WASHINGTON — As pressure builds on the US Air Force to keep the beloved A-10 alive despite crushing budget cuts, the service is taking another look at the future of close-air support (CAS) and the most effective way to protect soldiers on the ground.

The conversation pits the cash-strapped Air Force and those who see the A-10 as outdated against members of Congress who are concerned the service's plan to retire the plane without a focused replacement endangers soldiers on the ground. The Air Force claims retiring the A-10, the service's primary close-in attack aircraft, could save $4.2 billion over the next five years. Defenders of the program accuse the Air Force of abandoning troops in ground combat.

Facing widespread uproar, the Air Force has recently hinted that a future single-mission CAS platform is in the works. In the most recent indication the service is embarking on further study of the issue, the US Air Combat Command's 2015 command strategy calls for "exploring opportunities" for developing a CAS aircraft.

"We must also continue to develop a balanced close air support (CAS) capability across all [Global Precision Attack] platforms, explore opportunities for a future CAS platform, and enact specific initiatives to ensure we maintain a CAS culture," according to the document, unveiled Aug. 10.

Top service officials have also suggested the Air Force is at least beginning to think about an A-10 replacement, often dubbed A-X. When asked about the notional aircraft at the Air Force Association Air Warfare symposium in February, ACC Commander Gen. Hawk Carlisle told reporters: "We're thinking about it."

"Another weapons system program may be something we need to consider as we look at the gaps and seams in the future and what we're doing," Carlisle said. "We're looking at all of that."

Meanwhile, the Air Force hosted a joint-service summit in March to work out options for the CAS mission.

As the Air Force looks to develop a future CAS platform — or platforms — analysts say the service must keep in mind that the mission has changed drastically since the A-10 was developed in the 1970s. Today, the Air Force can perform CAS with bombers and fighter jets like the F-35, which uses advanced sensor technology to improve the pilot's situational awareness. UAVs like the MQ-1 Predator and MQ-9 Reaper can also supplement the mission while keeping pilots out of danger.

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"Close-air support in an era of precision munitions and all of that is radically different than when any close-air support aircraft developed," Doug Birkey, executive director at the Washington-based Mitchell Institute for Aerospace Studies, said . "The key to any of these things is knowing what to hit and when, and if you don't have that data, then you're just floating around hoping to run into something."

With today's technology, the Air Force can more effectively perform the CAS mission by using new multi role aircraft to manage information and give pilots a clearer picture of the battle space, argued Rebecca Grant, president of IRIS Independent Research, Washington.

"Close-air support is a lot more, in a way, about managing the information: who is on the ground, who needs what, what's the developing situation," Grant said . "This is really not about the pilot flying and looking down and trying to see the situation on the ground. If that's how they are doing it, well, that's how our grandfathers did it in World War II. That's not the gold standard today."

The A-10 performs well in an environment of total aerial dominance, as in Iraq and Afghanistan, Birkey said, but may not be survivable in less permissive environments. In a notional land engagement in the Asia/Pacific, the A-10 may not have applicability, he added.

The Air Force could design a replacement A-10 that is capable of multiple missions, said Mark Gunzinger, senior fellow at the Center for Strategic and Budgetary Assessments, Washington .

"If you are thinking about the future and the kind of operational environments that the Air Force is prepared for, should prepare for, to me it doesn't make a lot of sense to have a single-mission" platform for CAS, Gunzinger said. "It makes a great deal of sense to have a multi-mission platform performing that mission. In fact, it makes a lot of sense to have many multi-mission aircraft capable of supporting that mission, not just one."

But with several costly projects looming in the next few decades, including the new bomber, the Air Force does not see a clear funding stream for a next-generation A-10 replacement. Given a better budget environment, the service would want a relatively cheap, next-generation aircraft to provide close support for ground troops — but that is not a realistic proposal today, Chief of Staff Gen. Mark Welsh said this spring.

"We need a low-threat CAS platform in the near future, if the money will allow it," Welsh said at an April event sponsored by Defense One in Washington . "It doesn't today, but we would certainly like to have something like that, that operates more efficiently than what we have today, that carries more firepower and does so in a low-threat environment."

It would be a challenge for the Air Force to squeeze another new aircraft into the budget plan, which already includes recapitalizing the bomber, trainer and Joint Surveillance Target Attack Radar System fleets, Gunzinger said.

One option is to combine the T-X and A-X programs, given the trainer's capability to conduct CAS missions, he suggested.

"It would be a multi mission system — light attack, close-air support, along with our training aircraft," Gunzinger said. "It could help defray the cost of developing an A-10 replacement, since the Air Force has already determined it's going to invest in T-X."

Unless there is a radical shift in the short-term budget environment, analysts see the Air Force potentially developing a replacement A-10 after the procurement "bulge" in the 2020s. Still, the Air Force must balance tight resources and technological advancements with calls to replace the A-10 one-for-one.