Spacecraft Classification

The sky is speckled with many different types of spacecraft. We can differentiate Spacecraft from one another using Spacecraft Classification. These are the main types of Spacecraft in space today: Flyby Spacecraft, Orbiter Spacecraft, Atmospheric Spacecraft, Lander Spacecraft, Penetrator Spacecraft, Rover Spacecraft, Observatory Spacecraft and Communications Spacecraft.

This classification uses the spacecraft function to differentiate the spacecraft. Other classification systems are possible, powered vs unpowered, crewed vs non-crewed, etc.

Flyby Spacecraft

Flyby spacecraft are designed to “flyby” a planet and take observations. Flyby spacecraft are not to be confused with Orbiter Spacecrafts because the primary goal of a Flyby spacecraft is to observe and record without being captured by the planet’s gravity. The spacecraft’s orbit will be designed to pass close by planets but never orbit one, instead following a larger orbit around the sun.

These types of Spacecraft have to be able to record science and data as their objects pass by. Flyby spacecraft must also be able to transmit and store data and science as well as survive very long periods in harsh conditions in the journey between planets.

Some notable examples of Flyby Spacecraft are the Voyager 1 and Voyager 2 missions which flew past Jupiter, Saturn, Uranus, and Neptune. Other examples include the Pioneer and Mariner series of spacecraft.

Orbiter Spacecraft

The Orbiter spacecraft although very like its brother the Flyby it does have many key differences. One main difference is that the Orbiter Spacecraft unlike the Flyby’s main goal is to orbit and observe one planet whereas the Flyby has the ability to observe many. However, the Orbiter spacecraft has the ability to conduct more in-depth scientific experiments with the advantage of being closer to the planet and in orbit, therefore, being able to observe the planet and its movements for a longer period of time. According to NASA, you can think of the Orbiter as a phase two to the Flyby with the initial reconnaissance followed up by in-depth study and research.

Scientists’ main concerns when designing and building an orbiter spacecraft are the concerns of Earth and Sun occultations. A Sun Occultation is when the planet gets in front of the spacecraft’s view of the Sun thus not providing it with the energy to fuel its solar panels. An Earth Occultation is similar but this time it is the planet blocking Earth from view therefore forcing the spacecraft to be unable to transmit data until Earth is in view.

Some notable examples of an orbiter spacecraft are the Cassini spacecraft to Saturn, the Mariner 9 spacecraft to Mars, and the Magellan spacecraft to Venus.

Atmospheric Spacecraft

Atmospheric Spacecraft is a very interesting brand of Spacecraft. Rather than having its own propulsion systems onboard, Atmospheric Spacecraft piggyback another spacecraft (usually an orbiter or flyby) to its destination. Atmospheric Spacecraft as the name implies its main objective is to observe and record data on a specific celestial body. The spacecraft then detaches itself and plunges into the atmosphere and collects key data such as atmospheric composition, barometric pressure, and many more interesting data points.

Since the Atmospheric Spacecraft does not require any specific propulsion systems Scientists take the opportunity to pack it with other scientific instruments. Of course, the spacecraft requires a battery to operate and telecommunications to communicate back to Earth or the ship it was detached from but otherwise, some examples of instruments would be a barometer, some sort of Mass Spectrometer, and other experiments relating to the celestial body it is studying.

A notable example of an Atmospheric Spacecraft is the Huygens Probe to Titan.

Robotic Spacecraft

The Robotic Spacecraft sector is one of the more well known. This includes Rover Spacecraft, Lander Spacecraft, and Penetrator Spacecraft.

Rover Spacecraft

We will start with the most known one which is the Rover Spacecraft. The Rover Spacecraft are spacecraft designed to move and operate on the surface of another celestial body. Rover Spacecraft are generally jam-packed with scientific instruments but scientists like to take advantage of being on the planet rather than orbiting and usually pack it with more rock observing and geology type-of experiments rather than atmospheric experiments which they could achieve with an atmospheric Spacecraft like the Huygens.

Some very notable examples of rover Spacecraft are the Mars Perseverance Rover as well as some other mars rovers such as the Curiosity, Opportunity, and Spirit rovers.

Lander Spacecraft

The second branch of Robotic Spacecraft is the Lander Spacecraft. Similar to the Rover Spacecraft these spacecraft land on the surface but do not move but simply sit in one place and record data that is transmitted back to an Earth Ground Station.

Some notable examples of a Lander Spacecraft are that of the Viking Missions to Mars.

Penetrator Spacecraft

The third is the Penetrator Spacecraft. This type of Spacecraft is relatively uncommon and has more recently been replaced with Impactor Probes. The Penetrator Spacecraft are spacecraft that’s main job is to dig under the surface of a celestial body and record data from underground.

Most Impactor Probes are prototypes so there are not many examples of this spacecraft.

Created by Anuj Krovvidi