Leslie Williams

NASA Dryden Flight Research Center

Phone: 661/276-3893

RELEASE: 00-88

NASA’s Dryden Flight Research Center has a proven history of
providing vital communications and tracking services in support of
NASA space programs – the latest of which is the International Space
Station (ISS).

Capitalizing on its earlier developments of highly successful
U.S.-based, real-time, redundant communications links between the
Russian space station Mir, Moscow mission control and Johnson Space
Center, Dryden’s network of test range data and communications links
now assists in communications for Space Shuttle missions, the ISS,
Moscow mission control, Johnson Space Center and the Kennedy Space
Center.

In 1995, Dryden’s Western Aeronautical Test Range (WATR) team
designed a VHF communications system that supported NASA
communications on 1,091 orbits of the Mir space station. Most
recently, Dryden served as a vital link for radar, telemetry and
audio/video communications for the STS-92 and STS-97 Space Shuttle
construction missions to the ISS, as well as for the station’s
resident crews.

“Dryden’s test range team has been frequently utilized on NASA’s
space programs because of its trademark style of innovative,
resourceful engineering, its expert tracking abilities and its
ability to design efficient, cost-effective communications solutions
for multiple scenarios,” said Gary Morse, Manager for Space
Operations Services at the Johnson Space Center. “These capabilities
contribute to the revolutionary leaps in technology development and
access to space at reduced costs necessary in today’s programs.”

“We have the best of the best in the Range community,” noted Dryden
Range Operations Branch Chief Craig Griffith, “Our team of civil
servants and contractors are considered to be world class.”

According to WATR Program Manager Jerry McKee, Dryden developed the
unique ground-based VHF communications system through the ingenuity
of Michael Yettaw, WATR communications facility work leader, and his
team. In conjunction with the Goddard Space Flight Center in
Greenbelt, Md., Dryden’s test range team quickly constructed the
communications link by customizing commercial-off-the-shelf
technologies, saving hundreds of thousands of dollars off projected
costs. The success of the Dryden-developed VHF communications system
prompted NASA to use the same equipment and installation methods in a
network of communications stations at sister facilities at Wallops
Island, Va. and White Sands, N.M.

The Dryden system, compatible with the Russian Soyuz and Zarya module
communication equipment, enables current communications between crews
and ground personnel and ensures continuity of communications in the
event an emergency egress requires ISS crews to relocate to the
docked Soyuz module. Although a new communications system is soon to
debut, Dryden is in the process of providing communications coverage
for an initial commitment of 22 weeks, 24 hours a day in 11- to
12-hour blocks of time until that system is fully tested and
validated. Following the end of its initial commitment, Dryden will
be providing five-day coverage during regular operating hours unless
the full commitment is extended by another 26 weeks. Dryden will also
continue to support ISS emergency egress communications requirements
until the permanent Crew Return Vehicle (CRV) capability is
established. The CRV is anticipated to be in place at the ISS by 2006.

Dryden is responsible for the tracking support as well, monitoring
all orbits of space shuttles and the ISS whenever they appear over
the five-degree elevation angle above Dryden’s horizon. Providing the
radar tracking are Bart Rusnak, the Dryden tracking systems facility
work leader at the Aeronautical Tracking Facility #1 (ATF-1), and his
team.

An example of Dryden’s combined communications and tracking support
occurred shortly after the launch of STS-92 on Oct. 11. The Space
Shuttle Discovery was found to have experienced problems with the
antenna that up-links communications to the Tracking and Data Relay
Satellite System (TDRSS). The antenna failed to transmit voice, data
stream and TV signals, requiring that Discovery’s crew and the
Johnson Space Center depend on the team at Dryden’s test range to
provide primary support for Discovery’s air-to-ground links and
tracking for all orbits viewable from California. With viewable
orbits occurring four to six times daily, Dryden’s test range team
supported the daily orbits for a total of nine to 12 hours, seven
days a week. In addition, Dryden’s teams were prepared to track the
Shuttle 24 hours per day to accommodate the shifting orbits
throughout the mission.

Focused on their goal of providing full support of the mission,
Dryden’s Range Operations assembled all of the resources necessary to
provide the UHF link between the Johnson Space Center and Space
Shuttle Discovery. Their support consisted of on-orbit and landing
assistance as well as all ground communication and data links between
Dryden range assets, the Johnson Space Center and the Kennedy Space
Center. Dryden’s team also provided radar tracking and downlinked
video on 182 orbits of the ISS and the Space Shuttle during the
STS-92 and STS-97 missions. Following Discovery’s landing at Edwards
on Oct. 24, Range Operations enabled the communications link between
the Kennedy Space Center and the Dryden Shuttle Processing Area for
post-landing support on the shuttle. Dryden then supported 140 hours
of post-landing orbiter data flow around the clock until Discovery
was powered down and mated to the 747 Shuttle Carrier Aircraft for
its ferry flight back to the Kennedy Space Center Nov. 2.

Regarded by Morse as a leading innovator in the field of space
communications, Dryden Range Operations has been awarded special
recognition for its excellence by the Goddard Space Flight Center and
Johnson Space Center. Dryden also provides regular input on shuttle-
and ISS-related issues at NASA Network Support Group meetings.

NOTE TO EDITORS:

Photos supporting this release (EC00 328-2, EC00 311-1, and EC00
311-3) are available on the Internet (high and low resolution) in
Dryden’s photo gallery at URL:

http://www.dfrc.nasa.gov/gallery/photo/STS-92/Small/index.html

For photo prints, please call (661) 276-3893.

NASA Dryden news releases are also available on the Internet at:

http://www.dfrc.nasa.gov/PAO/PressReleases/index.html