Obama Protection 42

President Barack Obama prepares to board Air Force One before his departure from Andrews Air Force Base, Md., Wednesday, April 20, 2011. Obama is traveling to West Coast to attended DNC fundraisers. (AP Photo)

President Barack Obama walks to his motorcade at the White House in Washington, Wednesday, April 20, 2011, to travel to Andrews Air Force Base and then onto California. (AP Photo)

US President Barack Obama greets guests after speaking at a town hall meeting on the national debt and deficit April 19, 2011 at the Northern Virginia Community College in Annandale, Virginia.

U.S. President Barack Obama walks up the stage for a town hall meeting at the North Virginia Community College April 19, 2011 in Annandale, Virginia. Obama discussed his vision for bringing down the deficit at the town hall meeting.

Marine One, carrying U.S. President Barack Obama, flies in front of the Washington Monument before arriving at the White House on April 15, 2011 in Washington DC. President Obama was returning from a trip to Chicago. Getty [More on missile protection below.]

President Barack Obama walks to Air Force One before leaving Chicago's O'Hare International Airport, Friday, April 15, 2011. (AP Photo)

U.S. President Barack Obama holds an iPad as he prepares to climb into his car after landing in Chicago on Marine One, April 14, 2011. Obama travelled to Chicago for Democratic party fundraisers. AP

President Barack Obama reads a note handed to him by a young supporter as he greets people on the tarmac during his arrival at O'Hare International Airport in Chicago, Ill., Thursday, April 14, 2011. (Pablo Martinez Monsivais)

[Obama expected to visit the Lincoln Memorial later, sounter-snipers on roof at upper right.] People take pictures at the Lincoln Memorial Saturday, April 9, 2011, in Washington. Rivals in a divided government, President Barack Obama and the Republican-run House, split their spending differences late Friday night staving off a federal shutdown, which would have closed the nation's monuments to the public, and agreeing on $38 billion in cuts over the next six months. (AP Photo/Alex Brandon)

President Barack Obama visits the Lincoln Memorial at the National Mall in Washington, Saturday, April 9, 2011. (Manuel Balce Ceneta)

President Barack Obama greets people on the tarmac during his arrival at JFK International Airport in New York, Wednesday, April 6, 2011. (Pablo Martinez Monsivais)

A Secret Service agent, center, stands watch as Air Force One, with President Barack Obama aboard, prepares to take-off from Andrews Air Force Base,Md., Wednesday, April 6, 2011, as the president was traveling to Pennsylvania and New York. (Cliff Owen)

US President Barack Obama leaves the White House in Washington, DC, on April 3, 2011. Obama was headed to the golf course.

U.S. President Barack Obama (2nd L) waves as he leaves after he spoke on the National Clean Fleets Partnership at a UPS shipping facility April 1, 2011 in Landover, Maryland. The five charter members of the partnership, AT&T, FedEx, PepsiCo, UPS and Verizon, will participate by incorporating electric vehicles, alternative fuels, and fuel-saving measures into their daily operations in order to reduce diesel and gasoline use in their fleets.

President Barack Obama, accompanied by first lady Michelle Obama, waves after greeting children on the tarmac upon their arrival in San Salvador, El Salvador, Tuesday, March 22, 2011. (Pablo Martinez Monsivais)

President Barack Obama, second from left, accompanied by first lady Michelle Obama, left, waves upon his arrival to La Moneda government palace in Santiago, Chile, Monday, March 21, 2011. (Roberto Candia)

President Barack Obama waves to people gathered on the street outside the Cidade de Deus (City of God) favela Community Center in Rio de Janeiro, Brazil, March 20, 2011. (Official White House Photo by Pete Souza)

U.S. President Barack Obama steps to the middle of the street to wave to locals after touring the Ciudad de Deus Favela in Rio de Janeiro, Brazil, Sunday, March 20, 2011. (Pablo Martinez Monsivais)

President Barack Obama prepares to salute as he steps off of Marine One, Wednesday, Feb., 23, 2011, at the National Naval Medical Center in Bethesda Md. (Carolyn Kaster) [Red circle indicates the forward port sensor of the Marine One missile irfrared countermeasure (IRCM) system. There are four sensors for the system, 2 forward, two aft.]

The Marine One helicopter kicks up snow and ice as it lands on the South Lawn of the White House in Washington, Tuesday, Feb. 22, 2011, prior to President Barack Obama's departure to Cleveland, Ohio. (Charles Dharapak) [Red circles indicate two IRCM forward sensors and two turrets below. Two aft sensors not visible.]