Phineas Freak Posted June 20, 2016 Share Posted June 20, 2016 BTW, for everyone with mad modeling skills (not really...) it is possible to get the OSIRIS-REx model and port it to KSP: http://nasa3d.arc.nasa.gov/detail/osirisrex-2013-comp. Blender can import .lwo files but the animations (solar arrays, sample arm) must be done from scratch. And it needs an SRC on top of that. Quote Link to comment Share on other sites More sharing options...
Nefrums Posted June 20, 2016 Share Posted June 20, 2016 (edited) Getting an intercept with Bennu was really hard as ksp for some reason don't give you the intercept distance unless you get your trajectory within SoI of the target bodies trajectory, in this case it is less than 2km. I did finally manage to get an intercept when I was about 1000km from Bennu. The method I used was to hyperedit a dummy craft to a 1680m orbit of Bennu. This caused the dummy craft to exit Bennus SoI, and I could target the dummy craft. This is a very inaccurate method as I am targeting something that moves away from Bennu and setting up an intercept with that years after it left Bennu. I had to repeat the process several times to get more accuracy. Edited June 20, 2016 by Nefrums Quote Link to comment Share on other sites More sharing options...
Tristonwilson12 Posted June 20, 2016 Share Posted June 20, 2016 (edited) 9 hours ago, Phineas Freak said: BTW, for everyone with mad modeling skills (not really...) it is possible to get the OSIRIS-REx model and port it to KSP: http://nasa3d.arc.nasa.gov/detail/osirisrex-2013-comp. Blender can import .lwo files but the animations (solar arrays, sample arm) must be done from scratch. And it needs an SRC on top of that. I am already talking with @IonStorm , making a mod , I already have everything modeled and animated, working on textures, Edited June 20, 2016 by Tristonwilson12 Quote Link to comment Share on other sites More sharing options...
Fyrem Posted June 20, 2016 Share Posted June 20, 2016 On 6/19/2016 at 9:17 AM, Jetski said: There is a Bennu mod, works well for both RSS and stock. Look a few posts up ok I must be blind... where is the STOCK mod? Quote Link to comment Share on other sites More sharing options...
Nefrums Posted June 20, 2016 Share Posted June 20, 2016 5 minutes ago, Fyrem said: ok I must be blind... where is the STOCK mod? The .cfg files for both stock and RSS are in the same zip. They are config files used by Kopernicus mod. Quote Link to comment Share on other sites More sharing options...
Fyrem Posted June 20, 2016 Share Posted June 20, 2016 (edited) 2 minutes ago, Nefrums said: The .cfg files for both stock and RSS are in the same zip. They are config files used by Kopernicus mod. ahhh ok, .. so.. RSS vers not RSS .. understood now. Edited June 20, 2016 by Fyrem Quote Link to comment Share on other sites More sharing options...
Nefrums Posted June 20, 2016 Share Posted June 20, 2016 Here is my entry for category 3. (It might also qualify for category 1 and 5). I mostly looked at the trajectories on http://www.asteroidmission.org/mission/#cruise and tried to mimic those in the Kerbol System. Total dV used was 4854 m/s. Please tell me if you want more images, I have hundreds of screenshots from the mission. Quote Link to comment Share on other sites More sharing options...
Phineas Freak Posted June 21, 2016 Share Posted June 21, 2016 12 hours ago, Tristonwilson12 said: I already have everything modeled and animated, working on textures Most excellent! I was awaiting from RaiderNick to make some additions to the US Probes Pack with the hope of including it but i am glad to hear that you have made progress. Quote Link to comment Share on other sites More sharing options...
TheUnamusedFox Posted June 21, 2016 Share Posted June 21, 2016 Dangit! I was hoping to leave off on KSP for a few more months while mods update and bugs get fixed, but I've got to try this. Got to install so many mods, and I don't trust ckan... I'll hopefully be popping back into this thread sometime soon with my mission attempt, failure or not. But first I have to get an RSS install stable with far too many mods Quote Link to comment Share on other sites More sharing options...
IonStorm Posted June 21, 2016 Author Share Posted June 21, 2016 7 minutes ago, TheUnamusedFox said: Dangit! I was hoping to leave off on KSP for a few more months while mods update and bugs get fixed, but I've got to try this. Got to install so many mods, and I don't trust ckan... I'll hopefully be popping back into this thread sometime soon with my mission attempt, failure or not. But first I have to get an RSS install stable with far too many mods Note that any version after 1.0 is permitted, so if you have an older stable build that is fine. It is also not due until October, so you can still stick to your schedule. Quote Link to comment Share on other sites More sharing options...
TheUnamusedFox Posted June 21, 2016 Share Posted June 21, 2016 (edited) Rather than go with the cube shape of the actual osiris, I made it egg shaped and rearranged instrument locations. It may not look all that like the genuine thing, but it has stand-ins for most of the instruments, and I absolutely hate trying to build replicas of something - I much prefer put my own twist to a design, within some of the originals specifications/limitations. The spectrometer is the TAGSAM, as its the closest thing to it I was able to find in the hour and a half I've spent building this. It uses UDMH/NTO, rather than hydrazine, for the engine, and the same for the RCS thrusters. The total area and wattage of the panels comes within the ballpark of the real thing, but it is twice as heavy as the osiris. Dry mass of mine is about the wet mass of the Osiris. I'm going to try and plan out the mission later because I'm going to sleep for an hour or two, I can't do something as precise as an asteroid rendevous on 3 hours sleep. Also, I'm using KillAshley's real mass RSS Bennu, frustration will abound. I've only done a handful of successful missions out of Earth's SOI, so wish me luck! ...Just realized I left the name as something random, don't judge my lazy naming habits Edited June 21, 2016 by TheUnamusedFox Quote Link to comment Share on other sites More sharing options...
IonStorm Posted June 21, 2016 Author Share Posted June 21, 2016 4 hours ago, TheUnamusedFox said: Rather than go with the cube shape of the actual osiris, I made it egg shaped and rearranged instrument locations. So this looks a little like an early OSIRIS concept. Have fun. https://dslauretta.com/2014/03/06/ten-years-of-spacecraft-design/ For those striving for spacecraft aesthetic authenticity, here are a couple hundred images (all approved for release). They are roughly in reverse chronological order of the construction, integration, and testing phase of OSIRIS-REx. Quote Link to comment Share on other sites More sharing options...
The_Rocketeer Posted June 21, 2016 Share Posted June 21, 2016 I've been lurking around this thread for ages, but it just occurred to me that this mission is basically playing the solar system's highest-stakes game of knock-and-run (AKA knock-knock-ginger/knock-down ginger/ding-dong ditch) with a fracking asteroid! Respect @IonStorm, respect. Quote Link to comment Share on other sites More sharing options...
Tristonwilson12 Posted June 21, 2016 Share Posted June 21, 2016 2 hours ago, IonStorm said: So this looks a little like an early OSIRIS concept. Have fun. https://dslauretta.com/2014/03/06/ten-years-of-spacecraft-design/ For those striving for spacecraft aesthetic authenticity, here are a couple hundred images (all approved for release). They are roughly in reverse chronological order of the construction, integration, and testing phase of OSIRIS-REx. Those will definitely come in handy. Quote Link to comment Share on other sites More sharing options...
IonStorm Posted June 22, 2016 Author Share Posted June 22, 2016 23 hours ago, IonStorm said: For those striving for spacecraft aesthetic authenticity... It may not be obvious, but the red things are remove-before-flight covers as the the plate (with sticker) over OVIRS. For example in this image you can see the RCS thrusters on the corners are covered in red, there are red lifting eyelets, PolyCam and MapCam have red jackets, and OVIRS has a tan plate with a logo sitcker. All removed before flight. Obviously, so is the bag over the SRC at OTES. Quote Link to comment Share on other sites More sharing options...
Bev7787 Posted June 30, 2016 Share Posted June 30, 2016 If all goes well, Im getting the launch as my birthday present... thats why I'm thinking of doing it in RSS/RO Quote Link to comment Share on other sites More sharing options...
HoloYolo Posted June 30, 2016 Share Posted June 30, 2016 @IonStorm Happy Asteroid Day! Watch out for the Scientist's rocks! Quote Link to comment Share on other sites More sharing options...
Dman979 Posted July 1, 2016 Share Posted July 1, 2016 @IonStorm, any new and juicy photos for us? Quote Link to comment Share on other sites More sharing options...
IonStorm Posted July 1, 2016 Author Share Posted July 1, 2016 9 hours ago, Dman979 said: @IonStorm, any new and juicy photos for us? Just the 237 in this album. Keep an eye out on: https://twitter.com/OSIRISREx https://twitter.com/rex_pen https://www.facebook.com/OSIRISREx/ http://www.asteroidmission.org https://www.instagram.com/osiris_rex/ https://plus.google.com/+OSIRISRExMission/posts https://www.youtube.com/OSIRISREx https://dslauretta.com Here is an interview with our PI yesterday for Asteroid Day: Quote Link to comment Share on other sites More sharing options...
Bev7787 Posted July 2, 2016 Share Posted July 2, 2016 What are the specs for the thrusters? Quote Link to comment Share on other sites More sharing options...
IonStorm Posted July 2, 2016 Author Share Posted July 2, 2016 5 hours ago, Bev7787 said: What are the specs for the thrusters? Details on the propulsion system are ITAR controlled, but here is some public information: https://dslauretta.com/2014/12/16/integration-of-the-osiris-rex-main-propellant-tank/ Quote OSIRIS-REx propulsion system uses a total of 28 engines that are divided into four groups: a bank of four main-engine propulsion thrusters, six medium-thrust engines, sixteen attitude control thrusters, and two specialized low-thrust rocket engines. and https://dslauretta.com/2013/12/03/six-degrees-of-freedom/ Quote The main engines are 200-Newton (N) thrusters directed at the spacecraft center of gravity. A Newton is a unit of force that is equivalent to the gravitational force exerted on a mass of roughly one-quarter of a pound on the surface of Earth. These engines are used to perform the deep space maneuvers, the asteroid approach braking burn, and the asteroid departure burn. In addition, the spacecraft has a set of 22-N Trajectory Control Thrusters that provide attitude control (pitch and yaw) during the large maneuvers described above. These engines also provide thrust to perform smaller trajectory correction maneuvers, which are used to clean up the spacecraft state after the large burns. Most importantly, two of these thrusters are used to accelerate the spacecraft away from Bennu after sample acquisition. The ultimate in spacecraft attitude control is provided by a series of 4.5-N Attitude Control System thrusters. These thrusters are mounted on each corner of the spacecraft and provide full 6-DOF control. They are used for small thrusting maneuvers. In addition, since the reaction wheels continuously build up momentum, these thrusters are fired to remove this momentum in a process called “reaction wheel desaturation” or “taking a momentum dump”. One of the most critical maneuvers that OSIRIS-REx will perform is the orbit departure burn leading to sample acquisition. It is essential that we line up the spacecraft orbit and the asteroid rotation with extreme precision, so that we fly over the desired sample site at the right time. For this ultra-fine maneuver, the spacecraft will thrust using a tiny 0.07-N low-thrust rocket engine. Fortunately for us, these engines were just recently developed and qualified for the NASA GOES-R mission. Further searching finds http://www.aiaa-space.org/OSIRIS-REx/ which states: Quote The propulsion system on OSIRIS-REx is a monopropellant hydrazine system “borrowed” from the Mars Reconnaissance Orbiter, the Juno probe that’s scheduled to arrive in orbit around Jupiter on July 4, and Maven, the Mars Atmospheric and Volatile Evolution probe that has been orbiting Mars. Additional searching gives http://spaceflight101.com/maven/spacecraft-information/ which states that Aerojet is the vendor for MAVEN. A search for GOES-R thrusters comes up with http://www.moog.com/products/thrusters.html as the vendor and a search for Aerojet gives http://www.rocket.com/propulsion-systems/monopropellant-rockets. So other you can study Moog and Aerojet brochures to get all kinds of details. Quote Link to comment Share on other sites More sharing options...
the_Demongod Posted July 2, 2016 Share Posted July 2, 2016 @IonStorm So how is the fuel tank pressurized in vehicles like this to avoid ullage problems? A membrane that separates the pressurized gas and the fuel? That's the only method I've heard of but I'm definitely no expert in reaction control systems. Quote Link to comment Share on other sites More sharing options...
IonStorm Posted July 3, 2016 Author Share Posted July 3, 2016 6 hours ago, the_Demongod said: @IonStorm So how is the fuel tank pressurized in vehicles like this to avoid ullage problems? A membrane that separates the pressurized gas and the fuel? That's the only method I've heard of but I'm definitely no expert in reaction control systems. I really can't go into details about the propulsion system https://books.google.com/books?id=P5dBC_JgSLEC&pg=PA67 discusses how it us often done. This post https://dslauretta.com/2014/12/16/integration-of-the-osiris-rex-main-propellant-tank/ (mentioned several times in this thread) explains much of what you are asking: Quote The helium tank is a high-pressure (4800 psi) composite overwrapped pressure vessel that supplies helium on demand to the propellant tank. The function of the overwrap is to evenly distribute pressure loads across the entire tank...The helium tank is needed because the OSIRIS-REx propellant system operates in a pressure-regulated mode for our large main-engine burns...For each of our major maneuvers the helium is used to maintain constant pressure in the propulsion system. Prior to the start of one of these burns an upstream latch-valve is opened, ensuring a steady flow of hydrazine to the rocket engines. The latch valve is closed at burn completion. With these regulated burns, OSIRIS-REx achieves a higher thrust. In addition, the precise control of system pressure allows us to accurately predict burn performance and timing prior to maneuver execution. For the maneuvers using the smaller thrusters, OSIRIS-REx operates in “blow-down” mode. In these instances, the latch valve to the helium tank remains closed, and the residual pressure in the main propellant tank is used to flow hydrazine to the rocket engines. This strategy works because the burns are very short, compared to the main-engine burns, and the thrusters use a very small amount of hydrazine. Quote Link to comment Share on other sites More sharing options...
AnTREXon Posted July 3, 2016 Share Posted July 3, 2016 This is not really an entry, but more of a summary of the mission and an invitation to others to participate Quote Link to comment Share on other sites More sharing options...
IonStorm Posted July 3, 2016 Author Share Posted July 3, 2016 6 hours ago, AnTREXon said: This is not really an entry, but more of a summary of the mission and an invitation to others to participate Cool. Did you notice that Dante Lauretta, PI of OSIRIS-REx (basically my boss) commented on your video: Quote Dante Lauretta2 hours ago Great job Anton! I am happy to discuss the acronym choice in more detail - maybe on a future episode? Quote Link to comment Share on other sites More sharing options...
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