Editor's note: A previous version of this article incorrectly stated that the EFT-1 spacecraft splashed down in the Atlantic, rather than in the Pacific. The Fool regrets the error.

Two days ago, America sent a spaceship soaring to the stars -- and we didn't need a Russian rocket to do it.

At 7:05 a.m. ET, Friday, Dec. 5, United Launch Alliance (working on contract to NASA), began the EFT-1 mission, sending an Orion spacecraft built by Lockheed Martin (LMT -0.12%) into space atop a Delta IV Heavy rocket built by Boeing (BA -1.08%). (Together, Lockheed and Boeing make up two halves of the NASA contractor United Launch Alliance, aka ULA.)

NASA promo shot of EFT-1 launch; YouTube still

The EFT-1 mission was scheduled to last just under four and a half hours, and aimed to test the workings of America's first spaceship, capable of manned interplanetary flight. It also marked NASA's first step in a 20-year plan to put American astronauts on Mars sometime after 2030.

I won't keep you in suspense: The test was a success. After an initial one-day postponement from the Thursday target window, the rockets worked flawlessly in Friday's exercise. EFT-1 went up, orbited the Earth, then blasted higher, turned around, reentered Earth's atmosphere, and splashed down in the Pacific right on schedule.

NASA promo shot of EFT-1 splashdown; YouTube still

So ... does this mean that America's reliance upon Russian rockets to put astronauts into orbit (and beyond) is finally at an end?

Not yet, but soon
As you may recall, earlier this year a series of unfortunate events in Europe culminated in America imposing economic sanctions on Russia -- and Russia retaliating with a mortal threat to the U.S. space program. Unless America lifted its sanctions, Russia would cut off the supply of RD-180 rocket engines essential to ULA's ability to lift satellites into space. Simultaneously, Russia vowed to deny U.S. astronauts access to its Soyuz spacecraft -- currently the only craft capable of sending U.S. astronauts to the International Space Station.

Responding to these threats, Lockheed Martin promised to team up with an American rocket-tech company to develop a "next-generation liquid oxygen/hydrocarbon first stage" rocket engine capable of replacing the RD-180 on its Atlas V rockets. "Multiple" design contracts were signed in June, with the aim of getting a design approved this year -- and launching a prototype in 2019.

Then, in September, Lockheed announced that it has made a selection: Blue Origin, the privately held space-tech start-up owned by Amazon.com (AMZN -1.64%) founder Jeff Bezos, will develop a new liquid oxygen and liquefied natural gas (LO/LNG) "BE-4" rocket engine jointly with ULA.

Scale model of the new BE-4 engine; Blue Origin video still

Why we need the BE-4
But you may be wondering: ULA already has a rocket -- and a rocket that seems capable of carrying astronauts farther out into space than they've gone at any time since the Apollo 17moon landing of December 1972. So, why would ULA need to order a new rocket engine from Amazon at all?

The answer boils down to math ... and money. Simply put, the "Common Booster Cores" (CBC) that powered this week's EFT-1 mission are "more rocket than we need" for the workaday task of putting Pentagon and other government satellites in orbit. (That's the mission that Russia's RD-180s have been pulling as the engine powering Lockheed's Atlas V rocket).

Powered by liquid hydrogen/liquid oxygen (LH/LO) engines built by GenCorp (AJRD), each CBC produces 710,000 foot-pounds of thrust at sea level. To boost EFT-1 into space, we needed three CBCs working in tandem to produce more than 2.1 million foot-pounds of thrust. In contrast, the Russian RD-180 engine produces 860,000 foot-pounds of thrust -- not enough to launch a mission to Mars, but just about the right amount to get a big satellite into orbit.

Lockheed intends to use paired BE-4 engines to replace the RD-180. Rated at 550,000 foot-pounds of thrust each (so 1.1 million total), they will actually give the Atlas V a bit more "oomph" than the RD-180 provides -- without going vastly over mission requirements, as a pair of RS-68As would do.

How much is this going to cost us?
Cost is another issue. At an estimated price of $14 million to $20 million per engine, the RS-68A used in a CBC could cost as much as twice the $10 millionprice on an RD-180 engine. And if ULA has to buy two CBCs to carry a payload that one RD-180 could handle, the economics look even worse.

BE-4 will probably be a less expensive option. Neither Lockheed nor Blue Origin have stated a price for BE-4 yet, saying only that the new engine will feature "dramatically lower cost" than ... something else. But we can make an educated guess at that cost.

Consider: One of the engines that was competing with BE-4, GenCorp's AR-1, was estimated to cost $10 million to $12.5 million per engine. Now, if Lockheed chose the BE-4 from start-up Blue Origin, over the AR-1 from a proven engine maker like GenCorp, it's likely that price was an important factor. This suggests that BE-4 probably costs no more than $10 million -- and may even cost less. (At least, once you exclude the estimated $1.5 billion development cost.)

Granted, it will still take two BE-4 engines to match the thrust capability of one RD-180 -- so call it $20 million for a pair of BE-4s, versus $10 million for a single RD-180. But even if paired BE-4s cost more than single RD-180s, it may be worth the price to ensure that Russia can't shut off ULA's supply of rocket engines on a whim.

Russia's RD-180 rocket engine is one powerful piece of machinery -- if you can get your hands on one. Photo: Wikimedia Commons

What it means for investors
Investors in Lockheed Martin and Boeing should be pleased that ULA is moving so quickly to end its reliance on Russian rocket engines. Investors in two other companies, though -- GenCorp and SpaceX -- may be less than thrilled.

GenCorp shareholders must certainly be disappointed that ULA tapped Blue Origin to build its next generation of low Earth orbit launch engines. GenCorp can (and will) still do good business selling its other rocket engines to ULA, however, which should soften the blow. From the perspective of SpaceX's private backers, meanwhile -- and for investors who hope to own a piece of SpaceX whenever it goes public -- ULA's alliance poses a real competitive threat.

On the one hand, switching from Russia's RD-180 engine to Blue Origin's BE-4 eliminates one of Elon Musk's strongest arguments against the Pentagon continuing to give the bulk of its space launch work to ULA. At the same time, ULA's teaming up with a low-cost, innovative space start-up to help it keep its own costs down steals some of the thunder from Musk's argument that SpaceX is the low-cost, innovative alternative in space exploration. Throw in the fact that Blue Origin, like SpaceX, boasts a private tech-billionaire owner, and you could say Blue Origin is almost the mirror image of SpaceX.

One thing's for certain: The space race got a whole lot more interesting when ULA teamed up with Blue Origin -- and for us peeking in from the outside, a whole lot more fun to watch.

SpaceX's Grasshopper experimental reusable rocketship -- no longer the newest (or the coolest?) kid on the space block. Photo: SpaceX