|Posted on Oct 28, 2009 08:45:51 AM | Dan Kanigan | 5 Comments ||
Remember that probe on the top of the rocket? It’s still being watched carefully today, and not just because of its hard-to-remove cover.
As we noted yesterday, the five-hole probe is a very important set of sensors for collecting aerodynamic data during the flight. It remained covered while Ares I-X was rolled out to the launch pad and just prior to launch because the avionics team did not want water, bugs, bird messes, or other debris getting on or in the sensors. Inside the five holes is a diaphragm of flexible material against which air vibrates to produce data. If water or foreign object debris (FOD) gets onto the diaphragm, there is a risk that the data from the sensors could be harder to interpret after the flight. Once the Ground Operations team removed the cover, there is no way to put it back on short of rolling the rocket back into the Vehicle Assembly Building. The I-X team knew this might happen, but now that the cover is off, what next? Just to add to the challenge, Cape Canaveral expected (and got) an inch and a half of rain on Tuesday night.
What NASA did was take a spare five-hole probe out to the pad, put it on the fixed service structre and gave it a similar exposure to rain as the flight hardware. The spare unit was tested before and after the rain to determine its effects on the sensors’ behavior. In this way, NASA will be able to account for any changes in sensor measurements due to water on the sensor and use that information to interpret the data after the flight. This is just one of many lessons the Ares team is learning as it continues testing on the Ares I-X rocket.
Tags : General