What describes a challenge that the engineer of a high altitude airplane would need to consider?

One major challenge an engineer of a high-altitude airplane must consider is the decreased air density at high altitudes, which affects both lift and engine performance. This requires the design of specialized wings and propulsion systems that can operate efficiently in thin air. Additionally, engineers must address temperature extremes and the potential for structural fatigue due to low pressure and temperature fluctuations. Ensuring passenger safety and comfort at such altitudes also presents significant design challenges.