PB-NUK Radioisotope Thermoelectric Generator

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PB-NUK Radioisotope Thermoelectric Generator
Part image
Generator by
Ionic Symphonic Protonic Electronics

Radial size Tiny
Cost (total) 23 300.00 Funds
Mass (total) 0.08 t
Drag 0.2
Max. Temp. 1200 K
Volume  ?
Impact Tolerance 7 m/s
Research Experimental electrics.png Experimental Electrics
Unlock cost 58 000 Funds
Since version 0.18
Part configuration RTG.cfg
Electricity generated 0.75 /s

The PB-NUK Radioisotope Thermoelectric Generator (RTG) is an electric generator that provides constant and reliable electricity for spacecraft. Although its weight/power ratio is worse than that of solar panels near Kerbin, it has the advantage of not requiring direct sunlight, allowing it to work on the night side of a planet or very far from Kerbol.

Product description

Through exploitation of the natural decay of Blutonium-238, this elegantly simple power generator can provide consistent, stable power for decades. Not to be used for providing heating during emergency rover excursions.

Ionic Symphonic Protonic Electronics


The Radioisotope Thermoelectric Generator is useful for purposes such as:

  • Traveling so far away from the sun that solar panels become insufficient.
  • Operating energy-consuming equipment on the night-side of a celestial body.
  • Removing the need to take special action to replenish electrical power stores.
  • Emergency backup for a stronger primary power supply.
  • Providing power while stowed in a fairing or cargo bay.

The alternative when there is too little sunlight is to use fuel cells. Which one is better depends on many factors. As a rule of thumb, two RTGs is equivalent in power to a single Fuel Cell after about 1.5 hours of operation, while 24 RTGs is equivalent to a Fuel Cell Array after about 2 hours of operation.

The electric output of the most common electricity source, solar panels, decreases according to the inverse square law. This means that the constant mass/power ratio of the RTG overtakes the mass/power of the fully illuminated OX-4L 1x6 Photovoltaic Panels at around 38,944GM from Kerbol, or slightly before reaching Dres. However, the RTG's cost/power ratio only overtakes the OX-4L at around 152,474GM, farther than the orbit of Eeloo.

RTGs also create heat, however under normal circumstances it's not noticeable due to it radiating heat quite well when they are exposed to space, however, many RTGs stacked in close proximity not exposed to space (such as in a cargo bay) they cannot radiate this heat, causing them to possibly overheat if left alone too long. this can be easily fixed by either opening the cargo bay or installing heat radiation systems such as extendable radiators, however it's probably safe to do both when in close proximity to the sun.

Also note that RTGs in KSP, unlike their real life counterpart, do not decay over time, (much to the realism lover's dismay) meaning that if you have a sort of "reactor" cargo bay full of RTGs with radiators, you can generate power forever.


  • The description contains a reference to The Martian, where Mark Watney used an RTG to provide heating in order to save power.
  • The design of the PB-NUK Radioisotope Thermoelectric Generator is based on the SNAP RTG used on the Pioneer 10 and 11 probes.
  • There are also two parts on the New Horizons probe that has the same appearance in-game.


  • Moved from Utility to Electrical
  • Mass reduced from 0.175 to 0.08, power output reduced from 1 E/s to 0.75 E/s.
  • Initial Release