Typical aerospace defences for a planet?

[Reaved]

I was hoping there was some indication of what the typical aerospace defences for a planet were? I appreciate that they are likely heavier on planets within 30/60 LY of the frontline and lighter on backwater worlds with primarily agrian startegic resources. It will also differ by era but as I'm not certain there's an abundance on information I'll take whatever people can offer.

Given the relatively small size of Clan militaries, do we know what their planetary defences would be?

I assume it can't be too high as most regiment+ formations seem to run little more than a wing and there wouldn't be much point turning up for a planetary invasion and finding yourself unable to land. Or are they reinforced with independent ASF formations specifically tasked with establishing air superiority during a landing?

[AlphaMirage]

Check out my Second Star League guide to Warships (link in Sig below) for my detailed thoughts on the matter.

Small craft with weapons exist and gave nice endurance compared to fighters. They lose out to actual fighters but can definitely threaten Dropships. I expect they would be commonly on patrol from their home planet to interdict incoming contacts.

Space Stations would be mostly used as fighter or shuttle bases and listening posts. Armed ones aren't that good since they can't take a hit and are susceptible to teleopersted missiles

[Daryk]

Convential Fighters en masse are the biggest (and cheapest) threat to landing DropShips, even if they bring air cover... 

[pokefan548]

It depends on a lot of factors. The planet's importance, the faction and it's ability to procure and distribute aerospace/SDS assets, and perhaps most importantly the era. A key Hegemony world at the Star League's apex could likely expect patrolling WarShips, orbital defense platforms, several wings of ground- and space-based fighters, and numerous ground-based space defense systems. Conversely, a small, relatively unimportant periphery world during the Succession Wars might be lucky to maintain a full squadron of fighters, with few if any heavies in there. If the planet has a local aeronautics industry, expect to see locally-produced variants of the big three conventional fighters.

[Cannonshop]

I was hoping there was some indication of what the typical aerospace defences for a planet were? I appreciate that they are likely heavier on planets within 30/60 LY of the frontline and lighter on backwater worlds with primarily agrian startegic resources. It will also differ by era but as I'm not certain there's an abundance on information I'll take whatever people can offer.

Given the relatively small size of Clan militaries, do we know what their planetary defences would be?

I assume it can't be too high as most regiment+ formations seem to run little more than a wing and there wouldn't be much point turning up for a planetary invasion and finding yourself unable to land. Or are they reinforced with independent ASF formations specifically tasked with establishing air superiority during a landing?

Typically, most worlds (not Clan) have "a wing and a prayer' for aerospace defense. (this isn't true for all of them, the Outworlds Alliance had quite a lot of investment in preventing raiders from landing or leaving...but that's only proportional to, say, the outback worlds of the Federated Suns.)

The clans, if they followed Kerensky's plan thoroughly, will have at least a Trinary available  (thirty fighters) on worlds that merit at least a Cluster's worth of Warrior Caste.  Important worlds will also have combat dropships and VITAL worlds may even have a couple of relic Warships.

but generally you can consider aerospace defenses to be more of an afterthought than an actual plan of action.  It's not what's rational, it's what 'is' in the setting.

[idea weenie]

I'd make the ASF strength proportional to the Mech strength defending a planet.  So figure what size Mech force would be defending the planet, and make the number of ASF defenders a fraction of that.

(My idea for actual numbers/ratio would fall under Fan Rules, and thus will not be listed here)

[pokefan548]

In-universe, it's typically one wing per-regiment (and thus one squadron per-battalion, one flight per-company).

Also worth noting that some planets without meaningful 'Mech forces often still have at least small aerospace contingents, even if only just a few light fighters. Worst comes worst, a group of tanks can still easily match an out-of-position 'Mech, but the only thing that can stop the enemy from having total aerospace superiority is at least a token aerospace force of your own.

[Jellico]

The basic problem with aerospace is it is expected to cover a mind boggling area. With the small forces available it is usually better to allow an enemy to land, effectively pin themselves, then respond with the rapid intercontinental deployment of Mechs and ASF.

[DevianID]

What I have seen based on reading for the clan invasion campaign stuff is there is a small aerofighter detachment per world.  The prior suggestion of 18ish fighters per mech regiment matches this like pokefan said.  Then there is the uncounted legion of conventional and support fixed wing aircraft that the milita deploys that doesn't get hard data.  In general militia is just 'there' and often engages in resistance for years without ever giving hard unit data--unit data is almost always reserved for mechs and other frontline combat vehicles.

Like, a military cargo plane doesn't count when tallying up the defenders planetary air forces, but its assumed they exist.

Edit:  there are stories of defenders launching all their aerospace assets to try an all or nothing opposed landing, but when it failed they were left without aerospace support for the ground battle (but they still had conventional).  Other times the attacker lands unopposed but farther from the target zone, leading to meeting engagement battles with both sides air assets being used as reserve support forces.

[Col Toda]

Varies wildly . Highly agraian backwater Has to have petrochemical industry for fertilizer and by extention Aviation fuel . So expect mech buster fighter and convetional bombers . Sometimes these worlds also have small munitions factories taking advantage of that same chemical industry.

For Lightly Industrial Many targets scattered over planet two or three lances of med to heavy fighters . It will attempt to hit drop ship a turn before the Space Atmosphere pilot check . Each lance approach 120 to 180 degrees apart force the division of escourt and or forcing extra station keeping fuel burn on the dropship's part delaying going through until enemy fighters withdraw . Rocket Launcher armed Transgressors can make landing impossible. 

Lightly or heavy industry concetrated on a peninsula  only intercept if they try to do a combat drop avoiding the defense in depth ground forces . As it is not certain that WMDs deployment instead of combat drop is going to happen ramming with a med or heavy fighter is in order preferably drone with booby trap . If they land beyond the peninsula let the ground forces handle the unloaded ground forces but tie down enemy aerospace by sending Boomerang spotter planes looking for the dropship . If in the unlikely event that they spotter plane get through Long Tom  Fire Bases or Long Tom Armed Naval Support will move to bombard dropzone . The object is to get enemy to expend fuel . The enemy will see a fighter cap over the Peninsula but nowhere else. Should convince the opposition to land 30-60 miles beyound it un apposed  . The defense in depth either works or not . The withdrawing dropship gets the two to three lances attempting to hit it at atmosphere Space barrier.  The pilot check is either made or not . If made it gets away . If not it likely crashes or leaves very damaged so doubles the material loss for the raid successfull or not .

Aerospace is only a primary defensive unit on desert worlds in which the planet controls the water sources . So the enemy cannot crack water for fuel in this scenario intercept happen in space hit the escourts and dropship preferable hitting with fly by attacks LB×20 , Heavy PPCs +:Capacitors  AC/20 ultra with one pass hoping for fuel loss crit . Let land win or lose . On exit  repeat  they either have enough fuel to get to the jump point or they don't.  If they do not have an Octypus on hand to tow it they have to surrender mostly intact drop ship to the system that does .

The objective in Aerospace can be as little as forcing the enemy to expend a minimum amount  fuel to land intact preferably more than the oppostion wants  . Make a 6 - 12 hour obective raid spend more fuel keeping fighters in the air destroying or force withdrawal of spotter planes . Battletech is supposed to revolve mech and convetional ground forces . Aerospace is just the vehicle to get those forces there . Objective Raids tend to work because militia has only the in place Garrison and maybe a rapid response force from the closest firebase at the point of contact to defend an objective.

[bmcauliffe]

The House Objectives from the end of the Jihad have a generic planetary militia estimate in the last few pages. It doesn't list aerospace forces, but it does give average militia size then you can add conventional fighters by regiment in the normal ratio.