Senators return from spring break with national security on their minds, as committees will hold their first congressional hearings since the deadly terrorists in Belgium last month. 
The Senate Homeland Security Committee will be the first to tackle the topic head on, with a series of outside experts testifying about the threat of religious extremism in Europe and the potential impact on Americans abroad and the United States homeland.

The Senate Armed Services Committee will hold five hearings next week, all ostensibly connected to the fiscal 2017 budget but likely to touch on terrorism and military preparedness as well.

House members don't return from their two-week break until April 11. Expect a flurry of budget activity then, as lawmakers eye an ever-shortening calendar for essential legislative business.

Tuesday

Senate Armed Services -- 9:30 a.m. -- Hart 216
Cyber Command
Adm. Michael Rogers, head of U.S. Cyber Command, will brief the committee on current threats and the fiscal 2017 defense budget request. 
 
Senate Foreign Relations -- 10 a.m. -- Dirksen 419
Iran nuclear deal
State Department Under Secretary for Political Affairs Thomas Shannon Jr. will discuss ongoing implementation of the nuclear deal with Iran and that country's other military intentions.

Senate Homeland Security -- 10 a.m. -- Dirksen 342
European terrorism
The committee will hear from outside experts on the threat of terrorism faced by Americans living in and traveling to Europe, in light of the recent attacks in Belgium.

Senate Armed Services -- 2:30 p.m. -- Russell 222
Shipyards
The commanders of U.S. Naval Sea Systems Command and Navy Installations Command will testify before the committee on the state of public shipyards and the long-term impact on naval readiness.

Senate Armed Services -- 2:30 p.m. -- Russell 232A
Army Modernization
The subcommittee on airland will hear from Army aviation and modernization officials on the fiscal 2017 defense budget request.

Wednesday

Senate Armed Services -- 2 p.m. -- Russell 222
Navy shipbuilding
The subcommittee on seapower will hear from Navy research and operations officials on the fiscal 2017 defense budget request.

Thursday

Senate Armed Services -- 9:30 a.m. -- Dirksen G50
Army budget
Acting Army Secretary Patrick Murphy and Army Chief of Staff Mark Milley will testify before the committee on current threats and the fiscal 2017 defense budget request.

Senate Foreign Relations -- 10 a.m. -- Dirksen 419
Ebola
Regional experts will brief the committee on the west Africa Ebola epidemic and lessons learned from the response.

Leo Shane III covers Congress, Veterans Affairs and the White House for Military Times. He can be reached at lshane@militarytimes.com.