Neutron S Type Super Dimensional Strategic Nuclear Missile (SBM)

Nuetron S Super Dimensional Strategic Nuclear Missile 2

ROBOTECH Technical Files

by Pieter Thomassen and Peter Walker

edited by Tim Wing


  • Neutron S reference file
  • Neutron S gallery

Designation: Neutron S Type Super Dimensional Strategic Nuclear Missile

Names and disposition:

None of these missiles ever received any names, merely numbers.

  • SBM-01, destroyed over Earth by the Invid, 2044
  • SBM-02, destroyed over Earth by the Invid, 2044
  • SBM-03, expended in a weapons test in the Sa’ars Nigme system, 2044
  • SBM-04, destroyed over Earth by the Invid, 2044
  • SBM-05, destroyed over Earth by the Invid, 2044
  • SBM-06, destroyed over Earth by the Invid, 2044
  • SBM-07, destroyed over Earth by the Invid, 2044
  • SBM-08, destroyed over Earth by the Invid, 2044
  • SBM-09, destroyed over Earth by the Invid, 2044

Ship’s complement:

  • None. The Neutron S missile was unmanned at all times.


  • Length: 2800 meters overall, 1050 meters warhead section
  • Diameter: 1000 meters main section, 1850 meters drive section cap, 1700 meters warhead section.
  • Mass: 340,000,000 metric tons
  • Fuel Mass: 101,000,000 metric tons

Propulsion systems:

  • Main power system: RRG Mk. 18 Reflex furnace cluster. The powerplant of the Neutron-S Missile can deliver up to 340 Petawatts of power for its main propulsion systems.
  • Maneuvering thrusters: None. The Neutron S missiles used a gyrostabilization system.
  • First stage reaction thrusters (20): Pratt & Whitney Pluto-9 fusion-plasma reaction engines with protoculture energizers.
  • Second stage reaction thrusters (16): Rolls-Royce Hades fusion-plasma reaction engines with protoculture energizers.
  • Space fold (1): Tirolian 542TrzD fold drive, similar to those built into Zentraedi flagships, but originally sold by the Tirolians for commercial use with the largest civilian freighter vessels. These units have been substantially upgraded by the Expeditionary Forces.
  • Planetary capabilities: The Neutron S missiles could not operate in an atmosphere, save for a single re-entry by the warhead section.

Endurance and mobility limits:

The Reflex furnace could operate in a stand-by mode for almost 70 years before an energizer rebuild became necessary.

First stage endurance was about 1.0 g for about 74 minutes (c. 43.6 kps).

Second stage endurance is about 1.5 g for 20 minutes (c. 17.6 kps), after which the fuel would be exhausted. The second stage engines would be good only for scrap after this, if they somehow survived the explosion of the warhead.

Space Fold (1): The performance of this upgraded version is unknown.

Total first and second stage delta-v capacity was about 61.2 kps.

Nuetron S Super Dimensional Strategic Nuclear Missile 8Weapon systems:

  • Nuclear warhead. Almost all details of this awesome warhead are classified. What is known is that the weapon was a fusion bomb using a LiD mantle around one or more fission initiators. Though it is hotly debated whether or not this weapon was supposed to be a single large warhead or numerous MIRVs, the total volume of the reactant is approximately 150,000,000 cubic meters, with an expected total yield of 15 million megatons, similar to the K-T event that struck the Yucatan 65 million years ago, leading to the mass extinction of the late Cretaceous. The weapon’s surface was lined with a neutron-rich material, for maximal neutron radiation emission on detonation and short-lived neutron-emitting fallout.


  • The Neutron S missiles mounted shadow devices, and EM-absorbing skin covers; although after launch their size and heat signature made them readily apparent to all belligerents.

Design notes:

Aside from the Robotech Masters’ motherships, these vessels were probably the most massive space warships ever built, and consisted of nothing more than a fold-engine, numerous reaction thrusters, and history’s largest nuclear weapon.

The forward-most section of the weapon was the warhead itself, to the rear of which was attached a battery of sixteen reaction thrusters for terminal delivery to the target. Aft of the warhead was a large cap lying between the main drive section and the warhead section, to which the warhead mounted. Sixteen aft pointing reaction engines were located on the exterior of the cap. In addition, the cap had a mounting point fitted, where an Ikazuchi-class large cruiser could dock for a non-remote arming of this dangerous missile. The cap was a total of 250 meters long.

Further aft of the cap was the main drive section, consisting mainly of reaction-mass tanks, the fold-drive, navigational computers, main powerplant, and the remaining four main reaction thrusters. To save design and production effort, the Neutron S missiles used salvaged Tirolian fold drives.

Nuetron S Super Dimensional Strategic Nuclear Missile 6History:

The lineage of this weapon can be traced to the mid-thirties, when the Expeditionary Forces and the Invid occupying Earth were locked in a deadly logistics race, to determine who would assert total control over the Earth in the near future. The Expeditionary Forces, considering that they might lose this race by dint of the Invid occupying the one planet with a significant supply of the Flower of Life, created the Neutron-S missile to insure that when the war was over, they would stand victorious, one way or another.

The basic premise of this weapon was based on reports of modern equivalents of ‘fire-ships’ used by the so-called Disciples of Zor. This group on occasion automated one of their larger starships, loaded it with a large number of nuclear warheads, then folded it close to its target, which it proceeded to attack. Unless the ship was intercepted before it entered missile range, the target (invariably a major planet or installation) would be utterly razed. The Expeditionary Forces took this concept and improved on it, designing a vessel for this purpose. The Neutron-S missile used an enhanced-radiation type warhead, and relied more on its size and armor to punch through defenses rather than on missile saturation. The weapon thus became easier to stop, but it was no longer intended to attack without a support fleet, and its final effects were far more deadly.

Nuetron S Super Dimensional Strategic Nuclear Missile 4In all, nine of these formidable missiles were built. To insure complete control of this planet-busting weapon, an Ikazuchi-class cruiser was docked with each missile until the launch of the warhead. When in 2042 a reinforcement attempt of Earth failed due to unexpectedly high numbers of Invid forces, and subsequent reconnaissance revealed that the Invid had, indeed, taken a lead in the logistics race, final construction of these missiles was moved up, and by 2043, all were operational. One of the missiles was then used in a weapons test on an uninhabited, lifeless planet, a test which the weapons system passed with flying colors. (Editor’s note: conflicting accounts exist regarding this weapons test. Some sources claim that the use of a single warhead caused a singularity event that lead to the planet’s mass collapsing into a newly formed black hole. It is also speculated by some that the SDF-3 was actually lost during this test, having been pulled over the event horizon of this black hole. Others claim that the SDF-3 was damaged during this event but was subsequently lost during a mis-fold.)

These weapons were brought to Earth in 2044, prior to what was to be a final attempt to dislodge the Invid without rendering the entire planet a radio-active wasteland. The attack went badly, and the missiles were in fact launched. Fortunately for Earth, the Regess had already at that point discorporated her race and proceeded to destroy the missiles, and much of the fleet that had launched them, on her way to parts unknown. Apparently she made the effort (which she could have more easily not have done) as a moral lesson.

In the years to follow, many of the surviving high-ranked UEEF Naval officers on Earth who had approved the Neutron S project were tried and several were executed for war crimes by the new Army-dominated government installed by General Horace Peckenham. However, because of the disappearance of the SDF-3, those charged with the masterminding of the plan to callously exterminate the hundreds of millions of innocent humans on Earth in the process of fighting the Invid, such as Admiral Richard Hunter, remain at large.



Robotech (R) is the property of Harmony Gold. Genesis Climber MOSPEADA (R) is the property of Fuji Television, Artmic Studio and Tatsunoko Production. This document is in no way intended to infringe upon their rights.

Original artwork by: Yoshitaka Amano, Shinji Aramaki and Hideki Kakinuma

Acknowledgement is extended to Peter Walker, Pieter Thomassen and Robert Morgenstern of the unofficial Robotech Reference Guide. Peter Walker, Pieter Thomassen and Robert Morgenstern are given credit for all quotes and paraphrasing of the unofficial Robotech Reference Guide that has been utilized in this publication. 

Images from – Art Book Genesis Climber MOSPEADA Complete Art Works (August 2009)

Content by Pieter Thomassen and Peter Walker, edited by Tim Wing

Copyright © 2016 Tim Wing