WASHINGTON — NASA space station managers hope to receive word this year on whether the orbiting outpost’s mission will be stretched beyond 2020 because an extension would require supporting investments starting as soon as 2015, a senior agency official said.

“We would like to get a policy decision this year,” Sam Scimemi, international space station (ISS) program director at NASA headquarters, told members of the NASA Advisory Council’s Human Exploration and Operations Committee. “In other words, during the [2015] budget process.”

If the decision is made this year, it could be factored into NASA’s 2015 budget request, which will be submitted to Congress as early as February.

“Within a couple of years, we have to start making contract decisions about what to buy, what not to buy,” Scimemi said. “We’re having discussions now [within NASA].”

Scimemi was not specific, but William Gerstenmaier, NASA’s top human spaceflight official, said one example is the photovoltaic panels that provide power to the orbital outpost. These panels have absorbed many hits from space debris and micrometeoroids, and would definitely need to be replaced for an extended mission, he said.

“Yeah, there’s quite a few hits to the solar panels,” Gerstenmaier told the committee. “They look like a west Texas stop sign.”

Generally speaking, NASA’s rationale for an extended ISS mission is scientific and technical research. Now that construction is complete, the U.S. agency wants to focus on making discoveries in low Earth orbit, and on using the ISS to test technology developed for crewed exploration of deep space.

But time is precious on the ISS, and crews currently use most of theirs just to maintain the facility, Scimemi said. That means NASA and its international partners will have to come up with clear research priorities for any extended mission.

As it grapples with the challenge of having the space station’s caregivers moonlight as lab techs, NASA is also hashing out the conditions for extending Boeing Co.’s massive space station support contract, which expires in October 2015. So far, NASA has paid Boeing about $17 billion under the International Space Station Vehicle Sustaining Engineering Contract, which dates back to 1993, NASA spokesman Joshua Buck said.

NASA plans to extend the contract with Houston-based Boeing Space Exploration until at least 2020, according to a July 23 notice the agency posted online.

Under the proposed extension, Boeing would continue to provide engineering and management support for the station’s U.S. segment, which includes both American modules and modules furnished by the European and Japanese space agencies. The company would be responsible for upkeep of most major ISS subsystems, and for providing international partners with common ISS hardware and software.

According to White House budget projections, the U.S. contribution to station and supporting activities will be about $4 billion a year through 2018.

Any plan NASA comes up with to operate ISS for most of the next decade will have to take into account the wishes of the agency’s international partners, especially Russia. Russia, which built the station’s core propulsion module and has more experience with long-duration, crewed space stations than any other nation, will “probably want to go beyond 2020,” Scimemi speculated at the meeting.

For Europe and Japan, the future is less certain. Japan is struggling with its own fiscal problems, and its space budget, like those of other Japanese government agencies, has been tapped to pay for ongoing cleanup efforts related to nuclear contamination caused when a tsunami struck a power plant back in 2011, Scimemi said.

Europe, meanwhile, is weighing its options.

The 20-member European Space Agency built the station’s Columbus laboratory module, and has kept ISS supplied with cargo using the Automated Transfer Vehicle. That spacecraft has made four flights since 2008 and is scheduled to make a fifth, and final, delivery to ISS in 2014. Compared with pure science missions, such as the ExoMars sample collection project the agency is conducting with Russia, ISS utilization is a low priority within the European Space Agency. However, like Japan, Europe has conducted its share of space-based research aboard ISS.

Discounting the space shuttle missions that made ISS construction possible, NASA has spent about $54.5 billion through 2012 on the program, Buck wrote in an Aug. 6 email. Tacking on shuttle costs brings the tab up to around $100 billion.