Conducted on 4/11/26 at bluShift (Brunswick Station, ME 04011)

Departure time: ~7:15am

Arrival time of van: ~9:15am

Arrival time of u-haul: ~9:30am

Unloading, test stand securement, fill system integration completion: ~11:30am

Transitioning from ASI to solid motor (option 1 to 2 in "What's changed" section): ~3:30pm

Integrated solid motor into the chamber assembly and chamber mounted on stand: ~5:45pm

Test attempt 1: ~6:00pm

Test attempt 2: ~6:30pm

Departure from bluShift: ~7:15pm

What's changed:

ASI concerns heading into the test after several tests within the blast chamber, leading to three options:

1. Get to blushift and attempt to fire the igniter (without the main propellants) using the boards on the stand instead of the new janky ones. If we can fire twice, we will attempt a hotfire.
2. If the igniter (ASI) still does not work, we will replace it with our solid motor igniter assembly, which is what we had during our CDR.
3. If both of these ignition methods do not work, we will cold flow the engine, which will give us important pressure data and confirm that the tanks and plumbing can handle the operating pressure (which is especially important for the higher pressure scuba line at 2100 psi).

Check valves on press system have been replaced (old ones were leaking real bad)

Pipes connecting the press system to the fuel and oxidizer tanks have shorter height so now we don't have to take them out to fit the test stand onto the U-haul (the initial configuration was too tall).

High-Level Overview

• We arrived at the site earlier than last time (10 am) and performed valve actuation tests with no major issues.
• Then, we spent a couple hours testing/debugging our primary igniter (ASI), and were able to see that spark plug power is the main issue that has been preventing ignition. When we replaced our coil with a stronger bluShift coil, the ASI lit.
• However, the spark plug was exhibiting weird behavior, most notably that it sometimes did not turn off when we asked it to. We experienced an extreme example of this where we unplugged the battery to the spark plug and it KEPT SPARKING. This is something we'll have to debug ASAP.
• Because of the sparking weirdness, we decided to switch to our solid motor ignition system, and were able to swap it out quite quickly, and even tested the solid motor by itself to make sure it worked. We then proceeded to our first hotfire attempt.
• During the first hotfire attempt, we were able to validate 90% of our main procedure, including filling the scuba tank to almost 2000 psi, filling our ox tank with nitrous, and pressurizing each propellant tank with nitrogen. These are all new things we have never done on Osiris!!
• However, when we tried to ignite, we realized that papy could not both log data and execute the ignition command, which caused the solid motor to light but the valves not to open. Since a solid motor is not reusable, we had to vent out the remaining liquid propellants.
• We then attempted a second hotfire without data logging. However, although the solid motor lit and the valves flowed, the engine did not light. We're taking this as proof that a solid motor ignition system is not enough to ignite the engine, which means that fixing the ASI is critical path for Osiris.
• All in all, this test was MUCH more efficient than the previous one, and I'm proud of the experience we've been able to build testing-wise over the last few months. We are excited because despite us "wasting" time trying to fix the ASI, we were still able to attempt a hot fire twice in a single day -- there is more potential for us to streamline things down the line

Reflection

There were many improvements in both the operations and test campaign of the test, much of the stuff that we improved on was directly because of lessons learned from the first hot fire. It goes to show the importance of eventually just testing and running through the full operational procedures of the engine, even if the end goal wasn’t achieved, because there are many issues that  only arise from testing.

The team did much better in sleeping earlier (about 12am for most members instead of 3am on hot fire #1) which seems to have some benefit for mental clarity, but more importantly it ensures a more consistent test campaign and that team members don’t feel as burnt out. We left campus at about 7:15 am (much better than the 9:15 am ish last time), we could be even earlier if we packed the stand and supplies into the U-haul the night before and the U-haul is full with gas to avoid having to stop at the gas station. With these improvements we can probably get to the site around 8:30-9am, which would give us more than 8 hours to test and troubleshoot at bluShift.

On a personal note, I need to do a better job having enough food (more than the Dunkin’s) so that we are fuller while testing instead of relying on snacks.

Our van got to the site about 15 minutes before the U-haul did, we checked to make sure the roof wasn’t leaking (our tape was still there from last time) and to see how difficult it would be to move the brick wall so the SO has more access to the fluids panel (we ultimately did not do this as it would take too much work). 

Once the u-haul got there, we did what we did last time: move our supplies out of the U-haul and onto tables while moving the forklift to get ready to move the test stand. Also, we should ratchet strap the tanks upright to the walls of the U-haul next time, it was a pain in the ass having to secure them with the tanks laying down. The first priority once the U-haul got there, which should be the case for all future test campaigns, is securing the test stand. Once we secured the stand it was a matter of organizing everything, assembling the fill system, and attaching tanks to the fluids system on the test stand. 

We also used helium to pressurize the tanks for system and ASI purging in order to save some pressure for the nitrogen tanks. This might not be the case next time, Bayanni was planning on adding the 3.5k nitrogen tank which would allow us to system purge and pressurize the tanks without having to change tanks in between purge and firing procedures (which takes about 15 minutes because the nitrogen tanks have to be un-ratchet strapped from the wall, carefully brought to the back of the fluids panel (next time we need to take into account Bayanni having access to the fluids panel), and re-strapped fitted with the regulator). 

The majority of the testing time was spent troubleshooting the ASI, finding out the spookiness with the spark plug, and creating the solid motor system (long-wire to control station as well as using a motor to ensure it fired). Using the solid motor as the ignitor was a temporary solution only for this test, it would be highly ineffective for the RO to need to flip the switch for the solid motor as well as running the command. You also cannot re-light the engine if something goes wrong with the propellants not flowing (such as what happened during our first try with the solid motor, which fired but the servos did not open) if it was an ASI the matter would be simply re-igniting the ASI and attempting another file run ignite sequence. The second attempt of the hot fire (which occurred after Gerard was nice enough to give us thirty minutes to see if we can put a new solid motor into the ignitor chamber) commenced and we found that the servos went on with propellant flowing… but no fire. We found out later that the solid motor did indeed fire, but there must’ve not been enough activation energy to light the mixture. We got our second cold flow of the day, and proceeded to run the propellants through the pressurized gas serving as a sort of purge afterwards. 

SOP has been updated to reflect some of the changes from the test, it becomes more important that I review the SOP as well as make a log the day after the test as well as write more notes during the test when it's still fresh in my mind. I should also record timesteps of major events at the test site so the timestamps on the top of the page are more accurate and add objectives for each test. Operationally, I think we are getting much better and that our third hot fire test should result in an actual hot fire... BOM.