Can you explain the importance of this, as you would do if talking to a literal child?
I had a quick look and I think it was previously a ground/sea-level launched missile, meaning a lot of energy is wasted accelerating and gaining altitude. Air launch raises the rage from 170km to 360km.
Although this is just Google-fu, so take it with a pinch of salt.
I’ll try.
Planes are big.
That’s all I’ve got.
So, why is SM-6 on F-18's important?
a) Anti shipping
Let me take you back to the 1980's. The majority of the Soviet surface Fleet are weird bastards. By weird bastards, I mean they designed ships with truly bizarre characteristics, akin to the French in the 1880's level of weird. You have stuff like Cruiser-Carrier hybrids. Basically, the Soviet Surface fleet wasn't a major "threat" to the overall US naval operations therefore a bigger focus was made on Anti-submarine warfare (ASU). The previous sentence is a bit of an oversimplication but let's not get too worked up into details. This meant that the missile of choice in the early 80's was the Harpoon. It didn't pack a great punch, with its 500lb warhead but NATO war-planners expected naval superiority in the air so quickly that they could just overwhelm Soviet Surface fleets with huge numbers of Harpoons from both Air and Ships. Sure, each missile didn't pack a punch but if 5x 500lb warheads smash through a ship, it's going to have a bad day. In contrast, the Soviets had these gigantic anti-ship missiles such as P-700 Granit with a 1500lb warhead or a P-500 Bazalt with a 2250lb warhead. The thinking was that not much stuff was going to get through and they were going to get overwhelmed pretty quickly, therefore any missiles that did get through needed to pack a huge punch.
Fast forward to the early 90's - and the Cold War has ended and the Russian Fleet exists on paper only. Nobody cares about the development of anti-ship missiles at this point. Who actually posed a threat to US/NATO surface fleets? China's navy was a bunch of obsolescent Soviet-based hand me downs, India barely had anything, and all the other major naval powers were US allies or in NATO. Couple that with the peace dividend and the GWOT, nobody cared about anti-ship missiles for about 25 years.
In mid 2010's, USA realizing the threat of China's growing surface fleet began to develop a anti-ship missile with a large warhead. No longer was the supremacy of the 7th Fleet assured, and with China's modernized navy, it was becoming considered a near-peer. Spamming harpoons through a well integrated naval missile defence network wasn't going to be feasible anymore. By 2020 US developed the LRASM missile, derived from the JASSM-ER Air to Surface missile, but modified for naval use. There was a big caveat, LRASM's are crazy expensive and it isn't integrated with anything else, setting up pure LRASM production lines that would be used solely by Naval Aircraft (and technically, air force aircraft) was prohibitively costly and there were huge teething problems that exist to this day.
So the US began research on long term solutions, high end hypersonic anti-ship missiles with huge warheads (HALO project) and hypersonic cheap anti-ship missiles with a light warhead that can just be spammed to completely overwhelm ships air defenses (MAKO). But these missiles aren't expected to be in service until 2028-2030. We have a problem. There's about a 5-8 year gap where there isn't enough LRASM's around to be able to use in depth against China in a shooting war in the pacific, Harpoons are not going to cut it. At first, the US sought to buy foreign missiles, such as NSM's from Norway and JSM which is joint project with Norway, again. However, there was still the problem of not having enough high-payload warheads that can sink ships or cripple them with 1 hit. LRASM was the solution but it's too expensive.
Then the Navy began testing an existing missile, SM-6 that has been in service for a decade and found that it had very promising anti ship capabilities. If they could be launched from planes, that would prove incredible as a stop gap solution until MAKO and HALO were ready and until LRASM could get up to proper speed. This is point number 1.
b) Missile Defense.
SM-6 is primarily an interceptor missile. To give you a bit more context, SM-6's is one part of a Carrier Strike Groups protection layer. SM-2's provide coverage for the slow moving, obvious, targets with a decent range and excellent interception rate. They form the backbone of US Naval Missile defense. Then come the SM-3's. They are solely developed for high trajectory, exoatmospheric interceptions of ballistic missiles (including ICBMs). SM-6 is the high end, most capable interceptor, capable of intercepting anything an SM-2 can, at an even better success rate, some things an SM-3 can and also has better internal sensors, guidance systems and electronics suites. Finally, there are quad packed ESSM's which are short-medium range missiles for stuff that got through everything else OR for really cheap interceptions for things that aren't worth an SM-2, SM-3 or SM-6. Take for example, a crappy Houthi drone in the red sea. There's other stuff as well such as SeaRam but it's not relevant for this discussion.
One of the biggest problems with defense at sea is that there is no sustainable way to reload after you've fired all your missiles. The Navy spent decades researching ways to replenish a warships arsenal whilst in a combat zone and found that it was practically impossible to do it well. That means when a warship has fired its wad it's completely vulnerable. Most US surface capital ships can fire around 96-150 missiles (dependent on loadout) before running out of missiles. The way this can be mitigated is by using a platform that can actually have the ability to reload. Aircraft on Aircraft Carriers.
A carrier can hold and store thousands of missiles and it takes less than 10 minutes to re-arm a fighter jet with a brand new set of missiles after a sortie. However, the current inventory of US A2A missiles isn't good enough. AIM-9X is far too short ranged. AMRAAM's require too much radar guidance from AWACS, isn't integrated with AEGIS and cannot operate at long ranges due to its sensor suites. This is where having SM-6's on planes really, really improves air defence. A strike group with 1 squadron of aircraft dedicated to air combat patrol with interceptor loadouts can carry 48 missile interceptors. They can land, rearm and refuel and go again. This really takes the pressure away from surface combatant intercepts and doubly, acts as a anti-ship threat as well as a missile defense screen.
c) Production and Cross-Platform integration
First we can talk about production. The biggest problem with SM-6 is the costs and the lack of serial production (same as LRASM). Why? Because there's one buyer. Only the Mk41 VLS system on ships can launch it and it's the luxury interceptor missile on US ships, the most capable sure but the majority of them are going to be ESSM's and SM-2's. This means that because the SM-6 has one buyer, in low numbers, Raytheon have no incentive to hugely expand production lines and to drive efficiency therefore bring the price down per unit.
With cross-platform integration this changes the calculus. Rather than the Navy only needing SM-6's for the ships, they need them now for the aircraft too. In the future, the Air force will also need to buy them. This means that whereas previously Raytheon had one customer that was going to buy 50-100 every year, they now have multiple customers willing to buy hundreds a year. This improves production lines and drives the cost per unit down.
https://comptroller.defense.gov/Por...dget/FY2024/MYP_Exhibits/SM6_NAVY_MYP_1-4.pdf
Look at the latest 2024 budgetary submission for SM-6 procurement. In 2024 Raytheon are able to produce 125 per year, by 2028 they will be able to produce 300+, simply because of the now surge in demand as aerial SM-6's become a thing. This will mean more abundance of the premier interceptor missile for the navy, at a cheaper cost, distributed across more platforms.
As you can see, initial estimates of the multi-year surge in buys, without any streamlining of production YET, has already yielded a 13.6% reduction in cost. Just from the expected increase in purchases. Once the production lines get going, expect further cost reductions, as mentioned in 5). The document explicitly highlights the expected reduction in cost due to this surge in demand.
Tl;dr SM-6 acts as an antiship missile, air defense missile, that with the current expansion of capable platforms means a huge surge in production and driving costs per unit down significantly. It will be a game changer in the Pacific.