探空火箭（英语：Sounding rocket）是一种比较特殊的运载工具，它只携带科学仪器进行亚轨道飞行。探空火箭一般为无控制火箭，具有结构简单、成本低廉、发射方便等优点。它更适用于临时观察短时间出现的特殊自然现象（如极光、日食、太阳爆发等）和持续观察某些随时间、地点变化的自然现象(如天气)。

探空火箭通常可按研究对象分类，如气象火箭、生物火箭、地球物理火箭等。气象火箭多用于 100公里以下高度的大气常规探测。生物火箭用于外层空间的生物学研究。地球物理火箭用于地球物理参数探测，使用高度大多在120公里以上。

A sounding rocket, sometimes called a research rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are used to carry instruments from 50 to 1,500 kilometres (31 to 932 mi) above the surface of the Earth, the altitude generally between weather balloons and satellites (the maximum altitude for balloons is about 40 kilometres (25 mi) and the minimum for satellites is approximately 120 kilometres (75 mi)). Certain sounding rockets, such as the Black Brant X and XII, have an apogee between 1,000 and 1,500 kilometres (620 and 930 mi); the maximum apogee of their class. Sounding rockets often use military surplus rocket motors. NASA routinely flies the Terrier Mk 70 boosted Improved Orion lifting 270–450-kilogram (600–990 lb) payloads into the exoatmospheric region between 100 and 200 kilometres (62 and 124 mi).