By Thomas C. White IV September 4, 2017
This summer, the Stanford Student Space Initiative's (SSI) Rocketry Team made the long trek to New Mexico to compete in the Spaceport America Cup against over a hundred teams from five continents. When it flew off the launch rail, SSI's rocket, the Heart of Steel, became SSI's highest launch to date, reaching within 1.5% of its altitude target of 30,000 feet, a maximum speed of 1.8 times the speed of sound, and a maximum acceleration of nearly 100g. And when the literal and figurative dust had settled, the rocket came in 1st place in its category, with a score more than 50% higher than the second-place team.
The nature of the competition required very strict testing. One question - key to the rocket's recovery and scoring - was whether the custom designed and manufactured GNSS hardware could continue to accurately locate the rocket under incredibly high accelerations. With the generous assistance of Vince Giralo at the Space Rendezvous Lab, a professional GNSS signal simulator was used to fake GNSS signal input into the avionics system. First, performance was assured by comparing simulator outputs to past test flights. Then, it was used to assure that the system would be able to reconnect after enduring the high acceleration of the final launch.