LAT Mass Comparison

The table below compares measured or calculated mass numbers for the LAT with values obtained from a partially updated simulation geometry.

Some part of the discrepancy is understood and can be remedied quickly. For example, radiators and cabling not included in the model at all currently account for 80 kg (mechanical) and 31 kg (electrical), respectively. However the > 10% shortfall in TKR and the huge underestimate for ACD are unsettling, to say the least!

Update (11 March 2007)

As of xmlGeoDbs tag v1r39 some additions have been made to the mechanical and electrical categories within the LAT, and the homogeneous cylindrical "spacecraft" has been replaced with reasonably correct representations of a few of the more massive components: primary structure, optical bench, propellant tank and propellant. Total mass of these components is about 710 kg. Here is a revised version of the table above:

Update (22 April 2007)

Additional spacecraft components (skirt and batteries) have been added. Total spacecraft mass for xmlGeoDbs v1r39p3 is about 850 kg.

References

The measured/calculated figures come from LAT-TD-00564-12, dated April 24, 2006. The summary table from p. 10 of this document is reproduced below.

Figures for the simulation come from a diagnostic program which reads the xml geometry description, including materials, and calculates masses by material and by logical volume type, and writes out the information The per-material table is reproduced below, with an additional column indicating subsystem.

See also version for tag v1r39.