B787_300

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Everything posted by B787_300

  1. I HIGHLY doubt that they needed to add another He tank. All they need to do is start loading earlier to load in at a slower rate for the He. Which isnt an issue as they start loading the RP1 well before the LOX.
  2. ack not entirely true. SpaceX said it was the strut and that is it. NASA (who has most of the data from SpaceX) said it was probably the strut but they cant be 100% sure. I would tend to agree with SpaceX on this one and say it was the strut overs NASA's well it seemed like the strut but could have been a couple of other things. ------------------------ Also PLEASE try to keep speculation to a minimum. Well informed guesses with sound science and engineering behind them are fine. and to be totally honest the one video that we have was being filmed from 2+ miles away which is really too far to be doing sound analysis on.
  3. Yes when they reach Mars. Which will be in 2025 according to Elon with people. So the IPO is at least 9 years away so no it is not forthcoming.
  4. But still you are treating it as a Mass limited system driven by amount of Fuel and launch costs and that launch and fuel are both super expensive. If SpaceX does what they are proposing to do (which is drastically drop prices to orbit) the ENTIRE math and solutions change because now there is no reason to use the ideal (6 mo) transfers. and Fuel is cheap (a falcon 9 uses something like $600 in fuel IIRC) the rocket is expensive... and expendable FH could launch ~8000 kg on a mars flyby using the upper stage for the TMI (during the ideal windows). if you use the upper stage and the payload to provide the TMI burn you can drop the transfer time (granted you wont be able to carry enough fuel to propulsively capture on Mars so i hope you are going straight in). But like I said they wont use FH for the Manned missions directly. maybe use them to launch components if needed but not where it would matter.
  5. I agree with that is what they actually sell. But the cost on the website was what I was talking about and could just be the cost for the rocket. Your right that cost is covered by the person paying for the contract. Right but that is a fringe case of the contract. Most contracts that are not with a government will not do things like that. And Falcon was mostly paid for by SpaceX itself. The Dragon not so much and there could have been some cross over in money of the funds used to develop Dragon v1 and v2 to pay for Falcon. Most people who think about the process and the amount of raw capital that they need to have to purchased all the materials and tooling for the rockets and capsules. While they are not swimming in cash they should have a good bit on hand. nope it is still going. they are actively hiring for them. to some extent it is. but it also isnt. if spacex launches the mission from their land in Brownsville there is little that the government can do about it without passing obstructionist laws that would not get the support of congress. Also it would be under the American Flag (kind of) as they are an american comapny. More realistically they will fly under the flag of SpaceX unless a government pays for more than half the mission. There have been no laws passed by the UN about companies in space and the Outer Space Treaty only binds governments from claiming land (and has been tentatively stretched but not codified to cover companies). There is ABSOLUTELY NO REASON for the UN to get involved and they wont. There is no precedent and no real reason (other than politics) but the US and SpaceX would just laugh at any thing that the UN tries to do unless the UN wants to invade the US and take control of the launch site or it is vital to prevent WWIII.
  6. No we dont, but we do know that they have enough capital to buy the machines and land they need to build and fly the rockets. Also while the published price is 60 Million that could only apply to the actual rocket and not the launch services (tracking, telemetry, integration, etc) . And the fact that SpaceX has enough money to be seriously discussing Mars Missions is also telling because most people wont pay for it. and how the Satellitie constellation is still being pursued (although they did get that huge investment from google IIRC) also implies that they are in the green. Also while Tesla & Solar City might be slowly losing money that probably isnt actually the case (or i have not seen concrete numbers to the contrary) or is misleading based on how companies account for their money. All I really know about Tesla & Solar City money situation is that Tesla managed to pay back the loan that they got from the government.
  7. Okay a couple of Points that need to be made in this thread. 1. Elon says numbers and things that while are not outright lies often take about twice as long as he said to happen. SpaceX will go to mars at some point (I hope that it will be in the 2020s with people) but will most likely be in the 30s 2. During the 60s NASA got about 4.5% MAX of the federal budget (which was lower back then) (and about 2x what they currently get when adjusted to 2014 USD). SpaceX is not totally relying on governmental money to do this (yes they have contracts with the government and got some money to make the rockets in the first place but not all that much) 3. Please dont bring Politics into this. what the candidates will or wont do is largely irrelevant. NASA has had HUGE effects on technology and science and thus is not likely to be totally dismantled. 4. Rockets fail all the time. another failure will not doom SpaceX just like all the Proton Failures have not doomed that rocket. Also The government will continue to buy launches for them if they think the pricing is right for the risks they are taking. if they want a surefire launch they will go with ULA. If they accept the risks of SpaceX and want to launch on a not quite perfect vehicle at a MUCH lower cost (60 Mil vs 120 Mil for comparable Masses to orbit) 5. Depending on the mission you can do a LOT with a single launch. My Senior Design project (for an aerospace engineering degree) was a Mars Sample Return Mission (unmanned) we could fit absolutely everything we needed into a single Ariane V launch. The lander and the orbiter were two totally separate spacecraft all for a low cost of 3.12 Billion dollars. (which over the ~8 year lifespan of the mission (from start of design to landing) is not a ton) . 6. We dont know what SpaceX's mars plans really are. We will find out in September when they announce more of the MCT and BFR architecture. 7. SpaceX does the (seemingly) impossible. No one thought that you could land a stage on a barge out in the middle of the Atlantic or bring it back to land with out huge costs. No one really thought that they could build a rocket that performs as well as the falcon for less that 100 million a launch (and there are still conspiracy theorists that think SpaceX is loosing money on every launch because their rocket really costs over 100 million). 8. the government can complain all it wants or try to stop them, they wont though because SpaceX is an American company and it would be a lot better for Americans to do it before the Russians or the Chinese (who are planning to get to mars by the 2030s). 9. the first unmanned missions that SpaceX flies to Mars will be on the F9 and Falcon Heavy. any manned missions will be flown on the MCT/BFR (which has already been confirmed to be larger than the Saturn V). And there has been a lot of advancement in materials and rocket technology since the 60s. 10. SpaceX has plenty of money sitting around and more will be forthcoming. They have a very profitable earth launching business which they are using to subsidize the development of needed technologies. Also SpaceX breaks the current Aerospace methodology by being able to do things at a MUCH lower cost than anyone else in the industry (mainly by being well vertically integrated).
  8. As a matter of fact I have both played KSP (and done almost everything possible in the game) and gotten a degree in aerospace engineering where my senior design project was a mission to mars. It is all about the energy you want to put into a mission. It is Theoretically possible to do a 3 week (and faster) Mars Transfers. Now the fuel costs on them are astronomical and you need a TON of fuel to slow back down but it is entirely possible with current chemical engines (not even talking about things like NERVA, EM drive, etc). Also fuel is just expensive in space because the only place to get it is down on the surface. If SpaceX get reusability down then the price of fuel will go down and thus you have fuel to burn. and yes while ideal windows only open every ~26 months, if you want to spend the fuel you can launch whenever you want (look at a porkchop plot all they are is a date matrix with fuel costs) As for sources try https://www.nasa.gov/pdf/373665main_NASA-SP-2009-566.pdf or http://www.lpi.usra.edu/meetings/marsconcepts2012/pdf/4181.pdf or http://space.stackexchange.com/questions/3223/why-not-travel-to-mars-in-2-months Seriously though it all boils down the the fuel costs and how much fuel you want to carry with you. if you dont mind launching a lot of fuel you can get your mission times down. However because launches and fuel are expensive it is better to minimize delta V and propulsive costs and that is why we only launch mars missions during the ideal windows about every 26 months. --------------------------------------------------------------------------------- Edit: just for the heck of it I used NASA's Trajectory Browser to look at all sub 180 day One way trips to Mars and found 21 of them http://trajbrowser.arc.nasa.gov/traj_browser.php?NEAs=on&NECs=on&chk_maxMag=on&maxMag=25&chk_maxOCC=on&maxOCC=4&chk_target_list=on&target_list=Mars&mission_class=oneway&mission_type=rendezvous&LD1=2017&LD2=2025&maxDT=180&DTunit=days&maxDV=20&min=DV&wdw_width=-1&submit=Search#a_load_results then i ran it for sub 90 day trajecotries and it found one of them. There are a LOT more they just weren't shown because the online system has a max delta V of 20 km/s. http://trajbrowser.arc.nasa.gov/traj_browser.php?NEAs=on&NECs=on&chk_maxMag=on&maxMag=25&chk_maxOCC=on&maxOCC=4&chk_target_list=on&target_list=Mars&mission_class=oneway&mission_type=rendezvous&LD1=2017&LD2=2025&maxDT=90&DTunit=days&maxDV=20&min=DT&wdw_width=-1&submit=Search#a_load_results This just goes to show that it is possible if you want to use the fuel to do it. A c3 of 30 or 50 is absolutely crazy at current prices of fuel and for launches.
  9. actually if you have the fuel to burn you can get to mars much faster than 6 months. Already SpaceX is talking 3 month transfers which take a LOT more energy and if you have the fuel at mars you can just slingshot and come right back. But ECLSS is by far the most limiting factor on long duration space missions with humans.
  10. Locked as this is a OLD post (2014 yikes) If you would like to discuss it please start a new thread.
  11. So what Thaicom 8 was deployed in is called a Super Synchronous Geostationary Transfer orbit. This orbit can help lower fuel usage to reach operational readiness because it is easier to do the 25 deg (roughly) to 0 deg plane change further out. also the circularization burn takes slightly less fuel and you can phase around the planet faster in the Super Sync orbit.
  12. Hey @ap0r what does your injector geometry look like also just using water as coolant and then dumping it?
  13. No it is not. It is in between the two number earlier posted. (at 11877 kg to a C3 of 7) http://www.silverbirdastronautics.com/cgi-bin/LVPcalc.pl is a wonderful website and pretty decently accurate
  14. Yes really. I have been working on a Senior Design Project that goes to Mars. Planetary protection is a thing that is nice but is very much optional. Especially if SpaceX is self funding it. Also If you think Mars is a pristine environment it is not as I said before the Russians (soviets as they were called back then) did not bother to do it. also while there are microbes in the Sky that could attach themselves to the spacecraft, most of them would not survive the 6 mo trip to Mars and those that would are the type that would probably make it through the sterilization process. Plus it doesnt really matter as the whole Mission of SpaceX is to COLONIZE Mars and Terraform it.
  15. Keep it on topic of the landing please. Also @Nibb31 the only thing that needs to be added for comms is a UHF radio that is COTS. (Electra by L3 Communications) everything else is just nice things. At this time SpaceX does not have a payload or any science that they want to do on Mars (that has been announced). Also with a PMR 60 days after landing this is not supposed to last for very long on the surface therefore Power and thermal is not much of an issue. Also planetary protection for going to mars is just a simple sterilization process that SpaceX is not bound to follow (the scientists would like it but the Russians have not sterilized some of their mars landers). And a sterilization is a simple thing to do (and no it does not have to be in the fairing to not get recontaminated)
  16. Welcome to the world of Aerospace Materials. Ill point you to a very nice NASA paper on the topic. " PERFORMANCE OF ROCKET NOZZLE MATERIALS WITH SEVERAL SOLID PROPELLANTS" http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660015713.pdf Even though it is from 1966 still reasonably good although I dont recognize the propellant names. Short answer is Graphite (look at Loki Research) or Graphite with Phenolic.
  17. Some first things Experimenting with rocket motors can be very very dangerous. be safe when doing it. A good rule to follow is "ALWAYS ASSUME IT WILL EXPLODE, WITH A FORCE 3 TIMES A GREAT AS YOU EXPECT" So Nozzle design is pretty in depth. And it sort of depends on what material you want to make it out of and what type of motor you are making. Graphite is the best all around one followed by metal and occasionally clay. Estes Motor nozzles are hardened clay. Most composite motors are graphite. Most main nozzles from liquid engines are metal. A good place to start is braeunig.us. Other good resources are books like Huzel and Huang.
  18. There is no science that cannot be done by bots BUT the issue is you have to build the bots to do the science before hand. also Curiosity costed about 2.5 Billion. A human mission that might be able to do about 4 times science of Curiosity would cost about 8-10 billion. But would be done on a much faster time scale as each rover takes about 3 years to build if not longer and then you have to wait for the right launch windows. While rovers where the right way to start, it is now time to send People there.
  19. No it is not. Curiosity can ONLY do what it is programmed to do with the instruments it has on hand. A human with a small lab kit would be able to do more science than the rover can. Also the rover is limited to what is right infront of it and what the science team tells it to look at. a human can look around and quickly go oh the back of that rock looks like it might be interesting but the rover might not be able to get there or even see the rock in the first place as it was not commanded to look there. and If you program the rover to do that then you have a much much more expensive rover that you have to send to mars.
  20. Why we havent been is a question of the money and time involved. Rockets have historically been very very expensive machines as they were built from absolute op of the line products and had multiple reduancies where possible. This meant that rockets and the things they launched were so expensive that very few companies and only governments had the capital to work on them. That has been changing recently and prices have started to come down. It also helped that back in the 60s and 70s there was the mentality of we have to beat the Soviets that was really spurred on by Sputnik. Remember the only thing that the Americans did before the Soviet Union was land a Man on the Moon, and land on mars. Everything else till the end of the space race the Soviets did first. While it is sad that we have never been to Mars with a manned mission it is probably for the best as we know a LOT more now than we did in the 70s and 80s. Also as to why Humans should go is because robots are very limited to what they have on had and their programming. Humans can improvise and nothing beats a good set of eyes for observations and tests. No you didnt, as none of those were "cheap" stunts when they were fist done. the Spirit of St louis was a VERY expensive plane which was totally custom built. the Nautilus was a stunt but one that proved a very important geopolitcal point of subs can be ANYWHERE (and was very expensive as that reactor was the first of its kind). Climbing Everest was probably the cheapest of the stunts that he mentioned but that was still important as it proved that people could do it.
  21. okay a couple of things. without baseline masses, isps, launch dates (in widow or not) this is a REALLY hard question to answer. Also all of these numbers are Really sensity to other factors. I (and my senior design group) have a SSTO MAV that can carry 3 kg of payload to LMO and it only weighs 500 kgs, but we increase payoad the mass goes WAY up
  22. Nope you get a overworked college student. too bad. But @Supernovy should be next.
  23. @damerellIf you loook at the studies they assume that the explosions are as clean as theoretically possible for the bombs. If you include the initial ground bursts to get Orion off the ground you are going to be creating TONS of radioactive particles from the ground (which they hand wave at and say they are launching from uninhabited places that are away from everyone (like launching from Midway or bikini atolls). The study was done in such a way to paint the best possible picture for the funding commitees that were going to fund orion. Also The study did not inculde a serious discussion of the EMP effects of the explosions. Back in that day the only poeple who really used computers and electronics were the military. IN todays world the effects would be disatrous
  24. Yeah if you dont mind irradiating the planet you are taking off from. An Orion shapeship would work. it is just a question of where you would want to use it. as you cannot use it on earth or withing parts of the magnetosphere because of the emp that a nuclear explosion creates. so now you have to get it out of earths gravitational well pretty far before you can use the nuclear pulsed propulsion. (I believe that you have to get it about 3x as high as the ISS is) Also yes the actual mode of propulsion wiith nuclear bombs has not been tested but an explosion is an explosion and the old video where they used c4 to fly a smaller model proves that the idea works. (granted a nuclear explosion has more energy in it and has the wonderful side effect of radioactive wastes)