Testing designed to simulate the vibrations NASA's Orion will
experience during its first trip to space successfully wrapped up inside
the Operations and Checkout Building high bay at NASA's Kennedy Space
Center in Florida. The completion of the testing marks another step
forward toward Orion's uncrewed December flight that will put to the
test the spacecraft that will send astronauts to an asteroid and
eventually Mars on future missions.
"It was a great accomplishment for the test team in preparation for
the Exploration Flight Test-1 later this year," said Rafael Garcia, the
Orion Program Test and Verification lead at NASA's Johnson Space Center
in Houston. "Following months of preparations and pretest analysis, the
multi-point random vibration test was conducted without any major issues
and was completed two days ahead of schedule."
To prepare for the vibration tests, which were conducted April 17-24,
a team of NASA and Lockheed Martin engineers and technicians
transferred Orion from the crew module assembly station to a special
vibration stand in a portable test chamber. The spacecraft was isolated
from the floor and stand on special footing. Orion's thrusters were
cantilevered out so they were isolated from the test, and its windows,
parachutes and drogue chutes were covered for protection.
Accelerometers and strain gages were placed around the crew module in
various locations. These were used to measure simulated acceleration
and strain levels on Orion's structure.
Two electromagnetic shakers, each capable of up to 4,000 pounds of
force, were attached to Orion on opposite sides. Baseline vibration
tests began at five megahertz and gradually were increased up to about
500 megahertz. After each test run, the shakers were relocated to
different points on Orion and systems specialists checked for any
changes or abnormalities in the spacecraft's structure.
Garcia said that preliminary analysis of the test data confirmed that Orion's structure performed as predicted.
Before each thirty-second test run, Orion's avionics, batteries and
electrical systems were powered up and its ammonia and helium tanks were
pressurized to 200 psi.
The tests were monitored in a separate control room near the high
bay, and the data after each 30-second run was analyzed to check for
imperfections or defects and how the crew module performed. A flight
following team in Firing Room 1 in Kennedy's Launch Control Center
monitored Orion during periods of powered-up testing.
"Shut-down limits were established in case the vibrations began to
exceed limits," said Trevor Kott, the Orion Crew and Service Module
ground test manager at Johnson. "This kind of test can be very
complicated. There's a science to finding the right balance."
During the vibration test, other instrumentation on Orion was monitored for its state of health.
"The completion of the test is a great accomplishment for the test
team and NASA's Orion Program in preparation for EFT-1," Garcia said.
Orion’s first flight will launch an uncrewed capsule 3,600 miles into
space for a four-hour mission to test several of its most critical
systems. After making two orbits, Orion will return to Earth at almost
20,000 miles per hour and endure temperatures near 4,000 degrees
Fahrenheit, before its parachutes slow it down for a landing in the
Pacific Ocean.
No comments:
Post a Comment