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May 31 2018

Progeny Mk6 Block I Flight 5 Analysis

After sending 4 rockets on southward trajectories to see if we could find an end to the hazardous radiation region discovered ~350km above the planet, the final flight in that series recorded no radiation increase above the baseline 0.01rad/hr found outside the atmosphere. To determine whether the same could be said north of the equator, this flight sent up earlier in the week was planned to mirror the third launch of the Mk6 Block I that found an increase, but not to peak levels of 10rad/hr. If we could record similar measurements on this flight, we could determine the field is fairly uniform around the equator, otherwise we could find significantly more or less to tell us the field is asymmetrical.

The Flight

Because the rocket needed to launch northwards, the launch base had to be moved out into the field north of the runway so the rocket would not risk damaging the new service towers constructed on the launch pad for Ascension rockets. This presented some issues that slightly delayed the launch as cables run out that far to carry power and data were not able to handle the distance initially, and relays/repeaters had to be installed. Although we’ve had rockets launch from this area before, the power requirements of the Progeny Mk2.1 were much less and no data was needed other than a simple electrical signal to trigger the launch.

Despite the delay all other conditions cooperated to allow the launch team to meet the second launch time and send the rocket on its way at 15:50:00.06 local time. In order to make this flight as close as possible to the third one, no changes were made to the rocket so its ascent into space was almost similar. Due to the ballistic nature of these rockets, flying the exact same trajectory is not possible, and deviations will occur. This rocket traveled on a slightly flatter trajectory, igniting its second stage engine 1.94s earlier than the third flight, which allowed it to carry more speed (~11m/s over the third flight) and reach space 80ms sooner. Despite the difference in trajectory, the rocket still made an apokee of 481.124km, only 2.190km lower than the third flight. No issues arose during ascent or coast back to the atmosphere.

Unfortunately the rocket did not survive after re-entry. Despite coming back at speeds that were recoverable, the parachutes did not deploy in time to slow down the rocket before it struck the ground at several hundred meters per second. Signal was lost due to terrain prior to impact however an airship sent out to survey the area found the impact site. Nothing remained that was recoverable.

Telemetry Data

Flight Analysis

Good Comm Relay

This flight was a test for the Ascension Mk1, which will launch on a similar trajectory to pass over Sheltered Rock and Ockr, which will then relay telemetry data via our ground line connections. We’ve spent the last several weeks setting up substations in their comm networks that we can dedicate to our needs and ensure that the data is passed to us promptly upon receipt by the antennas located atop their highest peaks. Throughout the flight signal was strong and received well besides short intervals of plasma heating that blocked the signal during ascent and return.

Recovery Issues

As mentioned, the ballistic nature of the rocket doesn’t allow for exactly matching the trajectory of the earlier flight. The flatter ascent angle led to a slightly lower apokee but the rocket also did not reach its intended matching inclination of 43°, entering space at 41° instead. This meant the rocket was traveling more parallel to the equator and combined with the extra speed it was able to travel further downrange to the east than initially planned.

Not only did this bring the rocket down over a region of terrain extending as high as 1km ASL which gave the rocket less time to slow down, the code for deploying the parachute and air brakes was not monitoring height above terrain. This meant the parachute was deployed only ~300-400m above the ground. It’s an embarrassing oversight that will need to be corrected but thankfully was found before the first Ascension launch, as the recovery of that rocket could be over land as well.

Radiation Results

The flight returned no indication of high radiation levels during its entire duration, even though it did not fly quite as far northward as intended. This means the hazardous radiation region could be a lot more dynamic that initially thought. Ultimately at this point we will have to wait for an orbital probe to really be able to map out what is up there, but nonetheless scientists were intrigued by the results and will be looking to adjust their models accordingly to see if they can come up with anything that matches what we have observed so far:

Future Plans

This marks the end of planned Mk6 Block I launches. We will definitely see more in the future although for what purpose and in what capacity we don’t yet know. Now comes the time to look for the Block II to make its debut next month and attempt to determine if the hazardous radiation region extends only so far from our planet. Scientists can’t come up with any reason why it wouldn’t have an upper boundary at some point, but they are ready to be surprised as always by our incredible universe.

In addition to reworking the recovery code to take into account height above terrain for chute deployment, the team plans to also make the air brake deployment smarter – it will monitor the dynamic pressure as it builds during descent and once it begins to decrease the air brakes will slowly be deployed. Right now they are considering what ratio of deployment amount to dynamic pressure is safest to ensure that the brakes don’t get put on so fast the fuel tank they are attached to can’t handle the load, or the brakes themselves can’t (engineers expect the tank would crush before the brakes fail however). Then the code will also take velocity into account for deciding when to deploy the chute, not just altitude as it does currently since we know the Block I has an acceptable rate of descent by that point.

Although the loss of parts due to not recovering the rocket was a blow and Head of Finances Mortimer refuses to free up funds for replacements, we have just enough remaining in the inventory to assemble both Block II rockets at the same time to launch them within days of each other. However not enough parts allow for both rockets to be fully completed at the same time. If the first launch fails to be recovered, it will significantly delay the second launch as we will then be forced to order some new parts.