JULIE WATSONCHULA VISTA, Calif. (AP) â¿¿ Arthur Lute's arduous journey from his days as a U.S. Marine to his nights sleeping on the streets illustrates the challenge for the Obama administration to fulfill its promise to end homelessness among veterans by 2015. Lute has post-traumatic stress disorder from the 1983 bombing of the Marine barracks in Lebanon. He spent years drifting through jobs, two years in prison for assault, then 15 months sleeping in the bushes outside the police department of this city south of San Diego. Today, he lives in a $1,235 a month, two-bedroom apartment in a working-class neighborhood. The federal government pays nearly 80 percent of the rent and mostly covers the cost of medicines for his depression, high blood pressure, and other health problems. State-funded programs pay for doctor's appointments for his 6-month-old son and therapy for his wife, who he said is bipolar. Lute receives a Social Security check and food stamps. A Department of Veterans Affairs case manager communicates with him regularly and helps avert crises, like when Lute's electric bill jumped in an August heat wave and he couldn't afford diapers. A county program provided the crib. The American Legion donated cooking utensils, dishes and other basics. An upcoming report is expected to show the number of homeless veterans has dropped by at least 15,000 since 2009, Secretary of Veterans Affairs Eric Shinseki says, and the drop is the result of an aggressive two-pronged strategy to not only take veterans off the street but also prevent new ones from ending up there. But Shinseki made a bold promise in 2009: The administration would end homelessness among veterans by 2015. The former four-star general says now they're "on target" to meet the goal. Officials and outside experts said it would take: â¿¿More than doubling of the current, record annual progress.