BK25.1123 was launched at 1705BST this Saturday, 15th September at the Midland Sky launch event at Norton-Juxta-Twycross, Leicestershire.
The launch was a spectacle of the awesome majesty of the Black Knight. However it wasn’t a perfect trial. There was an unexplained anomaly in the recovery system at apogee. Drogueless separation (which worked in ground trials, and the previous firing) failed despite both the primary and redundant pyro both initiating correctly. The rocket came to a stop at around 3,500ft (as planned), turned over and in the absence of a separation event and consequently a stable configuration, promptly began accelerating back to the Earth (definitely not planned). At something like 250mph and 800ft in altitude, the main primary and redundant pyros initiated as per the mission profile (for the altitude at least); bringing the chute out to a dead stop in a microsecond and probably ~10,000g of instantaneous shock. At the forward end of the rocket the parachute took all the brunt of the deceleration and tore apart as it inflated. The nosecone and forebody, saved by the damage to the parachute, were unscathed and descended under a flailing canopy to a gentle(ish) touchdown. Whilst the parachute was shredding apart, the fincan/forebody joint, that should have separated at apogee, was catapulted apart and the bolts attaching the shock cord to the fincan were ripped through the internal bulkplate. The fincan then plummeted some 600ft, to a hard landing which caused significant damage.
We are yet to interrogate the flight computers and obtain the exact flight details, such as max altitude, speed, etc. Perhaps these data will yield an answer as to why she didn’t separate at apogee on this occasion. Unfortunately we shall probably never know for sure what caused saturday’s anomaly. The recovery system on BK26 will be completely different and so there is no chance of replicating this failure in the subsequent design… but this doesn’t make it feel any less painful to see our beautiful creation in her current state.
The recovery of the rocket for this trial was very much the secondary objective; with the primary goal being another demonstration of the static stability of the Black Knight, and reinforced confidence that the configuration could be launched in the full scale variant. This objective was met outstandingly, BK25.1123 erupted from the tower as if she were fired from a bow, that is to say “straight as an arrow”. On the back of this launch, we have no doubts that a BK26 rocket which is faithful to the same proportions and attributes, will replicate the same awesome display (but on an unimaginably enhanced scale).
BK25.1123 has done us proud, we will not allow her to remain in her current state. We will lovingly restore her to her former grandeur, never to launch again (she has performed two launches better than we could ever have hoped), but to act as a constant reminder of our ultimate goal, a reference and anchor to keep us on course and also just to behold the awesome sight of a Black Knight rocket in our workshop and wherever Crusade Rocketry exhibit our mission.