Budweiser plans to release another version of its “Reserve” series beers this year, according to new label filings approved by a federal regulator.

Budweiser Discovery Reserve, an American red lager, is inspired by an “archival malt-forward recipe brewed at the time of the Apollo moon missions,” according to its label, which was approved by the Alcohol and Tobacco Tax and Trade Bureau last month.

The 5 percent alcohol-by-volume beer is brewed with Voyager barley grains “for a toasted malt taste with a hint of toffee, a light hoppy aroma, and a sharp finish,” its label says. It will be packaged in 12-ounce bottles and 16- and 25-ounce cans, according to its label submissions.

Budweiser Discovery Reserve will be the fourth beer in the Reserve series, which kicked off in fall 2017 with Budweiser 1933 Repeal Reserve, an amber lager. That was followed in spring 2018 with Budweiser Freedom Reserve Red Lager. Bud last fall unveiled the third beer in the series, Budweiser Reserve Copper Lager, which is aged on Jim Beam barrel staves. All have been packaged in stubby bottles.

It is unclear when the beer will be released. An Anheuser-Busch spokeswoman declined to comment.

The latest Bud label is part of a broader effort by Anheuser-Busch to generate new interest and boost sales through line extensions on its biggest brands, including Bud, Bud Light and Michelob Ultra. Bud Light, for instance, last year rolled out nationally Bud Light Orange, which performed well and is slated to come back again in 2019. Fast-growing Michelob Ultra also has launched a pair of line extensions: Michelob Ultra Lime Cactus and Michelob Ultra Pure Gold, an organic beer.

Anheuser-Busch also appears poised to release a new take on the base beer called Michelob Ultra Infusions Lime & Prickly Pear Cactus, which it describes as a “light lager with real exotic fruit and natural flavors.”

The flurry of line extensions comes as AB executives publicly reevaluate how they invest behind their U.S. portfolio.

Anheuser-Busch Chief Executive Michel Doukeris said last fall that the world’s largest brewer has looked “too much” to Budweiser and Bud Light and is increasing investments behind brands such as Michelob Ultra to fuel growth. His boss, Anheuser-Busch InBev CEO Carlos Brito told investors the company is taking a “fresh look” at its U.S. strategy and putting “more gas” on shifting its portfolio toward higher-end beers.

Nonetheless, he’s mentioned Bud Light Orange and the Budweiser Reserve series as key players in its strategy. Brito told Wall Street analysts in October the Reserve series was “among the top share-gainers in the U.S. this year,” and called out the product as an innovation “driving incremental growth to our portfolio.”

But while such extensions have run up significant sales for AB, they haven’t been enough to buoy flagships Bud and Bud Light, both of which have been locked in steady decline.

Even with the two Reserve beer releases in 2018, the Bud franchise fell 5.5 percent in sales dollars and 6.3 percent in case volume through Dec. 29, per Nielsen all-outlet and convenience data. Bud Light, meanwhile, dropped 6.3 percent in sales dollars and 6.6 percent in volume over the same period, which was rough overall for American premiums and premium lights.