat.
• We assume space here means a rocket reaching space altitude, not necessarily orbit.

Concept / Approach:
The first animals to reach space were fruit flies launched by the United States on a captured V 2 rocket in 1947. The rocket reached high altitude beyond the commonly accepted boundary of space, and the capsule with the flies was recovered. Later, other animals like monkeys, dogs, and mice were sent on higher profile missions. Laika, the dog, was the first animal to orbit Earth in 1957, but she was not the first animal in space. To answer correctly, you must distinguish between being the first in space and being the first in orbit.

Step-by-Step Solution:
Step 1: Recall that early US experiments after World War II used V 2 rockets to send biological specimens into space.Step 2: Remember that in 1947, fruit flies were launched as the first living animals to cross into space and return for study.Step 3: Note that Laika the dog became famous later as the first animal to orbit the Earth, not the first to reach space at all.Step 4: Monkeys such as Albert II and other animals were also sent later in chronological order.Step 5: Therefore, the correct answer for the very first animal to be sent into space is fruit flies.

Verification / Alternative check:
Historical timelines of space exploration show that on 20 February 1947, the United States launched fruit flies aboard a V 2 rocket to study radiation exposure at high altitudes. These flies became the first animals in space. Laika's orbital mission in 1957 and subsequent missions with monkeys and dogs are well documented but occurred later. This sequence confirms that fruit flies are correctly identified as the first animals sent into space.

Why Other Options Are Wrong:
Option A: Dog (Laika) was the first animal to orbit Earth but not the first animal to enter space.Option C: Monkey Albert II was among the early animals in space but was launched after fruit flies.Option D: Mice were used later and were not the first.Option E: A cat, such as the French cat Félicette, was sent to space later than the other animals mentioned.

Common Pitfalls:
Many learners confuse the phrase first animal in space with first animal in orbit, leading them to choose Laika the dog. Another common mistake is to recall only high profile mammals and forget that very small animals and insects were used in early experiments. To avoid such confusion, carefully distinguish between different milestones: first in space, first in orbit, and first human in space.

Final Answer:
The correct answer is Fruit flies.