Surviving fall from orbit

[Wanderer]

Something I got curious about after seeing the latest crop of comics-related sci-fi blockbusters...

 

What kind of Characteristics and Defense Powers would a character need in order to make it semi-plausible (s)he survives atmosphere re-entry and fall from orbit relatively unscathed (i.e. no significant Killing Damage) ??

[Bloodstone]

Re: Surviving fall from orbit

 

Survive or walk away virtually unscathed? Big difference after all...

 

Terminal velocity is 30DC normal damage, which averages 30 BODY and 105 STUN.

 

So PD in the low to mid 30's pretty much guarantee you will not take any BODY from the impact. I don;t know off hand how much damage reentry would cause, but I'm going to assume it's less than 10d6 killing, so similar levels of rED should take care of the BODY from that too. Mind you, it will still hurt like hell and probably knock you out, since a bunch of STUN will get through, but you will survive.

 

Some extra (nonresistant) Defenses, Damage Reduction (possibly STUN Only) and a decent CON and REC will let you walk away from it with truly minimal pain and no lasting damage.

[Edsel]

Re: Surviving fall from orbit

 

The heat generated from ballistic reentry can be enormous. In a science book I have it states that a vehicle traveling at 7.8 km/sec will generate a peak temperature in the neighborhood of 7800K (briefly), the surface of the sun is only about 6000K. However the temperature varies greatly depending on how you enter. For instance see the "feathered" reentry that Space Ship One used. It didn't even require heat shielding, of course it only entered from 100 miles up and had no starting momentum.

[Wanderer]

Re: Surviving fall from orbit

 

Survive or walk away virtually unscathed? Big difference after all...

 

As I said, no significant Killing Damage. You may be (likely) knocked out unconscious by the impact, if you free-fall it all the way, but once you awaken from it, you are pretty much fine and ready to rumble.

[Vanguard]

Re: Surviving fall from orbit

 

Terminal velocity is 30DC normal damage, which averages 30 BODY and 105 STUN.

 

 

It's normal or killing damage depending on surface that you land on. I would make it Killing damage, no matter what surface you fell on if you're talking about falling from orbit.

 

Adding to what Edsel said, I'd also have to find a decent amount of damage for the heat/fire that you would encounter on reentry. I'd have to assume that you would be at the most ill favored reentry angle since you are, for the most part, falling.

 

So off the top of my head, I'd give you a 30D6 KA upon impact with the ground. While suffering reentry I'd say maybe another 10D6 AP/Penetrating, Continuous attack (can't find damage levels for the sun at the moment) for as long as you were suffering the heat of Reentry.

 

So you'd need pretty uber defenses to survive something like that.

[Bloodstone]

Re: Surviving fall from orbit

 

That's an optional rule, mainly for if you land on something sharp.

 

In any event, when you convert 30d6 of normal damage, it only turns into 10d6 of killing damage. Both of those are equal to 30DC's. You still would only need around low to mid 30's rPD to resist the BODY damage of a 10DC killing attack.

 

The Stun could still be brutal without additional defenses though...

[JmOz]

Re: Surviving fall from orbit

 

I would require some LS as well

 

LS:High Pressure/Vacuum (for the bends)

LS: Immune to heat (For friction

LS: Self contained breathing (For the cave in you will find yourself in)

[Hyper-Man]

Re: Surviving fall from orbit

 

I would require some LS as well

 

LS:High Pressure/Vacuum (for the bends)

LS: Immune to heat (For friction

LS: Self contained breathing (For the cave in you will find yourself in)

 

 

So Life Support with 25 rPD/rED and 50% Physical Damage Reduction should do it. The character might bruise some ribs but won't necessarily be knocked out as they would only take ~2 Body and ~40 Stun from the average 30d6 impact.

[Drhoz]

Re: Surviving fall from orbit

 

Something I got curious about after seeing the latest crop of comics-related sci-fi blockbusters...

 

What kind of Characteristics and Defense Powers would a character need in order to make it semi-plausible (s)he survives atmosphere re-entry and fall from orbit relatively unscathed (i.e. no significant Killing Damage) ??

 

Surviving a fall from orbit is what our group uses as a basis for character toughness.

 

I refer you to the appropriately named Project Excelsior, from 1959 and 1960.

Project Excelsior was a series of high-altitude parachute jumps made by Captain (later Colonel) Joseph Kittinger of the United States Air Force in 1959 and 1960 to test the Beaupre multi-stage parachute system. In one of these jumps Kittinger set world records for the highest parachute jump and the longest parachute freefall, both of which still stand (as of 2007).

 

He jumped from 20 miles up.

 

He reached a speed of over a thousand kilometres an hour.

 

he didn't open his main shute until 4 and half minutes later.

 

So, even assuming that you were dropped straight down from low Earth orbit (thus avoiding the worst of reentry heating), the problem isn't going to be how hard you hit the ground, but how long you can survive without oxygen, in temperatures of 70 C below zero.

 

let alone tumbling hopelessly and totally disorientatingly.

[Edsel]

Re: Surviving fall from orbit

 

What about G-Forces? I mean if you are zipping through space at the aforementioned 7.8 km/sec and then enter the atmosphere, how fast are you going to slow down? Will the G-forces be enough to cause black out or red out?

[薔薇語]

Re: Surviving fall from orbit

 

I would require some LS as well LS:High Pressure/Vacuum (for the bends)

 

 

 

I don't think you would worry about 'the bends' in the case. Becuase it is the result of moving from high preasure, where Nitrogen and other gases compress into your body, to areas of low preasure to quickly. Cuasing the aformentioned Nitrogen to rapidly reform into its gas state and, essentially 'boil' out.

 

And as a side note to the minus 70 degrees C survival idea. If you want to know what it would be like to survive that temp, here is how to simulate it. Fill your fridge full of Dry Ice till it adjust temp and stand in there(w/ some form of air supply, otherwise you will suffocate). Dry ice is about -80C. If you can still feel your toes and fingers after 10minutes, you might be able to survive the atmospheric temp.

 

La Rose

[Drhoz]

Re: Surviving fall from orbit

 

What about G-Forces? I mean if you are zipping through space at the aforementioned 7.8 km/sec and then enter the atmosphere' date=' how fast are you going to slow down? Will the G-forces be enough to cause black out or red out?[/quote']

 

the uncontrollable tumbling blacking you out would be even more crippling, probably - the guy I mentioned earlier needed a stabiliser chute during the 4 minute freefall bit to keep himself from blacking out

[Sean Waters]

Re: Surviving fall from orbit

 

I don't think that the falling rules are a particularly good emulation of falling damage, but then a 'good' emulation would be quite difficult so they do not do a bad job.

 

I've always thought that 30d6 was too high, and that the damage should scale differently. The optional falling rules are an improvement, but a bit moe comlpicated.

 

That will always be the trade off.

[Sean Waters]

Re: Surviving fall from orbit

 

Ran a game a long time go and we had a were leaopard character (yes, I know). He was in a plane 3 miles up which exploded and he fell. Terminal velocity was reached (OK, it was not from orbit, but the FALLING damage was the same).

 

Did not have huge defences but did have 3/4 damage resistance. Fortunately he did not fall on silver...

 

30 Body, 105 Stun, less about 15 pd gave him 15 Body and 90 stun damage, which got quartered to 4/22.

 

He had a decent recovery and regeneration/2. He hit on segment 12, was on his feet immediately and without a mark on him within 13 seconds.

 

Not bad....

[Nekkidcarpenter]

Re: Surviving fall from orbit

 

I have no problems with the damage a superheroic character takes from falling. However, the ability of a character with NCM to survive the same fall rankles me. The maximum Body for NCM is 20, which IMO is too high but thats another topic. With an 8 PD, such a character would only be at -2 Body on average from a terminal fall and has a pretty decent chance of waking up on his own before he bled out!

 

Both PC's and NPC's have a 0 point Disad in games I run; 2x Body from damage where the DC is => than double the applicable defense. This rarely has an effect on PC's but means that 'normals' and NPC's can be killed by large attacks. This means that Supers can't indiscriminately throw their biggest attacks at normals, and also means that non Supers pretty much always die from terminal falls, just like irl.

 

I actually implemented this rule not as a way to keep PC's from firing their 10d6 EB at normals (which is sometimes a problem but can usually be solved by talking to the PC in question) but in order to allow my villains to occasionally kill a victim without having to blast it over and over. It's nice to be able to one-shot disintegrate a normal for a huge PRE attack without having to worry about firing the same attack at a PC later in the fight.

[Hyper-Man]

Re: Surviving fall from orbit

 

...The maximum Body for NCM is 20' date=' ...[/quote']

 

Actually, 20 is just the maximum before cost doubling. The suggested maximum is 30 for normals (for most characteristics besides INT).

[Trebuchet]

Re: Surviving fall from orbit

 

I have no problems with the damage a superheroic character takes from falling. However' date=' the ability of a character with NCM to survive the same fall rankles me. The maximum Body for NCM is 20, which IMO is too high but thats another topic. With an 8 PD, such a character would only be at -2 Body on average from a terminal fall and has a pretty decent chance of waking up on his own before he bled out![/quote']Subtracting 8 PD from the 105 Stun an average 30d6 terminal velocity fall generates is going to put most characters comfortably in the "GM's Discretion" range of unconsciousness. I can't imagine any non-brick waking up before he bleeds out from such a scenario without immediate medical attention. If he Bleeds out at -1 BODY per Turn, it's only going to take him 18 Turns to die. That's only 3 minutes and 36 seconds. Unless he miraculously falls into a hospital emergency room lobby, he'll be dead long before an ambulance even gets there, much less before anyone has time to apply Paramedics (at substantial penalties to boot).

 

Additionally, IME very few non-brick characters (even supers) have 20+ BODY. I see lots of 13's, 15's and 18's, but seldom 20 BODY or more except on bricks (who will have much higher defenses anyway).

[Lord Mhoram]

Re: Surviving fall from orbit

 

There is always breakfall at the extraordinary skill roll levels. That was one of the examples for XS rolls "A character falls a long distance, and takes no damage"

 

 

As a side note - I have a character whose origin story involves falling to earth from orbit. He has 13 body (plus regen) 10 armor and 75% reduction.

[Vanguard]

Re: Surviving fall from orbit

 

That's an optional rule, mainly for if you land on something sharp.

 

In any event, when you convert 30d6 of normal damage, it only turns into 10d6 of killing damage. Both of those are equal to 30DC's. You still would only need around low to mid 30's rPD to resist the BODY damage of a 10DC killing attack.

 

The Stun could still be brutal without additional defenses though...

 

Oh . . good point there Bloodstone. I forgot all about that.

[Comic]

Re: Surviving fall from orbit

 

Of course, a lucky 8 PD, 20 Body normal would hit a highrise building (or a series of them), slowing down with each wall (or floor) impact. A 3 Body, 5 DEF wall takes 8 BODY and does 8d6 (less if the character makes a breakfall roll -- at these speeds likely needs to roll a natural 3 -- or uses his 20 STR to take 2d6 off the damage by leaping and absorbing it to his legs).

 

The 6d6 version does 13 Stun past defenses and leaves the character falling at 22". He can't jump again this round, but he gets to use that breakfall roll if his CON is above 13, albeit at -11 (still likely needs a 3).

 

Odds are he takes the full 8d6 for puncturing the next wall/floor, taking no Body and 20 Stun (which should Stun him but not yet knock him out) and leave him moving 16" (higher by 1-2" if he accelerated between walls/floors).

 

Next wall/floor, another 8d6, definitely in danger of being knocked out and by law of averages will have taken 1-2 Body from one of the three wall/floor impacts so far. He's going 8" or slightly more, enough to puncture one more floor, but not two.

 

This last floor is special, since he's unconscious, he takes double stun. (Assuming none of the surfaces he's impacted have been 'soft' for half damage.) Already in the negatives, he's going to end up in GM's discretion, but not by very much.

 

So, a terminal velocity fall isn't so bad, for a normal.

[Markdoc]

Re: Surviving fall from orbit

 

 

So, a terminal velocity fall isn't so bad, for a normal.

 

Well IRL a few people have survived falls at which they reach terminal velocity, so it can happen (but don't try this at home, kids!) but in the example you gave (8 PD/20 BOD), while theoretically in the "normal" range is by no means normal. I don't think I've even seen a super with 20 BOD!

 

And since highrises are usually built out of reinforced concrete, you're going to be impacting an 8 DEF, 5-7 BOD surface for a 13-15 d6 attack. So you'll make a hole in one, maybe two floors. Your 8 DEF/20 BOD character will have taken about 12 BOD, and be at GM's option, but alive (unless like I would, the GM converts the damage to killing in that situation, given the effect of falling through a network of steel reinforcers, in which case he's a lumpy stain on the floor). A more normal normal is going to be a stain on the floor in any case.

 

cheers, Mark

[gojira]

Re: Surviving fall from orbit

 

Not having read the whole thread... the world record sky dive is held by an astronaut from the 50's (?) who jumped out of a weather ballon from 22 miles up. Not quite outer space, but far enough out to require a space suit most of the way.

 

He didn't have any problems with heat, mostly because he had no angular velocity. He was falling straight down, starting from basically a dead stop. Objects like meteors hit the atmosphere at high velocity basically because they are already moving at escape velocity (or more). Just falling doesn't generate enough velocity to produce appreciable heat.

 

Now, if you fell all the way from Saturn, that might be a different story, but there's a lot more energy involved in pushing you out there, so that's what you are bleeding off as you fall back to the Sun/Earth.

[Alibear]

Re: Surviving fall from orbit

 

I have no problems with the damage a superheroic character takes from falling. However, the ability of a character with NCM to survive the same fall rankles me. The maximum Body for NCM is 20, which IMO is too high but thats another topic. With an 8 PD, such a character would only be at -2 Body on average from a terminal fall and has a pretty decent chance of waking up on his own before he bled out!

 

Both PC's and NPC's have a 0 point Disad in games I run; 2x Body from damage where the DC is => than double the applicable defense. This rarely has an effect on PC's but means that 'normals' and NPC's can be killed by large attacks. This means that Supers can't indiscriminately throw their biggest attacks at normals, and also means that non Supers pretty much always die from terminal falls, just like irl.

 

I actually implemented this rule not as a way to keep PC's from firing their 10d6 EB at normals (which is sometimes a problem but can usually be solved by talking to the PC in question) but in order to allow my villains to occasionally kill a victim without having to blast it over and over. It's nice to be able to one-shot disintegrate a normal for a huge PRE attack without having to worry about firing the same attack at a PC later in the fight.

 

Normal people have 2 ed/ed and 8 body. A 10d6 EB is gonna put people in a very bad way already. For all intents and purposes they are already dead unless a paramedic comes and stabises them.

[McCoy]

Re: Surviving fall from orbit

 

So' date=' a terminal velocity fall isn't so bad, for a normal.[/quote']

Yep, falling, even at terminal velocity, isn't that bad.

 

It's the sudden stop at the botttom that's the problem.

[Cancer]

Re: Surviving fall from orbit

 

I think LS: self-contained breathing & safe in low pressure, plus an exceedingly difficult (I'm thinking 19- here: absolutely impossible without the right equipment and an immense amount of skill & planning) Gliding Skill roll, plus the right TF (TF: hyper-advanced parachuting? TF: Personal re-entry non-vehicles ?) would be enough, under the right conditions.

 

Going to RL now. A planned re-entry from a decaying orbit can be managed. Aerobraking, a technique first used for the Magellan mission to Venus in 1990, is now the preferred method for circularizing the orbits of interplanetary spacecraft. This means choosing the apopoint of the orbit to be in the very high atmosphere, so in each orbit you get an interval with some drag to bleed off the orbiter energy, but not so much the mechanical and thermal stresses damage the spacecraft. You have to get the trajectory right or lose everything, of course, and it takes quite a while: lots of orbits, several weeks of time. Now, circularizing the orbit is by no means the same as landing, but it gets the point across: if you are in control of the re-entry trajectory, and you have time both to plan and to execute the plan, it can be survived.

 

Most stuff burns up or gets broken apart on re-entry because it isn't on a trajectory that's surviveable, and it doesn't have a shape that lets it manage the stresses of re-entry. I recall a paper from about 1998 discussing just this topic in the context of meteorite entries ... non-aerodynamic objects coming in at 10 km/s build up not just a lot of heat, but a huge pressure gradient across them from the shock wave on their leading surface to vacuum on the trailing surface. That pressure gradient, combined with some rotation, will make for drastic stresses on the object, far in excess of their breaking strength. For a broad range of size & composition for macroscopic objects, you expect them to break up in the atmosphere (dissipating a lot of its kinetic energy this way) as they come down. I'll see if I can track down that paper and if I do, I'll edit this and add the link.

 

EDIT: Here is the paper, PDF format. Turns out it's from '93, not '98. Technical journal article, but you gotta love anything titled "The Fragmentation of Small Asteroids in the Atmosphere". Just the abstract is fun, too: there's some useful numbers for what destructive power you get from what size asteroid, not from the crater it makes (which is none), but from its airburst.

 

You avoid that problem, even with a relatively weak object (something as strong as your armored steel sphere has no problem in this context) with a properly selected trajectory and a carefully engineered shape.

 

So the question is: when you're asking about surviving entry from low orbit, is this a one-time long-planned thing for injecting a few agents into a planet from space, or are we talking about the losers of low-orbit space dogfights ejecting and making it safely after being shot down? The former is quite manageable, I think, with today's tech. The latter is some time away.