Rakaydos

Ss far as getting a biomass through flicht and null g... what about an expandable habitat, which compressed id completely filled with water, but once in orbitvand spinning it is inflated eith compresded air to provide a mixed environment. Thoughts?

But... but that's CHEATING! *agast*

If we get that far, I'd be willing to bet we can borrow something. Personally, I'm looking at this less as a kerbal forum mission, and more as a kerbal forum presentation to the Cubesat Community- "We could totally do this if we had a million dollars! (and a ride) Really! Here's how!"

Has to be RSS or it doesnt count. also the launcher you use has to deploy something else in geosynch orbit, to calibrate the misson properly- since we're depending on a Geosynchronus Transfer based launch orbit.

Excuse me if I'm leaping on a slip of the toungue, but if alpha and beta radiation (energetic particles) are more of a concern than gamma rays (Ionizing EM radiation), would maintaining an active magnetic field on a drive make electronics more reliable? Would the field strength required even be reasonable as a solar powered drive system? (I know I'm going afield of the current topic- I'm still working on the "advanced mission" in another topic, and would love your input) What about combining this idea (the gravity jar) with the tether centerfuge idea? the biosphere would be in (or expand from) 1 cube, and the cable connecting it to the other cube would relay camera and sensor data from the hardware in the second cube.

Out of curiosity, how good is titanium, tugstin, or another "heat shield" grade metal as radiation shielding? perhaps a more adventerous cubesat could have a single mass penalty do double duty? If alpha or beta rays are the problem, then for a design that uses an ion drive, can the magets for the drive remain powered even outside operation, and use that for shielding? As I recall, the range of the magnetic field is usually a problem for that approach, but a cubesat is a tiny target.

So, from a feasaility standpoint, Lunar flyby just needs a GTO carrier and a few hundred Dv. Science is limited to stand-off instraments- visual imagry, possibly laser spectrography. More ideas appreciated. For beyond the moon, what range of Lunar angles can we, (with a perfect lunar insertion) get a solar semimajor axis of 1 AU? (I expect this will be limited by the lunar surface on one extreme, but what would that angle be, and what is the other angle, where we fail to leave earth's SoI/never enter the moon's SoI at all?) Some angles will require more DV from GTO than others, of course, but I want a hard look at the how different lunar slingshots can generate the possibility of an exact 1 year flight time. Science for a solar orbit is a question of command and control endurance outside earth's magetosphere, possibly a first for such a small craft. Any other science we do would pale in comparison, I believe- the very thing that makes this so hard is why it is so interesting scientifically. Once returning to earth's SoI, we can aerocapture in the upper reaches of the atmosphere- we wont really have much interplanetary velocity so we dont need much aerocapture Dv at all. A basic heat shield, and a record of flight instriments is again all the science we would need, as we would be pushing new boundaries. Once that trinity is complete, we can look at the sequal- the earth slingshot, a mars aerocapture from earth control, and the phobos orbit/crash/landing.

finished this a few days ago... might as well cross post. http://forum.kerbalspaceprogram.com/threads/57197-The-ultimate-Jool-5-challenge-land-Kerbals-on-all-moons-and-return-in-one-big-misson?p=1263192&viewfull=1#post1263192

here's an idea... for a reentry test, having a U1 cubesat unfold from this: Into something like this: ...using the hinges for flight control. The wings, of course, would have to be made of a sutibly heat tolerant material, but the idea is to gain flight control with a cubesat's launch characteristics, while protecting anything on the glider's backside.

Agreed. There is plenty of fun in designing a mission and then challanging the eggheads to do it in our place.

You mention that a cubesat would need custom hardened eectronics if it needed the endurance we need out of it- gotcha. That's a speciaty that is not mine, however, so I'll leave that to forumers who know what it means to rad harden things. You mention that NASA is unlikely to underwright a LEO ride, let alone a GTO ride- understood, but this topic is more foused on the design of the craft to make completing the final goal possible. Did I miss any? While not quite a Sifi Theory thread, it is very much a structured "what If" topic, intended as much to keep the phobos topic OUT of the main thread as any real benifit.

Nasa releases satelites into GTO all the time. How do you think they get up to GSO in the first place? They have to make the circularization burn themselves. (well, Ok, NASA doesnt do it anymore... but my point stands, the shuttle wasnt made to reach Geostationary orbit, but it put plenty of satelites up there.)

GSO is out of the picture. GTO, however, is better than GSO would have been. The Geosynch citcularization burn is a huge Dv hog that doesnt get the probe anywere. Geosynch TRANSFER orbit, however, has all the energy of getting out to geosynch, with more oberth effect at periapse. It's the periapse burn that makes Lunar transfer a viable option.

My bad, I meant apollo 8.

Did you allow for the "free" delta V we get from launching from a GTO flight? The numbers K2 has posed suggests that it only takes another 600 or so Dv beyond GTO to reach LTO- from there, just wait a few orbits and you've got a lunar flyby. Even if the probe dies there, it's already gone furthur than any other "minor" probe has before. But if we can put it specifically in a solar orbit with a 1 AU semimajor axis, we would have an opportunity for more. Rosetta used that very maneuver to slingshot off earth to mars- assuming we had perfect control of our probe, there's no reason we couldnt do the same, for no fuel costs at all. (or we could just practice interplanetary aerocapture off earth- it's not like a 10 lb probe will be a danger to the ground even if we fail) If we reach mars, aerocapture or burn up, we'll still have made it there years before any manned mission, and done what even major nations havnt done. Phobos is the cherry on top of this fortunate turn of events. If we make it through each of the previous trials, it will take a certian amount of Dv to orbit Phobos, and a certian additional amount to land. And THAT landing, planting a kerbal flag on Phobos, is something NO eartly nation has done... and we might have done it first. If all goes well. It's not just a phobos mission. Phobos is just having contingencies for success. This is a valid concern. It is something we will have to answer, before this topic is done. Thank you for raising it. We need a ship before we can put a science payload o it. Apollo 8 didnt bring much scientific equipment to the moon besides a camera... but the photo of Earthrise is one of the most influentual images to come out of the modern era. Like apollo, this would be a publicity stunt, not a scientific undertaking- science comes second to showing that "we the people" can send things to other worlds... the moon, mars, perhaps even phobos.

For the highlighted, I would suggest a flexible timetable over a concrete launch date- that is, a list of launch windows that can be made to work, the more the better. Ideally, you would want to build enough flex in our plans that any lift we get could be usable, even if we have to go for venus instead of mars, or some such. I merged your first three as "commandand control capability for at least 3 years", but I appreciate the clarification. I would argue with your comments on aerocapture, given K2's commentary- a modest heatshield should be plenty. But my assertion should be backed by better simulation and testing before we can consider this "done" "Land on phobos" seems to break down as either a minimum TWR on an empty fuel tank or shock absorbing/lithobreaking structure. Do you have any other ideas for that?

Not from the ground... but if you can retrieve old nasa space debris and assemble it into a spacecraft, all power to you.

It's a cubesat, not a colony ship... there's no room for the manpower of a small nation onboard.

if you want to talk about impossile missions, I've asked a question in the Phobos Cubesat thread, whether I've missed any requirements needed for the mission. Then I welcome people ripping into why those requirements are impossible.

Assuming noone pokes any holes in my flight plan above, here's what I see being the requirements for a phobos lander. A GTO lift at the right general time of year (For a mars intercept) An Ion drive with at least 1500 ms of dv. A reaction control system or reaction wheel setup to point the sat where it needs to point. A way to identify which way the ship was pointed to start with. At least 3 years of reliabe command and control endurance A titanium heat shield on at least 1 quadrent. Something that is at least notionally "science" payload. Can anyone think of something else to add? Then we can start listing reason why each point is impossible and we dont know what we're doing... so we can start figuring out how to do it.

Given a launch to gto... Within less than a month of waiting in orbit, the moon will be in position to slingshot you to solar orbit- your delay can be any multiple of your orbital period, which can be any value between gto and lto without any additional dv. The moons position relative to earth+sun is based on our (forced by launch provider) initial orbit, but the lunar slingshot height csn be adjusted to generate a solar orbit with a semimajor axis of one AU from most positions. Earth/mars orbital positions can be manipulated by solar orbit course correctios... within reason, of course. Did I miss anything?

What about inflatable struts for an aintenna arm? Lightweight hollow plastic pressurized at less than .1 bar would still become rigid in vacuum, and be lighter than most structural materials.

Thats not actually a problem if we are willing to do a few orbits first. We can delay lunar insertion for any multiple of our orbital period, and our orbital period can be anything between GTO and LTO without affecting our Dv budget. With a course correction 9 months into solar orbit (apoapse and 3months from earth flyby) we can trade dv for martian launch window. There are technical problems with the phobos mission, but that particular one is solved.

Im on my phone right now so I cant copy and paste, but can someone copy the phobos relevant info over to the Ke rbal 2 Magic Boulder thread? I want to kerp that kind of planning info in one place.

Can someone find the range ee would need to hiit for an aerocapture? Whats the weakest dv change ee would need to avoid going back to interplanetary space, vs the greatest Dv change without crashing on mars?