NASA Goddard GSFC Simulations and Compatibility Test Branch Patch

Before a spacecraft ever left the ground, a Compatibility Test Van from Goddard Space Flight Center could drive to the factory or the launch site and make sure that spacecraft could actually talk to NASA's tracking and data networks. CTV is stitched right on this patch, next to SIMS and TESTING. Those three words were the work of Goddard's Simulations and Compatibility Test Branch. A spacecraft that cannot be heard on the ground is lost no matter how well it flies. The people on this branch made sure that did not happen.

Goddard, in Greenbelt, Maryland, managed NASA's tracking and data networks, the Space Network with its Tracking and Data Relay Satellites and the Ground Network of tracking stations. The Compatibility Test Vans were based at Goddard and traveled to the spacecraft, where they checked out its radio interface with the networks and gave the mission operations control center a direct link to the spacecraft on the factory floor. A van could also send spacecraft telemetry through the Ground Network and NASCOM, NASA's communications network, and serve as a data source for network verification tests. Back at Goddard, the Simulations Operations Center ran Space Network simulations and data flows, with an RF facility that could talk to a Tracking and Data Relay Satellite through a small earth terminal on the center. Through its NASCOM link it could reach every element of the ground data system during simulations and end-to-end tests.

The patch is a 4 inch circle with a red merrowed border and a white outer ring. SIMULATIONS AND COMPATIBILITY TEST BRANCH runs around the ring in red block letters, with NASA GSFC across the bottom. In the blue center, a white Space Shuttle orbiter climbs to the right with UNITED STATES on its wing. Off its nose is a satellite with two big round dish antennas and solar panels, the outline of a Tracking and Data Relay Satellite. TESTING, SIMS and CTV are stacked in white, and an American flag waves across the bottom of the field. It has an iron-on backing.

Nobody watches a compatibility test on the evening news. It is hours of checking frequencies, data formats and links, run again after every change until the numbers are right. When a shuttle crew or a science satellite talked to the ground on the first try, it was because a team like this one had already proven it would work. The orbiter and the relay satellite on this patch belong together for that reason. The branch's job was the connection between them and the ground.

It fits a shadow box with Goddard, TDRS and shuttle mission patches, or the jacket of someone who rode along in a test van or ran sims at Greenbelt. It is also a good gift for a family member who spent a career keeping spacecraft and ground stations in step. Every good pass started with a test.