Jump troops

[Fritz_Brown]

Even so, those 200+ kg of equipment/supplies are more than what a trooper may cary, even in BD, and if eery troopser 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.

So what? It doesn't limit the mobility of the unit one bit. If they need to move out, they can and will leave supplies behind. Since they are moving forward, they aren't leaving those supplies for the enemy, but for follow-on echelons - or, even, for their reinforcements. The fact that the pod can carry all this gear is not a reason to not use the pod, itself.

There aren't loadmasters/jumpmasters/dropmasters standing around, scratching their heads, "Well, dang, Sgt Bubba, I can't find anymore useful stuff to shove in this drop pod. Should I just fill the rest with lead?" When it's wanted, the capability is used; when it isn't wanted, it's not used.

BTW, the load limits are just that - limits. You don't have to maximize the load. The load limit is based on what the grav chute can successfully slow down. If you wanted to pack the thing with 1,000kg, you probably could - just don't expect the grav chute to slow you enough to prevent planetary crust penetration.

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,

Well, if we're talking a hot atmospheric entry from orbit, they won't survive long enough to matter, since they'll explode before ever getting into the regime where they might do some good as decoys. And, there definitely is a material that could survive that sort of thing. They make drop capsules out of it.

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.

If the box (containing a bunch of supplies) uses the same theory the capsule uses, then aren't you just talking about a ... drop capsule? And, when you say "free fall" you're not saying anything that is different from a drop capsule falling through the sky. An un-encapsulated trooper and an encapsulated one are both in free fall until something engages to inhibit that fall. The only difference is whether the trooper (along with his gear) is inside an armored shell or not. That's it.

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.

I don't think dropping from relative velocity of 0 will reduce the time of descent at all. It might change the trajectory of descent, however (less of a parabola - but that really depends more on the physics in any particular case than on starting relative velocity). To reduce the time of descent, you would want a more aerodynamic shape - like a capsule - to achieve a higher terminal velocity. That will reduce your descent time.

If we asume the descent/landing will take only a few minutes,

I meant from the higher orbit launch position. The time difference from there to the lower orbit that is normally assumed.

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

I suppose you could, but a capsule will make a better bullet. It might be less freaky for the trooper involved, too.

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.

Nope. That APC has a lower terminal velocity than the drop capsule (see Aramis' post). If you improve the velocity of the APC by making it more like a fighter jet/rocket, it becomes much harder to get people in and out of it. (One of the key trade-offs of vehicular design.)

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.

You need to remember, however, that "supersonic" is slower at high altitude than it is at sea level. At sea level, it is 1,236km/h. At 36km up it is barely over 1,000. And, yes, the trooper could reach that speed - but he won't stay at that speed. As the air thickens, the trooper will slow down. The capsule (being streamlined) will go even faster - and won't stay at that speed, either. But it will still be faster than the trooper in just his BD. Here's a quote from that graphic Cryton linked:

As Baumgartner descends he enters thicker air. His speed slows but he risks going into a deadly spin so violent that he could lose consciousness.

The drop capsule doesn't have that problem (if designed properly).

 

[Fritz_Brown]

Geostationary's a bit over 3 kps for Earth, 10,800 kph.

I'm not sure we're looking at the same things. When I said "geostationary" I meant "staying above one spot on the ground" while at the limit of the atmosphere. I didn't mean geostationary orbit. (I know that means it will have to actually not be "in orbit" as that term is commonly used.) If an object is staying over one spot on the earth at, say, 100km above the earth, how does that compare to the air at that altitude? I dare say the air is not stationary with respect to the spot on the ground. What is the difference (and perhaps 100km is too high for that difference to mean anything), and what does that mean to someone "inserting" into the atmosphere? Is it necessary for a "zero-relative-velocity insertion" to be on a 'downwind' to the target? If you want to go *straight down* will it require working against the atmosphere to do so?

(I think the answer is yes, based on my pilot's knowledge of "winds aloft" but I don't know when you get to that sort of altitude.)

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).

Very good point. (The rest of the post is good stuff, too.)

 

[Reban]

I just realized McPerth that you may have been referring to the cargo space in the Manned Drop Capsules rather than the Cargo Jump Capsules.

Well that extra cargo might represent a trooper's "pack" or the BD and CA version of a pack or the extra ammo for the squad's support weapons and launchers. assuming this it could be attached to the trooper, either directly on the armour or on a line (for paratroops this is to keep the mass away from the trooper and make his landing easier. Individual weapons were carried like this too, you don't want to land heavily with an unbendable hunk of wood and steel strapped to one leg which is your shock absorber).

In short I think it will be tethered to the trooper. Whether with rubber bands, bungie cords or some high tech data carrying cable depends on what it is.

I can't see the need for a traditional "soldier's pack" because BD and CA should have everything needed for the trooper to fight and survive. It might represent special weapons or sensors above and beyond standard issue weapons.

Other things that could make up such cargo in the manned Drop Pod could include: Specialist Equipment, Mission Specific equipment, Marker Beacons for the LZ, Medical Packs, Meteorological monitoring equipment, NCB (and nano and cyber) sensors, Extra and back-up Comms equipment.

But as noted by Fritz_Brown above, load limits are upper limits you don't have to put anything in there. Although filling it with lead might be a good idea on a nuclear battlefield

One thing almost every trooper will carry, especially if the trip takes about 3 minutes is, ahem, traditional reading material...no not the manual

 

[McPerth]

So what? It doesn't limit the mobility of the unit one bit. If they need to move out, they can and will leave supplies behind. Since they are moving forward, they aren't leaving those supplies for the enemy, but for follow-on echelons - or, even, for their reinforcements. The fact that the pod can carry all this gear is not a reason to not use the pod, itself.

There aren't loadmasters/jumpmasters/dropmasters standing around, scratching their heads, "Well, dang, Sgt Bubba, I can't find anymore useful stuff to shove in this drop pod. Should I just fill the rest with lead?" When it's wanted, the capability is used; when it isn't wanted, it's not used.

BTW, the load limits are just that - limits. You don't have to maximize the load. The load limit is based on what the grav chute can successfully slow down. If you wanted to pack the thing with 1,000kg, you probably could - just don't expect the grav chute to slow you enough to prevent planetary crust penetration.

Of course, limits are just that, and you can load it less tan the limits, if you're going to conduct a hit and run raid, to give you an example, but if you don't need those supplies, then the advantage the capsules have of being able to carry them is nullified, and having them only half full might even altre its equilibrium in the descent (that's why sea ships carry ballast when not carring cargo).

If the box (containing a bunch of supplies) uses the same theory the capsule uses, then aren't you just talking about a ... drop capsule? And, when you say "free fall" you're not saying anything that is different from a drop capsule falling through the sky. An un-encapsulated trooper and an encapsulated one are both in free fall until something engages to inhibit that fall. The only difference is whether the trooper (along with his gear) is inside an armored shell or not. That's it.

Once again I feel I'm not explaining myself as well as I would like. I was only pointing that the same box, as you said, would alter the aerodynamics of the trooper, but that alteration could also be to improve them for the critical reentry phase. If you consider that a capsule, it could be so called, but what I disagree about the capsules is as the method of full descent and stop the falling at the ned, something more easily attainable (IMHO) with gravitics, if you have it (one of the major diferences, AFAIK, among Heinlein's universo and OTU.

I don't think dropping from relative velocity of 0 will reduce the time of descent at all. It might change the trajectory of descent, however (less of a parabola - but that really depends more on the physics in any particular case than on starting relative velocity). To reduce the time of descent, you would want a more aerodynamic shape - like a capsule - to achieve a higher terminal velocity. That will reduce your descent time.

It will reduce the time a little, but I'm not sure if it will matter. What in truth I intended to say is that it will reduce the distance travelled in the descent, as it was straight line instead of parabolic descent, and as speed limits apply to the current vector, the fact of the vector being perpendicular to ground is what will slightly (or not so slightly, I'm not sure at this point) reduce the time.

I meant from the higher orbit launch position. The time difference from there to the lower orbit that is normally assumed.

Perhaps here we have different doctrine. I think about troops being launched from LPO, so reentry phase will not be at too high speed.

I'm not an expert in the matter, but AFAIK, the cause of the high tempreatures objects entring in atmosphere (be them shuttles or meteorites)reach is due to the high speeds they already have when entring atmosphere. Those troops don't need to have those high speeds at this critical momento if launched from a more or less geostationary (as yourself described in you last post) from LPO, so most speed will be achieved while in atmosphere, and will not reach the one where such high temperatures are reached.

I suppose you could, but a capsule will make a better bullet. It might be less freaky for the trooper involved, too.

Well, if the launcher is gravitically (repulsor) shooting the trooper, it can launch a CA/BD trooper as easily as a capsule. What made easier in Starship Troopers is that they were launched by compressed air (again, there are no gravitics there), and I agree making a CA/BD to fit enough the launcher would be quite difficult (to say the least).

About being freacky, I guess they will not have to endure more acceleration tan most combat pilots in RW fighters.

Nope. That APC has a lower terminal velocity than the drop capsule (see Aramis' post). If you improve the velocity of the APC by making it more like a fighter jet/rocket, it becomes much harder to get people in and out of it. (One of the key trade-offs of vehicular design.)

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

So, trooper about 2000 kph. Specially designed vehicles 3000 kph. They are specialized tropos, be them in capsules or CA/BD, so it's logical they have those specially designed vehicles. And I always said about them to provide direct armored support (tanks) and to carry equipment, not tropos, so the fact it's more difficult to get tropos into and out of them is not a problem.

You need to remember, however, that "supersonic" is slower at high altitude than it is at sea level. At sea level, it is 1,236km/h. At 36km up it is barely over 1,000. And, yes, the trooper could reach that speed - but he won't stay at that speed. As the air thickens, the trooper will slow down. The capsule (being streamlined) will go even faster - and won't stay at that speed, either. But it will still be faster than the trooper in just his BD. Here's a quote from that graphic Cryton linked:

The drop capsule doesn't have that problem (if designed properly).

Here you give me a doubt about what they mean when they talk about breaking the sound barrier. They may mean, as you said, the local sound barrier, or they may mean it was faster than mach1 (I assumed the latter, but your point is good here too).

About the trumbling, I guess the grav belt may help in that too, as they sure have stabilizing controls it the people using them don't trumble usually, and the tropos could be better trained than Baumgartner, as for him it was his first such drop, and he had no means to be trained.

 

[Carlobrand]

I'm not sure we're looking at the same things. When I said "geostationary" I meant "staying above one spot on the ground" while at the limit of the atmosphere. I didn't mean geostationary orbit. (I know that means it will have to actually not be "in orbit" as that term is commonly used.) If an object is staying over one spot on the earth at, say, 100km above the earth, how does that compare to the air at that altitude? I dare say the air is not stationary with respect to the spot on the ground. What is the difference (and perhaps 100km is too high for that difference to mean anything), and what does that mean to someone "inserting" into the atmosphere? Is it necessary for a "zero-relative-velocity insertion" to be on a 'downwind' to the target? If you want to go *straight down* will it require working against the atmosphere to do so?
...

Oops, sorry, misunderstood.

Lessee ... Earth has a circumference of 40,000 km and completes one rotation in about 24 hours, so turns at 1667 kph. Increase the altitude, increase the speed to maintain the same relative position: PiD=40,000, Pi(D+100)=~40,314, figure you've got to speed up by about 13 kph for every 100 km altitude? And, of course, you're thrusting upward to maintain altitude, or to keep your descent to some manageable speed.

High altitude winds get pretty fierce, up to a couple hundred kph, or so I've heard, but that's more a navigation problem - and if you've got a good weather read, you can factor that in and drop so you maintain equilibrium with the local wind speed at the varying altitudes and end up arriving where you want, or close enough that a bit of last-minute correction should put you on target.

So, yes, you should be upwind and let the wind take you down to target - though it's not vital, I'm pretty sure the grav belt puts out enough speed to counter high altitude winds.

I am not understanding this great capsule verses grav belt debate. Frankly, it's sounding a lot like debating whether tanks or artillery are a better weapon - they're for different missions, ain't one better than the other.

First, let's get rid of the notion of a flaming re-entry. A flaming re-entry is as necessary to a far future spacegoer as a long landing strip is to a helicopter. Besides, ain't no such thing as a stealthy flaming re-entry - you start heating up, their infrared says, "TARGET," and then you die. My guess is these capsules include enough gravitics and battery power to get a man to the ground without attracting the attention of the enemy's infrared sensors - they'd have to, or all that talk about controlling them is nonsense.

That being said...

If you're dropping where people are going to be shooting up at you in a big way when you drop, you drop in a capsule. Whatever other attributes they have, the prime one is they give you an extra layer of armor protection that helps make sure more of you get to the ground alive - or to a lower altitude where you can hide behind the horizon and fly the rest of the way NOE on grav belts, if that's your thing. As near as I can tell, there's nothing that says a capsule's easier or harder to detect than a man by his lonesome, so there's no real benefit in foregoing that extra armor protection. The extra cargo's useful if you figure you're going to be stuck there a while, but it's not vital. (If they can drop you in a capsule, they can drop supplies in a capsule.) The main thing is to get through the opposing AA in one piece - you drop in a capsule when it's the only way to get down alive.

If you're dropping where people are NOT shooting up at you - or not so fiercely or accurately as to need a sneaky way down - and you want the extra cargo and firepower, you drop in APCs. However, if there is any kind of monitoring of orbital and atmospheric space, as a class-A/B/C starport or anyplace with any reasonable volume of air traffic, they'll probably know you're coming. You drop in an APC when they know and can't do much about it and your intent is to use a sledgehammer when you get there.

If you're dropping commando - with the intention of getting there with the bare minimum warning to the enemy and then kicking butt special-forces style - and you aren't expecting a need for extra armor to accomplish it, then you drop in a grav belt; you drop more or less directly on your target and then tell them to say hello to your little friend. Near as I can tell, the only thing a capsule can do that a man with a grav belt can't is carry cargo and provide that little bit of extra armor protection - and I don't see any reason why you HAVE to have a man in there to get cargo down; preprogram that little on-board computer and make it a drone. You drop in a belt when your intent is to use finesse.

So, three different drop styles for three different mission profiles.

 

[aramis]

Drop capsules, as defined in Traveller's Digest, had stealth and EM Masking. They are thus harder to detect with many types of sensor than a man in a grav-belt.

Plus, normal deployment also used ECM capsules jamming the heck out of detected actives while inbound. ECM caps lacked a man inside...

 

[Carlobrand]

Drop capsules, as defined in Traveller's Digest, had stealth and EM Masking. They are thus harder to detect with many types of sensor than a man in a grav-belt.

I was under the impression that the chameleon surface over the individual's armor would provide some of that.