A More Balanced View
5 May, 2005
DSS 43 Hydrostatic Bearing Upgrade

In late July 2005 the Hydrostatic Bearing Assembly (HBA) Upgrade downtime for the 70-metre (230 foot) antenna Deep Space Station 43 (DSS 43) will commence.

The hydrostatic bearing is the annular azimuth oil pressure bearing which is about 24 -metres across and supports the entire rotating mass of the antenna, around 4000 metric tonnes.

That massive weight is transferred via the girder structure to three rectangular pads separated 120 degrees apart that sit atop the annular runner.

The pads "float" and thus lift the antenna by about 0.017mm (10 thousandths of an inch) when high pressure hydraulic oil is forced through wells in the bottom of the pads.

The runner is a 20cm (7-inch) thick flat steel annular ring that in turn is supported by the circular concrete antenna pedestal. The floating mass of the antenna is centred by an internal and separate radial bearing.

The purpose of the upgrade is to extend the life of the entire hydraulic system that comprises the HBA, as many of the components are up to 33 years old. JPL requires that the 70-metre antenna be life extended, in order to meet upcoming mission requirements. The antenna was completed in 1972 and originally designed for a 15-year lifespan.

To allow for the upgrade the antenna will have an extended downtime for nearly 6 months. During this time all HBA high pressure pumps will be replaced and low pressure pumps upgraded. Cooling, dewatering, and filtering systems will be upgraded and electrical cabling and piping renewed. A separate but complimentary task will replace the antenna controller with modern digital control technology.

The project is being undertaken by Raytheon Australia in conjunction with a number of Australian sub-contractors.

Author: Tim LeMesurier - Antenna & Site Facilities Manager