VANDENBERG AIR FORCE BASE, Calif. -- With safety being an integral aspect of the space business, Vandenberg is looking to adopt an innovative safety measure known as the Autonomous Flight Safety System.
The AFSS is a device that is placed on the rocket and collects a variety of essential data from the vehicle during flight. This data is then used to determine if the rocket is maintaining a safe flight or if termination is required.
“The AFSS is fundamentally a device that rides on the rocket, and receives a variety of sensor inputs – sensors contained within the device and sensors available from the vehicle,” said Jeffrey Cherry, 30th Space Wing Safety engineer. Sensors such as “the Inertial Navigation System or Global Positioning System receivers determine where the rocket is in space at all times; its velocity, acceleration and attitude. The AFSS device evaluates the data against range safety established criteria. Safety criteria is based on the trajectory of the vehicle, the objectives of the launch, and the performance capabilities of the vehicle.”
“There’s also a whole subset of ground infrastructure that we no longer need for an AFSS launch,” said Col. Andy Wulfestieg, 30th Space Wing chief of safety. “For example, the command transmitters cannot terminate a missile or a rocket in flight, for an AFSS launch. It’s still the same level of safety, but it’s just a different way of doing it. By putting the system on the rocket itself it reduces our dependency on a lot of ground systems.”
Before the use of the AFSS, a Mission Flight Control Officer would closely monitor the flight for all launches in order to initiate termination actions if required – for launches utilizing the AFSS, this task will no longer be performed by the MFCO.
“AFSS will give us a little bit more flexibility, because it allows us to support a wider range of performance for the rocket that was previously limited based on the line of sight constraints, signal delays, processing and display delays, and response times of the MFCO,” said Wulfestieg. “If the vehicle is doing it itself, we can take away some of the conservative assumptions we had to make to account for those issues.”
The development of the AFSS has withstood rigorous checks over the years to ensure safety is not compromised at the expense of efficiency – and the system is expected to be utilized in the following months.
“There are still certain rules related to on-board system failures that could result in a mission being terminated, just as launches that are controlled on the ground,” said Wulfestieg. “We have gone through extensive testing to make sure all AFSS components are working the way they’re supposed to and there is no single point of failure, so we have an equivalent level of safety as the existing ground systems. AFSS is going through final testing right now, to make sure that Space X’s system is ready to go for an upcoming launch scheduled later this fall.”
For members of all the different organizations who have put in the work to painstakingly confirm and verify the feasibility and practicality of this new system, their efforts are expected to soon pay off.
“This is a big change, something we’ve never done before,” said Wulfestieg. “I’m confident that we’ve had the right people looking at it, and everybody – from the wing to the headquarters, engineers and the customers – collectively completed the amount of work necessary to make sure that this system is ready to go. Before the safety office makes our final recommendation, giving the go-ahead for a launch to the wing commander, we will be certain that a user’s AFSS has met all safety requirements. It is an exciting time and AFSS will allow for some new and unique opportunities in the future.”