DRAKE TEST VEHICLE

Executive Summary
The Drake flight vehicle test portion of the Drake/Terra Nova motor feed staging system project was scheduled to be conducted at the “BALLS 15” event at Black Rock, Nevada, September 29 - October 1, 2006. A group of Tripoli Pittsburgh members comprising the majority of the Drake team were present for this purpose, as well as for pursuing several individual rocket projects. When conducted, on Sunday, October 1, the flight of the Drake failed to successfully demonstrate the motor feed staging principle. This fight resulted only in the first stage firing successfully, while the second stage did not ignite in the ascent phase. However, the second stage did ignite after the drogue parachute was deployed in the recovery phase. Although this created a severe rotation during descent , the recovery parachute and harness held together, the main parachute deployed at 1,100 ft., and the rocket was safely recovered. Post flight inspection revealed that the Rouse CO₂ system did not engage and eject the first stage/ignite the second stage as planned. It is probable that either the stress of recovery deployment or the deployment of the first stage recovery system inside the airframe (since it did not eject as planned) had jostled the whole motor stack, resulting in enough movement to at least partially eject the first stage sabot and engage the second stage ignition switch, causing it to fire while the motor feed piston was not locked in the downward position. This in turn caused the second stage motor to thrust forward into the airframe while burning, distorting the internal rack and largely destroying the lower airframe tubing. Post flight inspection revealed that all systems, save the Rouse CO₂ system, had functioned as designed, and the failure of the Rouse unit to deliver pressure was the result of faulty assembly by the project team leader. Most of the flight vehicle is intact as are the motor sabots (with the exception of the fiberglass recovery section of stage one, which is missing). With some fabrication effort, the flight vehicle could be rebuilt, with far less effort than was the case for the original.

Narrative
All members of the project team who were scheduled to participate were present at Gerlach, Nevada by Thursday afternoon, September 28, 2006 (some members had arrived the previous weekend). Activities for the weekend were laid out. Since Friday, September 29 was the only day Dave Rose and Joe Pscolka could attempt their planned L-3 certification flights, the team agreed that this would be the focus for that day, with Saturday, September 30 identified as the flight day for the Drake. Accordingly, Thursday evening was 100% devoted to prepping for the Rose/ Pscolka Friday flights. Some mild pre-work on the Drake was performed by the team leader, such as fitting the fins. As planned, Friday was a day that the project team plus NASSA members focused on support for the Rose/ Pscolka flights, both of which were successful.

It was planned that the team would focus on flight prep for the Drake at Bruno’s Motel in Gerlach on Friday evening. The four key tasks to be completed were building two motors, completing recovery arrangements for stage one, preparing ejection charges, and building the Rouse CO₂ unit. Prepping motors was challenging, in that the K-1100 reload supplied by the vendor was incomplete, and pieces/parts had to be taken from a non-involved motor reload kit to complete the first stage. Also, it was discovered that the upper stage was problematical because that sabot had an extended-delay forward closure, and the J-415 motor kit was not one with an extended delay. The team leader was obliged to cut/modify delay grains and liners, piecing together an ad hoc extended delay.

Unfortunately, due to competing commitments and various interactions with BALLS attendees, the flight team was not able to as fully support the Friday prep effort as planned. This situation, exacerbated by to the motor prep problems, meant that several of the tasks intended to be completed were left to be performed in the morning at the field, not least of which was assembly of the Rouse CO₂ unit.

Similar problems of competing priorities plagued the flight team at the field on Saturday morning, a situation made even more challenging by many questions and interruptions directed to the team leader from other BALLS participants, and at least one period in which he was obliged to discuss TRA organizational matters with a New York Times reporter. Flight prep thus proceeded in fits and starts, but by late morning, it looked as though Drake was at last ready for flight. However, just as final arrangements were being made to take the Drake to the launch pad, a considerable afternoon-long dust storm prohibited the flight for the rest of the day. The flight was re-scheduled for Sunday.

Realizing that the same potential existed for a dust storm on Sunday, it was agreed that Drake should be flown as early as was feasible. At about 10:15 AM the Drake was ready for flight.

Following an LCO miscue, in which the Drake flight was announced but another rocket launched, the Drake was ignited. Take-off was fast and a strong, stable first stage boost was seen. However, the expected firing of the second stage did not occur, the rocket arced over at first stage apogee, and the recovery system deployed the drogue parachute. At some point in this phase, the second stage was seen to ignite, and the Drake spun violently under its recovery system until the motor burned out. The rocket then descended normally, and at 1,100 ft., the main parachute was deployed. Fortunately, the second stage motor burn was completed well above the ground, and the recovery system survived (albeit becoming fairly tangled), so the rocket landed safely at a normal rate of descent.

It appeared that the second stage motor had fired as a result of the recovery deployment, and not as a result of the piston engagement. When the rocket was recovered, the lower airframe was burned, cracked, and bent at about a 30-degree angle. This revealed that the piston had not engaged, and one of two scenarios then occurred: 1) the force of the parachute deployment forced the motor stack downward far enough (the shear pins initially retaining stage one are weakened and/or burned by the motor exhaust – an expected feature of the flight) for the second stage ignition switch to engage. 2) the motor ejection charge of stage one, designed to deploy a parachute after this stage was ejected, fired off inside the airframe (since the motor was not ejected) and this pressure either triggered the second stage ignition switch, or blew stage one motor clear of the airframe, permitting stage two to drop down and fire. In either case, with the piston not locked in the downward position, the second stage motor traveled back up into the airframe under power and burned the lower airframe, motor rails, and lower retaining hardware. The first stage was spotted and recovered by Christine. Its parachute section was missing and the case was blackened. It is not clear if this was the result of its own recovery charge deploying while still in the airframe or if it was in proximity to the stage 2 motor when it fired.

Post flight inspection revealed that all systems except the Rouse CO₂ system had functioned as designed, and the failure of the Rouse unit to deliver pressure was the result of faulty assembly by the project team leader. The electric match holder of the Rouse unit contains two small wells for redundant matches. These holes are drilled though from the inner area where the pyro charge fires the piercing piston into the CO₂ cartridge, thus pressurizing the system. Each electric match fills this hole and keeps the pyro charge pressure contained to power the piercing piston. If two matches are not used, the extra hole must be plugged, as was done on all four Drake ground tests. However, during assembly for this flight, plugging the second well was overlooked. The pyro charge had clearly fired (initially, the team leader thought the G-Wiz board had failed to trigger the pyro charge – this was an incorrect assumption), but because the unused e-match well was not plugged, much of the pyro charge pressure vented out through the hole and the piercing piston was not propelled sufficiently to pierce the CO₂ cartridge. Thus, the lack of a plug of material the size of an electric match head prevented a successful flight.

Vehicle Condition Details
The following is an inventory of the major components of the Drake, and post-flight condition:

Conclusions
It is believed that the design principles of the Drake are sound, and would have resulted in the vehicle performing as designed had the prep error not been made. It was a extremely disappointing to have come so far and have the first flight test fail, with significant damage to the rocket, as a result of a preventable error. The project team leader, as the one who made the error must bear the chief onus of the failure. It was also clear that prep efforts of such a relatively complex rocket were too repeatedly interrupted, and had contributed to the potential for human error. Too much delay and resource loss was permitted, and this translated into flight prep in which all systems were not as carefully prepared as necessary, with some, but not all, being double-checked.

In effect, the first flight test of the Drake became an unexpected test of the human factors in group project team dynamics. Learning from this, it is believed the following steps should be taken with this and future group projects:

Reasonably balanced responsibilities and associated schedules must be determined, explicitly communicated, and understood by all team members.
Sufficient and realistic task completion times must be part of this scheduling, to avoid hasty and less than thorough attention to detail.
When project schedules are agreed, they must be supported and not derailed by “on-the-fly” re-prioritization of project or non-project activities.
Check lists must be established for all phases of preparation of flight vehicles. This is especially true of complex projects. It is also desirable to establish a practice of a team member performing a second quality-check review of all steps that are completed on the checklist, to ensure errors are caught.
Whenever possible, and as much as safety will permit, preflight tasks should be performed off the flying field in controlled and well-lit conditions. Distractions from non-involved people should be avoided/minimized. Preparation tasks that must be performed on the flying field should be done following a “back table” practice (i.e. on a table facing away from, and not readily accessible to, non-involved individuals).

Next Steps
Most of the flight vehicle is intact, as can be seen from the details above. With some moderate fabrication effort, the Drake flight vehicle could be rebuilt, with far less effort than was the case for the original. However, the project leader has conferred with the chief engineer, and several safety features which will disable an unplanned firing of stage 2 should the normal staging sequence not occur are deemed desirable and feasible. Preliminary revised plans (specifically to the recovery system for stage 1, and to the method of arming/disarming stage 2 ignition, have already been submitted to the chief engineer. There will be some delay in the off-season due to work commitments, but it is believed an alternative venue for a second test flight may be planned for early 2007. Proof of the basic concept must occur before plans are begun for the scaled-up Terra Nova.

CHECK OUT KEN'S TERRA NOVA PROJECT HERE