The Houston Astrodome
A modern domed stadium built in Houston, Texas, in 1965. The largest previous
covered sports arenas provided only limited performing space and seated no more
than 20,000 persons. The Astrodome, however, built on the principle of the dome,
completely protects a sports area suitable for baseball and American football, with
seating for 66,000 spectators in six tiers.  

The Birth of AstroTurf
When the Astrodome opened, it used a natural Bermuda grass playing surface. The
dome's ceiling contained numerous clear plastic panes made of Lucite. Players quickly
complained that glare coming off of the panes made it impossible for them to track fly
balls, so all of the panes were painted over, which solved the glare problem but caused
the grass to die from lack of sunlight. For most of the 1965 season, the Astros played
on green-painted dirt and dead grass. As the 1966 season approached, there was the
possibility of the team playing on an all dirt infield.

The solution was to install a new type of artificial grass on the field, ChemGrass, which
became known as AstroTurf. Because the supply of AstroTurf was still low, only a
limited amount was available for the home opener on April 18, 1966. There wasn't
enough for the entire outfield, but there was enough to cover the traditional grass
portion of the infield. The outfield remained painted dirt until after the All-Star Break.
The team was sent on an extended road trip before the break, and on July 19, 1966,
the installation of the of the outfield portion of AstroTurf was completed and ready for
play. The infield dirt remained in the traditional design, with a large dirt arc, similar to
natural grass fields. The "sliding pit" configuration, with dirt only around the bases, did
not arrive in Houston until the mid 1970s. The sliding pits were introduced by Cincinnati
with the opening of Riverfront Stadium on June 30, 1970. It was then installed in the
new stadiums of Philadelphia in 1971, and Kansas City in 1973. The artificial turf fields
of Pittsburgh and St. Louis were traditionally configured like the Astrodome, and would
also change to sliding pits in the 1970s.