If a large space ship crashes on a planet, what could kill passengers without obliterating the ship?

Question

The situation I'm considering is as follows:

A large research vessel with a crew of about 100-200 attempts to land on a potentially habitable planet, but something goes wrong during the descent. A few crew members who happened to be close to the escape pods managed to escape the ship and land nearby (about 100-200 meters).

I would like the survivors to be able to investigate the crashed vessel, but they should find everyone dead or missing. The vessel should only have minor damages, implying little atmospheric burn-up; presumably because the descent complications happened closer to the planet's surface. I also want the ship to eventually explode, perhaps due to a nuclear reactor meltdown. This could happen days later, giving the survivors some time to explore the ship.

I'm wondering what could have happened to the ship during the descent that would:

• Leave the vessel relatively intact.
• Kill or "remove" the crew.
• Leave the survivors unharmed in their escape pods.
• Be undetectable from orbit because the crew of a scientific research vessel should know better.
• Potentially be the cause of the ship exploding, though it could be assumed that the reactor meltdown is caused by the physical impact of the ship against the planet.

Ideas I was considering include:

• An electrical disturbance, such as an undetectable storm or an abnormality in the planet's ionosphere (?) that killed the crew by electrocution, but the escape pods weren't struck. Though, this seems too "convenient".
• A gravitational disturbance that violently shook the massive ship, killing the crew, but had little effect on the small escape pods.
• If there could be no effective "natural" explanation, I could resort to alien interference, such as an advanced weapon. Though I'm unsure if I want there to be intelligent life inhabiting the planet.

Answer 1

A failure of the inertial dampeners. The overengineered ship hits the ground at 100 m/s and skids, scuffing up the hull and tossing things about in the interior... including the crew. All are dead from trauma by the time the ship, still functional, comes to a rest.

Answer 2

High altitude depressurization. It has happened in real life: Soyuz 11

Soyuz 11 was USSR space mission launched on June 6, 1971. After successful completion of work aboard space station Salyut, on June 30, 1971 the spaceship started the return trip. Everything was normal until audio contact with the crew was lost before reentry began. The descending capsule had landed visibly intact, and only after opening the hatch the ground crew discovered that the three cosmonauts aboard were dead.

Kerim Kerimov, chair of the State Commission, recalled: "Outwardly, there was no damage whatsoever. They knocked on the side, but there was no response from within. On opening the hatch, they found all three men in their couches, motionless, with dark-blue patches on their faces and trails of blood from their noses and ears. They removed them from the descent module. Dobrovolsky was still warm. The doctors gave artificial respiration. Based on their reports, the cause of death was suffocation."

The three crew members of Soyuz 11 are the only humans known to have died in space.

Answer 3

A leak of some kind from the piping that runs throughout the ship¹, which exposes the crew to toxic gasses. A handful of the crew who are near the escape pods survive, but the rest die horribly. The ship is in automated descent mode and lands safely.

The leak could be in the reactor coolant. Without that coolant, the reactor will eventually "explode".

¹ All ships have miles of piping and conduit running through them. Some of those pipes will carry necessary but hazardous chemicals.

Answer 4

A simple hull breach will do. The ship might land softer than a bird, but there is very little oxygen in space and in the upper atmosphere.

If you don't like the idea of a breach, it might just be that the O₂ generator of the ship stopped working. This may allow for select individuals or animals in extasis to still be alive, and will be less damaging to the ship than most other options. The ship may land intact, piloted by AI.

Answer 5

Time dilation field.

I really like the "removed" possibility. The investigators find the crew is gone.

In the version I am thinking of, the crew is gone. The interior of the ship is OK but has changed in several ways from how it was a few hours before when the escapees left in their pods. There are extensive repairs of things that had not been broken before. Entire rooms are purposefully rearranged. Many things are falling apart, worn out. The survivors find a classroom for grade school children. There had not been any children aboard the ship.

Around the planet is some ancient alien tech - a field used to help launch ships to escape velocity or some such. The field interacts with the research ships tech to produce a time dilation field. From the perspective of the persons in the ship, the outside world froze. Inside the ship, six hundred years has passed. The crew is still aboard the ship, as are their children and their grandchildren. They are dust.

Answer 6

If you want a reactor meltdown, you could have a random failure of the reactors, leading to high levels of radioactive material throughout the ship that killed everyone through radiation poisoning and or/outright toxicity (such as plutonium poisoning). The ventilation spread it through the ship without the reactor failing catastrophically immediately. Perhaps combine that with some weird coolant that melts human tissue if you really need some disappearances. Eventually a coolant leak caused the reactor to overload, explode, whatever you need.

Perhaps the descent required additional power, such as to maintain heat shields, and the increase in energy usage led to a previously-undetected problem with the reactor (or a problem they thought at the time was only a small one) to cause a failure. Or you could combine it with something else, such the failure being cause by a gravitational anomoly or just some unexpect air pockets that shook the ship a little too much. Again, the crew might have known about such potential issues, but thought the reactor could handle it.

And there is always the possibility of outright sabotage of the reactor, or someone not doing their job properly, or cutting corners to save cost, etc.

Answer 7

Sudden Deceleration is easily lethal

Never mind the escape pods (unless they're integral to your story elsewhere), due to miscalculation the ship hits atmosphere much sooner than expected, and slightly off-kilter. The sudden deceleration, and desperate corrections by the pilot fling everyone within the ship around like ragdolls. The few folks who are in crash couches (like the pilot) suffer minor bruising. Anyone who isn't strapped down is thrown violently across whatever room they're in. Additionally any unsecured items could also be potentially lethal. If escape pods are integral, remember they probably have crash couches as well, and a few people are likely to have been near them and just barely had time to enter and activate them. If you want the pilot dead, maybe she has time to enable autopilot/emergency systems but not enough time to strap in (or even faulty straps).

Injuries suffered during crash and evacuation

A less than perfect landing could easily cause a pretty big fire in the crash zone, dangerous to escape through, and dangerous to evacuate wounded through (assuming some people got lucky and survived getting tossed around during reentry/crash). Alternatively if the ship lands in a precarious position (cliff/hillside) it could slide minutes or hours later, injuring or killing everyone who thought it was safe to get out of the crash couches and tend to the wounded/evacuate.

Answer 8

G-Force (Spinning)

It has happened before. If the craft goes into a spin, it can easily kill the crew without doing any damage to the craft.

Answer 9

Atmosphere getting in, if the hull breaches at lower altitude it may not be decompression that is the issue. Depending when in the descent a small breach forms:

• plasma from aerobraking could cook the crew while leaving the independently heat shielded escape pods intact.

• toxic trace gases in the atmosphere that may or may not have been detectable on a long range spectral scan could leak in and kill the crew but the escape pods have their own air supply and remain intact.

Upon landing the ship may start a fire in the local environment, if the gases given off by the native vegetation are toxic the first you find out about it could be when you open the hatches after you land, you have no reason to scan an atmosphere you already "know" is safe. Equally if the hull has a small breach, ordinary immaterial to normal operations, toxins from burning otherwise harmless plants may leak in and kill those without a closed air supply.

Answer 10

It rather sounds like you would prefer the ship to be found empty. I have a solution for that: Intoxicants.

The scenario goes something like the following. An explosion occurs on board the ship when some piece of equipment fails near the escape pods. In addition to cutting off communications between that compartment and the rest of the ship, it also contaminates the life support system with an intoxicating chemical. The isolated crew members panic in the belief that the ship is coming apart and hop into the escape pods.

The air quality monitoring systems do not pick up this particular intoxicant in time, as it is something outside the scope of their design. (Possibly even formed during the abnormal conditions leading to the explosion. Details will depend on your technology.) The crew get drunk as lords before they can realize what happened and go ahead with the landing. The computers handle the landing which goes ahead mostly as planned, although hampered by the damage to the ship and the improper behavior of the crew.

After landing, the intoxicated crew decide it sounds like a great idea to go on an excursion while taking useless junk and leaving their survival gear behind. They get eaten by a grue or any environmental hazard.

While all of this goes on the cabin air continues to circulate through the filtration system and is eventually cleared of intoxicants before the survivors show up.

Systems damaged or improperly repaired by the drunken crew—or equipment not properly strapped down for landing—can cause enough damage to lead to whatever type of explosion you wish to destroy the ship with.

One last thing: This scenario assumes that the crew must be breathing the cabin air. Normally we expect the crew to be wearing IVA suits for landing (Soyuz 11 had a lot to do with that). It is preferable if the accident happens on approach rather than during atmospheric entry, so no-one had put on their suits yet.

In case anyone were wondering, I based the scenario on (probably false) claims of how Franklin's expedition could have been lost as a result of insanity caused by lead poisoning.

Answer 11

Overheating. The ship could be approaching at the wrong angle, suggesting that the ship will burn up on re-entry. This is why the escape pods were launched.

The ship did overheat, reaching an internal temperature of 150-200c for a sustained period of time. Enough to kill the occupants but not destroy the ship entirely.

The escape pods either have better heat-shielding (it's easier to shield a smaller vessel) and/or had their own propulsion systems that allowed them to adjust their entry angle.

Answer 12

Some options come to mind:

• An experimental virus that cracked open when the ship crashed.
• A toxic leak from some sort of equipment.
• The escape or cryo pods could be cushioned. Anyone not in one could die on impact or due to a gravitational disturbance during re-entry.

Answer 13

Subnautica has this plot, even some of the finer details are there.

The Aurora is a 1.2km long ship with a large crew which attempts to perform a slingshot maneouvre around an ocean planet on its way to another destination.

It is attacked from the planet's surface, and the captain attempts a controlled descent. He guides it into shallow water inside a volcanic crater. Thanks to his efforts the ship lands mostly intact, but he dies in the process.

A sizeable portion of the crew gets into escape pods and these mostly land within the volcanic crater, within about 2 km of the ship. A lot of these evacuees survive initially and some are able to rendezvous.

Hours later a radioactive explosion happens on board. Though this explosion does little further damage to the ship, it unleashes a wave of radioactivity on its surroundings.

With the appropriate radioactive protection, the player can investigate the ship (even after the explosion), but they find no living occupants, other than the few ocean creatures which have swum or crawled inside.

I have not played the game fully but there are teleporting creatures which I think are able to remove people from inside an escape pod.

So to fit this in to your question,

• The ship lands mostly intact because the captain was able to bring the descent under control.
• The crew left behind in the ship were killed on impact, and the survivors who escaped in pods were eventually hoovered up by teleporting aliens.
• Some of the people in escape pods were able to last a few hours when left to their own devices, because they were often trained, they landed in water and the pods had survival gear installed.
• The turret which attacked the planet was small enough not to be easily seen from orbit.
• The radioactive explosion was caused by the impact.

I know you weren't looking for an explanation caused by intelligent life. I just thought you described the plot of this game so perfectly, that I had to bring it up.

Answer 14

Use a non-earth material for the vessel

You did not specify, what material the vessel is made of. In that case I'd suggest you to say, that they got the material for the vessel from a different planet and it's nearly indestructible.

This would help you in different ways:

• Leave the vessel relatively intact:
  • Even though it fell "from the sky" it still wouldn't break
• Kill or "remove" the crew
  • The ship is still intact, but because of the impact, the crew died
• Leave the survivors unharmed in their escape pods.
  • It's a research crew. They don't carry weapons while they're on the vessel. You could say, that there wasn't enough time to get weapons because they were stored at the bottom of the vessel / in a save (this part of the vessel could also burn or be unreachable because of a different reason)

Answer 15

There is the always fun option of Artificial intelligence tasked with maintaining the ship, and the safety of those aboard the ship, designed to always keep the ship going even at the expense of some crew (well all the crew are dead if the ship stops being a ship)

As they are approaching the planet a gravity fluctuation causes a issue with the reactor, getting to work the AI realises the best option for saving the ship is to harvest McGuffinium a rare isotope that has ended up in the crews bodies as a trace element from contanimination of living on the ship (and is also the reactor)

This process involves centrifuging out the McGuffinium liquefying the crew, as as the maintenance bots get to work shredding some of the crew, the AI also forcibly ejects those with a good survival chance out of the ship in the escape pods as much as they resisted and tried to stop their crew being killed.

Answer 16

How about a software failure?

The crew noticed some unusual activity in the nearby sun. They foolishly decide to investigate and get caught in a solar flare that acts like an EMP, damaging the circuitry of the shipboard computer which maintains all systems. It recovers... but not completely. Some of the processors are malfunctioning and every time they are accessed a few more errors are introduced into the system.

Things start going wrong. The course calculations look off. The entertainment system hiccoughs. Communications shut down and restart. The crew decides to land on the planet to effect repairs. They get weird readings from their sensors. They send a guy down in a pod to do a visual inspection of the landing site. Unbeknownst to them, life support has not been functioning correctly and carbon dioxide has been building up inside the ship. While he is gone, everyone suffocates. He is able to land the pod manually. The ship lands itself more or less correctly with little or no external damage but the software gets progressively worse. Eventually, the reactor safety system fails and there is an explosion.

You have the option of introducing a few more disasters or mysteries along the way like strange, garbled messages being broadcast or thrusters suddenly firing for no reason.

Hope this helps.

Answer 17

The planet was mapped and entered into the Galactic Claims Database by a US vessel a hundred years ago. When the brand new research vessel enters into a de-orbiting trajectory, parts of the crew are in escape pods (harboring the secondary bridge and data backups as well) as a matter of protocol.

As soon as the vessel passes the point of no return, systems adjust themselves to planetary protocol. Which because of the nationality of the claim-stakers a century ago encompasses a switch to US units. Some software was written by people unaware of alternatives to metric... Life support scrambles to achieve atmosphere at psi numerical values of pascal. The capsules eject. Everyone still aboard shakes their fists, groans, and dies.

Fuel pellets that need only be added every few days get readjusted from mm to inch-values, spelling doom for the vessel as soon as they get inserted into the tokamak.

Answer 18

A previously unknown and undetectable molecule within the alien planet atmosphere.

As the ship descended, at an atomic level this mysterious molecule had a violent and combustible/electrical reaction and integration into the molecules that make up the metal parts of the ship.

Anything organic in nature that had contact with metal during its molecular change was vaporized. This process was super fast and intense. Afterwards just as quickly the metal stabilized, but now it has this added molecule. (investigations afterwards will detect and isolate the change in the metal, recognizing belatedly that this molecular reaction will be planet-wide to all alloys of metals not native to this planet)

This difference can explain why your reactor will eventually degrade its once effective metallic protections and safeguards and go into meltdown mode.

Also, you can explain how the crew in their escape pods survived. Firstly, (purely by luck or happenstance) they are not metal but maybe a super advanced life saving type of non-organic nanotech. Also, you could incorporate how different alloys of the ship delayed or sped up the violent molecular reaction. Thereby giving crew in different parts of the ship the ability to escape while other others had no chance. (metal seats/restraints for pilots, ceramic tile walkways, etc.)

As an additional measure you could employ various levels of injuries to the survivors because they were wearing metal belt buckles, glasses, hair clips, etc.

Answer 19

As the ship is heading in to land, it is heading over a spot where a strong nuclear chain-reaction is going on, down at the bottom of a volcano (or other hole that limits the beam of emitted particles to directly above). A few crew members see the Cherenkov glow coming up ahead and jump into the pods and leave, but the body of the ship passes through the enormous flux of neutrons (or maybe gammas -- have to worry about atmospheric transmission, though), which kills everybody remaining on board.

Answer 20

When a plane is landing, crew usually strap themselves with (seat)belts as a security measure.

Your ship didn't use physical belts, but magnetic anchor points (kind of like magnetic door holders but stronger), powered by the ship's electrical systems.
During the emergency landing, the ship's Automated Integrity Control system detected an excessive speed and diverted all power to the propulsion systems (and maybe front shields, if your ship has them), ensuring that the ship won't be damaged... but also causing the magnetic anchors to lose enough power that they could be unlocked with just a hard push.
The ones that realized this before the crash are the ones who survived.

You could turn this into a pretty intense before-the-crash moment, when one of the crew discovers they can detach from the supposedly-locked magnetic anchor and realizes what happened with the AIC and lock systems and what that'll mean upon impact. So they try to warn the rest of the crew but everybody is kind of panicking / too busy trying not to crash and so only a handful of people listen to them... eventually deciding to abandon ship even though they know everybody else will probably die.

NOTE: I just re-read your question and realized that you want the survivors to investigate the crash. Somehow I thought that it was a different team sent over to investigate and find the survivors. My answer does not fit your question, because the survivors already know what happened :| Ah well. I'll leave it posted anyway.

Answer 21

Fire

Without knowing too much about your vessel and tech level, I'd recommend an electrical fire. It's a pain to put out without harming the crew, especially with a huge generator supplying extra energy, and it can easily spread across the ship (since pretty much every area uses power), making it difficult to contain.

A lucky few escape in pods, lack of oxygen and toxic smoke kill the rest. After the fire dies down, life support restores a breathable atmosphere, but a lot of wires are fried and several systems, including the reactor's coolant pumps, are now running on emergency power. Whether it's for lack of time, required skills and tools, or simply ignorance of the issue, the survivors do not manage to restore power or do an orderly shutdown before the cooling system fails and the reactor goes critical.

Answer 22

You have possibilities beyond mechanical damage to the ship. You can get to that situation by damaging the crew only.

Specifically, you could imagine a virus (a common trope in SF, I believe Lem has some typical examples). The ship lands well, and the crew is soon dead. Your survivors (no need to be near the escape pods) happen to have a mutation which prevents the virus from killing the host. This is compatible with hard science fiction, for example, people with sickle cell disease (caused by a mutation in a single gene) are immune to malaria. You could just as well have a random, harmless Earth allele prove efficient against the planet's killer. You can set up its frequency at whatever you want, there are alleles shared by the majority of human population and others that turn up once per several thousand humans, so it is easy to have the exact number of survivors you want no matter the size of your crew.

If you don't want it to be contagious, you can also come up with an airborne toxin to which some people happen to have immunity, again for genetic reasons. Thus the survivors won't bring it back to Earth if they or their descendants manage to go back.

Answer 23

Inert gas leak - your body only detects the buildup of CO2. From wikipedia Inert gas asphyxiation:

When humans breathe in an asphyxiant gas, such as pure nitrogen, helium, neon, argon, sulfur hexafluoride, methane, or any other physiologically inert gas(es), they exhale carbon dioxide without re-supplying oxygen. Physiologically inert gases (those that have no toxic effect, but merely dilute oxygen) are generally free of odor and taste. As such, the human subject detects little abnormal sensation as the oxygen level falls. This leads to asphyxiation (death from lack of oxygen) without the painful and traumatic feeling of suffocation (the hypercapnic alarm response, which in humans arises mostly from carbon dioxide levels rising), or the side effects of poisoning. In scuba diving rebreather accidents, there is often little sensation, however, a slow decrease in oxygen breathing gas content has effects which are quite variable.[7] By contrast, suddenly breathing pure inert gas causes oxygen levels in the blood to fall precipitously, and may lead to unconsciousness in only a few breaths, with no symptoms at all.[3]

Answer 24

My favorite scenario for this sort of thing is to have the passengers in some sort of stasis pods. Perhaps it is a form of hibernation or perhaps time is stopped for them. But in either case they are shielded from radiation and protected from violent acceleration (or deceleration). They are probably protected from radiation or contaminants.

Sometime after the crash, an emergency timer lets the passengers loose. By this time the surviving crew members have left the ship, thinking that the passengers are safe in stasis. But they don't come back. Perhaps the radiation or toxins got them. Perhaps an alien race?

There are lots of scenarios listed in the other answer that could cause the death of the crew. Me, I'd go with a radiation leak. The crew managed to patch it, so there is only a little leak.

The passengers would have to think of checking for radiation and then get out of the ship before they die!

I'm assuming that they can't go back into stasis because of reasons. Perhaps they don't have the authority to do this. Perhaps they don't know how to do this. Basically they have to escape before they all die. And there are groups within the passengers that don't want to escape because they don't believe the doomsayers. Think of Steven King's "Lagnolers."

Answer 25

Spoilers for a near 20 year old game.

Halo: Combat Evolved seems to have a similar story. In it, the Pillar of Autumn, a large man made deep space vessel, crash lands on one of the Halo rings, an Earth-like object built by sentient life. Many marine soldiers abondon ship in escape pods, but still quite a few (such as the captain) go down with the ship. The ship remains intact and the crew (or at least a group of them) are captured by the alien alliance known as the Covenant.

Later in the game, the protagonist, the Master Chief, realises that the Covenant have released an ancient parasite, the Flood, which consumes all life. It is later found that the Halo ring is actually a powerful weapon which when detonated, will explode and kill all life in a large radius, which is the only way to stop the Flood from spreading (kill the food sources, AKA life).

An AI, 343 Guilty Spark, stops the Master Chief from detonating the ring to eradicate the Flood. By killing the Flood, the Chief can save the human race. The Chief decides to use the crash landed Pillar of Autumn to blow up the ring. When he goes back, he is swamped by the Flood, which is a mix of infected humans and Covenant (who boarded the ship as it was crash landing). Chief blows up the Vessel which detonates the ring.

---

I'm not sure if you're writing a story or you're just curious, but I believe that the events in Halo: CE are similar to what you are looking for. Also, if I'm wrong in my Halo history, please correct me (I haven't played Halo: CE in a while).

Answer 26

Depends on the kind of sci-fi and ship.

Radiation from the damaged engine/reactor, which unfortunately killed everyone before the auto repair system could fix the problem.

Life support critical failure as engine coolant leaks into the oxygen making it toxic.

The people in escape pods would be safe because the escape pods are radiation shielded (because they have to survive in space) and were outside the ship.

Answer 27

I don't know why nobody answered that (or it someone did, I missed it, cause someone even pointed at Subnautica), but to me the simplest solution is...

Water

Your pilot managed to make the ship enter the atmosphere relatively unscathed and aimed for a point where the impact would not outright turn your vessel into a fancy ball of crumpled metal.

Alas, the landing didn't go as planned, and while espace pods have been scattered during the descent, the shock busted most of the exits, bent the doors, provoked a general black out or whatever do no float that boat.

Water will kill everyone very efficiently. Drowning, suffocation for those trapped in an air pocket, hypothermia, starvation, dehydration... Someone stranded in the middle of the sea without the proper equipment is as good as dead. Make us a nice Rose and Jack scene, where Rose dies on her door cause nobody came to pick her up.

Your escape pods can provide enough equipment to visit a shallow wreckage (make it a good 100-150, your pilot was just that good), but anyone inside it at the moment of the crash who did not reach for his tuba and pressured suit is 100% dead. (Plus, if you need it, you can make some of them survive. And you don't need to devise a virus that could come bite you later in the story).