Northern Munar Monolith
Oct. 1st, 2018 06:24 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
the_sky_callsLots of things to do on this mission. Primarily, the Anomaly Surveyor add-on to Contract Configurator still has anomalies to find. TMA-6 is to be found near the northwest rim of the Northern Basin.
Referencing the Temporary Kerbal Maps website, the terrain of the area is pretty steep but there are some very small spots where the slope is flat. These will either be the tops of hills or the saddles between hills. The resolution of the map makes it hard to tell which it is but I suspect the monolith will be found on top of a hill. There shouldn't be a problem landing there.
There is another contract to “Plant a flag on the Mun.” One would think that would be easy but I think I forgot to do that on the previous munar mission.
Tech level advancement has purchased a new experiment; the Seismic Impact Hammer from the DMagic Orbital Science mod. (Details below).
There is also a contract to perform an observation with the DMagic Orbital Telescope while docked at M.O.L. Celestia and return it to Kerbin.
And though not a contract, in visiting the munar orbital station, and engineer and scientist will be rotated, bringing Bill and Sebastien home and replacing them on station with Frando and Berby.
Mission Designation : LUN-7
Rocket Model : Lunaria A-VI LM (Craft file)
Mission Objectives : Investigate TMA-6. Telescope Observation at M.O.L. Celestia
Total Mass (Mass to Orbit) : 241.2 tons (36.5 tons)
Total delta-V (dV to Orbit) : 7,422 m/s (4.064 m/s)
Surface TWR : 1.44
Total Cost : 124,949 funds
Contract for Construction : Year 3, Day 317
Nominal Build Time : 38 days
Launch Site : KSC
Launch Date/Time : Year 3, Day 363 @ 04:35
Pilot : Bilwel Kerman
Engineer : Frando Kerman
Scientist : Berby Kerman
At just short of two minutes into the ascent, the Dang It! mod generated a gimbal failure on one of the Protyle-style booster's six RE-I5 “Skipper” Liquid Fuel Engines. Were it a general failure, I might have had to shut down the Skipper opposite it to keep the thrust balanced. At that point of the flight, the loss of two engines would not have prevented the craft from reaching orbit. That is, so long as the failure was not explody. If the engine was overheating, it could have lead to an exposition, necessitating the use of the Launch Escape System. With just a gimbal failure, the thrust vectoring of the other engines was sufficient to keep the craft fully under control for the remainder of the ascent.
The transfer to the mun and orbital insertion was nominal. Optimal, in fact, because the trajectory into orbit lined up nearly perfectly with the landing zone with less than a full orbit to the deorbit burn. Recall the last time the craft needed to stay in orbit for nearly two days as the Mun rotated beneath it to get lined up on the landing.
I was right about the hilltop location of the monolith. There was a flat zone perhaps 300 meters across on top of a very steep sided dome structure.
The Dmagic Orbital Science mod includes a two-part science package. The first part consists of a Seismic Impact Hammer which is exactly what it sound like, a piston that thumps into the ground to send out seismic waves and listen for the reflection to determine the makeup of the subsurface. The system also includes Seismic Sensor Pods. These are small, discus-shaped probes that are hurled away from the craft with small decoupler charges. When they come to rest, their dispersal can improve the science returns from the Seismic Impact Hammer by 20%.
The problem is the decoupler. The charge goes off and the probes are hurled away from the craft. If they impact the ground at too high a velocity, they will be destroyed. You can adjust the decoupling force, like you can with any decoupler, but you need to do that in the VAB before launch. Set it too high and the velocity will be too high and destroy the probe. Set it too low and they won't be thrown far enough away to gather good science.
Another thing that can affect the survivability of the sensors is the terrain. Decouple them on flat terrain and their ballistic arc will have them impacting with the same velocity they left with. But, on top of a hill as this landing was, the sensor would fall below the elevation of the launch, accelerating further.
I had three sensors and was launching them with the default decoupling force.
The first one ended up landing at a lower elevation than it started, exploding on impact of about 73 m/s.
The second also landed at a lower elevation than it started but hit 2.8 km from the launch point at about 70 m/s and survived, skipping like a stone across the munar surface. Eventually, it slowed down but as it was on a slope it began to roll down the hill. And roll. And roll. It rolled for nearly half an hour before finally coming to rest at the bottom of the hill 2.4 km away from the craft.
The third sensor exploded like the first, slamming into the basin wall.
With one sensor, the hammer was only able to provide 70% of its optimal science.
The landing site rests in the Midlands biome and because I had landed in a midlands biome previously and set up a Surface Experiment Package there, I had decided not to bring a redundant SEP. That was a mistake because that previous landing was earlier in the tech tree when I only had two experiment modules. There are now seven modules available and I could have set up five of that seven that hadn't been deployed as yet. On the plus side, though, the midlands module is a pretty common place to land and so I will try to remember to pack an SEP on a future mission.
So, having done all the science available on the surface and planting the requisite flag, it was back to orbit to rendezvous with M.O.L. Celestia. Once there, the Orbital Telescope observation was performed and collected and the 495 points of science researched by the Mobile Processing Lab MPL-LG-2 since the last crew rotation was transmitted. The lab will replace those points at a rate of 9 points a day.
Even after the 45 degree inclination change, the Lunaria-6 craft had docked with the station with 542 m/s of delta-V. Needing only about 300 m/s of dV to break munar orbit and return to Kerbin, that extra fuel would be useful as I also realized that there was a contract available that I had missed during mission planning. Raying Kerman was trapped in munar orbit and needed rescuing. And so, instead of bringing Sebastian home as originally intended, he would remain on station until the next mission so as to leave an open seat on the Lunaria-6, which would rescue Raying and bring him home.
Mission Summary
Mission Elapsed Time : 3 days, 1 hour
Landing Site : Ocean 43 km east of KSC
Science : 36 points
Referencing the Temporary Kerbal Maps website, the terrain of the area is pretty steep but there are some very small spots where the slope is flat. These will either be the tops of hills or the saddles between hills. The resolution of the map makes it hard to tell which it is but I suspect the monolith will be found on top of a hill. There shouldn't be a problem landing there.
There is another contract to “Plant a flag on the Mun.” One would think that would be easy but I think I forgot to do that on the previous munar mission.
Tech level advancement has purchased a new experiment; the Seismic Impact Hammer from the DMagic Orbital Science mod. (Details below).
There is also a contract to perform an observation with the DMagic Orbital Telescope while docked at M.O.L. Celestia and return it to Kerbin.
And though not a contract, in visiting the munar orbital station, and engineer and scientist will be rotated, bringing Bill and Sebastien home and replacing them on station with Frando and Berby.
Mission Designation : LUN-7
Rocket Model : Lunaria A-VI LM (Craft file)
Mission Objectives : Investigate TMA-6. Telescope Observation at M.O.L. Celestia
Total Mass (Mass to Orbit) : 241.2 tons (36.5 tons)
Total delta-V (dV to Orbit) : 7,422 m/s (4.064 m/s)
Surface TWR : 1.44
Total Cost : 124,949 funds
Contract for Construction : Year 3, Day 317
Nominal Build Time : 38 days
Launch Site : KSC
Launch Date/Time : Year 3, Day 363 @ 04:35
Pilot : Bilwel Kerman
Engineer : Frando Kerman
Scientist : Berby Kerman
At just short of two minutes into the ascent, the Dang It! mod generated a gimbal failure on one of the Protyle-style booster's six RE-I5 “Skipper” Liquid Fuel Engines. Were it a general failure, I might have had to shut down the Skipper opposite it to keep the thrust balanced. At that point of the flight, the loss of two engines would not have prevented the craft from reaching orbit. That is, so long as the failure was not explody. If the engine was overheating, it could have lead to an exposition, necessitating the use of the Launch Escape System. With just a gimbal failure, the thrust vectoring of the other engines was sufficient to keep the craft fully under control for the remainder of the ascent.
The transfer to the mun and orbital insertion was nominal. Optimal, in fact, because the trajectory into orbit lined up nearly perfectly with the landing zone with less than a full orbit to the deorbit burn. Recall the last time the craft needed to stay in orbit for nearly two days as the Mun rotated beneath it to get lined up on the landing.
I was right about the hilltop location of the monolith. There was a flat zone perhaps 300 meters across on top of a very steep sided dome structure.
The Dmagic Orbital Science mod includes a two-part science package. The first part consists of a Seismic Impact Hammer which is exactly what it sound like, a piston that thumps into the ground to send out seismic waves and listen for the reflection to determine the makeup of the subsurface. The system also includes Seismic Sensor Pods. These are small, discus-shaped probes that are hurled away from the craft with small decoupler charges. When they come to rest, their dispersal can improve the science returns from the Seismic Impact Hammer by 20%.
The problem is the decoupler. The charge goes off and the probes are hurled away from the craft. If they impact the ground at too high a velocity, they will be destroyed. You can adjust the decoupling force, like you can with any decoupler, but you need to do that in the VAB before launch. Set it too high and the velocity will be too high and destroy the probe. Set it too low and they won't be thrown far enough away to gather good science.
Another thing that can affect the survivability of the sensors is the terrain. Decouple them on flat terrain and their ballistic arc will have them impacting with the same velocity they left with. But, on top of a hill as this landing was, the sensor would fall below the elevation of the launch, accelerating further.
I had three sensors and was launching them with the default decoupling force.
The first one ended up landing at a lower elevation than it started, exploding on impact of about 73 m/s.
The second also landed at a lower elevation than it started but hit 2.8 km from the launch point at about 70 m/s and survived, skipping like a stone across the munar surface. Eventually, it slowed down but as it was on a slope it began to roll down the hill. And roll. And roll. It rolled for nearly half an hour before finally coming to rest at the bottom of the hill 2.4 km away from the craft.
The third sensor exploded like the first, slamming into the basin wall.
With one sensor, the hammer was only able to provide 70% of its optimal science.
The landing site rests in the Midlands biome and because I had landed in a midlands biome previously and set up a Surface Experiment Package there, I had decided not to bring a redundant SEP. That was a mistake because that previous landing was earlier in the tech tree when I only had two experiment modules. There are now seven modules available and I could have set up five of that seven that hadn't been deployed as yet. On the plus side, though, the midlands module is a pretty common place to land and so I will try to remember to pack an SEP on a future mission.
So, having done all the science available on the surface and planting the requisite flag, it was back to orbit to rendezvous with M.O.L. Celestia. Once there, the Orbital Telescope observation was performed and collected and the 495 points of science researched by the Mobile Processing Lab MPL-LG-2 since the last crew rotation was transmitted. The lab will replace those points at a rate of 9 points a day.
Even after the 45 degree inclination change, the Lunaria-6 craft had docked with the station with 542 m/s of delta-V. Needing only about 300 m/s of dV to break munar orbit and return to Kerbin, that extra fuel would be useful as I also realized that there was a contract available that I had missed during mission planning. Raying Kerman was trapped in munar orbit and needed rescuing. And so, instead of bringing Sebastian home as originally intended, he would remain on station until the next mission so as to leave an open seat on the Lunaria-6, which would rescue Raying and bring him home.
Mission Summary
Mission Elapsed Time : 3 days, 1 hour
Landing Site : Ocean 43 km east of KSC
Science : 36 points
