SHUTTLEPOWER

7 MILLION POUNDS OF THRUST, 77 MILLION HORSEPOWER, 17,500 MILES PER HOUR

Reusable Solid Rocket Motor and Solid Rocket Boosters

The reusable solid rocket motor (RSRM) is assembled and tested by ATK Thiokol Propulsion near Promontory, Utah. Each motor consists of four steel tubes, or segments, lined with 1.1 million pounds of solid fuel propellant. An igniter is installed in the forward segment and a nozzle in the aft segment.

The four RSRM segments are mated with the solid rocket booster (SRB)
assemblies to form the flight configuration SRBs.

A Thiokol worker smoothes the liner inside
the steel casing of an RSRM segment.
Insulation is then added and propellant poured.

Equipment to mix fuel, oxidizer, and binder
into solid propellant uses designs borrowed
from the baking industry.

The RSRM segments are shipped by rail to the Kennedy Space Center. At KSC, the RSRM segments are joined with subassemblies built by United Space Alliance at KSC: the forward assembly, aft skirt, frustum, and nose cap. These structures contain the booster guidance system, the hydraulics system that steers the nozzles, booster separation motors, and parachutes.

The combination of the reusable solid rocket motor segments and solid rocket booster subassemblies make up the flight configuration solid rocket boosters (SRBs).

The SRB forward assembly, consisting
of the nose cap, frustum and forward skirt,
is joined to the RSRM forward segment at KSC.

The SRBs come to life when the thrust vector control (TVC) system is activated, 28 seconds before launch. After the main engines are running, the boosters are ignited by an electrical spark that sends flames from the igniter down the center of the propellant. The boosters go to full power in two-tenths of a second. At the same time, the hold-down nuts are severed, and the Shuttle lifts off.

At the instant of ignition, nuts on each of
the SRBs four hold-down bolts are exploded, freeing the Shuttle from the launch platform. A large sand bucket captures the bolts as they snap downward.

The propellant in the forward segment of the RSRM is designed to provide fast acceleration, it burns out 50 seconds after launch. The remaining propellant is shaped to burn at a slower rate to reduce stress on the vehicle and the crew during the period of maximum dynamic pressure. After about two minutes, all of the propellant is consumed and the boosters burn out and separate at 28 miles altitude, at a speed of 3,100 mph.

The speed of the SRBs causes them to
coast upward for 13 miles before beginning
their fall into the ocean.

Three 136-foot diameter parachutes
slow the SRBs to a safe splashdown in
the Atlantic Ocean.
The boosters coast upward to a 41 mile altitude, then parachute back to the Atlantic Ocean about 140 miles from the launch site.

After splashdown, recovery ships tow the boosters back to Cape Canaveral for disassembly and recycling. The motors are returned to Utah for final cleaning, inspection, and propellant reloading.

The SRBs are towed from the splashdown site back to KSC,
where they are prepared to be used again.

The booster subassemblies (the frustum, forward skirt, and aft skirt) go to the United Space Alliance Assembly and Refurbishment Facility at KSC. The parachutes are refurbished at the Parachute Refurbishment Facility.

A device called a "hydrolaser", spraying
water at 17,000 pounds per squares inch,
strips insulation from the boosters as part
of the refurbishment process.

Last Updated: July 20, 2006
Responsible NASA Official: Yolanda B. Harris
Curator: Shuttle Curator

NASA Privacy Statement

Reusable Solid Rocket Motor and Solid Rocket Boosters

The four RSRM segments are mated with the solid rocket booster (SRB) assemblies to form the flight configuration SRBs.

A Thiokol worker smoothes the liner inside the steel casing of an RSRM segment. Insulation is then added and propellant poured.

Equipment to mix fuel, oxidizer, and binder into solid propellant uses designs borrowed from the baking industry.

The SRB forward assembly, consisting of the nose cap, frustum and forward skirt, is joined to the RSRM forward segment at KSC.

At the instant of ignition, nuts on each of the SRBs four hold-down bolts are exploded, freeing the Shuttle from the launch platform. A large sand bucket captures the bolts as they snap downward.

The speed of the SRBs causes them to coast upward for 13 miles before beginning their fall into the ocean.

Three 136-foot diameter parachutes slow the SRBs to a safe splashdown in the Atlantic Ocean.

The SRBs are towed from the splashdown site back to KSC, where they are prepared to be used again.

A device called a "hydrolaser", spraying water at 17,000 pounds per squares inch, strips insulation from the boosters as part of the refurbishment process.

The four RSRM segments are mated with the solid rocket booster (SRB)
assemblies to form the flight configuration SRBs.

A Thiokol worker smoothes the liner inside
the steel casing of an RSRM segment.
Insulation is then added and propellant poured.

Equipment to mix fuel, oxidizer, and binder
into solid propellant uses designs borrowed
from the baking industry.

The SRB forward assembly, consisting
of the nose cap, frustum and forward skirt,
is joined to the RSRM forward segment at KSC.

At the instant of ignition, nuts on each of
the SRBs four hold-down bolts are exploded, freeing the Shuttle from the launch platform. A large sand bucket captures the bolts as they snap downward.

The speed of the SRBs causes them to
coast upward for 13 miles before beginning
their fall into the ocean.

Three 136-foot diameter parachutes
slow the SRBs to a safe splashdown in
the Atlantic Ocean.

The SRBs are towed from the splashdown site back to KSC,
where they are prepared to be used again.

A device called a "hydrolaser", spraying
water at 17,000 pounds per squares inch,
strips insulation from the boosters as part
of the refurbishment process.