WASHINGTON — Two more Air Force nuclear missile launch officers have been charged with illegal drug use in cases stemming from an investigation that led to the disclosure last year of a separate exam-cheating scandal, the Air Force said Friday.

1st Lt. Michael Alonso and 1st Lt. Lantz Balthazar, both members of the 12th Missile Squadron at the 341st Missile Wing at Malmstrom Air Force Base in Montana, face hearings to determine whether they will be court-martialed. One of their fellow missile officers who was a target of the same investigation pleaded guilty to illegal drug use in January and was kicked out of the Air Force.

The Malmstrom missile wing operates 150 of the Air Force's 450 Minuteman 3 intercontinental ballistic missiles, or ICBMs. Launch officers are trained to operate ICBMs that are armed with nuclear warheads and are on constant alert for possible launch.

Alonso was charged with violations of the Uniform Code of Military Justice for illegal possession, use and distribution of ecstasy and for "conspiracy related to the drug offenses," according to Malmstrom spokesman Josh Aycock.

Balthazar was charged with illegal possession, use and distribution of ecstasy and cocaine and for conspiracy related to the drug offenses. He also was charged with illegal use of Pentedrone, which Aycock said is commonly called bath salts.

Both officers were charged April 17.

Aycock said their cases will be reviewed at Article 32 hearings, which are akin to a civilian grand jury proceeding, to determine whether there is enough criminal evidence to warrant a court-martial. The hearings have not been scheduled, Aycock said.

Alonso and Balthazar were among three Minuteman 3 launch officers at Malmstrom who were under investigation for illegal drug use. The other, 2nd Lt. Nicole Dalmazzi, was charged in December and court-martialed in January.

Dalmazzi, a member of the same squadron, pleaded guilty to illegal use of ecstasy and was dismissed from the Air Force and sentenced to a month of confinement in a Montana jail. The Air Force had also charged her with obstructing the Air Force Office of Special Investigations probe by allegedly dyeing her hair to alter the results of hair-follicle drug tests, but that charge was later dropped.

The cases at Malmstrom stem from a drug investigation that began in August 2013 at Edwards Air Force Base in California. When investigators examined the cellphones of two airmen at Edwards they found text messages to or from 11 other Air Force officers at several other air bases, including Malmstrom. The messages allegedly detailed specific illegal drug use and led to the discovery that some had also improperly exchanged answers to ICBM launch officer proficiency tests.

The ICBM force, which also operates from bases in Wyoming and North Dakota, has been under the public spotlight in recent years for a series of embarrassing missteps related to low morale, disciplinary problems, a lack of resources, training lapses and leadership failures. Last November, then-Defense Secretary Chuck Hagel announced plans for top-to-bottom changes in management of nuclear forces and said the Pentagon would spend $8 billion to fix it.

In testimony to a Senate panel this week, an administration official who headed a detailed review of the nuclear forces for Hagel last year said her group believed that as much as $25 billion could be needed to fix an array of problems.

"The problems that we found were worse and they were much more systemic" than expected, Madelyn Creedon said in her testimony Wednesday.

Creedon, who was head of the Pentagon's nuclear policy shop at the time and is now principal deputy administrator of the National Nuclear Security Administration, said her review found that morale in the nuclear Air Force was "not good." Nuclear missile crews told her they "felt trapped" in their job.

"They would say, 'Well, I have the nuclear stink on me so I don't have much of a future in the rest of the Air Force,'" she said.

The Air Force says it has begun to change that attitude by implementing a range of changes and improvements that are being felt across the force.