Carter's drive off Texas starter Matt Harrison cleared the right-center fence 360 feet from home plate at the Alamodome, designed primarily for football and special events such as the NCAA Final Four.
Despite an inviting right-field porch at 271 feet, Carter said he wasn't trying to hit a long ball with every swing.
''I just went up there and tried to hit the ball up the middle instead of trying to hit it one way or another,'' he said. ''And wherever it goes after that is where it goes.
''When I first looked at the field, I was thinking that you could hit a ball badly to right and it would still go out. But I just went up there and tried to make contact and I was able to get a hold of one.''
Home plate was moved back about 10 feet, which contributed to the right-field line being 14 feet shorter than last season when the Rangers played the San Diego Padres in a two-game series that drew more than 75,000 fans.
''Our guys didn't have any complaints about the field or playing conditions whatsoever,'' Astros manager Bo Porter said. ''I had heard there was some complaints about the lighting (last year), but I was told they moved home plate in line with the lights so that wasn't an issue for us.''
Rangers designated hitter Adrian Beltre hit his first homer of the spring in the second inning, almost in the same spot as Carter's, to cut the Astros' lead to 4-1.
Michael Choice hit a two-run shot to trim Houston's lead to one with nobody out in the ninth, but the Astros retired the next three batters to end it.
Houston starter Jerome Williams gave up one run on three hits and struck out two in three innings.
''I felt good,'' Williams said. ''I left a ball up to Beltre, but other than that I thought I threw the ball well. I felt like this was the last (game) to do well and get that momentum going into the regular season.''
Harrison allowed four runs and five hits in three innings. He walked three and struck out two.
Texas shortstop Elvis Andrus, playing his first game since March 17 due to forearm soreness, went 1 for 3. He went through fielding drills the last couple of days with no issues and played the infield for five innings against the Astros.
''Elvis has done everything he needed to do and has done everything you'd have to do at shortstop,'' Rangers manager Ron Washington said. ''He's ready to go.''
Kevin Kouzmanoff hit a solo home run in the eighth for the Rangers.
Hall of Fame pitcher Gaylord Perry threw out the ceremonial first pitch to Texas Rangers great Ivan ''Pudge'' Rodriguez during pregame festivities. St. Louis Cardinals great Lou Brock also was on hand to watch the game.
Kirkman, the longest tenured Rangers player, had spent his entire professional career in the organization.
Texas also signed right-hander Scott Baker to a minor league contract. He is expected to open the season with Triple-A Round Rock.
Baker, who had Tommy John surgery in April 2012, spent the spring in camp with the Seattle Mariners as a non-roster invitee. He was released on Tuesday.
ON THE MEND
Texas ace Yu Darvish is expected to begin throwing Saturday after being sidelined with neck stiffness. Darvish, runner-up for the AL Cy Young Award last year, will throw on flat ground and possibly have a bullpen session in Arlington.
Darvish missed his scheduled start last Friday. He said he slept on his neck wrong and assumed he'd be back in two or three days. But he hasn't been able to throw, and he visited back specialist Dr. Drew Dossett on Wednesday. Dossett found no structural damage in Darvish's neck and cleared him to begin throwing.
The right-hander will be re-evaluated after Saturday's session. There is no timetable for his return to the rotation.