Rockets of Today

RS1 — USA, 2022?

ABL Space Systems is working on a rocket quite similar to the Firefly Alpha, with two — no, three — no, nine — kerosene engines on the booster, and a tiny one on the upper stage. It aimed to carry 0.6 — no, 1.2 tons, which is on the high side for a smallsat launcher, but if someone has a sat that size, it gives them a spot in the market with no competition from the existing smallsat companies. They raised that goal to 1.35 tons once their engine performed better than planned. They quote a flat price per launch of $12 million, which is not that low compared to some of the other outfits. Rocket Labs sells Electron launches for significantly less, and Astra is promising they will dramatically undercut the Electron’s price. And heck, there’s a Russian/Spanish company called SpaceDarts which, if they can be believed, might someday be able to put something tiny in orbit for under $50,000 if you buy in bulk. Of course, they all have lower capacity.

(The real threat they should probably worry about is the list of companies working toward a rocket that is both small and reusable. Several European and Asian groups are pushing in that direction.)

Like many other smallsat companies, they are trying to leverage 3D printing to make an expendable rocket engine cheaply. But they use it only for selected components, such as the combustion chamber; for a lot of parts, they stick to copying designs already known to work dependably. Their whole philosophy is that innovation means nothing unless you know it will work, so proven reliability trumps all other goals. The rocket body is traditional aluminum — no carbon fiber here.

They thought they could develop a new rocket faster than other companies, but we’ve heard that before... in the end, they had to repeatedly revise their plans. At first they were contracting to buy staged-combustion engines from another company, then they switched to making in-house gas generator engine, then they changed the tank diameter, then they gave up on their first stage engine and just dotted the bottom of the booster with nine second stage engines, as that was the only one they’d got working.

Like several other American builders of small rockets, they are trying to fulfill the Pentagon’s desire for a launcher which can be deployed very quickly. They plan to launch it from a heavy truck, like a Chinese ICBM — no wait, now they say that what they’ll use is a portable mount that can be delivered in a shipping container and set down on a paved surface. They have given this portable pad the unfortunate name of the Launch Stool.

Their long term plan is to so thoroughly automate the launch process that no live human being needs to be present at the site; someone can just push a button remotely and up it goes. They’re getting some Air Force Space Force money to pursue that goal. The Pentagon wants this to be doable from “austere” locations — like maybe they’re thinking of camouflaging the truck and keeping the launch site hidden.

One aspect of this cost-cutting portable approach is that they want to use cheap jet fuel, which is available everywhere, instead of RP-1 kerosene. This may get them in trouble, as jet fuel can have contaminants that react with metals in the engine, or long-chain impurities that congeal into gunk in small passages. Issues like these are why a lot of companies are looking to cleaner fuels like methane and propane, despite their lower density and higher risk of explosions. But South Korea’s Nuri is a rocket that got away with using jet fuel.

ABL's founders are former SpaceX engineers, notably Harry O’Hanley and Dan Piedmont, who are now CEO and CFO. The whole company is full of industry insiders and veterans. And in 2021 they somehow sold Lockheed on a deal in which the larger company would hire them for dozens of launches. Nice work if you can get it, and quite a vote of confidence in a rocket that was far from ready at the time. They’ve raised quite a lot of capital without going at all public.

But so far they aren’t showing us any reason to be more confident in them than in any of their main competitors. For a long time their maiden launch was perpetually just a few months away, and when they finally got it down to weeks, their second stage had a “hard start” and blew up on the test stand. So we’re still waiting.

RS1: mass unknown, diam 1.8 m, thrust 560 kN, imp unknown, type Gk, payload 1.35 t, cost hopefully $9M/t.