Jump troops

[Fritz_Brown]

Would they burn without those bubbles? IIRC comat armor and battledress can endure quite high temperatures (over 1000 degrees Celsius), and the mounts up quite quickly once on free fall. In the article Cryton gave us the link it says he crossed the sound barrier in 40 seconds...

Not sure what Traveller is assuming, but there's way too many points and things sticking out on a BD trooper falling into atmo. Those things 1) heat up more rapidly and to a higher temperature than other surfaces, and 2) make you un-aerodynamic so you tumble. There's also the issue of the trooper's gear - like weapons - heating up - rounds cooking off (or melting) and such.

(Actually, a gauss weapon might have problems with all the plasma around it if it weren't in a capsule: might generate electromagnetic effects that could disable or "cook off" the rounds in the magazine.)

 

[Carlobrand]

In some respects, one must be cautious of canon. Canon gives us squadrons of great powerful dreadnoughts -that under Meson spinal attack amount to oversized coffins. Canon gives us fearsome battledressed Imperial soldiers - who can be killed by a cheap TL7 rifle grenade. Canon strives to give us some of the cooler standards of conventional Sci-Fi - while giving us rules that make them impractical.

With all due respect to Loren - and I don't know zip about GURPS weapons or whether the same would apply in that rules system - and aside from a few specialized circumstances, there is NO way in Hades that I would field an all battledress battalion against anything remotely like a competent and well-armed opponent. We've discussed before the problem with the cost of battledress against the ease with which the wearer can be killed. There are only a few settings and situations where en masse battledress makes a real difference - urban house-to-house fighting, fighting in vacuum or hostile atmospheres, and so forth. Otherwise, it just doesn't work in Traveller - it's like having a Navy consisting exclusively of battleships.

In other situations, having one or two battledressed men in a combat-armored squad is more than sufficient to take advantage of the suit's advantages without incurring such great costs and increased maintenance that your opponent can wear you down through attrition or by cutting you away from your maintenance tail. For the price of a suit of battledress, you can send a fireteam out in a little combat car with some point-defense capability and then walk away from it if the enemy manages to isolate you from your spare parts lifeline.

As to jump capsules - yes, they're pretty useful, at least as envisioned in the MT errata:

The basic capsule isn't much, just a way to get down with some equipment, but it only costs Cr 16,000. Only real advantages are it's a good deal cheaper than a grav belt and can deliver a nice chunk of weight in addition to the trooper: 430 kg, less the trooper and his own carry-load, so typically the trooper lands with 250-300 kg of useful equipment - shoulder-fired missiles, extra ammo, mines, whatever can fit in there with him. It delivers a wee bit of armor protection - F8. I do not know how MegaTrav handles multiple armor, but under Striker, that little extra bit would boost the armor rating of your TL14-15 battledress by 4 points.

In Striker, that's enough to mean the literal difference between life and death if the enemy decides to deal with your drop by firing off nukes: your net armor of 22 vs the secondary blast zone penetration of 20 means a 10 in 36 chance of escaping without injury and a 20 in 36 chance of getting away with only a light wound; worst case, a 6 in 36 chance of a serious wound*. In (TL14-15) battledress alone, you'd have faced a 6 in 36 chance of death and a 20 in 36 chance of a serious wound.

The advanced capsule, though twice the price of the basic, gives you a nice chunk of armor, and increased payload to boot: 683 kg. Gives the trooper 500+kg of useful equipment, and factor-20 armor means something has to hit the capsule pretty hard before it even has a chance to encounter your own armor. Again, I don't know how MegaTrav plays that; in Striker, you in TL14-15 battledress in this capsule would be like you behind F27 armor - infantry lasers are no longer a threat, and a 33 in 36 chance of escaping injury in the secondary blast zone*. And, the shell makes dandy improvised cover on the ground.

The High Survivability capsule's pricey - Cr 67,000 - but gives you even more armor protection (F28 - in combination with your armor, enough to get you to F32) and ten decoys that deploy to drop with you, though the payload drops to 476 kg. Those can be pretty useful given that an opposed landing is going to be facing SDB-fire, planetary defense fire, and possibly rapid-fire energy weapons as they get closer to the ground.

Meanwhile, a 50-passenger troop transport comes in at Cr 12,800,000 and presents a much bigger and more appealing target, though it does have the advantage of a larger payload and the ability to make multiple trips. A grav belt, while attractively priced, limits the trooper to his usual carry-load (and increased maintenance needs, under Striker) - and nothing stops a trooper from wearing a grav belt inside a drop capsule, to be used after he arrives.

In a nutshell the drop capsule is useful when you want to increase the odds of the person getting to the ground and deliver enough extra food, ammo, and support munitions to let him set up a defensible position for a couple weeks or deal with heavier threats, and the shell can be used as improvised breastworks.

*It pretty much goes without saying that anyone in the primary blast zone is going to land as a rain of black soot.

 

[Fritz_Brown]

Good analysis, Carlobrand.

 

[rancke]

It's always nice when the rules turn out to support the setting description.


Hans

 

[McPerth]

Agreed, a good analysis, but I guess the landing of supplies should be better done with grav APCs or armored interface crafts.

If each trooper lands with about half a ton of supplies, they must either leave them in a cache (so mounting a supply base), carry them or abandon them. As they can not carry them (a BD equiped trooper may only carry that much weigth, and a CA equiped one even less), that makes them mostly inmobile, and, as some dispersion is to be expected (as happened with paratroopers in WWII, but to a greater extent), that will produce some clusters of troops arround the supply bases they might mount with those supplies and mostly reverting to defensive hedgehogs where they should be on offensive (IMHO that's he main use for jump troops).

OTOH, if they land in free fall, as HALO troops do, assisted with grav belts to direct the land and to avoid crushing, they will only land with the supplies they can carry, for good and bad, so they wil lbe more supply dependent, but more mobile. ALso I guess the grav belts could aslo be used to direct the fall, so reducing the dispersion problem. If they can expand their beachhead, they can mount a supply base where shuttles could land supplies.

As I envision a jump assault, the main mission of the jump troops is to land and try to expand the beachhead (spacehead? skyhead?) ASAP, to allow follow up troops and supplies to land as seccure as they can, so mobility is paramount in their role, and excess supplies (mostly if there are no vehicles to move them) will be more a hindrance tan a help, at least for the first hours or days of the assault, and after that they are lost anyway if they have not achieved the beachead.

APCs may also land with supplies and some support equipment, taking the role the LTVs took in Tarawa. Again IMHO the most vulnerable for those APCs would be if thei try to reach orbit again, as then they must spend the full time said in Traveller (world size in hours, IIRC), but to land I guess they can be quite faster, also using free fall and low grav activation.

About the decoys, nothing forbids them to be droped together with the troops. Just a more or less antropomorph bag, resistent enough to sustain a few minutes of free-fall and filled with warm water to fool IR could gain you some time, and free falling troops won't need much to reach low altitudes, where they can begin maneuver.

And about Price, if your troops are already equiped with grav belt (as I envision most of those high-tech troops), any cost of capsules is over usual costs, not instead of it.

Not sure what Traveller is assuming, but there's way too many points and things sticking out on a BD trooper falling into atmo. Those things 1) heat up more rapidly and to a higher temperature than other surfaces,

That does not happen to HALO troops, and they are not equiped with anything like CA or BD to absorb the heat or protect from it.

and 2) make you un-aerodynamic so you tumble.

All men jumping in paradrop are un-aerodinamic, and yet they don't thrumble as much as you say, or they learn to control this trumbling. CA and BD are human form, so I don't envision they as having much more problema tan a unequiped man (more or less like the man making the record jump Cryton told us about, as he was in vacc suit like equipement).

There's also the issue of the trooper's gear - like weapons - heating up - rounds cooking off (or melting) and such.

(Actually, a gauss weapon might have problems with all the plasma around it if it weren't in a capsule: might generate electromagnetic effects that could disable or "cook off" the rounds in the magazine.)

Such delicate weapons could be protected. IIRC some pratroopers in WWII carried most of their equipment in bags hanging under them, and that could also be used, using protecting boxes instead of bags. I guess this could even help to avoid the trumbling you told about, but I'm not an expert.


In any case (grav belts or drop capsules), one important thing about jump troops must be the unit cohesion above small units, as they will probably fight quite intermingled in this sense due to individual troopers dispersion, at least on the first hours (even days) after landing.

 

[Reban]

The utility of Jump Troops

The utility of Jump Troops


I have a couple of thoughts on the delivery of Jump troops and what they might be useful for in the overall order of battle. I’m going to stick to Jump troops and not follow the branch that this debate has taken into jump/drop capabilities of the Marines although most of what I have to say could apply equally. I’m assuming that Jump troops can be classified as light infantry in that they are equipped with infantry weapons and do not have organic armour and support resources.

Delivery
Just because you can drop a man and his weapon from orbit doesn’t mean you will every time you have to deploy him. If you consider Jump troops as descendants of current airborne forces one might get a feel for the multiple ways of getting troops to the target. The way you deploy your Jump troops will depend heavily on the situation on the ground (or in the planetary battle space, if you like).

Deployment by Drop Capsules might define what makes Jump troops, “Jump troops”, but it doesn’t mean they will always be deployed that way. Consider your own nation’s military’s airborne forces. How many times have they been deployed since their formation and how many of those deployments have been full scale parachute drops? I’ve always thought of Drop Capsules as providing the armour/ablation required for atmospheric entry, the countermeasures (including dummy capsules), manoeuvring in the upper atmosphere and cargo capacity (some of those capsules will carry the unit’s wedge; its crew served weapons, ammo, rations etc.). Like Starship Troopers I’ve always thought the capsule would break away at some point allowing the trooper to make a controlled decent on a grav chute or a grave belt.

There are several cons of course. Against a target well equipped with anti-aircraft and anti-ballistic missile defences, dropping, even “small” objects at “high” speeds may not be a good idea. It must also be more expensive and time consuming to organize and mount a drop with specialist drop capsule firing craft. Finally in airborne operations a major concern is clearing the drop zone. With Drop Capsules you’ll have to deploy resources to retrieve the used capsules. Also what’s the public relations consequence of a chunk of ablation material falling through the roof belonging to one of those natives your force is liberating?


Sometimes the situation might dictate that your Jump troops will be carried into the drop area by dropships which might have the advantage of greater armour, speed or stealth. If a dropship deorbits below the targets horizon and then travels to the target following the nap of the earth (NOE) your Jump troops might achieve greater protection or surprize. Getting to the drop zone by dropship might help you avoid AA and anti-ballistic missile defences (if they are localized). Using dropships doesn’t mean the final drop won’t consist of the Jump troopers exiting the dropship and descending on grav belts from atmospheric heights more associated with traditional airborne troops. Dropships also allow air-landing of those Jump troops allowing them to conserve both their own energy and the energy of their grav belts.
Finally there will be many many times when command decides that its best just to send everybody down in a couple of big landing craft or shuttles to a safe Starport or landing zone. The final decision on how to deploy should always depend on the situation “on the ground”.


On the Ground
While airborne forces get to use their parachute just once (they hope) to enter battle, Jump troops can continue using their grav belts. As light infantry, mobility is a major advantage to them both for offense and defence. Using the grav belt to “bound” forward or travelling nap of the earth, Jump troops can patrol and dominate larger areas than pure leg infantry

Equally grav belts carry Jump troops into areas and types of terrain that Lift infantry cannot enter whilst retaining the speed and support of their vehicles. Finally Jump troops even if wearing battledress can still be literally “light” infantry. If the grav belt cancels the weight of their armour they can go where other battledressed “heavy” infantry can go. Not all floors and stairs will be built to carry the weight of battledress. When fighting in built up areas Jump troops can go places other armour infantry can’t.

Give your jump troopers gloves and boots with Gecko adhesive pads and they become human flies able to crawl, walk or even run on the outside surfaces of high rise buildings and arcologies. The best way to assault any building is from the roof down, grav belts make it that much easier to get into the ideal position by bounding onto or landing on the roof. Having the advantages of Light Infantry and using Combat Armour or Battledress whilst being able to move in 3D make Jump Troops ideal urban infantry.

Being equipped to travel from orbit to surface implies other advantages. Their armour and personal equipment will probably have higher than normal protection against hazards of atmosphere, radiation, heat, cold etc. These advantages might make them the first choice for fighting on nonstandard planets and hostile environments.

Given all that it begs the question: why are so few units designated as Jump troops? Carlobrand’s post above goes a long way to answering the question. I’d add the difficulty of recruiting “exceptional individuals” who are willing to jump out of perfectly serviceable spacecraft, the amount of training required, demand and attrition on units

I hope this is of some value.

 

[Reban]

As I envision a jump assault, the main mission of the jump troops is to land and try to expand the beachhead (spacehead? skyhead?) ASAP, to allow follow up troops and supplies to land as seccure as they can, so mobility is paramount in their role, and excess supplies (mostly if there are no vehicles to move them) will be more a hindrance tan a help, at least for the first hours or days of the assault, and after that they are lost anyway if they have not achieved the beachead.

I forgot to make it clear in my previous post that this is pretty much how I see the primary mission of Jump Troops too. But like all soldiers they are infinitely adaptable to the situation at hand.

Actually this might be another reason why they are relatively rare. If they are seen as to valuable or too specialized as assault troops, only enough to spearhead invasion forces might be raised.

I like the term "orbit head" in place of beach head or landing zone. Drop zone works too if its purely a jump troop operation.

 

[McPerth]

Like Starship Troopers I’ve always thought the capsule would break away at some point allowing the trooper to make a controlled decent on a grav chute or a grave belt.

If the capsule breaks away at some point (I understand before reaching ground) and the trooper ends the landing in grav chute/belt, then what happens with the supplies carried in the capsule, that is one of the main advantages Carlobrand gives to them?

In this case, troops will have to collect the supplies containers that have fallen in the drop zone, akin of the problems German Fallschirmjäger in Crete, whree most of their equipment was droped in separate capsules, and had to devote the first moments in ground to retrive them.

I hope this is of some value.

All opinions and posts (well, spammers excepted) are of value

 

[Limburger59]

As to jump capsules - yes, they're pretty useful, at least as envisioned in the MT errata...[/SIZE]

Excellent write-up. Thank you.

 

[Fritz_Brown]

That does not happen to HALO troops, and they are not equiped with anything like CA or BD to absorb the heat or protect from it.

No matter what some guy tells you in a bar, HALO troops are not encountering re-entry. What they go through is pretty intense, but what the Columbia went through is much more so.

If each trooper lands with about half a ton of supplies,

Not quite. Even the Advanced Capsule might not make half a ton of supplies. Remember that the 683kg includes the marine and his BD and personal weaponry. It's sort of nit-picking in the case of this capsule, but you have to keep that in perspective when talking about them. I think you also need to look at how far from the action they will be dropped: any idea how fast a squad of soldiers could burn through 200+kg of ammo?

As they can not carry them (a BD equiped trooper may only carry that much weigth, and a CA equiped one even less)

Not sure what you mean here. A BD-equipped marine can certainly carry a lot of gear. You're also arguing against one of the advantages of a drop capsule, and trying to claim that advantage as a reason not to use it. It doesn't work that way. Just because the capsule can hold ~500kg doesn't mean it *has to*. However, if you want to drop all those supplies (or HQ gear that will be rounded up by the command folks once the riflemen have moved out) you can. Yes, you *could* bring supplies in with a nice landing zone, but if things are still hot, that's a risk you might not want to take.

OTOH, if they land in free fall, as HALO troops do

Dude, if they land in freefall, how much they can carry won't matter much! :toast: :rofl: (I know what you meant, just ribbing you. )

Just a more or less [anthropomorphic] bag, resistent enough to sustain a few minutes of free-fall and filled with warm water to fool IR could gain you some time

I'm telling you it will be a lot more than "warm" once it hits atmo. That sucker will boil and explode in no time.

All men jumping in paradrop are un-aerodinamic, and yet they don't thrumble as much as you say, or they learn to control this trumbling....
Such delicate weapons could be protected. IIRC some pratroopers in WWII carried most of their equipment in bags hanging under them, and that could also be used, using protecting boxes instead of bags. I guess this could even help to avoid the trumbling you told about, but I'm not an expert.

There's a HUGE difference in dropping from a hi-altitude platform and dropping from ORBIT in terms of "aerodynamic". Especially if you're going to tie a box or bag to the poor marine. It is *much* simpler and more effective to stick your marine into a little ablative pod.

If the capsule breaks away at some point (I understand before reaching ground) and the trooper ends the landing in grav chute/belt, then what happens with the supplies carried in the capsule, that is one of the main advantages Carlobrand gives to them?

It primarily depends on how high that occurs. If it's 2,000m AGL, that's a problem. If it's 100m AGL, it won't be much of a problem. I would expect the marine to activate the grav belt (or the pod will deploy a chute - grav or air) before separation. Otherwise, your real problem will be having to dig the supplies out of the ground when the capsule augurs in. They could also tie the supplies to the trooper, so when the pod separates the supplies drop down much as a regular paratrooper might. (BTW, those things tied to the paratroopers were *not* released from the 'package' of paratrooper/chute/gear until the chute opened. Opening shock would otherwise rip an appendage off said paratrooper. Much like a pod releasing its occupant and gear.)

 

[Carlobrand]

Not sure what Traveller is assuming, but there's way too many points and things sticking out on a BD trooper falling into atmo. Those things 1) heat up more rapidly and to a higher temperature than other surfaces, and 2) make you un-aerodynamic so you tumble. There's also the issue of the trooper's gear - like weapons - heating up - rounds cooking off (or melting) and such.

This presupposes a high-velocity re-entry. We moderns tend to think in terms of high-velocity re-entry because that's the only way our vehicles can manage it - no spare power to make a low-velocity re-entry. Orbital velocity for Earth, low Earth orbit, ranges around 7 to 8 kps; that's the speed an orbiting craft needs to shed as it hits atmosphere.

In the Traveller universe, a ship can come in fast, come rapidly to a complete stop (relative to the planet) at a precalculated position above the planet, and dump out whoever or whatever needs to get dumped out - and then that all starts coming down accelerating from a speed of 0, instead of having to bleed off orbital speed. An object deadfalling from orbit would need 12-13 minutes (assuming 1G planetary gravity) to reach the same velocity as that modern craft re-entering from orbit that we mentioned above; during that time it would travel around 2.5 thousand kilometers. Clearly, an object deadfalling from speed 0 and low orbit is never going to have a chance to get anywhere near the kinds of re-entry velocities we moderns tend to think of when we think of re-entry. It'll start hitting atmosphere soon after release, and the atmosphere will start braking it. From there, it's about terminal velocity and how that plays out with respect to thinning atmosphere and altitude.

There might be a tactical advantage in dumping them out with speed, but the stop-and-drop option definitely exists.

Agreed, a good analysis, but I guess the landing of supplies should be better done with grav APCs or armored interface crafts.

If each trooper lands with about half a ton of supplies, they must either leave them in a cache (so mounting a supply base), carry them or abandon them. As they can not carry them (a BD equiped trooper may only carry that much weigth, and a CA equiped one even less), that makes them mostly inmobile, and, as some dispersion is to be expected (as happened with paratroopers in WWII, but to a greater extent), that will produce some clusters of troops arround the supply bases they might mount with those supplies and mostly reverting to defensive hedgehogs where they should be on offensive (IMHO that's he main use for jump troops).

OTOH, if they land in free fall, as HALO troops do, assisted with grav belts to direct the land and to avoid crushing, they will only land with the supplies they can carry, for good and bad, so they wil lbe more supply dependent, but more mobile. ALso I guess the grav belts could aslo be used to direct the fall, so reducing the dispersion problem. If they can expand their beachhead, they can mount a supply base where shuttles could land supplies.

As I envision a jump assault, the main mission of the jump troops is to land and try to expand the beachhead (spacehead? skyhead?) ASAP, to allow follow up troops and supplies to land as seccure as they can, so mobility is paramount in their role, and excess supplies (mostly if there are no vehicles to move them) will be more a hindrance tan a help, at least for the first hours or days of the assault, and after that they are lost anyway if they have not achieved the beachead.
...

As I understand the game system, the main mission of the jump troops is to land in circumstances where traditional landing is impractical or impossible. FFW lets them land when regular troops can't. IE allows them to take less damage from planetary defenses and SDBs while landing. Ergo, you use the jump troop when you can't use APCs. In IE, if I recall, their best use was to land close to PD units and try to take those out so follow-on forces would not have to face PD fire. In such a role, that extra equipment is vital - it may be a long while before they can be reinforced or even recovered. Me, I figure the headquarters company is responsible for collecting and securing all the extra gear while the rest of the battalion deploys to fight; if you can drop a man in a capsule, then you can drop a few capsules with the HQ company with little man-sized grav-sleds inside instead of men, to throw equipment on and transport it around where needed.

I don't know of rules governing actual use of the drop capsules, but the capsules themselves are described as having radios and an inertial navigation system controlled through a hand computer, so scatter is not going to be the problem it is with paratroopers. I expect there'll be a bit - some hapless soul will always fail his roll - but for the most part the unit should land mostly intact.

If you are attempting a hot landing, I'd rather have the men inside an armored shell than floating through air with nothing but whatever armor they're wearing. Even if the battle plan calls for them to go in with only what they can carry and then fly on grav belts to some objective, the added armor protection during the initial drop means many more will survive to pursue the mission.

On the other hand, if your target does not have SDBs and planetary defenses to make your high-altitude life miserable, then a drop on grav belts is perfect strategy - APCs can land separately and set up a retreat point for them to fall back on while they're off hitting the targets fast and hard.

 

[Limburger59]

There's a HUGE difference in dropping from a hi-altitude platform and dropping from ORBIT in terms of "aerodynamic". Especially if you're going to tie a box or bag to the poor marine. It is *much* simpler and more effective to stick your marine into a little ablative pod.

Therein lies what seems to be the sticking point in this debate. When I think of Jump Troops, I assume from ORBIT.

I'll agree that a Grav-belt is probably sufficient for many high altitude operations, though I'd think once you're in the atmosphere - with higher TL scanners, jammers, armor, and weapons - in may be better to get down to a lower altitude before diving out of the APC. I imagine the higher speeds and evasive maneuvers possible with the APC are safer than the grav-belt.

 

[Carlobrand]

Therein lies what seems to be the sticking point in this debate. When I think of Jump Troops, I assume from ORBIT.

I'll agree that a Grav-belt is probably sufficient for many high altitude operations, though I'd think once you're in the atmosphere - with higher TL scanners, jammers, armor, and weapons - in may be better to get down to a lower altitude before diving out of the APC. I imagine the higher speeds and evasive maneuvers possible with the APC are safer than the grav-belt.

And extensive ECM, and point defense weapon system, and heavy armor, depending on the APC. About the only thing that favors the man in the grav belt is that he's smaller and isn't putting out infrared like a steel plant furnace.

 

[aramis]

Simply put: Trooper in pod has a terminal velocity in 1 Atm of about 2000km/h. Trooper in suit has a terminal velocity of about 300km/h.

Well designed GAPC has terminal velocity of about 1000km/h. Poor designed one has Terminal velocity of about 120km/h. Specially designed ones may reach 3000km/h

Tracked APC has terminal velocity of about 400km/h, but doesn't survive the sudden stop at the end.

 

[Carlobrand]

...Tracked APC has terminal velocity of about 400km/h, but doesn't survive the sudden stop at the end.

:rofl:

 

[Vladika]

What ECM on something the size of an APC is going to be particularly effective against a much more powerful ground detection system (whatever it might be)?

I'd rather get down faster with 10-15 individual targeted Troops with a small target signature than 1 slower, larger APC target with all 10-15 Troops in it.

 

[Fritz_Brown]

This presupposes a high-velocity re-entry. We moderns tend to think in terms of high-velocity re-entry because that's the only way our vehicles can manage it - no spare power to make a low-velocity re-entry. Orbital velocity for Earth, low Earth orbit, ranges around 7 to 8 kps; that's the speed an orbiting craft needs to shed as it hits atmosphere.

Let's specify "low-relative-velocity" but you are right. Though I was wondering the other day how much differential there is between "0-entry speed" relative to the highest altitude of atmosphere that matters and a geostationary position at that altitude. In other words, would you have to be non-geostationary to match the atmosphere at that altitude?

In the Traveller universe, a ship can come in fast, come rapidly to a complete stop (relative to the planet) at a precalculated position above the planet, and dump out whoever or whatever needs to get dumped out - and then that all starts coming down accelerating from a speed of 0, instead of having to bleed off orbital speed. An object deadfalling from orbit would need 12-13 minutes (assuming 1G planetary gravity) to reach the same velocity as that modern craft re-entering from orbit that we mentioned above; during that time it would travel around 2.5 thousand kilometers. Clearly, an object deadfalling from speed 0 and low orbit is never going to have a chance to get anywhere near the kinds of re-entry velocities we moderns tend to think of when we think of re-entry. It'll start hitting atmosphere soon after release, and the atmosphere will start braking it. From there, it's about terminal velocity and how that plays out with respect to thinning atmosphere and altitude.

Again, you're right. Of course, coming to a relatively stationary insertion point makes you a much easier target.

If you use the pods, can you "drop" from a higher orbit? The pod could provide supplemental life support for a longer drop.
The pods would also allow you to "shoot" them from your troop carrier, providing a *very* high entry speed to help defeat defensive targeting solutions.

What ECM on something the size of an APC is going to be particularly effective against a much more powerful ground detection system (whatever it might be)?

ECM doesn't have to make you invisible to be effective. You can scramble sensors and jam guidance signals. Even optical sensors can be spoofed or chaffed. It might not be 100% effective, but it will add survivability.

 

[McPerth]

No matter what some guy tells you in a bar, HALO troops are not encountering re-entry. What they go through is pretty intense, but what the Columbia went through is much more so.

I know they don't endure the reeentry to atmosphere, after all they are released from airplanes, not from orbital crafts.

In any case, drop capsues could be used for resupply, I'm not saying they're useless. I guess they can be given enough precison to be droped unmaned into the "liberated" zone.

Not quite. Even the Advanced Capsule might not make half a ton of supplies. Remember that the 683kg includes the marine and his BD and personal weaponry. It's sort of nit-picking in the case of this capsule, but you have to keep that in perspective when talking about them. I think you also need to look at how far from the action they will be dropped: any idea how fast a squad of soldiers could burn through 200+kg of ammo?

Not sure what you mean here. A BD-equipped marine can certainly carry a lot of gear. You're also arguing against one of the advantages of a drop capsule, and trying to claim that advantage as a reason not to use it. It doesn't work that way. Just because the capsule can hold ~500kg doesn't mean it *has to*. However, if you want to drop all those supplies (or HQ gear that will be rounded up by the command folks once the riflemen have moved out) you can. Yes, you *could* bring supplies in with a nice landing zone, but if things are still hot, that's a risk you might not want to take.

Even so, those 200+ kg of equipment/supplies are more than what a trooper may cary, even in BD, and if every trooper land with them (and assuming some troopers will be knocked off in the drop and some of their supplies might survive, they will probably have more than those 200 kg/trooper, limiting quite a lot the mobility of the unit, that has more supplies than it may carry.

Dude, if they land in freefall, how much they can carry won't matter much! :toast: :rofl: (I know what you meant, just ribbing you. )

I must agree my post was poorly phrased. Some comic relief always is useful anyway

I'm telling you it will be a lot more than "warm" once it hits atmo. That sucker will boil and explode in no time.

Sure, and so? if they survive 2-3 minutes (and I guess at TL15, as Imperial Marines are there are materials that can achieve it) they've accomplished their misión, as you don't expect them to survive. And sure they will be dirty cheap.

There's a HUGE difference in dropping from a hi-altitude platform and dropping from ORBIT in terms of "aerodynamic". Especially if you're going to tie a box or bag to the poor marine. It is *much* simpler and more effective to stick your marine into a little ablative pod.

This same box can help to make the soldier more aerodinamic, by using the same theory that capsules use, but I stil lthink the descent itself would be better acheved in free fall and grav belt brake and landing.

It primarily depends on how high that occurs. If it's 2,000m AGL, that's a problem. If it's 100m AGL, it won't be much of a problem. I would expect the marine to activate the grav belt (or the pod will deploy a chute - grav or air) before separation. Otherwise, your real problem will be having to dig the supplies out of the ground when the capsule augurs in. They could also tie the supplies to the trooper, so when the pod separates the supplies drop down much as a regular paratrooper might. (BTW, those things tied to the paratroopers were *not* released from the 'package' of paratrooper/chute/gear until the chute opened. Opening shock would otherwise rip an appendage off said paratrooper. Much like a pod releasing its occupant and gear.)

I wonder how sould those 200+ kg of supplies affect the descent and landing of the trooper if tied to him. After all the boxes/bags I told about above (and that used by paratroopers in WWII were quite more light.

Let's specify "low-relative-velocity" but you are right. Though I was wondering the other day how much differential there is between "0-entry speed" relative to the highest altitude of atmosphere that matters and a geostationary position at that altitude. In other words, would you have to be non-geostationary to match the atmosphere at that altitude?


Again, you're right. Of course, coming to a relatively stationary insertion point makes you a much easier target.

That what I envision, most troops reléase will be from relative speed 0, alloing them a vertical descent, both to reduce the time of the descent and to make easier the reentry.

If you use the pods, can you "drop" from a higher orbit? The pod could provide supplemental life support for a longer drop.

If we asume the descent/landing will take only a few minutes, this supplemental life support is not needed until after they are landed and probably have already organized the units.

The pods would also allow you to "shoot" them from your troop carrier, providing a *very* high entry speed to help defeat defensive targeting solutions.

And what precludes you to do it with CA/BD equiped troopers?

What ECM on something the size of an APC is going to be particularly effective against a much more powerful ground detection system (whatever it might be)?

ECM doesn't have to make you invisible to be effective. You can scramble sensors and jam guidance signals. Even optical sensors can be spoofed or chaffed. It might not be 100% effective, but it will add survivability.

I'd left ECM to the supporting crafts, as they can carry more powerful equipment that any trooper/APC

I'd rather get down faster with 10-15 individual targeted Troops with a small target signature than 1 slower, larger APC target with all 10-15 Troops in it.

APCs may be as quick as the tropos if they are released in fre fall also and use the same grav braking tactics than troopers.

Simply put: Trooper in pod has a terminal velocity in 1 Atm of about 2000km/h. Trooper in suit has a terminal velocity of about 300km/h.

This record paradrop Cryton refered to us reached supersonic speed in about 40 seconds (or so says the article). That's quite more than 300 km/h, and I dont see why CA/BD troopres could not reach those same speeds.

 

[Carlobrand]

What ECM on something the size of an APC is going to be particularly effective against a much more powerful ground detection system (whatever it might be)?

I'd rather get down faster with 10-15 individual targeted Troops with a small target signature than 1 slower, larger APC target with all 10-15 Troops in it.

I agree.

We should perhaps acknowledge some limitations in our paradigm: we are discussing Traveller, a game in which a ship less than a light-second away, one that glows in infrared like a spotlight on a dark night, can be hard to hit with a laser - and harder because it has a better computer than you. That being the case, what will happen is likely to be decided as much by what makes the game fun and interesting as by reality.

Traveller gives us no information about ground-based installations. However, the ship-based ones in MegaTrav have no particular problem picking up a 10 dT boat within 25,000 Km, and that little puppy's about the size of the typical APC. I don't see any reason ground-based radar should have a problem, least of all when there are likely to be several working together instead of just one. And, ground-based detection is not limited to radar: fusion-powered APCs glow quite nicely on neutrino detectors, and their mass would show up nicely on the far-future densitometers. My rough guess is that the APC's about as easy a target for planetary defense batteries as a 10 dT fighter would be for a dreadnought - which means the only real defense for an APC-mounted force is to be so numerous that they can't all be shot down before they get themselves below the horizon with respect to that PD battery. Kind of a bloody way to do things.

As to drop capsules - no neutrino signature, mass a tiny fraction of what an APC masses, and a pretty tight little radar cross section compared to an APC. My guess is if we examined the physics in detail, the things should still be easy to spot for some far-future radar capable of detecting targets to 500,000 km range, but the aim is not to make a planet invulnerable, it's to make an interesting game setting. In that context, the drop capsules (and by extension the cavalrymen on a grav belt) are going to be the best hope for landing a force without losing half of it.

Let's specify "low-relative-velocity" but you are right. Though I was wondering the other day how much differential there is between "0-entry speed" relative to the highest altitude of atmosphere that matters and a geostationary position at that altitude. In other words, would you have to be non-geostationary to match the atmosphere at that altitude?...

Geostationary's a bit over 3 kps for Earth, 10,800 kph. Earth has a circumference of 40,000 km and completes one rotation in about 24 hours, so turns at 1667 kph. In other words, an object at geostationary that starts heading earthward is fast enough to go completely around the planet in about 4 hours. Well ... he'd actually end up in an eccentric orbit if he didn't shed some of that vector or smack into the atmosphere first, but you get the idea. He'd be doing something close to Mach 9 when he hit atmosphere, not counting acceleration groundward - which itself would be considerable since he's falling from an altitude of over 35,000 km.

 

[Reban]

If the capsule breaks away at some point (I understand before reaching ground) and the trooper ends the landing in grav chute/belt, then what happens with the supplies carried in the capsule, that is one of the main advantages Carlobrand gives to them?

In this case, troops will have to collect the supplies containers that have fallen in the drop zone, akin of the problems German Fallschirmjäger in Crete, whree most of their equipment was droped in separate capsules, and had to devote the first moments in ground to retrive them.

Well there are a couple of possible solutions:

1) Unlike unguided parachutes used during WW2 a drop capsule should have enough onboard guidance and maneuverability to land supplies in a relatively tight area. Suppose we drop a battalion sized unit. Platoons drop on the landing zone in an outer perimeter and cargo capsules drop inside that perimeter. Perhaps this supply cache will have its own light logistics component to carry forward required supplies to where they are need or see (2)

2) Cargo capsules break away at some point above the ground to reveal a resupply drone powered by lifters or a grav modules equivalent to a troopers.This drone is programmed to home on a beacon or to go to a prearranged pick-up point where they can be collected by squads or sections. Such a cargo drone could stay with a fast moving Jump trooper unit. Squad level load carrying robots/drones are already in development although with wheels or legs (we really need to get the egg heads to hurry up with the CG).

3) What I'm envisioning as the cargo is not the crew served weapons & ammo, recoilless guns, bicycles and motorbikes that the Fallschirmjäger were retrieving to enable their assault. A Jump trooper in BD or CA should be carrying enough weaponry and ammo to overcome any resistance on the LZ and to establish security in the first few minutes.

When it comes to moving on to secondary objectives or resisting a counter attack they'll need to call up their reserve of ammunition (usually held by higher levels in other units, but in a Jump unit there won't be as much logistics and admin support to look after this) Such cargo could also include entrenching tools and remote/sentry weapons systems in case things go badly, and the Jump troops have to hold the LZ.

Putting this type of cargo down with the drop means that the follow-up landing craft can concentrate on containing combat formations for the break-out and the equivalent of beach-masters and military police to direct them off the LZ.

Then again maybe a BD or CA trooper can carry everything they need for 24 hours to 3 days of fighting, and perhaps "all" is a lot less then we can imagine, especially using airborne logistics as our reference.