Accident Analysis of the Imperial Death Star Mk2 (Part B – Circumstances)

Part A – Executive Summary

The Death Star

The Death Star (see Figure 1) was the second platform of that name. It commenced construction after the destruction of the first Death Star at the Battle of Yavin in 0 ABY. The Death Star was spherical in construction, with a diameter of 900 kilometres. The main power supply was a hyper-matter reactor. Propulsion was via Ion drives, although these were not operational at the time of the Death Star’s destruction.

Death Star

Figure 1 - Death Star Shortly before Destruction

In addition to the main armament (a Superlaser) the Death Star carried turbo-lasers and tractor beams for point defence, and small-craft docking and re-arming facilities. On-board accommodation was provided for up to 15 million crew and civilian contractors. The accident occurred whilst the Death Star was still under construction in orbit around the second moon of the gas giant Endor. All weaponry was fully operational, but the shields, ion-drives and portions of the superstructure had not yet been assembled and commissioned.

The Executor

The Executor was the lead vessel of a class of capital ships for the Imperial Navy. SSD Executor was approximately 20 kilometres in length, and was build from titanium-reinforced alusteel. Her primary armament consisted of several thousand turbo-laser batteries and ion cannons. Defences included laser batteries and deflector shield generators.


The Battle of Endor was a planned counter-terrorist operation involving co-ordination between the Death Star, the Imperial Battle Fleet and ground forces on the 2nd Moon of Endor (the “forest moon”). In response to the asymmetrical warfare tactics employed by terrorist forces, the operation made use of carefully planted mis-information to expose the terrorist forces to a set-piece battle.

The plan for the operation called for a shield around the Death Star, generated from a bunker on the forest moon, to be maintained constantly. This shield failed due to catastrophic battle damage to the bunker approximately thirty minutes after the main phase of the operation began.

Subsequently, multiple small craft evaded both the fixed and mobile small-craft defences of the Death Star and entered the unfinished portion of the superstructure.

At approximately the same time the SSD Executor suffered battle damage to the primary command deck, losing attitude and propulsion control. The Death Star was unable to manoeuvre to avoid the path of the Executor, and the bow of the Executor struck the Death Star. It is believed that most of the casualties on board the Executor occurred during this collision.

The small craft within the Death Star superstructure fired on the reactor, and both vessels were destroyed by the explosion of the reactor core.

Timing for subsequent events has not been determined. Eye-witness reports suggest that there were survivors alive directly below the Death Star’s orbit on Endor for several hours following the explosion. Some theories suggest that portions of the Ewok population residing on the far side of Endor may have survived for several months before radiation and nuclear-winter effects rendered the surface uninhabitable.

Despite the availability of numerous Imperial and Rebel platforms in the region, no attempt at evacuation appears to have occurred at any time.


Return of the Jedi at IMDB


The Endor Holocaust


Accident Analysis of the Death Star Mk2 (Part A – Executive Summary)

Part B – Circumstances


The Imperial Navy Death Star was a bespoke counter-insurgency platform. In 4 ABY the Death Star collided with SSD Executor, a Star Dreadnought. All crew aboard the Executor were killed, and both vessels received substantial damage from the impact. The Death Star subsequently incurred further damage from small craft operated by terrorist agents, and exploded. The estimate of direct casualties is 13 million, but due to poor record keeping the precise numbers of civilians and military personnel on board the Death Star at the time of the accident is unknown. Further casualties occurred when the wreckage fell to Endor, causing substantial environmental damage and killing the entire Ewok species.


  1. Whilst the incident occured during active operations, it cannot be dismissed as attrition through enemy action. The puny rebel fleet should have been no match for the power of a fully operational battlestation.
  2. The Imperial Navy responded to the destruction of the first death star by introducing technical improvements to platforms and equipment, without responding to the wider organisational problems. These structural and cultural issues led directly to the circumstances of the second Death Star accident.
  3. The trade-offs between safety, operational effectiveness, and project schedule were made without due regard for the level of risk involved in this decision making. In particular, the visible importance that senior management placed on meeting deadlines overshadowed all other considerations.
  4. There was systematic misalignment of authority and responsibility throughout the Imperial Navy, leading to poor decision making in times of crisis.
  5. The absence of a Just Culture within the Imperial Fleet discouraged staff from raising concerns. This choked vital reporting mechanisms which could have alerted senior management to the systematic problems.
  6. The rebel fleet was overly reliant on “heroic individuals” to achieve organisational goals. This ad-hoc approach to management achieved short-term effectiveness at the expense of addressing systemic risk and longer-term fallout from their actions.
  7. The design of the Death Star incorporated defence-in-depth protection mechanisms, but these were subverted by common-cause failures.
  8. The effects of the accident were made significantly worse by overconfidence and lack of emergency response planning.
Part B – Circumstances


Return of the Jedi at IMDB


The Endor Holocaust

What exactly is a “failed experiment”?

In non-scientific life, an experiment is when we try something out to see what happens. A failure, for such experiments,  is when we don’t get the outcomes we want. Legalisation of soft drugs for example, would probably be reported in the press as a “bold experiment”. This doesn’t mean that it would actually be an experiment in any sort of formal sense. It just means that we don’t know for sure what will happen when we do it.

In a scientific sense, experiments are more precisely defined. In an experiment we are trying to distinguish between competing explanations of the world. We may expect one particular explanation to be correct, but it isn’t necessarily a failure if we turn out to be wrong. Either way, we may acquire knowledge. There is still such a thing as a failed experiment though. Since the goal of an experiment is to distinguish between hypotheses, we may get to the end of the experiment and still not have managed to do this. The only knowledge we gain is that the experiment wasn’t good enough.

Let’s take, for example, the search for the Higgs Boson. In a formal sense, the overall search is not an experiment. If we believe that the Higgs exists, as the Standard Model predicts, then the search for the Higgs is a  search for confirmation, rather than trying to falsify any particular hypothesis. We could search for a long time and still not have disproven the existance of our shy God Particle. However, each individual experiment within the program is set up to be able to state confidently that the Higgs does not appear at particular energy levels. So CERN is generating new knowledge whenever they learn with confidence that a particular version of the Higgs isn’t there.

Contrast this with those unlawful hooligans and now almost certainly non-existent particles, the faster-than-light neutrinos. If it turns out that the measurements are untrustworthy due to a cable connection, this is a failed experiment. We have learnt nothing except to take better care with cables. If it turns out to be something more subtle, we may advance our experimental methods so that future findings can be more certain and less error-prone.

Concern about failed experiments entered my life during a recent grant application. I was designing an experiment to test whether Fault Tree Analysis (FTA) produced trustworthy results. When it came to discussing the size of the experiment and the types of controls, I realised that my experiment had three outcomes. The expected outcome was that FTA would prove not to be trustworthy. This would justify my reasons for wanting to conduct the experiment, since many people place faith in FTA. A negative result would not find the untrustworthiness that I was looking for. This would still be knowledge, even though it is a negative outcome. I would have given FTA a solid workout, and confirmed the faith that is placed in it. The third outcome is that my results would be within the margin of error, or confounded by factors in the experiment design – ie, I could not draw positive conclusions either way. This would be a true failure, the chance of which could be reduced by increasing the size and cost of the experiment.

Not all experiments worry about margin of error. In medical drug trials, for instance, failure to show effectiveness above a certain significance factor is considered the same as not showing effectiveness at all. This does not confirm the null hypothesis, that the drug has no effect, but the research community is far more concerned with finding definitely effective drugs than in certain knowledge about ineffective ones. This does not mean that medical trials cannot fail – it is still possible to discover flaws which invalidate the knowledge gained. For example, if the dropout rates of experimental and control groups differ beyond what the experiment allows for, the original statistical design is broken and the experiment has failed.

As a general rule, there is a trade-off between experiment cost and the chance of failure from known causes. A bigger experiment has better power to detect differences between groups and samples, and can put in place more controls to avoid confounding factors. One big experiment which succeeds provides much more certain knowledge than many small experiments which are unable to distinguish between different possibilities. It is often possible to ask in advance whether an experiment has the power to find the effect it is looking for. On the other hand, there are always sources of failure which can ruin even well designed experiments. A poorly connected cable on a particle detector is a very expensive and embarrassing way not to learn anything.