Kerbal

Kerbal astronaut in EVA

Kerbals are the native denizens of the planet Kerbin, and cartoonish in-game analogs for humankind.

Kerbals display no variance in height or weight. They stand roughly 0.75 meters tall (2'5½"). A Kerbal in an EVA suit has a mass of 93.75 kilograms (206.68 lb.), which is 0.09375 in-game Mass units. However, this only counts toward the mass of a craft if seated in an EAS-1 External Command Seat; Kerbals add no mass when in a command pod or PPD-10 Hitchhiker Storage Container or the Mobile Processing Lab MPL-LG-2.

The only Kerbals seen in-game work at Kerbal Space Center or are found in orbit during specific contract missions.

Kerbal astronauts are often called "Kerbonauts".

Biology

Kerbal from Kerbalizer

Kerbals have massive heads with respect to their bodies with roughly half of their total volume accounted for the head. Kerbal eyes protrude from their heads significantly, as do their corneas from the eyes. Kerbals appear to lack any irises, or they are perfectly black in color. They also possess no eyelids.

Judging by official artwork and in-game models, Kerbals appear to have two large teeth that span the length of their gums, one on the mandible and one on the skull. However, this may be due to the cartoonish art style of the game and not actual fact.

Their skin hues appear to range from light green to pale green, if they range at all. Although Kerbals appear mostly hairless, they have notable hair growth occurring on the top of their heads and Wernher von Kerman can be seen to have a mustache.

Kerbals also appear to be warm-blooded, given their ability to sweat.

Kerbals have an awkward, sprawling walk due to their wide pelvis and short legs. A Kerbal's walking speed on Kerbin is about 0.87 m/s, it's running speed is about 2.35 m/s.

Anecdotal statements in the descriptions of the Rockomax HubMax Multi-Point Connector and the RoveMax Model XL3 suggest that Kerbals may die from shock when exposed to unexpected technological innovations. This could also be marketing hyperbole.

Kerbals seem to be in infinite supply, the in-game description of planet Kerbin saying its conditions support a "seemingly undepletable population of the eager green creatures".

Their most prominent personality traits are their Stupidity and Courage, as these are about the only individual traits to be seen beyond a name. Some Kerbals, such as Jebediah Kerman, have the rare "badass" trait, which makes them continually enthusiastic and without fear.

Gender

Artwork of Valentina Kerman

Up until 1.0, all incorporated Kerbals seemed to be male considering their masculine names and general appearance. C7— a developer at Squad— has said that, “There were no plans to add female Kerbals,” also noting that they didn't have any specific sex in mind.^[1] Arguments have been made though, that while no gender has been officially expressed, a clear masculine/male gender bias was placed on the models.^[2]^[3]^[4]

On February 21st, the KSP developer team Tumblr page posted an artwork of the first official female Kerbal named Valentina Kerman. Valentina is a reference to Valentina Tereshkova, who is the first woman to have flown in space.^[5]

As of Version 1.0, Female Kerbals (aka Kerbalinas) are available for hire at the Astronaut Complex, and Valentina Kerman is a default kerbonaut.

Speculation

Kerbonauts can be seen to spend years in space without showing any signs of muscle atrophy or other ill effects and can survive for years with vastly less food and oxygen than humans would require. There are various theories why this is possible:

They may enter a state of hibernation to endure long space travels
- This is unlikely, as they appear always awake when controlling the craft (although they still might hibernate whenever their ship isn't active).
It is also possible that they have the ability to enter a known psychological state which slows their perception of time through utter joy, or adrenalin. Which can explain their constant grin, and why they don't seem to care about being in a tiny capsule for years.
They may also not need oxygen to breathe, as they have no nose and can survive with their mouth closed. However this only solves a small part of the problem - the question still remains how Kerbals get energy.
Their green skin may contain chlorophyll allowing them to photosynthesize. They would, like a plant, gather solar energy and use that to convert carbon dioxide and water into oxygen and sugar. The Kerbal could then respire the oxygen and sugar to make carbon dioxide, water and usable energy when needed, allowing the Kerbal to survive entirely on light. However, Kerbals can also survive without light seemingly indefinitely.
Kerbals do eat, but life support simply has not been implemented into the game.
Another theory states that worrying about life support might simply not be considered fun.
By comparing the mass of a Kerbal in EVA to that of the average Apollo astronaut and then removing the weight of the A7L EVA suits one can estimate the weight of the average Kerbal to be around 52.55 kilograms (or 115.85 lbs)

Kerbal eyes may be a vulnerable spot for injuries due to protrusion, size, and lack of eyelids. If Kerbal eyes truly lack irises, their eyes would be very sensitive to bright lights.

Kerbals' awkward, sprawling walk may indicate that their species only recently evolved to the point of bipedal movement.

Language

Kerbals speak backwards Spanish. Their speech can be heard in the Astronaut Complex as well as the end of the credits theme. However, the credits theme is cut-off at the end, so the music file has to be got out of the game files to hear it. In trailers as well, they speak reverse Spanish (aka "loñapsE").^[6] However, Wernher von Kerman and Gene Kerman do emit sounds like "a-ha" and disappointed groans during in-game tutorials and at Mission Control. Curiously, They seem to write in modern english, not appearing as backwards spanish.

All kerbonauts have a random generated first name and "Kerman" as the surname. The first name is either a combination of phonetic syllables or chosen from a list of preset names.^[1] There are also a few uniquely named Kerbals, most of whom are apparent homages to real-life figures in NASA.

Kerbals refer to their species as "Kerbalkind" in several in-game texts. This parallels with the real-life term "mankind" or "humankind" English-speakers use.

Speculation

Kerbal larynxes would need an interesting structure to be able to pronounce phonemes that humans either cannot or would at least have great difficulty pronouncing. In addition, their language is full of sudden sharp sounds, unmelodic syllables, and impressively difficult pronunciations, owing to its nature of being a reversed human language. Given the cartoonish nature of Kerbals, their language may "simply be" without any realistic explanation for their vocal abilities.

Material culture and technology

Limited observations make things difficult to determine.

The technology and architecture appears to share many similarities with the modernized nations of Earth during the 1960s-2000s. However, currently^[outdated] Kerbin has no visible cities, homes, or any buildings other than those related to aerospace (barring a few easter eggs). The text for the EVA Report while flying in the lower atmosphere over Kerbin's Grasslands biome, however, mentions being able to "see my house from here", implying that Kerbals may live in houses visible above ground even though they are none to be seen in-game yet. Additionally, the text for a Temperature Scan while landed in the Grasslands biome says it "is quite pleasant, and would be a nice place to live." Coupled with reference to Kerbals' love of green, it suggests that Kerbals may have a preference for living in Kerbin's grassy plains.

From the humorous descriptions found in-game, it can be assumed that Kerbals are even more foolish and accident-prone than humans. Kerbals have accidentally mistaken planets for dust or smudges on a telescope lens or mistaken how telescopes work entirely.

In a scenario's instructions, Gene Kerman makes reference to an apparent video game called “Galaxy Intruders” which sounds similar to real-world classic arcade game Space Invaders.

“

Asteroids. Awesome to look at and great to have around; not so much when one lands on your house. Today we're going to learn how to keep that from happening. As anyone who has played Galaxy Intruders for more than ten minutes can tell you, it's not about firing at where they are, it's about aiming at where they're going to be.

— Gene Kerman, Intro to scenario “Asteroid Redirect Mission, Part 1”

”

A necessarily short list of technologies Kerbals possess includes:

Liquid-fuel, air breathing, and solid-fuel engines, and ion-drives
Electric power generation and storage
Radio communications
Computers
Telescopes and optical instruments
Steel and concrete building construction
Some understanding of atomic technologies (e.g. RTG, LV-N)

In some mods, they even have more advanced technologies than humans do. Interestingly, they still seem like to have all kind of random accidents and totally unsafe components according to the descriptions.

Speculation

It appears that their culture revolves solely around the process of designing, building, launching, riding (and crashing) rockets and planes, as every structure on Kerbin (excluding a certain Easter Egg) is devoted to either aviation or spaceflight.

One explanation of the scarcity of buildings on Kerbin theorizes that Kerbal civilization may live underground, or underwater, due to some unknown factor. Of course, this may be because KSP is a game that does not necessarily mandate cities, or they are planned but not yet implemented.

Some theories state that Kerbals, if their anatomy and biology resembles plants, can be cloned. This idea could be supported by the fact that all Kerbals have the same surname, and that all of them look alike but have different personalities via artificial memories, meaning that all of them are clones of one original Kerbal with “Kerman” as the surname. This could possibly be Jebediah Kerman, since the "Selection Process" labeled him as #0001. Also, it could be supported more by the fact that at least some Kerbals, Jebediah, Bill and Bob, can respawn or un-die.