How Do Spacecraft Slow Down? We Asked a NASA Technologist

Spacecraft slowing down in space is a crucial aspect of space exploration, and NASA technologists play a pivotal role in making it happen. To understand this process better, we spoke to a NASA technologist who shed light on how spacecraft slow down.

When a spacecraft is hurtling through the vast expanse of space, it initially maintains its velocity due to the absence of friction. However, to rendezvous with celestial bodies, enter orbit, or safely return to Earth, slowing down is essential.

One of the primary methods employed by spacecraft to slow down is engine firing. Spacecraft are equipped with rocket engines that expel high-speed propellant, producing thrust in the opposite direction of their motion. This thrust follows Newton's third law of motion: for every action, there is an equal and opposite reaction. By expelling mass at high speeds in the opposite direction, the spacecraft gradually reduces its velocity.

Additionally, gravity assists can be employed for deceleration. When a spacecraft approaches a celestial body, such as a planet or moon, it can use the body's gravitational pull to its advantage. By executing a carefully planned trajectory, the spacecraft utilizes the planet's gravity to steal some of its momentum, effectively slowing down or altering its course.

Aerobraking is another ingenious technique used to slow down spacecraft. This involves dipping into a planet's atmosphere, where air resistance generates drag that reduces the spacecraft's velocity. Repeated passes through the atmosphere gradually bleed off speed until the desired velocity is achieved.

In some cases, mission planners may opt for more unconventional methods, like utilizing solar sails or deploying drag sails to interact with the solar wind or interstellar medium, respectively, for deceleration.

In conclusion, spacecraft slow down through a combination of engine firings, gravity assists, aerobraking, and innovative technologies, all orchestrated by the expertise of NASA technologists. These methods ensure that spacecraft can achieve their mission objectives and explore the mysteries of the cosmos.