MRO Magazine


Pump monitoring system is one key to successful launch of Atlantis Space Shuttle

July 12, 2001 -- The U.S. Space Shuttle Atlantis was launched this morning on its flight to the International Space...

July 12, 2001 — The U.S. Space Shuttle Atlantis was launched this morning on its flight to the International Space Station.

In the hours preceding blast-off, the NASA/United Space Alliance launch team was making final preparations and filled the Shuttle’s external fuel tanks. Fuelling is a critical phase in the launch process, and the process must be closely monitored. Two pumps are used to fill the Shuttle’s externally mounted liquid oxygen (LOX) tanks. Typically, one of the pumps is started about 12 hours before launch. Once the LOX tank is full, the pump continues to operate in “replenishment” mode until just before launch (since LOX evaporates).

Normally only one pump is used for this operation, but if this pump has problems, then the reserve unit must be switched on before the countdown is interrupted.

Here’s where a product supplied by Rockwell Automation plays a role. The company’s Entek Entrx conditioning monitoring device monitors vibration from the two LOX pumps. Console operators in the Launch Control Center continuously review Entrx data during fuelling. If Entrx signals an alarm, or a controller perceives that a problem is developing, then the second pump can be started before the launch cycle is interrupted.

In other industries, Rockwell says its Asset Management capabilities, such as Entek conditioning monitoring, computerized maintenance management services (CMMS) and on-site asset management, have been shown to reduce downtime by 25 per cent through predictive maintenance and cut capital expenses by 15 per cent.

The STS-104 is the first shuttle to go to orbit with a new Main Engine. The new engine, the Block II configuration, gives the crew a safer ride to orbit due to a new high-pressure fuel turbopump. The modification results in a more reliable and safer engine because of increased pump robustness. Also, the time between engine overhauls should increase.

The STS-104 crew spent its first full day in orbit preparing for its arrival at International Space Station. The mission’s three space walks will be conducted to assist in the installation of the Atlantis’ primary payload, the Joint Airlock, onto the space station. Docking is slated to occur at 9:53 p.m. CDT Friday July 13. Total mission time is just under 11 days.

If you’d like to follow the progress of the flight, visit on the Internet.