Everything You Need to Know About NASA's Space Taxi Announcement

Three years from now, NASA astronauts will fly into space on capsules and rockets built by American companies, ending a hitchhiking partnership with Russia that started in 2011. NASA will announce the winner or winners of its space taxi competition this afternoon.

Washington has become increasingly eager to end NASA's $70-million-a-trip astronaut rides on Russian Soyuz capsules, and a trio of companies have submitted unique bids to get Americans to the International Space Station. Early reports indicate Boeing and SpaceX have won multibillion-dollar NASA contracts to build space taxis, with Boeing earning the larger share of the work.

NASA has relied on Russia to reach ISS since the agency closed the space shuttle program in 2011.

Boeing's CST-100 and SpaceX's Dragon are both seven-passenger capsules that can also be fitted to carry cargo. A non-crewed version of Dragon has already delivered cargo to ISS.

Boeing's program is reported to be further along in its development goals.

Perhaps most interesting is Boeing's pending Wednesday announcement, one that is speculatedto revolve around a new American-made engine. That engine would be built in partnership with Amazon founder Jeff Bezos' secretive Blue Origin company. At present, Boeing launches its Atlas V rockets with Russian-made engines, which SpaceX and other rivals contend could threaten the supply chain if tensions with Russia escalate.

Even without an engine supply cutoff, many elected officials are becoming increasingly wary about sending more money to a country with which our relationship is tenuous at best. Announcing a new, American-made engine to power its Atlas V rockets could insulate Boeing—and its government partners—from criticism over funding a rival power.

One NASA official, speaking on condition of anonymity, said the agency had not been briefed on Boeing's engine plans, nor had they played into NASA's contract decision. "If they were to make an announcement about rocket development, that would certainly impact us, but we would have to go through a process [before] we decide to actually decide to buy their rocket," the official said. "Blue Origin is the best at keeping secrets. They're pretty remarkable. I don't blame them for not telling us."

The official also declined to confirm reports about NASA's contract awards but indicated a contract split among multiple companies—as some outlets have indicated will be the case—could be advantageous. "The safety of the astronauts is No. 1, paramount," she said. "But how do we best dole out the money Congress has given us for this commercial crew program to ensure redundancy? If we only have one provider, then we're back to the same situation we had with the shuttle, which is only a single way to get to space."

Still, the official said, NASA is subject to the whims of congressional budget writers (many in Congress believe NASA should choose just a single provider as a cost-saving measure), and it will be closely watching the continuing resolution and budget battles on Capitol Hill as it moves forward with its plans.

It's possible cuts could even extend NASA's reliance on Russian launches. "We've set a goal to get these [U.S.] launches done by 2017," the official said. "But that's with the existing budget. If something changes wildly with NASA's budget, that will impact launch schedules."

Some House Republicans have expressed displeasure with the Obama administration's focus on Earth science—a category that would include most space station operations—at the expense of planetary science funding.

NASA is also pressing forward with Orion, a deep-space vehicle built by Lockheed Martin that one day could take astronauts to Mars.

Meanwhile, the commercial competitors are touting their potential as they continue to vie for the government's money. SpaceX claims to be the most cost-effective; it has told the Air Force it could save hundreds of millions per launch over its current rocket provider, a Boeing-Lockheed conglomerate. It's also developing a self-landing, reusable rocket, which could further reduce costs.

Boeing likes to point to its track record of success—its joint venture with Lockheed for the Pentagon has achieved nearly 100 consecutive successful launches. Some believe that NASA has determined Boeing is indeed the most reliable option.

A third competitor, Sierra Nevada, has its own unique proposal, a winged vehicle that can touch down on a runway.

SpaceX and Sierra Nevada have said they will continue development with or without a NASA contract, partnering with other international agencies or private ventures. Boeing hasn't revealed its plans should it lose out, but the company has acknowledged the difficulty of financing the project without NASA dollars.

Boeing did not return a request for comment; SpaceX declined to comment.