Early Space History – Identify the correct statements Which of the following statements about the earliest Earth-observing and space-imaging milestones are correct?

Introduction / Context:
Foundational milestones in the Space Age set the stage for today’s Earth observation. Understanding the timeline helps contextualize the evolution from the first artificial satellite to routine meteorological imaging and reconnaissance, which in turn spurred civilian remote sensing missions.

Given Data / Assumptions:

• Basic dates of key missions: Sputnik 1, Explorer 6, TIROS, and CORONA.
• Focus is on first occurrences and program starts rather than detailed capabilities.

Concept / Approach:

Sputnik 1 marked the beginning of the Space Age in 1957. Explorer 6 transmitted early images of Earth in 1959. TIROS initiated systematic weather observation by satellite in April 1960. CORONA, a declassified reconnaissance program, began returning film-based imagery around 1960, laying technical groundwork for later civilian imaging systems.

Step-by-Step Solution:

Verification / Alternative check:

Historical mission summaries and declassified archives corroborate these dates and roles.

Why Other Options Are Wrong:

Any single statement alone would omit other true milestones, so the combined option is the only fully correct choice.

Common Pitfalls:

Confusing first satellite (Sputnik 1) with first human in space (Yuri Gagarin, 1961), or mixing TIROS with later NOAA operational constellations.

Final Answer:

All of these.