B787_300

Upsilon, you went to NARAM? also we should reboot the Model Rocket Thread (again)

and what forum this is posted on is more of a clue as my camp did not offer Aviation MB (but i have taught the Underwater Basketweaving and Cit in the Universe Class) also i wonder if i taught any of yall

so Neil did you enjoy watching my schools rocket? we were the one with the Quad copter in it

Eagle Scout, Gold Palm, OA Brotherhood, Camp Counselor (WSR), 35 MB (one MB and A week short of getting Silver... ) Anyone want to guess what i taught?

Shynung that is because they are really good insulators. a heat sink is different than an insulator, the whole point of the shuttle tiles are to keep the interior structure cool, a heat sink as discussed in the ebook i linked would have been way too heavy and still transmitted too much heat to the interior structure necessitating exotic alloys and a more expensive construction. Yes you are right that the shuttle had to be left to cool down, that is because the interior of the blocks heated up and stayed heated. There are plenty of you tube videos of people holding the red hot blocks of shuttle tiles shortly after they came out of an furnace. a true heat sink would cool down much much faster and would not be able to be held.

yes they can although efficiency is a HUGE issue. there are linear aerospikes that were tested as part of the NASP which were nominally rectangular but the issue becomes manufacturing cost and efficiency

they are NOT heat sinks... they are just really really good insulators. An ablative is any substance that burns away and releases gas. The benefit of the gas is that it helps carry heat away from the structure being protected and the char is a decent insulator until it gets blasted off by the air. The reason the Shuttle did not use ablative materials on the underside (the top side white fabric looking thing is an ablator, but normally doesn't get hot enough for it to start ablating) is that an ablator will not hold a very aerodynamic shape when it is ablating. IE the ablator will not burn off equally and leave divots and pits in the material which are really really bad for aerodynamics. On simple capsule designs maintaining such a perfect aerodynamic "mold line" is not as important. There were old ideas on using large metal (copper normally) heat sinks that would just absorb the heat, but were much to heavy. If you want to read more there is a free EBook by NASA on the subject that can be found at https://www.nasa.gov/connect/ebooks/coming_home_detail.html

to put it in an easily uderstanable context, In orbital mechanics everything is a Conic section (a parabola, a hyperbola, an ellipse, or a circle) to make the orbit math easier you have what are called Spheres of Influence, which are regions in which ONE body is really providing all the gravitational force. ( F = (G*M*m)/(r^2) ). if you are doing interplanetary stuff or going to a moon you use a system called patched conics for the preliminary orbit design, so you look at the orbit of an object until you reach the edge of a SoI, then switch SoIs and look at the orbit there, until you reach your destination. then you combine (Patch) all the individual conic sections together into one overall picture. that is why it is called Patched conics. Just as an aside when go from earth to mars (IRL) you look at 3 different SoI, the Earth, the Sun, then Mars. The math behind it is reasonably simple, but can be confusing. If you were to look at the more complex method then you have to do n-body physics which is very hard. the Forces due to gravity only become F = (G*M*m)/(r^2) + (G*M*m)/(r^2) + (G*M*m)/(r^2) + (G*M*m)/(r^2) + ... which is very very hard to solve.

/me wanders off to the corner and starts crying about how little rep he has as a Mod but congrats Duo, now take down Red Iron Crown

this is really just to help prove that the technology is all there, i would bet that another company would actually have to build the first real tracks and system.

5th go read Harv's Dev Blog for more about the developemnt plus some of the major devs just got off a vacation, and two days of work (IIRC) would have resulted in a dev blog much like last weeks

I would like to point out that the US is currently in transition between the two units. All school children are taught both metric and imperial and in STEM metric is much more common. In fact, most of my college professors prefer to use Metric because of the easy way the units work and will give us imperial to make sure that we know our conversion factors.

/me wanders in cough cough okay so as has been mentioned, the main issue is turn around. Remember an airliner can immediately turn around and go back out with a cursory inspection (the pilot's walkaround). The issue so far is that spacecraft have to deal with much more powerful forces than a plane. When it was originally designed the Space Shuttle was supposed to fly ~50 times a YEAR, about a launch every week. When NASA was promoting it to Congress they said turn around would be like an airplane. The images below show the projected turnaround procedure and then the actual one. Projected Actual NOW if both SpaceX and Airbus and ULA, manage to get it working the winner will be SpaceX with a reflight stack costing around 45 Million or so. BUT that is only if they dont have to overhaul the craft. The engines are the most expensive part of the craft and are designed to be used many times even if they are only fired 3 times overall. The most overkill are the Russian engines that are designed with a service life of 100+ firings even though most are fired 3 times (acceptance testing, Hot Fire, launch). if you dont have to do the engineering tear down that happened to the RS25s (SSMEs) then you are pretty good. The tanks are reasonably inexpensive, they are just hard to make well. this is the main issue with SpaceX's idea, if the tanks dont hold up well they have to take the time to replace them. Neither airbus nor ULA have that issue as the tanks are a separate component that "snaps" into place. The biggest issue with ADELINE is that it has WINGS and propellers. both of those ad crazy complexity to a rocket. plus with adeline then you really cant do a whole bunch of strapon boosters. The aerodynamics of the wings at hypersonic speeds when they are designed to produce lift at subsonic speeds is nuts. plus they add a lot of drag to the rocket. Overall, if they can get airplane like reusability, spaceX and airbus are the best suited, land near pad on pads or runway, where as ULA is the hardest, catch something that is heavy with a parachute using a helicopter. BUT it all depends on how fast turn around is. on a side note, Glider ADELINE in KSP (Real Drag, Strict Area rule FAR)

Hey probus, if it is possible could you post a list of mods that are sorta crucial to the tree working? so something like Crucial Mods (wont get very far or very very hard to get to end game) Highly Recommended (fill out the tech tree in unique ways (like firespitter maybe?)) Recommended (fill out the tree more) Compatible Non-compatible

lol, so they are pouring money into a plane that has no purpose?

It is Semi-Official Official that Exoliner/Juipter is out of CRS2. If you think about it it is WAY over engineered for a ISS supply run. The only way that it gets built is if LockMart funds it itself and does something like launch to GEO and use it to either deorbit the old geosats or put them in a Graveyard orbit. (and have people pay them to reopen the slots in the geobelt.

Wesreidau, uuummmmm Black Powder motors are reasonably common (as in almost all low power motors (A-E)) I dont know what process they use to get consistent burns though

Hey ven what are the specs on the lights on the Docking ports? I would love to get a lamp that can light something up from 300 km away notes Only shows in warp

present Vexx

nope hrm Goodle

They are the black plastic things in this photo They help guide the rocket along the rail until there is enough airflow over the fins to provide stability Oh and Budgie, if the guys at the field did not say it... CONGRATS and welcome to the big spending leagues, get out your checkbook.

Stranded... that is impressive that it stayed up for so long. hey Budgie how did it go?

landing on the moon?

No, no, no, no, no. This is a TERRIBLE argument. Remember WHY we went to the moon. It was to beat the USSR to the moon. Once it was obvious that we had reliable rockets and that we landed on the moon and the USSR had 3 explosions of their moon rocket and cancelled it there was no reason for the US to continue to go to the moon or to push on to mars. As a side note, the USSR severely beat the US in the Space Race. The only thing that we beat them in are some long term spacecraft (voyager, surveyor) and getting to mars (and doing !SCIENCE!), and landing on the moon. SpaceX is NOT NASA. and they are two different organizations and have different goals. Without getting too much into the politics. NASA is very constrained by the US government, who controls the budget (congress) and the direction (executive). NASA's goal has been changing about every 8 (sometimes 4 years) as the presidents change. Also NASA has to cover almost all of Aerospace Science. So NASA does not have a bunch of money to spend. SpaceX on the other hand is (currently) a launch provider. They provide the rocket, they don't really deal with the payload design and manufacturing (yet). YES they are making Dragon V2 (DragonRider) and have made and flown Dragon (cargo only). They are not responsible for large amounts of aerospace science. So SpaceX is NOT NASA. This is the wrong idea. In the 50s and 60s most of the rockets NASA launched failed. Even the great Saturn V had tons of development issues. NASA needs to stop being so worried about the safety and being OVERLY cautious and get back to testing things. NASA should be pushing the leading edge of space technology, not having other companies do it for them. And if NASA is not going to push the edge they are going to end up being a regulatory agency like the FAA or the FDA. I am not saying they should throw caution to the wind, but they should NOT be afraid of failure and they should be less cautious development. it was not as much as a debacle as people thought it was. It did not live up to its design or press requirements but that is because there were too many cooks in the kitchen. The main reason why the shuttle was designed the way it was was because of the USAF. Originally all military payloads would have been launched on the Shuttle. As such the payload bay was much bigger than NASA wanted it to be. (The USAF getting involved was because of funding issues) The shuttle also had to have the capability to land AT the launch site after ONE orbit of the earth. This was a hard requirement to fulfill and thus caused the design to be bigger and heavier. Over all if NASA had been able to design the shuttle it wanted and not the one the USAF wanted it MIGHT have been better than what it ended up being. Even though the shuttle had issues it could do things that no other spacecraft can or could. It could take off with a large payload and then land on a runway with said payload still in the cargo bay. It had a great UP mass capability and an astounding Down mass capability. It was the only craft flown to ORBIT that landed like a plane. and it helped do a ton of science that would not have been possible without it. Also the ISS would have been a LOT smaller and made up of more pieces had the shuttle not aided in the construction. Yes it is, but NASA is a research organization. The bill should be second or third on the list of priorities, not the only thing on the list like it is now. Let NASA do the research and companies like SpaceX and ULA and Ariane make cheap, reliable launchers. no they are not. The path of nasa changes every 4 or 8 years. sometimes faster if congress gets involved because of pork barrel politics... ______________________________________________________________________________________________________________________________ Over all the future is not TOOOOOO dark. I mean Mars One is a Scam, but we have Virgin Galactic for the tourism, Blue Origin (who just tested their rocket) for some more tourism and possibly crewed missions to orbit, Bigelow for large inflatable habitats and stations, SpaceX for launching on the inexpensive side of things, ULA for when cost is no object, SNC for their Dreamchaser (if it gets more funding), Boeing and the CST-100 for some LEO crewed missions, Lockheed Martin and the Jupiter Tug for servicing and maneuvering, the up and coming ISRO, heck even Iran's space program is starting to get interesting.

plus there is very little need for station keeping at *some* of the L-points which is nice because you can stay there almost indefinitely. Plus if you put a fuel depot/ station there it is a good place for spacecraft to stop on missions