Steve Jackson Games Forums

Steve Jackson Games Forums (https://forums.sjgames.com/index.php)
-   GURPS (https://forums.sjgames.com/forumdisplay.php?f=13)
-   -   Orbital Base Jumping (https://forums.sjgames.com/showthread.php?t=76129)

Snoman314 01-07-2011 08:30 PM

Re: Orbital Base Jumping
 
Quote:

Originally Posted by Allu (Post 1102748)
I'm more then willing to concede that a loiter time of eight seconds isn't really useful (though I'd allow a 24 second burn at 1G). The problem is that there isn't really any way around that problem (with a SM+4 craft). If you know you're only going to be dropping it on planets with atmospheric oxygen then you can exchange the chemical rocket for a jet engine but that means they can't get to the atmosphere on their own power (which might or might not be a problem).

A better solution is probably going to be something along the lines of the drop ships in SS4.

Surely the weapons on molokh's design would be more about suppressing ground defenses on final approach, rather than any sort of hovering gunship. The craft was designed to get marines down on the ground.

Braun 01-07-2011 09:36 PM

Re: Orbital Base Jumping
 
Tai, the drop capsule is in GURPS: Traveller - Star Mercs.

"...disposable atmospheric reentry capsule for meteoric assaults...allows reentry to take place in 2-3 minutes..."

DR 4,000 expensive fireproof ablative, 9 HP

Clusterfrak 01-07-2011 10:26 PM

Re: Orbital Base Jumping
 
Quote:

Originally Posted by Snoman314 (Post 1102746)
Brett: You do realise that with sufficiently precise guidance, its possible to glide in after an aerobrake maneuver lasting many orbits, with very low peak heat load, low enough that passive cooling would be sufficient. Basically it requires crossing skip-reentry with aerobraking. Aerodynamic lift is used to hold the craft at a constant dynamic pressure, with constantly decreasing velocity and altitude.

But would that really be practical for a combat landing?

Agemegos 01-07-2011 11:34 PM

Re: Orbital Base Jumping
 
Quote:

Originally Posted by Snoman314 (Post 1102746)
Brett: You do realise that with sufficiently precise guidance, its possible to glide in after an aerobrake maneuver lasting many orbits, with very low peak heat load, low enough that passive cooling would be sufficient.

Maybe, though that sounds very slow and rather conspicuous.

Quote:

But I put it to you that DR100+ is not necessarily a requirement for re-entry. That the higher the DR/heat shielding, the easier and faster aerobraking is, but that it is not impossible for less well shielded craft.
Well, strictly speaking DR is the capacity to resist penetration by projectiles, and some materials that are excellent for heat shielding have no DR to speak of. Shuttle belly tiles, for example.

Quote:

The box on pg 40 has been discussed in the past, and if I remember correctly, the consensus was that 0.1mps was for each landing attempt after the approach to the ground had already been completed.
Just so: it is for a landing attempt after braking has been completed. And so, I contend, is the glide-in rule in the same box.

Quote:

The fact that the passage on vertical landings mentions that streamlined craft can land quicker, to my mind supports the idea that streamlined craft are able to aerobrake/re-enter, otherwise how else is the extra deceleration accounted for?
Possibly they touch down with forward velocity rather than landing vertically.

Quote:

Streamlined hulls do appear to explicitly include shapes suitable for aerobraking.
Sure, but the existence of an overlap doesn't make the categories identical.

Quote:

Finally please don't take my rebuttal personally Brett
Okay.

Quote:

I'm mainly just trying to keep the magic alive :).
It strikes me that this particular piece of magic is not very realistic, doesn't make much sense under RAW, and isn't what the OP asked for. Fundamentally, I think that problem is that a vehicle that compromises between being a personnel carrier and a gunship, between an aircraft and a re-entry capsule will do all four jobs badly and at excessive cost.

The way for the OP to get what he wants would seem to be to use a Drop Capsule (from Ultra-Tech) and some sort of flying capacity such as a flight pack (Ultra-Tech, p.230)) or parawing.

The way to get space marines down to the ground with a CAP capacity would seem to be to build a cheap disposable landing bus consisting of passenger seating, a soft landing system, a hangar bay with an 'A'-configured armoured vertol in it, and a cargo bay with gear and ammo.

Personally, if I were a space marine I would be saying "if they can't land a lighter to put us down, how are they going to pick us up?", and I would want to land in a drop ship with enough oomph to SSTO. Aerial drones and orbital laser batteries will do me for CAP, thank you, provided that I get a ticket back to up.

sir_pudding 01-08-2011 12:05 AM

Re: Orbital Base Jumping
 
Quote:

Originally Posted by Brett (Post 1102820)
Personally, if I were a space marine I would be saying "if they can't land a lighter to put us down, how are they going to pick us up?", and I would want to land in a drop ship with enough oomph to SSTO. Aerial drones and orbital laser batteries will do me for CAP, thank you, provided that I get a ticket back to up.

Yes, I tend to think that any force that practices individual meteoric drops would try to avoid doing it operationally as much as real-life paratroopers avoid combat jumps operationally. It's great training, chicks (and dudes) dig it, and you get a cool badge to wear on your uniform, but in real combat you (and your brass) generally would prefer to have some kind of sustainable logistical support.

Send the drones if you aren't sure about being able to CASEVAC, let them secure the LZ, and then I'll be happy to ride a reusable drop ship down. Oorah?

teviet 01-08-2011 12:20 AM

Re: Orbital Base Jumping
 
À la Starship Troopers, you use itty-bitty drop capsules and lots of dummies to make the initial assault as confusing and hard to target as possible. The clumsy big transport follows once you've secured the landing zone (good luck!). One-way drops make sense if the orbit-capable recovery vehicles are too vulnerable to risk in the initial assault.

TeV

sir_pudding 01-08-2011 12:43 AM

Re: Orbital Base Jumping
 
Quote:

Originally Posted by teviet (Post 1102848)
À la Starship Troopers, you use itty-bitty drop capsules and lots of dummies to make the initial assault as confusing and hard to target as possible. The clumsy big transport follows once you've secured the landing zone (good luck!). One-way drops make sense if the orbit-capable recovery vehicles are too vulnerable to risk in the initial assault.

TeV

Robotics are severely retarded in that setting. In anything less retro why not secure the LZ with drones?

Agemegos 01-08-2011 12:49 AM

Re: Orbital Base Jumping
 
Quote:

Originally Posted by sir_pudding (Post 1102838)
Oorah?

Close enough for me.

But then, the chances of my being a space marine are kind of slim.

Tai 01-08-2011 01:01 AM

Re: Orbital Base Jumping
 
Quote:

Originally Posted by Brett (Post 1102820)
Personally, if I were a space marine I would be saying "if they can't land a lighter to put us down, how are they going to pick us up?", and I would want to land in a drop ship with enough oomph to SSTO. Aerial drones and orbital laser batteries will do me for CAP, thank you, provided that I get a ticket back to up.

Maybe some backstory in this might help then - the players work for a mercenary company who specialize in security, whether it be mundane (mallcop command), defensive (protecting a VIP from assassination) or offensive (securing a hostile LZ).

The various militaries tend to be tied up in bureaucracy and diplomatic treaties that prevent them from mobilizing as quickly as they could, so the mercs often get first-response as a deniable resource if something goes down - and given there's a TL10^ cyborg zombie army using hit and run tactics, things go down often enough to keep profits high.

For this reason, it's not entirely unexpected to have to drop into a ground war with no way back out until it's over - their job is to end it, or at least pave the way for conventional forces/the military to enter the fray. They'd rather -not- do it simply because of the likelihood of fatalities, of course, but if the price of saving a few lives in the company is the entire population of the colony...

Plus, knowing these players, if I leave them on a planet in a warzone with no rescue, within ten minutes one of them will have built a new ship, another will have shot down two more in repairable condition, the third will have convinced the zombies to give her another, and the fourth will be piloting them all simultaneously somehow ¬.¬

Agemegos 01-08-2011 01:26 AM

Re: Orbital Base Jumping
 
Quote:

Originally Posted by Tai (Post 1102863)
Maybe some backstory in this might help then - the players work for a mercenary company who specialize in security, whether it be mundane (mallcop command), defensive (protecting a VIP from assassination) or offensive (securing a hostile LZ).

Fair enough. I'll have to be a very highly-trusted company to be allowed the wherewithal to drop things out of orbit, but that's in keeping with genre.

Quote:

For this reason, it's not entirely unexpected to have to drop into a ground war with no way back out until it's over - their job is to end it, or at least pave the way for conventional forces/the military to enter the fray. They'd rather -not- do it simply because of the likelihood of fatalities, of course, but if the price of saving a few lives in the company is the entire population of the colony...
The Imperial Marines in my setting train for meteoric drops, and assault carriers have missile launchers big enough to stuff drop troopers through. But marines (with the exception of some crazy PCs) get all lemony when they are told off for meteoric assault. It's a sure sign that the stuff has already hit the thing, and that "pear-shaped" is a fond and fading memory. Drops are do-or-die missions, and if you are ever in such a strong position that you are guaranteed to win you don't need to do a drop.

Quote:

Plus, knowing these players, if I leave them on a planet in a warzone with no rescue, within ten minutes one of them will have built a new ship, another will have shot down two more in repairable condition, the third will have convinced the zombies to give her another, and the fourth will be piloting them all simultaneously somehow ¬.¬
Yeah, I get that sort of thing from players too. Once I had two marines and a naval officer captured as the only survivors of an Imperial Survey frigate getting bushwacked by four alien cruisers (first contact scenario gone banana-shaped). By the time a trillion crowns worth of Imperial Navy Combat Taskforce and two divisions of Imperial marines showed up to rescue them them, the PCs had overthrown the government of one planet, dealt a fatal blow to the internal prestige of the aliens' pocket-sized empire, and they had a ship for coming home in and were working on deciphering alien navigation instruments. Jolly good show! Iron Stars all 'round, and a DSC for Lt. Tollonen. Thirty years later aliens from that Empire who joined the Imperial Service were calling on Sergeant Crowe to salute him in person.

NPC marines still hate meteoric drops.


All times are GMT -6. The time now is 06:11 PM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.