Milestones Set the Stage for NASA Shuttle Discovery’s Return to Flight

The pace of preparations for Return to Flight is picking
up, with several key milestones in recent weeks marking
important progress in readying the Space Shuttle Discovery
for its next mission.

Discovery is progressing after the completion of extensive
wiring for Return to Flight, as well as the transition from
its modification period to more regular processing at the
Kennedy Space Center (KSC), Fla. Meanwhile, the first piece
of Discovery’s twin Solid Rocket Boosters was moved to a
processing facility on site and workers are installing
several important components.

Though Discovery appears unchanged from the outside, the
orbiter is very different on the inside. The power-up on July
27 follows safety improvements and modifications to enhance
vehicle monitoring during flight. Technicians have installed
cabling for wing leading-edge sensors and to support a
digital camera to document the External Tank as it separates
from Discovery. Wiring also has been installed to support a
boom extension for the Shuttle’s robotic arm that will
provide the ability to inspect nearly all the outside areas
of the orbiter’s Thermal Protection System in detail.

On August 9, the first segment of the Solid Rocket Boosters
designated for Discovery’s flight was moved to the Rotation
Processing and Surge Facility at KSC. The aft skirt — the
bottom, skirt-shaped section of the boosters — will have two
other components installed: an aft motor segment and an
External Tank attach ring. Next month, the structure will
move to the Vehicle Assembly Building for stacking
operations.

Engineers and technicians have applied many of the
modifications laid out in NASA’s Implementation Plan for
Space Shuttle Return to Flight and Beyond.

“The Vision for Space Exploration begins with safely
returning the Shuttle to flight and resuming assembly of the
International Space Station,” said Michael Kostelnik, Deputy
Associate Administrator for International Space Station and
Space Shuttle Programs. “These processing milestones show
we’re moving toward that goal,” he added.

Eighty-eight sensors will be installed on each wing. Sixty-
six will measure acceleration and impact data and 22 will
take temperature data during Discovery’s climb to orbit.
Ongoing tests have demonstrated these sensors can detect very
small impacts.

Wiring has been added to the umbilical well under Discovery
to accommodate a digital camera, which will transmit External
Tank photos to the ground quickly. When the tank is separated
from the Shuttle, an automatic sequence will capture 24
images, at one frame every 1.5 seconds. These images will be
downlinked to Mission Control at the Johnson Space Center in
Houston for review and analysis.

“The Program’s first line of defense was to redesign the
External Tank so that debris of a critical size never impacts
the orbiters again,” said Bill Parsons, Space Shuttle Program
Manager. “We have done that. Combined with ground, airborne
and onboard cameras and lasers, the addition of sensors will
provide more detection and inspection capability than the
Program has ever had,” Parsons added.

The visible progress in Florida and other locations around
the country parallels work by the Space Shuttle Program and
its many contractor and subcontractor teams in response to
the Columbia Accident Investigation Board’s recommendations.
NASA’s Space Flight Leadership Council is the internal body
reviewing the Shuttle Program’s work, and the Stafford-Covey
Return to Flight Task Group provides independent, external
oversight. NASA is working toward a launch planning window
for Discovery that opens in March 2005.

Since September 2002, Discovery has been in a regularly
scheduled Orbiter Major Modification period for maintenance
and upgrades. In addition to the Return to Flight work, more
than 100 modifications have been performed, including the
addition of the Multi-functional Electronic Display System,
or “glass cockpit.”

“Along with the power-up, we have passed several significant
milestones during the last few months with the installation
of the Forward Reaction Control System, the Reinforced
Carbon-Carbon nose cap and wing leading-edge panels,”
Discovery Vehicle Manager Stephanie Stilson said. “I am very
optimistic we are moving toward a launch next spring,” she
concluded.