Steven Chu, designated survivor. (Getty Images) Steven Chu, designated survivor. (Getty Images)

Outgoing Energy Secretary Steven Chu will not attend the State of the Union, the White House announced Friday.

Because the president, vice president, lawmakers, Cabinet secretaries, Supreme Court justices and members of the military’s Joint Chiefs of Staff are all sitting together in a confined space in the Capitol, one Cabinet member is chosen to skip the speech every year. 

The tradition dates back at least to the 1960s and the White House first publicly released the names of designated absentees during the Nixon administration, according to the Senate Historical Office.

What does a “designated survivor” do on their night off? Eat pizza or head to the theater, according to colleague Al Kamen.

Chu resigned two weeks ago after four years in the White House. He will stay in his post until at least the end of the month; President Obama has not named a replacement.

Here’s the full list of absent Cabinet secretaries since 1984, as compiled by the Senate Historian’s Office:

Jan. 24, 2012: Agriculture Secretary Tom Vilsack

Jan. 25, 2011: Interior Secretary Ken Salazar

Jan. 27, 2010: HUD Secretary Shaun Donovan

Feb. 24, 2009: Attorney General Eric H. Holder Jr.

Jan. 28, 2008: Interior Secretary Dirk Kempthorne

Jan. 23, 2007: Attorney General Alberto Gonzales

Jan. 31, 2006: Veterans Affairs Secretary Jim Nicholson

Feb. 2, 2005: Commerce Secretary Donald Evans

Jan. 20, 2004: Commerce Secretary Donald Evans

Jan. 28, 2003: Attorney General John Ashcroft

Jan. 29, 2002: Interior Secretary Gale Norton

Feb. 27, 2001: Veterans Affairs Secretary Anthony Principi

Jan. 27, 2000: Secretary of Energy Bill Richardson

Jan. 19, 1999: HUD Secretary Andrew W. Cuomo

Jan. 27, 1998: Commerce Secretary Bill Daley

Feb. 4, 1997: Agriculture Secretary Dan Glickman

Jan. 30, 1996: HHS Secretary Donna Shalala

Jan. 24, 1995: Transportation Secretary Federico Pena

Jan. 25, 1994: Agriculture Secretary Mike Espy

Feb. 17, 1993: Interior Secretary Bruce Babbitt

Jan. 28, 1992: Agriculture Secretary Ed Madigan

Jan. 29, 1991: Interior Secretary Manuel Lujan

Jan. 31, 1990: Veterans Affairs Secretary Edward J. Derwinski

Feb. 9, 1989: No absent cabinet member

Jan. 25, 1988: Interior Secretary Donald P. Hodel

Jan. 27, 1987: Agriculture Secretary Richard Lyng

Feb. 4, 1986: Agriculture Secretary John Block

Feb. 6, 1985: Commerce Secretary Malcolm Baldrige

Jan. 25, 1984: HUD Secretary Samuel R. Pierce Jr.