Terraformers at max difficulty is hard enough as it is, but here we’ll go into the specifics of the scenario Per Aspera Ad Astra and Settling Sol. The twist is here, terraforming is only for your survival, because the real way you will make points towards achieving victory is by completing space projects. And more specifically with Settling Sol, you *absolutely* have to complete Extra Martian Missions, and those are few and far between. So you have to have an excellent strategey to even consider getting to the end of this harrowing scenario. Settling Sol especially took me a humongous amount of time to figure out and lots of different tries before I could actually win it.

Also, the harsh truth is that not every game can be a winning one. Even when doing the very best at everything you’re given, it’s still majorly driven by luck, so don’t despair if you lose a few. I’ve lost way more than I’ve won, and that’s simply because you can’t control everything.

Here’s a quick summary of what I’ll be addressing:
Early game: prioritize Power, Titanium Tritium. Have a production of everything ASAP.
Mid-game: Look out for Tech/Building/Leader combos, don’t overlook passive bonuses, terraform, explore as much as you can, and expand your Trade Routes.
Late-game: Optimizing and Efficiency is the key to keep up against the clock.

This is where you set your course for the entire game, so the way your early game unfolds will have an impact until the end, and I can usually tell within the first 10 turns if I have a chance at winning or not. Having a chance doesn’t automatically guarantee a win, but you at least have a fighting chance. You should absolutely prioritize finding Titanium and Tritium from the very start. Those are the two resources that will get you running early on. Titanium for Robots and mining and Tritium for Power. There’s a reason there are so many Tritium Thermo-Generators in the first 10 turns! That’s a BIG hint that it’s one of the most efficient ways of generating Power. I usually set up my first city with 3-4 Thermo-Generators with a Resonance Station (22 Silicates) in the middle, connecting to all of them. This creates a nice flow of Power that you can then use for Robots, mining, exploration and space projects. Power is needed in all kinds of contexts, so it’s almost impossible to have too much of it, especially at the start. By the 10th turn, at the very minimum have a production income of +10 total (for instance +2 Food, +2 Tritium, +2 Titanium, +1 Nitrate +3 Power). Water is of course also important for eventually settling, but in the early turns, you can get 10 easily with exploration, so if you have to choose, I would go for Power first of all. Same with Food. They often drop +10 Food 2-3 times, which helps settle your second city. I do this typically around the 10th turn, to get the extra Resources I'll be missing. The other reason to not focus too much on food and water at first is that you can always expand with robots. Those save you a lot of time and help you develop other useful resources like Nitrates and Silicates that come in handy for Science and Terraforming goal projects.

Also, beware of going for the larger mines right at the start. They are good once you have them, but sometimes the amount of resources they require versus the ones you can manage isn’t worth it. Those are likely to make you stall just a bit too much to be comfortable enough for what comes next. Better to start modestly and build on that than have nothing for 5 turns and have to catch up with a bunch of lost projects and other crises that may happen at any time. I usually start with the smaller version and add a second one a few turns later. Again, robots and bus stations and the like are really your allies here. Once your base production is kicked off, that will help you get the ball rolling for mid-game. Be wary of any lulls between the 10th and 20th turns. I try to avoid them at all costs, because they can be very detrimental in the longer run. To win U++++, you absolutely have to do the most you can with the little resources you have because by the 20th turn, Expectations and Sandstorms or Marsquakes will really start to hit you hard and you need to be prepared to withstand all of it.

You will also have your first Extra Martian Exploration Missions early in the game. My favorites to start with are probably Ceres, Europa and Jupiter, because Ceres really helps especially in the beginning when you need as much Titatnium as you can get, Europa boosts your oceans quickly thus helping with the spreading of vegetation and Jupiter boosts Atmosphere and later on offers radiation protection, which is nice once you have a few cities up. This said, don’t be afraid of settling Venus: the heat bonus—especially when you’re not getting heat projects or methanogenium quickly enough—can be very beneficial even with the negative support. The key here is to not have those Missions parallel to your survival on Mars, but actually supporting it. They are fairly rare to come by, so you have to make them work with your general strategy. Do they supplement a Resource you’re low on? Do they help with another Body’s Resource Shortage? Will they eventually help with a Terraforming building? Will they support boosting Mines or Power? etc etc. It’s inevitably going to be a lot of math and calculations.

Once you have your foundations up, pay good attention to the helpful buildings, techs and leaders that you will have to choose from. Techs can make a huge difference here. For instance, a combination I have found to be extremely life-saving is Research & Development Centers and Reverse Engineering. These are one of the most useful “bonus” buildings, because they both produce more Projects to research and give you more slots to hold them. Keeping in mind this game is also very dependent on luck, the more projects you can be offered and hold, the better your stats. Throw in Reverse Engineering in there, when you have an excess of projects you don’t need, sell them off for support and that may just buy you enough time to make it to the finish line.

It goes without saying that you *have* to terraform whilst you’re doing all this, and that’s the whole challenge. You’re not only trying to survive on this planet, you have to also expand to space in every single way you can. But if you want to have a fighting chance against the clock, you have no choice but to terraform, to mitigate Sandstorms and to maintain Mars Enthusiasm. It’s easy to overlook when trying so hard to get everything up but don’t forget this will reduce if you don’t settle more cities. The more you keep it up, the less likely you will have nasty expectations hitting you hard and fast. Settling cities also has the added bonus of reducing the Exploration cost. It’s a really pivotal investment in the game! Having a good few Rover Exploration Centers comes in really handy as well, both when you’re running out of Power and are going for complemenging Resources, as well as when you’re going for the Leader’s specialized skill (ex. Henry Carnegie who quickly raises your Heat and Atmosphere).

Specific leaders can also come in useful if only for their passive bonuses, such as Stanislaw Bialkowski who has a passive of increasing your support per new Celestial Body developed to Outpost, but also will give you free Exploration Missions and even settle a new city for extremely cheap. Another is Nailya Bolatbek who will add a Trade Route for every 3 you create. Tatiana Jirasek gives you free Observatories, which will undoubtedly come in handy for support, science and enough Exploration mission projects for you to win. For Settling Sol, an interesting one is Harry Leclerc, who helps with Resource shortages on different Celesital Bodies. In this particular scenario, having a lot of trade routes pays off, because when you sell Resources (via Earth trade routes) that correspond to whatever the Celestial Body is missing, if you hit the number, you get a free upgrade. Those upgrades never come easy and they are usually at high cost, so Harry Leclerc coming in and reducing the required numbers by 15 for ALL of them is actually not negligible. You need to be in a comfortable spot with the required resources for this to work, though. For instance, if Mercury needs 30 Silicates and you have the choice between settling Io, which gives +1 Silicate per turn and Saturn wit +6 Support per turn, choose Io. You can pile up your Silicates and then send some back to Mercury, and so on.

Moreover, Mid-game is definitely where you should focus on expanding your Trade, because this is where the rhythm accelerates quite a bit. You need to keep up the pace and be able to, at the same time as having a healthy production of everything, complete space projects quickly. Some of them (ex. Deimos Moon-City) will use more resources, but then give you way more points to your total in Per Aspera ad Astra, although doesn’t really translate well in Settling Sol. The choice of projects depends on 4 things:

• the Resources you have available and can produce
  
• the number of Trade Routes you have
  
• how many Space Projects you can choose from, and
  
• how much space you have in your Space Projects slots.

I also will often use Trade Routes to compensate for Production and calibrate what I need. Sometimes this kind of tweaking is what makes the difference between a winning and a losing game. Always be on the lookout for how to optimize your resources and efficiency. U++++ is definitely all about efficiency.
All techs like Urban Planning (free expansion in every new city) or Smart Electrical Grid (knocks 20% off cost of Regional Buildings, especially with Jorge Dromedo, will make building a lot more comfortable), or Improved Aerogel Manufacturer (+1 Support per resource transported) Or Interplanetary Shipping Database (+1 Trade Route per new Celestial Body developed to Outpost, especially handy for the Settling Sol scenario) can help you go a long way.
Do not sleep on Observatories! You need Space Projects, so increase your chances of getting them any way you can. You need to do as many as you can ASAP. And the Extra-Martial Development Center is a MUST have if it shows up in your projects, again in Settling Sol.

On the ground, explore as much as you can. How I usually choose my spots is I go for the ones that give you support first, not only because they give you support, but because they also reveal where you can settle cities, so you can strategize your mapping quickly whilst buying time to withstand the rising expectations. Of course always follow the direction of the Resources you need! Often there will be a bunch in one area and it’ll turn out that you need a lot of it for a particular Project. Go for it! Anything for efficiency.

Don’t worry too much about things like the mafia or Marsolympics. The resources they will take you to manage versus the compromise they’ll ask you to make usually aren’t worth it. Focus on your task at hand rather than letting yourself be distracted by these random events. You don’t have time to spare. Sometimes, as well, when there are events such as Sandstorms or Marsquakes, it can be worth not using all of your resources right away to fix the problem, and instead wait a few turns so it’s cheaper. There is loss of support yes, but if that means you can accelerate your expansion, it shouldn’t go overlooked.

This is the make or break phase. By this point, there is no surviving if you haven’t got the ball rolling in mid-game, and it’s absolutely crucial that you keep your eye on the prize at all times here. Expectations will be ruthless and you have to be efficient enough to know exactly how you will reach your goal before your people revolt! At this point, you should have a healthy production of all Resources, and a steady flow of Space Projects running. At this point, because I usually have already installed a few Research & Development Centers, I sell a lot of my extra projects and focus on optimizing everything I already have. I keep a close eye on my Trade Routes, and I’ll usually have an excess of some resource, often Science or Food. In these cases, I’ll convert them to other resources, always to further my goal and complete the Space Projects as early as it will let me. Settling Sol always ends up using more turns (60+) because of how rare the Extra Martian Space Missions tend to be. So it's crucial to keep your support up until you finish all of them. I like to convert my Mars Enthusiasm to Support by settling new cities by the end when I have food to spare, even if I'm not really going to use the cities. It also helps with maximizing exploration.

Hopefully this quick strategy guide helps you for the specific scenario of Per Aspera Ad Astra. Don’t hesitate to comment if you have other tips or if you’ve found some way to go about it that could complement what I’m saying!