Question: Rick Mears' first Indy 500 victory out of four, in 1979, was the second for his car owner who has been a major figure in IndyCar ever since. Who is he?

Context paragraphs:
1988 Indianapolis 500: The 72nd Indianapolis 500 was held at the Indianapolis Motor Speedway in Speedway, Indiana, on Sunday May 29, 1988.  Team Penske dominated the month, sweeping the top three starting positions with Rick Mears winning the pole position, Danny Sullivan at the center of the front row, and Al Unser, Sr. on the outside.  Mears set a new track record, becoming the first driver to break the 220 mph barrier in time trials.  On race day, the Penske teammates proceeded to lead 192 of the 200 laps, with Rick Mears taking the checkered flag, his third-career Indy 500 victory.  The race represented the milestone 50th victory in Championship car racing for owner Roger Penske and Penske Racing.

2001 Indianapolis 500: The 85th Indianapolis 500 was held at the Indianapolis Motor Speedway in Speedway, Indiana on Sunday, May 27, 2001.  Race rookie Hélio Castroneves, a three-year veteran of the CART series, led the final 52 laps and won his first Indy 500.  Penske Racing swept 1st-2nd with Gil de Ferran the runner-up.  Winning car owner Roger Penske scored his 11th victory at the Indianapolis 500, and his first-ever 1-2 finish in the race.  It was a redemption from the team's previous attempt at Indy (1995) in which both of his cars failed to qualify; subsequently followed by a five-year absence (1996-2000) due to the open wheel "split."

1979 SCCA/CART Indy Car Series: The 1979 SCCA/CART Indy Car Series was the inaugural season for the CART Indy car series.  It was the first national championship season of American open wheel racing sanctioned by CART.  The season consisted of 14 races.  Rick Mears was the national champion, and the rookie of the year was Bill Alsup.  The 1979 Indianapolis 500 was sanctioned by USAC, but counted towards the CART points championship.  Rick Mears won the Indy 500, his first of four victories in the event.

1979 Indianapolis 500: The 63rd 500 Mile International Sweepstakes was held at the Indianapolis Motor Speedway in Speedway, Indiana, on Sunday May 27, 1979.  Second-year driver Rick Mears took the lead for the final time with 18 laps to go, and won his first of four Indianapolis 500 races.  It was also Mears' first of a record six Indy 500 pole positions.  Brothers Al and Bobby Unser combined to lead 174 of the 200 laps, but Al dropped out around the midpoint, and Bobby slipped to 5th place at the finish nursing mechanical issues.  It was also Roger Penske's second Indy 500 victory as a car owner.

1991 Indianapolis 500: The 75th Indianapolis 500 was held at the Indianapolis Motor Speedway in Speedway, Indiana, on Sunday, May 26, 1991.  Rick Mears won from the pole position, becoming the third four-time winner of the Indy 500, joining A. J. Foyt and Al Unser.  During time trials, Mears also established an Indy record by winning his sixth career pole position.  The month of May for Mears was tumultuous, as he suffered his first ever crash at Indy since arriving as a rookie in 1977.  The wreck during a practice run totaled his primary car, and injured his right foot.  Mears later admitted that pain he was experiencing during the race was so bad, he had to cross his legs in the car and push the accelerator pedal down with his left foot.

Penske PC-17: The Penske PC-17 was a CART Penske Racing car which was constructed for competition in the 1988 season.  The chassis swept the front row at the 1988 Indianapolis 500 with Rick Mears winning the pole position, Danny Sullivan qualifying second, and Al Unser, Sr. third.  Mears went on to win the Indy 500, and Sullivan the season championship.

Jerry Karl: Jerry Karl (April 29, 1941, Manchester, Pennsylvania - February 16, 2008, Baltimore, Maryland), was a former driver in the USAC and CART Championship Car series.  Starting out in midget car racing and sprint car racing, he made his Champ Car debut in 1969 and qualified for his first Indy 500 in 1973 driving an Eagle chassis powered by a twin-turbo Chevrolet V8 engine fielded by legendary car owner Smokey Yunick.  He raced for another team in 1974, but returned to drive for Yunick in 1974 and finished 13th at Indy.  In 1980 he entered the CART series and began modifying his own McLaren chassis that he dubbed the McLaren-Karl.  In the final race of the 1980 season at Phoenix International Raceway, Karl and his chassis ran at the front of the field in second place until engine trouble dropped him back to 9th.  In total, Karl raced in the 1969-1984 seasons, with 74 combined career starts, including the 1973-1975, 1978, and 1980-1981 Indianapolis 500.  He finished in the top ten 8 times, with his best finish in 7th position in 1974 at Ontario Motor Speedway.  He later owned a racing products distributor in Wellsville, Pennsylvania.  He died at the age of 66 due to a road car crash in Baltimore on February 16, 2008.

1984 Indianapolis 500: The 68th Indianapolis 500 was held at the Indianapolis Motor Speedway in Speedway, Indiana on Sunday May 27, 1984.  Rick Mears, who previously won in 1979, won his second Indy 500 driving for Penske.  Contenders Tom Sneva and Mario Andretti dropped out of the race in the second half, leaving Mears alone two laps ahead of the field, and he cruised to the victory.  Three months after the race, however, Mears would suffer severe leg injuries in a practice crash at Sanair.

1988 CART PPG Indy Car World Series: The 1988 CART PPG Indy Car World Series season was the 10h national championship season of American open wheel racing sanctioned by CART.  The season consisted of 15 races, and one non-points exhibition event.  Danny Sullivan was the national champion, winning for Team Penske.  The rookie of the year was John Jones.  The 1988 Indianapolis 500 was sanctioned by USAC, but counted towards the CART points championship.  Rick Mears won the Indy 500, his third victory at Indy.

Rick Mears: Rick Ravon Mears (born December 3, 1951 in Wichita, Kansas), also known by the nickname "Rocket Rick," is a retired American race car driver.  He is one of three men to win the Indianapolis 500 four times (1979, 1984, 1988, 1991), and is the current record-holder for pole positions in the race with six (1979, 1982, 1986, 1988, 1989, 1991).  Mears is also a three-time Indycar series/World Series champion (1979, 1981 and 1982).

Supporting paragraphs: 1979 Indianapolis 500 Rick Mears
Answer: Roger Penske