Barbara L. Kakiris
Media Relations Office
Glenn Research Center
21000 Brookpark Road
Cleveland, OH 44135-3191
(216) 433-2513
Lori J. Rachul
Media Relations Office
Glenn Research Center
21000 Brookpark Road
Cleveland, OH 44135-3191
(216) 433-8806
Release: 00-32
After 81 months of operations and far exceeding its planned 24-month
mission, NASA’s Advanced Communications Technology Satellite (ACTS)
will conclude its extensive experiments program tomorrow, May 31.
Launched in September 1993 as a partnership among NASA, industry
and academia, ACTS opened the door for U.S. satellite communications
technology in demonstrating the use of the high frequency Ka-band
(30/20 GHz). Until ACTS, this frequency was virtually unused — the
majority of communication satellites used lower frequency bands called
C- and Ku-bands. Exploring Ka-band technology was designed to relieve
orbital crowding and demonstrate the first band of frequency wide enough
to carry simultaneous services ranging from multiple voice, video and
data communications to computer connections at optical fiber data rates.
“The ACTS Experiments Program has been an outstanding research and
development achievement that resulted in a unique operational capability
for the Center and the Agency,” said Donald J. Campbell, NASA Glenn
Research Center Director. “It was a bold step to put a new communication
satellite into operation with minimal support, and based on program
results, it was the right decision because it laid the foundation for
advancements in communication satellites.”
Throughout its impressive lifespan, ACTS, which is managed by the NASA
Glenn Research Center, Cleveland, OH, opened new frontiers by utilizing
a unique hopping spot beam antenna system that generated 51 tightly
focused signal beams. Each spot beam typically had a diameter of
150-200 miles and was able to “hop” from one location to the next,
covering up to 40 locations in a millisecond. Concentrating satellite
power in such a way permitted significantly smaller and less expensive
Earth stations.In addition, the spot beam was better able to penetrate
through rain and mitigate rain fade.
“The ACTS Experiments Program had the foresight to step beyond the
conventional thinking and prove the technology needed for the future,
as well as the present,” said Joseph H. Rothenberg, NASA Associate
Administrator for Space Flight.
The ACTS Experiments Program has achieved remarkable milestones with
103 experiments and numerous demonstrations involving over 200 diverse
partners, paving the way for the next generation of communications
satellites. The experiments program succeeded in areas as diverse as
advanced networking, medicine, education, defense, emergency response,
maritime and aeronautical mobile communications, and science and
astronomy. Examples include:
* Telemedicine — ACTS transmitted data-intensive imagery that linked
urban medical specialists to under-served areas of the U.S.* Electric utility companies — ACTS controlled power grids by using
ultra-small terminals to poll the grid in remote areas, demonstrating
potential cost saving.* Distance learning — ACTS improved high-quality interactive video and
audio for delivery of advanced degree, continuing and remedial training
to people in remote locations.* Business — ACTS utilized its high-speed links with major computers
to integrate design teams that used remote research equipment to explore
natural resources. This process increases the possibility of saving
millions of dollars in annual cost.* Personal and airborne mobile communication services — ACTS
demonstrated technologies such as enabling advanced passenger services
onboard the U.S. commercial airline fleet.
“The timeliness of ACTS technologies could not have been better,” said
Robert A. Bauer, ACTS Project Manager. “Had they arrived too early, few
would have been ready to utilize the bandwidth being offered. Had they
arrived too late, fiber may have completely shadowed the satellites’
consideration in offering wideband services to diverse and remote
locations.”
ACTS set the standard for next generation communications satellites. Its
pioneering advanced technologies for space communications have shown
the feasibility of the next generation communication satellites to meet
ever-growing communications needs.
Its successes have been recognized through numerous awards including
induction into the U.S. Space Foundation’s Space Technology Hall of Fame
in 1997, an R&D 100 Award in Significant Technology in 1995 and the
prestigious Federal Technology Leadership Award in 1995.
For more information on the ACTS Program, please visit:
For more information on the Glenn Space Communications Program, please
visit:
