Featured image credit: William Black. https://www.deviantart.com/william-black

There are more natural resources on asteroids than have ever been mined in the history of the Earth.

– Dr. Neil deGrasse Tyson

A portmanteau of robotic astronauts, the primary purpose of these cards is to prospect and claim a site. They are also one of the two required cards to build a factory. Finally, robonauts can refuel your rocket if the site is wet enough for its equipment to extract the necessary fuel.

In our last post, recall that what gives “Thrusters” the ability to move rocket stacks isn’t because the card is a “Thruster” type, but the fact that it has the thruster icon with the necessary stats showing how to operate it. Crew cards can also act like thrusters because they possess the same icon (and as we’ll see some robonauts also have the icon and stats indicating they can be used in this fashion too!). Similarly, what gives robonauts prospecting and refueling capabilities isn’t the card type but rather the ISRU rectangle graphic with the value indicating how good it is and an icon indicating the type of ISRU capability. If you check crew cards, they also possess the graphic. In fact, a few crew cards have two such symbols instead of one! Just like all thruster cards have thruster icons with stats, all robonaut cards have ISRU icons and values.

Now let’s talk about the different kinds of ISRU types. In my initial post, I glossed over the fact that these ISRU capabilities exist in three different forms. They all do the same thing but each one has its own special advantages that make certain targets more attractive than others. Let us recall the procedures for prospecting and refueling:

1) Prospecting: pick a card with an ISRU capability. It’s value must be equal to or less than the number of water drops on a site. Roll one six sided die, if the result is less than or equal to the site size then you are successful. If not, then the site is “busted” and can no longer be claimed by anyone. This means sites of size 6 or higher will always be successful and you don’t need to roll for them.

2) Site Refueling: pick a card with an ISRU capability. Add to your rocket tanks of fuel equal to 1 plus the number of water drops on the site minus the ISRU value of the card. Example: you have a card with ISRU 2 on the site of Deimos which has 3 water drops. For a site refueling operation you would 1 + 3 (water drops) – 2 (ISRU) for a total of 2 tanks of fuel. In practical terms this means that in order to add at least one tank of fuel your ISRU value must be equal to or lower than the number of water drops on the site which is exactly the same requirement as prospecting. The only difference is that you can refuel even if the site has been busted and can’t be claimed.

The Missile Robots

With that in mind, let’s see what the icons mean. First up is the “Missile” robonaut, which appropriately enough, has a missile graphic. All of these cards also have a thruster icon which is not a coincidence; all missiles have thrusters. These robonauts can perform the dual function of prospecting operations and pushing the rocket stack. Two for the price of one! That’s this type’s primary advantage. You will find that, generally speaking, they are not terribly efficient in fuel consumption and tend to have average ISRU values.

HF Missile Robonauts
Thruster cards? Where we’re going, we don’t need Thruster cards!

The robonaut deck comes with four of these basic white side missile robonauts. The Kuck Mosquito is a 10 thrust 8 fuel efficiency ISRU 3 card (see above) that used to be a go-to robonaut in previous editions for the Japanese Shimizu (Orange) or United Nations (Purple) factions; their crew cards didn’t have a thruster capability that the other three factions naturally possessed. On the plus side their cards were also mass 0. In the third edition all crew cards have thrusters and are mass 1 so the mosquito has been devalued somewhat, though the same old factions may still have use for it since it still has higher thrust than their crew. Its black side is the Ablative Laser. It has 3 thrust, a fuel efficiency of 1, it’s solar powered with an ISRU of 1. This is OK, but there are better thruster cards. Again, the two for one aspect comes into play and the mosquito is very light and the laser has negligible mass.

The Tungesten Resistojet and MET Steamer are very similar basic cards. They both have thrust 5 and poor fuel efficiency of 4. They vary in mass (2 and 3 respectively) and ISRU (3 and 2 respectively). One key difference is their black sides. The jet’s advanced technology is the MITEE Arcjet (yes, I pronounce that as “Mighty” and you should too!) with better ISRU, better fuel efficiency, the same mass but at the cost of slightly less thrust. The steamer’s advanced tech is actually a buggy robonaut (see next section), the nanobot. Always keep in mind when bidding on all robonauts to check the black side. Just because the white side is one particular type doesn’t mean the black side will remain the same type.

The 3rd edition added the Nuclear Drill missile robonaut which is very similar to the jet except its black side becomes a dirt based thruster and it adds Ray Gun capability giving it two types! This benefit comes at some cost because the thruster characteristics remain the same (except no afterburn) and the mass INCREASES. As with everything in High Frontier, there are trade offs involved with each decision you make or card you decide to use and produce.

The Wheeled Robots

We are the only country with an operating rover on Mars. We are an amazing country on tech.

– Megan Smith

The second type is the “Buggy” robonaut, which has a wheeled vehicle for an icon. This card type may not have a thruster but possesses two attractive advantages. The first one is that if you fail your prospecting roll you get a re-roll. This greatly increases the chances of a successful claim in smaller sites like Hertha which is a size 3 world. The second is that if you land on a large, multi-site planet (like Mars, the Moon, Mercury, Titan, Ganymede, etc) you are allowed to prospect not just the site the buggy is on but also all the sites along the yellow dotted lines that connect the planet.

HF Yellow Connections
Follow the Yellow Brick Road!

Some crew cards include a buggy already (but at ISRU 4). This means that if you decide on a comet strategy and you have the right crew you only need a robonaut for industralization not prospecting. In summary, these robonauts are good for multi-site worlds, primarily Mars but the Moon, Mercury and the Galilean Moons also qualify. The re-roll capability works with any site so it’s useful for landing on the smaller size (1-4) worlds to greatly enhance your chances of a successful claim.

HF Buggy Robots
Like the curiosity rover, but on steroids!

The deck has three such buggy robonauts (other than cards that can be produced as buggies on their black side). The Cat Fusion Z-Pinch Torch, Rock Splitter (added for the 3rd Edition) and the Flywheel Tractor. The cat has better ISRU and the black side is an ISRU 0 missile robonaut called the H-B Cat Inertial which has fantastic (fractional) fuel efficiency but only modest thrust. The tractor’s advanced tech is an ISRU 0 buggy called an Electrophoretic Sandworm, it’s a lighter and much more capable version of the tractor. The splitter is underwhelming since it’s no better than a crew buggy (and more massive to boot!). It’s advanced tech is an interesting Mag Beam which is both missile and ray gun. The prospecting capability is still pretty average though it has a very efficient if feeble solar powered thruster. Any of them will help with a buggy-centric strategy, though the cat is noticeably more massive.

Lasers…IN SPACE!

The key to this plan is the giant “laser”. It was invented by the noted Cambridge physicist Dr. Parsons. Therefore, we shall call it: the Alan Parsons Project.

– Dr. Evil

HF Free Electron Laser
Giant Laser. Check the astronaut graphic on the card for scale

The last type is the “Ray-Gun” robonaut. It has the ability to prospect a site from an adjacent space. I mean, you can land and prospect on a site like any other regular robonaut but in the case of the moon for example you can just prospect without having to brave its punishing gravity. To understand how this works you have to grok the game’s concept of ADJACENCY. It’s defined such that your stack is adjacent to another space if it can reach it along a line that doesn’t go through an intersection, another empty L-point, a Burn space or to a site with an atmosphere (so you can’t prospect Mars from orbit with a laser, to give one example).

HF Simple Adjacency
Simple Adjacency: From the HEO space depicted you can use a ray-gun to prospect Lutetita. Similarly, sitting on the intersection next to Fortuna allows you to prospect it.

One additional benefit: you are not limited to a single site, if your space is adjacent to multiple sites this allows you to prospect several of them with just one operation. But you must roll for each site.

HF Multi-site Adjacency
From the L-spot circle (high inclination retrograde) you can ray-gun prospect all the moonlets and Phoebe!

Note that lander burns and hazards (whether with or without burns) are exempt as obstacles to adjacency rules. This is because those spaces aren’t “real” orbits but navigational challenges for your rocket ship and don’t count, they are illustrated as spaces to keep the mechanics of rocket movement a little simpler.

HF Crash Hazard Adjacency.png
Top Left: you can prospect YORP from either L-spot empty circle. Top Right: You can sit on either intersection and prospect Mathilde. Bottom: You can use a ray gun to prospect Comet Holmes sitting on the first burn spot from the left; neither of the crash hazards prevent adjacency. Similarly, you can prospect Elatus from the “elbow” corner with a ray-gun.

Do note that the yellow slash lines that connect multiple sites on a planet are NOT adjacent for the purposes of laser prospecting since the connecting space is beyond the horizon of the site (all such locations are large spherical moons or planets, in many cases with atmospheres).

The “Ray Gun” robonaut is fairly common in the deck and they tend to have good ISRU values but also lean on the massive side. Three of them are mass 5: the Solar-pumped MHD Exciplex Laser, Neutral Beam and Free Electron Laser. The first two have ISRU 2 while the last one has ISRU 1 making it the best white card prospector in the game. The Explosive Gas Dynamic Laser has a lower mass (3) with good ISRU value (2). The 3rd edition introduced the Phase Locked Diode Laser which has similar mass but average ISRU (3). Two of these robonauts (the Neutral Beam and F.E.L) have black side technologies that are missile robots, with modest thrust values but good fuel efficiency. The other three are still ray-gun robonauts with better mass or ISRU (or both).

The primary advantage of using a ray-gun is not having to land on a site to prospect, which gives you more flexibility to go and stake your claim early, avoiding some navigational hazards or prodigious fuel consumption from the safety of orbit. You can figure out the landing later. Another is the ability to hit multiple targets at the same time within the same asteroid families. One famous example is the Koronis family of asteroids, with an ISRU 0 robonaut there is a spot that allows to attempt prospecting on ten (10!) different targets with just one operation.

HF Koronis Family.png
The Koronis family of asteroids. The green blob marks the spot from where you can prospect the entire family of rocks. Assuming your ray-gun robonaut is ISRU 0 of course.

Picking what type of robonaut to auction and acquire has similar decisions to that of thruster cards. Are you going to go comet hunting? Are you landing on big worlds? Are you focusing on small asteroid groups? Do you already have a thruster card? Or perhaps you’re going to use a missile robot and save yourself a card? You may have a target in mind and you want to try for a specific card. Other times you see what comes up and choose your target based on what you would do with the card. It may be more important to get off the ground and claim real estate sooner than pass and cycle through the deck finding the card you want. Flexibility to adapt current available technologies with your plans is key to executing your strategy.

In the next post we’ll take a quick look at refineries, industrial production and revisit a little of all of them (thrusters and robonauts) to see how the letters impact strategy while looking at ways to achieve synergy with different card combinations.


Featured image credit: William Black. https://william-black.deviantart.com/