With political tensions between the United States and Russia running high, both the U.S. government and the American spaceflight industry want to reduce their reliance on the Russian rocket engines that power a number of American private and military space launch vehicles. But even as Congress considers banning Russian launch technology from U.S. military satellite launches, Orbital Sciences’ search for a new rocket engine following a spectacular late-October rocket explosion demonstrates just how difficult it’s been for American space launch companies to wean themselves off of Russian rocket hardware—or to field new, American-made replacements.

If you’re not familiar with Orbital Sciences ORB , it’s the less-flashy competitor to Elon Musk’s SpaceX. Orbital has long track record in the spaceflight industry, and alongside SpaceX its Antares rockets and Cygnus spacecraft serve as NASA’s only homegrown means of resupplying the International Space Station. Orbital was attempting to make one of its NASA-contracted runs to the ISS on October 28 when one of the refurbished Soviet-era AJ26 engines malfunctioned just seconds after liftoff, bringing the rocket and cargo down in a magnificent fireball.

With pressure already mounting to move away from Russian rocket hardware, Orbital announced a week later that it would stop using the AJ26 engine. But just how it will replace it and get back to launching is anybody’s guess. Orbital would like to end its reliance on Russian rocket engines. But with contract obligations to NASA and no obvious replacement option on the market, the company may not have any choice.

“These are complicated, absolutely cutting edge pieces of equipment,” says Jonathan Beland, a senior analysts at Avascent Group, D.C.-based consultancy serving the aerospace and defense industries. “You can’t just go down to the corner store and pick one up, the timeline for development is several years.”

That’s a problem for a domestic rocket engine industry that is dominated by two non-competitive companies: Aerojet Rocketdyne, which produces liquid-fueled rocket engines, and Alliant Techsystems ATK , whose expertise lies in solid-fuel rockets. Both companies, especially the former, serve government clients that tend to push up the price of hardware beyond what the private space industry wants to pay.

Likewise for United Launch Alliance, a collaboration between Boeing BA and Lockheed Martin LMT that has a virtual monopoly on U.S. national security launches. In an effort to wean itself off of Russian built RD-180 engines, ULA is in the process of developing a new home-grown rocket engine alongside Blue Origin, the commercial spaceflight company started by Amazon CEO Jeff Bezos, but that engine won’t be available until at least 2019.

Orbital’s problem is more acute. To keep its obligations to NASA, Orbital needs a new rocket engine, one that’s built to the proper specifications, readily available, and—perhaps most importantly—affordable. To maintain its schedule the company has indicated it intends to launch its Cygnus spacecraft on another launch vehicle, perhaps atop one of competitor SpaceX’s Falcon 9 rockets, until it can fly on its own again in 2016—ideally with a new, non-Russian engine.

“I don’t see how Orbital, given all the negative publicity around Russian engines, could go with another Russian engine,” says Marco Caceres, space industry analyst for aerospace and defense consultancy Teal Group. “How could the CEO explain another accident to shareholders? I think you have to go with a red, white, and blue company.”

But finding that company could prove daunting. Aerojet Rocketdyne’s existing production line produces powerful engines for the Delta IV and NASA’s new super-heavy-lifting Space Launch System—likely too much engine for Orbital’s medium-sized Antares rocket, Caceres says. Orbital could ask Aerojet Rocketdyne to redesign something more in tune with its needs, but that requires time and money. Or it could try to buy some engines from SpaceX, which makes its own propulsion systems, though it’s certainly not clear SpaceX would have the engines to spare. (Each Falcon 9 flight requires 10 of SpaceX’s Merlin engines.)

Orbital does have a safety valve in this situation. A merger with ATK agreed to earlier this year and blessed by the Department of Justice last week could allow Orbital to take advantage of its new partner’s solid-fuel rocket technology, Caceres says. “If they do that, they’d get a fairly reliable, powerful engine from the company they are merging with,” he says. “It would be cheaper than anything they can buy, they would immediately have a vertically integrated vehicle, which would make them more competitive with their primary competitor, SpaceX. And ATK has them ready to go.”

But it’s not clear if Orbital will go that route, as ATK’s expertise in solid fuel rockets doesn’t necessarily dovetail with Orbital’s Antares rocket, which would ideally employ liquid-fueled propulsion. (Among many key differences between the technologies: liquid-fueled engines allow for adjustable throttling during flight, whereas solid-fuel engines do not.)

If Orbital can’t look to an American rocket manufacturer, and it can’t look to Europe—“There’s nothing the Europeans do that’s remotely affordable,” Caceres says. “It’s a jobs program”—there is a country out there that will happily deal in inexpensive rocket engines. In fact, that country has the right liquid-fueled engines for the job, and it has them now.

That country is Russia.

In fact, in the wake of Orbital’s October launch incident, Russian media reported that Orbital would power future Antares rockets not with the failed AJ26, but with the RD-193 produced by Russian spaceflight tech firm Energomash. But while it’s true that Orbital had opted to buy the RD-193 for future Antares missions before the accident, the company has not said if it will go forward with the deal. Those Russian media reports may have been an attempt to push Orbital to make good on the deal. Given the U.S. market for rocket engines, Orbital may not have much of a choice anyhow.

“It comes down to: What are your options?” says Carissa Christensen, managing partner at Alexandria, Va.-based space and technology research firm Tauri Group. “If you can get a Russian engine cheap, and your other option is to wait years and spend hundreds of millions of dollars, maybe that’s what you do. It’s going to be a hard call.”

The takeaway, especially in light of SpaceX’s success, might be “vertically integrate or die,” though its technology is far from legacy; a mishap with its Falcon 9 rocket or Merlin engine would put America’s private spaceflight industry in a serious bind, underscoring the industry’s lack of options where rocket engines are concerned. Don’t expect another U.S. aerospace giant to jump into the saturated rocket engine market in the near-term—though as the private spaceflight industry continues its upward trend, that could change.

“I don’t see the market growing strongly enough in the next few years to spur new entrants into the market,” Avascent’s Beland says. “But in the long term? I can’t say anything about that. The space industry has bucked too many long-term trends over the decades.”