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Hmm.... there seems to be a misunderstanding of relativity. Light speed is always constant, ALWAYS. Everything else is relative. The thought experiment previously discussed in this thread with the two space ships that meet somewhere in space is interesting. You cannot add anything to the speed of light. But if different observers witness the event (light beam) while their respective space ships travel at different speeds, this is not a problem for the theory because time and space are the variables. Every observer lives in her own inertial system with its own time and space. So the speed of the space ship itself is irrelevant. But distances can shrink for one observer while time may expand for the other. Only c remains constant.
With respect to the second thought experiment about the flashlight that shines from one end of the ship to the other. Well, it always takes five minutes for the light to travel a certain distance but the closer our ships gets to c, the more it will shrink, for the outside observer. Again time and space are the varibables not light speed.
And by the way bobunf is entirely right. Special Relativity is classic in the sense that it doesn't require quantum theory. In fact Einstein never really understood quantum theory and he rejected it: "God doesn't throw dice".
23 May 2008 Ariane 5 ECA launches Skynet 5C and Turksat 3A
Secure military communications for Skynet 5C
Telecommunication services and direct TV broadcasting for Turksat 3A
18 April 2008 22:17 UT Ariane 5 ECA launches with dual payload
http://www.arianespace.com/site/news/ne … index.html
Successful launch
Just adding to the previous statements: There is a law in the US that any private US company can use whatever constructional data NASA has developed. This is why Bigelow can use the Transhab technology free of charge. The same would apply for the Saturn V, all the other caveats not withstanding, of course.
The main problem with the Saturn V is not so much, whether the original blueprints still exist. Even if they did exist, somebody would have to read them and the old engineering teams don't exist anymore. So it would probably be just as expensive to rebuild the Saturn than it would be start a new development.
By the way, there is one more problem. The 1960s spare parts and components are no longer available. Even if you wanted, you couldn't build a carbon copy of the Saturn V. Although Soyuz has been in production for about 40 years, the Russians are having more and more trouble getting the parts for it. That's one of the reasons why they will have to develop something new like Kliper or ACTS.
The Russians had a project called MAKS in the late 80s / early 90s. It was supposed to follow Buran. It was abandoned during the turmoil in the final days of the Soviet Union.
MAKS was supposed to be launched from an Antonov AN 224 Aircraft. The aircraft exists and flies even today. At an altitude of about 8000 meters and a speed of about 900 km/h the MAKS shuttle would launch from the AN224 platform and go orbital. It was supposed to deliver a payload of up to 7 tonnes to a very low orbit of 200 km.
In my view, this whole project is not much different from an SSTO craft. But some folks believe in the virtues of air launch and believe MAKS could one day be built as the next generation Russian space ship. What do you think? I believe that's just a pipe dream and by the way, MAKS was supposed to have aluminum tanks, possibly drop tanks.
And more generally: What do you guys think about air-launching really big rocket stages from an aircraft? In my mind, it makes a lot more sense with smaller rockets like the Pegasus. With air launch you gain very little in terms of orbital velocity and altitude, but your whole launch process becomes terribly complicated and expensive. The major advantage seems to be that you can launch from a much less dense atmospheric medium.
Sure you could do a suborbital stunt, but why would you want to? Ares 1 will have a payload capacity 5 times higher. Even Falcon 9 will have twice the payload to GTO, let alone LEO. You will need about 7-8 tonnes to LEO, to do something useful.
The problem is, that you need a very heavy heat shield to get back from orbit, and this hasn't changed very much since the 1960s.
Well, the whole program was discontinued in 2004. Given the small payload capacity, you couldn't even launch a Soyuz.
Atlas2 ? About 5.6 tonnes to LEO
I think we just don't know whether SpaceX will be successful or whether they will just go broke. We have a few statements from them that seem to put a positive spin on their recent misfortunes. This may be sincere, but we have no way to tell. So let's stay tuned and lets wait till they got some real success to show to world. I wish them the best of luck especially for Falcon 9 and COTS. If they are successful they have the potential to be a real game-changer, but "it's hard to predict, especially the future" (Nils Bohr).
it's easy to understand (just reading my articles and posts) ... I'm against every too expensive and too long to develop space-hardware, while, I'm in favor of ready (or soon) available and (relatively) cheap things
Well, in that case you can fly to the moon with off-the-shelf technology, but still at incredible costs, but you will never really open up the space frontier. Griffin has often criticised abandoning the Apollo hardware in favor of the shuttle an refocusing NASA on LEO operations only.
While he might have a point in his criticism of the shuttle, the original intention that was behind the shuttle concept was right. It's the old battle between destination-driven and technology-driven concepts. I think it would be good if NASA focused on Earth-to-LEO transportation first. Our ultimate priority should be to lower launch costs to LEO. It's all about raising productivity. Using Apollo technology will not help us open up the space frontier. If we continue down this path, in 50 years time space will just as inaccsessible as it is today.
If we had all the return-to-the-moon funding and could devote it to the development of a new efficient RLV, that is orders of magnitudes more efficient than currently available ELVs, that would be real progress. The main obstacle, it seems to me, is that politicians will have to spend an awful lot of money first, the risk of failure is high, and when they are done, they will have no capability beyond LEO to show for it. Seeing astronauts playing golf on the moon, has a much greater PR value than even the most efficient RLV could ever have. And as the failure of the Venture Star program will tell, there is a tremendous risk of failure. But still it's the right approach.
Ha ha. No neviden, we don't know that, all we know is the flight history and it's not impressive. Keep watching.
Well, Ariane hasn't had a major problem since 2002. Proton had three launch failures during the last 24 months. Sealaunch had a launch failure. Atlas 5 is the only commercial US launcher. It has got a good track record in terms of reliability but it's too expensive.
For all these reasons, Ariane 5 has more commercial launch contracts than all it's major competitors combined. Don't forget that Ariane 5 has now a series of 23 successful launches in a row and almost each time they launch, they launch a dual payload. I think it's a really good program. I just hope that they will eventually finish development of the ECB upper stage with the Vinci motor. This will not only increase payload to GTO by two tons but also increase flexibility with mutliple burns in orbit. Remember, to launch the ATV they had to rely on the old Aestus engine with storable propellant in order to have multiple burns.
Ah well, don't forget the extraordinary reliability record of Ariane 4. Ariane 1-4 had some reliability issues in the 1980s, but by 2002 when the program was finally shut down, it had become one of the most reliable launchers ever. This just demonstrates that even the most reliable launchers can have problems during the first couple test launches.
Well I'm in no position to really tell how far they are and yes, I agree, the space elvator will need a lot more basic reasearch. But they have made a lot of progress recently. They have greatly improved the technology to produce nanotubes. They can make them quite a lot bigger now. They know so much more about fullerenes and the whole physics behind it. Sure they are nowhere near what it would take to build a space elevater 100000 km in length, but it's promising.
We should spend a lot more on these CATS enabling technologies. Maybe going to Mars the Mars Direct way is wrong???
Pete
Yes, absolutely stunning!! I particularly liked the longterm implications for a Moon base and Mars.
Great!!
Looking for a lunar landing using as much off the shelf stuff as possible. If Russia had an HLLV, then no need for so much on orbit assembly. A plan based on re-starting Energia lines is an option, of course but then its less off the shelf. if we are talking about re-opening production lines. Rather like modular EELV versus shuttle derived HLLV.
Well, that's why I never liked O'Keefe's plan with the EELVs. It would have been tremendously expensive and risky. Griffin is right with the Shuttle derived HLLV.
Brazilian Astronaut, Marcus Pontes To Travel To ISS In March 2006
Yes, and the Indonesian government has recently signed a deal for the delivery of Russian made Suchoi jet fighters. This includes a trip for that country's first astronaut to the ISS.
Three Blocks D should do the trick, alright. But, wow, that's an awful lot of automatic docking. Pretty risky stuff! None of this has ever been tested. Your plan sounds extremely complicated.
By the way, why do you insist on Methane LOX. NASA will use it for their CEV, because they have plans for insitu propellent production on Mars. The Russians have a lot of experience with Kerosine which has almost the same isp as cryogenic methane and it's much easier to store. And don't forget, your LEM will have to be replaced regularly, especially if you plan to use LOX tanks.
Just some thoughts
Well I think GNCRevenger is generally right on this issue. This is why airlaunch is a rather rare launch method. But think about the American Pegasus. The Russian MAKS shuttle was supposed to be airlaunched from a Ukrainian AN 225 and think about the Vinci Project (X-Prize participant).
For smaller rockets airlaunch can make sense because smaller rockets suffer most from air drag. Apart from drag and kinetic energy there are a host of lesser advantages like acoustic insulation etc... that work better in 40 km altitude.
But when rockets get bigger fuel increases by the power of 3 (with increasing volume) whereas drag only increases with the power of two. For big rockets drag is not an important factor.
Peter
More answers:
FGB-1 was launched via Proton and is now part of ISS.
I remember this very well, but L1 needs more energy than LEO, right? Correct me if I'm wrong.
Soyuz + Block D should be able to get to L1, ok.
Business model? Fly the first Brazilian to the moon. The first Indian. The first Japanese. The first Korean. The first Australian. etc. . .
Do you think Brazil will pay for a multi billion joy ride? A trip to the ISS is something quite different.
Re-fueling? I'd suggest standardized tanks of LOX and methane for the re-useable lander. Use a plug-n-play format. No zero gee fuel transfers.
I don't even think there is anything like a standardized LOX methane engine. This would have to be developed first.
Don't get me wrong. I admire the Russians for their ability to develop reliable and cheap hardware. But up to now they haven't even got a single space tourist for the circumlunar trip with Space Adventures. It is far too early to talk about commericial lunar landings. The Russians will phase out Soyuz in 2014 anyhow. Such a trip would therefore have to be done using Kliper from French Guyana. You're right Spacenut.
Now i fully understand that this idea unfortunately is impossible or at least difficult
Why?
I doubt you can pull that off. There are far too many unknowns. Is the mothballed FGB 2 really ready to be deployed, probably not. Transhab certainly isn't. NASA has abandoned the project and Bigelow is still a long way from finishing it.
What about launch costs for Proton? 55 billion is just the net launch cost. Russian cost calculations are problematic to say the least. What about Baiconur? Can you launch something as heavy as the FGB 2 from Baiconur to L1? I doubt it although I haven't done the maths. Energetically and inclination-wise, Baiconur is a lousy launch site.
The Russians have almost no experience with anything beyond LEO, apart from a few unsuccessful Mars probes and some highly successful Venera and Lunochod probes.
What about the Soyuz / Proton D arrangement? Can they not only reach the moon on a low energy direct return trajectory but actually enter into a useful lunar Orbit to deploy the lander? I'm not sure.
I still have lots of other questions concerning refueling in lunar orbit etc.. etc..
And what's the business model supposed to be? How do you want to make money? ... have space tourists pay 10 billion per launch?
Peter
By the way, GNCRevenger, why do you rule out Kliper going translunar? The Russian say they can go to the moon. I'm not an expert in reentry aerodynamics but I'm confident Kliper is sufficiently different from anything like the shuttle that they can solve the reentry physics.
Peter
Well just ask all your friends if they want to contribute 100 billion bucks. Sure they can't expect to get any money back from their investment. After all, it's just for fun.
100 billion dollars, which is the suggested price tag for the mission according NASA boss Mike Griffin, is actually almost a bargain price because it's 55 percent of what the Apollo project would cost in today's dollars. But if you plan to do something more ambititious, maybe like a little colony, your friends will have to pay a little extra, easily a few trillion dollars.
But even 100 billion is half the GDP of a country like Greece.
Oh I doubt that Josh. Private industry doesn't have a prayer of being NASA's salvation because they can't radically reduce the cost of what NASA needs. Sure they could save some hundreds of millions off ISS ferry duty, or a few hundred million off Moon/Mars stuff, but those aren't going to save enough money to really be a paradiegm shift or anything that would speed up a Mars trip signifigantly.
NASA is still the only outfit in town that will go to Moon/Mars without a clear and safe financial payback.
Oh yes, I couldn't agree more. What's the incentive for private business of spending 100 billion bucks on a trip to Mars? What's in it for them. Oh you're saying, they can do it more efficiently. Ok, but only after completely new technologies become available. Private business will not be able to pay for their development. I hate to say it, but only the government can spend something like 20 billion dollars on let's say a Prometheus-type nuclear-electric propulsion system, invest one or two decades in development time and not worry about ever recouping this investment with one or two decades of interest.
So the government wil have to go ahead and when technologies are sufficiently developed private enterprise will have a shot at making a profit and fine-tuning technology.
Peter
Haha, yeah right. Now, who's probe needed to hitch a ride to Saturn?
Come on, this was a great success for both NASA and ESA. You guys built the Orbiter the Europeans built the lander. Why not?
Yeah, thought so. They aren't serious at all, I mean, just look at their miniscule budget... with the cost of aerospace technology in Europe, thats a useless sum. And Russia? Come on, their vehicle can't survive reentry from Lunar transit velocities, so it will be stuck in LEO just like Shuttle. Doing what? Why, propping up the ISS to go in circles of course. Maybe a few million from tourists... big deal.
Well, I think ESA is doing quite a lot with its small budget e.g. Rosetta, Mars Express, Venus Express, Smart1 and a host of other unmanned missions currently in progress. I could go on and on. In terms of unmanned missions ESA and NASA are on eye-level. Unfortunately there are a lot of politicians in Europe who just hate the idea of spending money on manned missions. With Kliper there is a real chance that this might change though. We know very little about Kliper thus far. The Russians say that it can go trans-Moon and survive reentry. I'm not sure about it but why not?
After all, Kliper is a small lifting body with very small wings. The concept is radically different from the US Space Shuttle. So it won't face the same problems with heat insulation. The Russians seem to be very interested in German technology originally developed for the X38. I forgot what it is exactly but it might be some form of carbon/carbon. I'm therefore not certain that Kliper cannot be used for a translunar trajectory. And even if Kliper has to stay in LEO, it can still be used efficiently to launch crews separately. After all crews have to be launched seperately in Mike Griffin's scenario as well.
Don't get me wrong. I'm not at all against NASA's plan. I think it's great and I wished ESA had this kind of funding! They will never have it and I think it's still remarkable how much science they get out of their budget.
Peter
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