Spaceports: Autonomous Flight Termination System


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The reference to multiple incoming boosters is of course talking about 3 Falcon Heavy boosters returning to LZ-1, at least initially. Later, with multiple commercial flights a day, they could see simultaneous launches and returns by different operators.

 

http://www.techbriefs.com/component/content/article/8-ntb/tech-briefs/machinery-and-automation/24084-ksc-13978

 

Autonomous Flight Termination System Reference Design Hardware

 

Created on Tuesday, 01 March 2016

John F. Kennedy Space Center, Florida

 

The current range ground-based infrastructure is extremely costly to operate and maintain. NASA has developed an Autonomous Flight Termination System (AFTS) that is an independent, self-contained subsystem mounted onboard a launch vehicle. The AFTS reference system eliminates the need for a ground-based infrastructure by moving the flight termination function from the ground to the launch vehicle. It will allow multiple vehicles to be launched and tracked at the same time. AFTS is necessary to support vehicles that have multiple flyback boosters.

 

The AFTS can augment or replace the functions of the traditional humanin-the-loop system. Redundant AFTS processors evaluate data from onboard Global Positioning System (GPS) and inertial measurement unit (IMU) navigation sensors. Configurable rule based algorithms are used to make flight termination decisions. The mission rules are developed by the local Range Safety Authorities using the inventory of rule types taken from current human-in-the-loop operational flight safety practices. The main benefit of the AFTS is to decrease the need for permanent ground-based range safety assets with a corresponding savings in operational costs, and to increase the number of potential launch sites and corridors.

 

The ultimate goal of this project is to produce an autonomous flight safety reference design that may be commercialized for industry use.

The system uses a commercial off-the-shelf (COTS) chassis, a NASA-designed custom board,NASA-developed wrapper interface software, and the Core Autonomous Safety Software (CASS) running on a COTS processor.

 

The range requires that the AFTS system consist of redundant chassis with redundant sensor inputs. The sensor inputs can be GPS, INS, IMU, accelerometers, or any combination thereof. All sensor inputs can be available to both chassis.

 

Each chassis is capable of initiating a flight termination. If both chassis are healthy, and either recommends a flight termination, the flight will be terminated. If one chassis is unhealthy, its fail safe must initiate a termination unless it can verify the other chassis is healthy. If both chassis are unhealthy, both failsafes will initiate a termination.

 

This work was done by Lisa Valencia, Robert Morrison, and Roger Zoerner of Kennedy Space Center. For more information, contact the Kennedy Space Center Technology Transfer Office at 321-867-5033. Refer to KSC-13978.

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  • 11 months later...

Falcon 9 CRS-10 was the first mission to fly an AFTS (AFSS in USAF parlance) in active mode. Previously it flew on Atlas V, Delta IV and Falcon 9 in the secondary/shadow mode.

 

No more guy with the big red button - a vehicle can track itself and commit seppuku if necessary.

 

Patrick AFB, 45th Space Wing, USAF....

 


Air Force Eastern Range innovates, expedites access to space

By 1st Lt. Amanda Herman, 45th Space Wing Public Affairs / Published February 24, 2017

PATRICK AIR FORCE BASE, Fla. --

The U.S. Air Force has been breaking barriers since 1947, and this year is no exception with the implementation of the Autonomous Flight Safety System.

The Eastern Range has supported more than 3,500 launches to date. With more stakeholders demanding access to space, both the Eastern and the Western Ranges were faced with developing innovative solutions to launch rockets without compromising public safety while accounting for aging infrastructure and recognizing that the wing has fewer resources and personnel accomplishing comparable and greater launch rates than before.   

AFSS provides the capability to not only reduce reliance on aging range infrastructure, but enhances the ability to support more launches by expediting range turnaround times with more stringent safety standards and fewer people on console while reducing overall launch costs.

A self-contained, independent system mounted to the launch vehicle, AFSS determines if the launch vehicle poses an unacceptable hazard to people or property by using pre-established, programmed mission rules developed by Range Safety Flight Analysts. These configurable software-based rules are reliant on redundant flight processors using data from Global Positioning System and inertial measurement unit navigation sensors. If necessary, AFSS has the ability to destroy the rocket to ensure public safety. This system is crucial to increase overall range throughput to keep pace with the growing demands for providing assured access to space.

Air Force Space Command partners with industry to advance our space capabilities.  AFSS allows us to increase the pace of launch, reduce costly infrastructure and more rapidly build a resilient space enterprise.  These benefits will be felt globally, said General Jay Raymond, Air Force Space Command commander.  It assures access to space while maintaining public safety.

AFSS provides greater positive control in flight further downrange with a faster response time. It also increases over-the-horizon capability, which means theres no longer limitations by ground equipment line-of-sight.

AFSS also supports multiple objects in simultaneous flight, which is crucial as companies build rockets with the intention to land multiple boosters simultaneously. This changes the expectation for legacy and new entrant companies of the space launch industry to implement AFSS at the earliest possible date.

 Our role to ensure public safety during launches using this system is unchanged, said 45th Space Wing Chief Engineer Howard Schindzielorz. Our Flight Termination System requirements still apply for design, test, operational performance and reliability. We still develop the mission rules to provide public safety, but the system works with mission rule data files loaded into the on-board AFSS units. This essentially shifts the workload to the front-end of the launch process.

AFSS also increases launch availability due to fewer instrumentation requirements.

Implementing AFSS on future launch operations allows us to increase our flexibility, adaptability and efficiency while providing more launch opportunities and greater public safety without having to add additional people," said Brig. Gen. Wayne R. Monteith, 45th Space Wing commander. "These changes will not only simplify ground support requirements thereby increasing launch on-time probability, but substantially reduce launch costs. 

By changing the legacy range operations paradigm, the use of AFSS reduces range space lift costs through reductions in range equipment maintenance and upgrades. It negates the need for operation, maintenance, and sustainment of extensive real-time software and redundant hardware ground systems as well as multiple training programs. AFSS also eliminates the costs of requirements needed for non-AFSS launches to include Uninterruptible Power Supplies, ground-system software, Independent Validation & Verification and testing equipment.   

Complete cost savings for the ranges and users can be realized when all range users implement AFSS, said Maj. Allan Fonseca, Chief of Range, Policy and Procedure at Air Force Space Command.

The first operational use of AFSS was the successful SpaceX Falcon 9 CRS-10 launch from Space Launch Complex 39A at NASAs Kennedy Space Center Feb. 19, 2017. Adding to the complexity of that mission was the return of a first-stage booster landing at Cape Canaveral Air Force Station minutes following the launch.

"AFSS implementation was another historic and innovative first for the 45th Space Wing and the Eastern Range," said Monteith. "It proved our teams ability to meet evolving range demands and clearly demonstrates our commitment to meeting our mission partners needs."

With more stakeholders demanding access to space, both the Eastern and Western Ranges will begin to launch at unprecedented rates, with the 45th Space Wing driving toward delivering a schedule that launches 48 missions a year by 2020.

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From the above official statement...

 

Quote

We still develop the mission rules to provide public safety, but the system works with mission rule data files loaded into the on-board AFSS units. This essentially shifts the workload to the front-end of the launch process. 

They develop the rules...which is fine...but who does the coding and who does the uploads to the system. I am sure that the AF Eastern Range will want to review the "coding" to ensure compliance, which is understandable...but who generates the code and uploads it, since a "coding glitch" could turn out to be less than ideal and may even have "liabilities" attached.

 

I like the system...but, would be better if stated as who does what....may have to do some digging....:s

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Once the NOTAM coordinates and flight track are posted it seems pretty straightforward.

 

Best guess: parameters are calculated from the above by the range, then uploaded into the launcher avionics and AFTS/AFSS  through the providers launch network. Double-check.

 

 

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I am quite sure the NOTAM data will be double checked for errors by both sides....yes, they have been known to have an error or omission on occasion. I believe there is much more in play than just Notam's through..ie AF self destruct protocols within that area at altitude, 

 

There must be a system in place where the AF and launch provider both have the opportunity for a double check and the upload to be verified correct by both. Not an area for an ooops. I like the system...but trust is a very expensive proposition here...therefore trust no-one' system with control of your launcher till one is satisfied.

 

:)

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Should have clarified concerns...autonomous control, in this respect is fine, it just waves a huge "red flag" for issues. Has anyone actually encountered software that was glitch free, on the initial code and more importantly...on revision. Both sides of the fence will want to have access to all code for verification before use.

 

As the $$$ increase, trust is not an option...it must be verified.

 

I am sure they have this worked out, but would be real interested in seeing how this is handled as a process to alleviate "nerve endings".

 

:D

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I assume as time goes on...someone will upload pertinent information, where upon, we can construct what is actually involved in the process, for both parties.

 

SpaceX used the system in "shadow" and "live', must be tolerable.  :D

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Here's some "light reading"....:s

 

RANGE SAFETY USER
REQUIREMENTS MANUAL, AIR
FORCE COMMAND RANGE SAFETY
POLICIES AND PROCEDURES

 

Certified Current 02 December 2016

 

98 page pdf

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