Tag Archive: RTG test

Nov 19 2020

Progeny Mk7-B Flight 4 Analysis

With all three previous missions failing for different reasons, the fourth and final planned mission for the Mk7-B received new objectives in the hope that this mission would be successful at last. The first change was to swap out the new booster for one that had been refurbished from a previous flight, which necessitated a launch delay that pushed the date back from 10/20 to 10/29. This booster was from the second Mk7-B flight back in late August and would be the first time we attempt to re-fly an engine. On the opposite end of the rocket we swapped out the parachute nose cone for a payload fairing that encapsulated a new Luciole smallsat prototype. This would be deployed onto the sub-orbital trajectory to test its systems and reaction wheels. Recovery would be of only the first stage booster and RTG casing from the payload, which did not contain any radioactive material for this mission. Other than the delay for booster integration, no problems occurred in the lead-up to launch.

The Flight

After good retraction of the support arms at T-5s the Boostertron II solid rocket motor successfully ignited for an on-time launch at 13:45 local, pushing the rocket upwards off the pad with an initial force of 3.3Gs while the fins actuated to begin rolling the rocket from 90° towards 34°. Less than 2 seconds after launch it had spun enough to allow pitch-over to begin as well, with the flight computer guiding it along a gradual and constant change rate throughout the ascent. By L+10s the rocket had locked onto its heading and thrust from the SRB had already begun to taper off from its max 74kN to reduce loads on the rocket as it approached Mach 1.

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Apr 21 2020

Kerbin I Mission Analysis

Originally planned to launch aboard an Ascension Mk1 in 2019, when that rocket was deemed unable to make orbit the payload was delayed and eventually committed to the Ascension Mk2, which was not able to fly until early 2020. The purpose of our first orbital satellite was to place our mission control team in charge of actual orbital operations, test the new Archtagon Aerospace RB-8 cold gas engine, test the new Probodobodyne OKTO common probe core and perform one final re-entry/impact test of the radioisotope thermoelectric generator (RTG). The probe carried a massive bank of batteries because the RTG remained non-functional, allowing for the probe to stay up in orbit for several days with the use of hibernation to save power. The mission got off to an uncertain start when the Viklun upper stage placed the satellite into an unstable orbit, leaving the team on the ground with the challenge of recovering the situation to still carry out the previously-stated mission objectives.

The Mission

Deployment to begin the mission was carried out once the Viklun stage came back into communications range of the ground via its more powerful 1.5Mm antenna. Having run out of power about an hour prior to this, it had been leeching electrical charge from Kerbin I’s battery banks to keep itself alive. Although Kerbin I only carried a 500km antenna, deployment was planned for now because afterwards Kerbin I could go into hibernation, conserving energy over the time it would have spent coming within its own comms range. The Viklun stage had enough residual power after separation it could continue to relay signal while Kerbin I transitioned into hibernation, after which the Viklun became derelict. How it fared after this can be read about in the Ascension Mk2 Flight 1 analysis.

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Feb 06 2020

Ascension Mk1 Flight 11 Analysis

Ever since the attack on KSC that damaged the launch pad and destroyed our last Ascension Mk1 rocket we have been working hard towards regaining launch capability. It took 2 months to repair the ground service structures as well as the actual pad surface itself, but coming into the new year and new decade we are once again able to send up rockets from the launch pad. This mission will renew the bid for orbit that began back in 2018, and was then suspended at the start of last year when the rocket proved incapable of flying a trajectory that would allow it to enter a decaying orbit without running out of fuel. After testing new guidance fins on the Progeny Mk7-A, it is now time to scale them up to 1.25m rockets and see whether they can give the additional control authority needed to allow the rocket to pitch over faster. This mission will also see new 1.25m payload fairings based on the 0.625m ones that flew on the Progeny Mk7-A, which will be tested to see how they perform under the heat and pressure of ascent. The payload itself contains another RTG test article so it can be slammed into the ground after the flight and analyzed afterwards to determine whether it successfully remained intact and would have not spilled radioactive material.

The Flight

Due to tightening operational budget constraints, we can no longer afford to fail fast for iteration – in fact we can’t really afford to fail at all. This has led to new policies and stricter launch commit criteria (weather, build process, flight quals, etc) going into effect this year. The result was some early delays for the launch due to weather being outside of acceptable constraints, but thankfully it did not remain uncooperative for long and the countdown was able to begin and run to conclusion with no further issues only a day later than planned.

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Oct 10 2019

Progeny Mk7-A Flight 2 Analysis

After the failure of the first flight earlier this year, the Mk7 project was mostly shelved as a stand-alone endeavor to develop an orbital small-sat launcher and had to wait until it could provide more use to future Ascension designs before enough reason existed to attempt another mission. In addition to making a second attempt at testing the steerable guidance fins, gimbaling engine and reaction wheel control system from the first mission, a new payload fairing system was introduced along with a test version of the radioisotope thermoelectric generator that we intended to crash into Kerbin so its casing could be tested.

The Flight

Although everything went smoothly during pre-launch operations a storm system out to sea made the weather over KSC inhospitable to rocket flight even though it was expected to improve by launch time. Forecasting is still a bit of a dark art and so we were forced to hold just outside of the final countdown at L-30 minutes and wait to see if conditions would become more receptive to launch before the end of the day cycle. Due to not needing to immediately recover the payload from the water we had no problems launching at night except for the fact that this rocket design is still new and we wanted good visual tracking conditions which meant at least some daylight. If we couldn’t launch before sunset we would have been forced to scrub for the day cycle.

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