These guys are just to land, look around, tell me whats there and then probably die - hoping they last long enough
This is probably a bad idea. Alien homeworlds usually are defended by multiple-million-tons of ground units. Your 5,000-ton scouting party will be mowed down in the first combat increment without providing any real intelligence - the intel you get in the first exchange of fire usually has error bars of +/- 100% - you might be able to confirm that the opponent
has tanks, but you won't have any solid numbers on how many tanks are actually present, for example. To be frank it's not really a surprise that the opponent has tanks, especially since most NPRs have balanced force compositions that lean infantry-heavy.
It's probably better and less wasteful to just land a similarly balanced force (or a force designed to counter a balanced opposing force, you do you here) in sufficient size to win the battle outright - taking into account the normal rules affecting detected ground force signatures in space (i.e., that the apparent signature is reduced by fortification level, so you may be facing 3x to 6x as many troops in reality). The ground combat mechanics are actually quite flexible in practice, at least at an operational and/or strategic scale, so any "reasonable" force composition will perform well enough as long as you have the advantage of numbers.
You're also going to run into a serious problem if you do try to use these:
UD4 Cheyenne Assault class Assault Transport
Maint Life 0.03 Years MSP 76 AFR 1190% IFR 16.5% 1YR 2,684 5YR 40,257 Max Repair 480 MSP
Macrinus Aeromarine Magneto-plasma Drive EP960.00 (2) Power 1920 Fuel Use 82.67% Signature 960 Explosion 15%
This design is classed as a Military Vessel for maintenance purposes
Due to the use of overboosted engines, the
Cheyenne class is counted as a military ship with an associated failure rate, and without appreciable engineering/MSP spaces that 0.03 years maintenance life may prove to be an optimistic overestimate. Your troops are going to end up uselessly floating around in Mars' orbital radius rather than reaching the AO and mowing down alien scum.
For opposed planetary assaults, I would recommend something more like this:
Off-Topic: Leviathan class Assault Transport • show
Leviathan class Assault Transport 223,972 tons 1,143 Crew 9,728.4 BP TCS 4,479 TH 6,000 EM 0
1339 km/s JR 3-50(C) Armour 12-328 Shields 0-0 HTK 285 Sensors 8/8/0/0 DCR 1-0 PPV 0
MSP 27 Max Repair 800 MSP
Troop Capacity 100,000 tons Drop Capable Cargo Shuttle Multiplier 20
Captain (JG) Control Rating 1 BRG
Intended Deployment Time: 3 months
Genesis HGC-4500 Commercial Hyper Generator Max Ship Size 225000 tons Distance 50k km Squadron Size 3
Hyperion HC-500 Commercial Impeller Drive (12) Power 6000 Fuel Use 2.24% Signature 500 Explosion 4%
Fuel Capacity 1,500,000 Litres Range 53.8 billion km (465 days at full power)
NM/BGN-4 Gravitic Navigation System (34M) (1) GPS 2400 Range 33.9m km Resolution 150
NM/SLQ-17 Auxiliary EM Detection Array (22M) (1) Sensitivity 8 Detect Sig Strength 1000: 22.4m km
NM/SRQ-21 Auxiliary Thermal Detection Array (22M) (1) Sensitivity 8 Detect Sig Strength 1000: 22.4m km
This design is classed as a Commercial Vessel for maintenance purposes
This design is classed as a Troop Transport for auto-assignment purposes
This is admittedly a rather large version appropriate to my roleplay setting, but the basic concept is sound: Large drop-capable troop capacity and extremely heavy armor to weather STO fire on approach to a planet. You may still lose a couple of these depending on how many STOs the enemy has (and how much preparatory bombardment you choose to do), but the idea is to have a large number of these, probably in the dozens, to deliver those multiple million tons of ground forces to the planet surface more-or-less intact.
You may balk at the cost of these ships, especially given that I'm suggesting to build dozens of them. To this I say, what did you expect? Planetary invasions are not supposed to be cheap and easy, after all... and that 100,000 tons of ground troops in each ship is going to cost you another 2,000 BPs at a minimum, probably more like 5,000 to 10,000 since you will want to have armored units for the most tonnage-efficient invasion force. Better start cranking out those GFCCs...
In the long-term, however, even these expensive monstrosities can pay for themselves eventually. Since they are commercial ships, once you build an assault ship it can be kept around and used whenever needed as long as your game goes on, and refitting the engines every tech level or two is a far cheaper affair than building a new model of these, so once you have a good-sized fleet built up then any survivors from one invasion can be used for the next one.
There are other approaches to drop ships - for example, you could reduce the armor (which makes up over 40% of the total cost here) and try mounting more engines instead, aiming for speed to reduce the number of hits taken rather than armor to suffer the hits (personally, I don't think this is as effective, but I am only trying to point out another possibility). However, no matter what approach you take, these will be horrendously expensive units.
Your chief alternative is to wipe out the STOs with orbital bombardment, at the expense of greater collateral damage, and then land your invasion force by a legion of much cheaper regular transport ships. Dropships are really only necessary in the face of STO fire, otherwise you have plenty of time to unload your troops unhassled by annoying laser beams and railgun rounds. This could save minerals and money on the up-front building costs, but the rewards of conquest are correspondingly less as well. Given that the up-front costs pay off over time, losing significant chunks of your booty every time you bombard another alien world may end up being not worth it in the bigger picture.
