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Comparison of Super-Heavy Launchers


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Looking at these, I have to say that I really admire NASA's taste for black stripe placement.

The black and white squares on the SLS renderings are just PR fluff to set it apart from Ares V and to evoke the Saturn V heritage. The tanks will likely be orange, just like the Shuttle ET, because it uses the same propellant and tankage technology.

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Wait, if the Shuttle/Buran are about 100 tons with payload each, the launcher must actually be really powerful. Why is it not possible to adapt that launcher to a payload that's not the shuttle and just cap the tank off at the top?

That's basically what the Shuttle-C proposal was about:

http://www.thelivingmoon.com/45jack_files/02archives/Shuttle_C_001.htm

The main problem was that it used SSME, which were too expensive to be disposable. One of the SDHLV proposals for Constellation was actually derived from the Shuttle-C concept, but with disposable RS-68 engines instead of the SSME. They figured that an inline version would be more efficient, which is basically what Arex V was.

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The black and white squares on the SLS renderings are just PR fluff to set it apart from Ares V and to evoke the Saturn V heritage. The tanks will likely be orange, just like the Shuttle ET, because it uses the same propellant and tankage technology.

Bzzt, wrong. The black and white squares are called Roll Patterns, and are painted on axisymmetric rockets for a very simple reason--they allow the engineers on the ground to track the vehicle's roll attitude independently from its on-board guidance systems. By being able to track roll, you can then also use the measured angle to the horizon to calculate pitch and yaw, again independently--allowing you to get accurate data as to the vehicle's attitude if the guidance system goes ape**** and starts reporting back false data. The white paint is also helpful for cryogenic tankage, as it reflects sunlight and thus helps prevent solar heating of the tanks and boil-off of the contents.

Shuttle eliminated the paint on the external tank starting with STS-3 to increase performance by reducing weight. The ETs used on STS-1 and STS-2 were painted the same gleaming white as the SRBs, at a cost of a couple of tons of mass. Ironically, it made the debris danger greater, as the paint both helped insulate the tank (reducing ice formation) and provided added structural strength to the insulating foam. Once they stopped painting the tank, foam strikes became a more serious threat than they originally had been.

I agree that there's a good chance that the Senate Launch System will eliminate most of the white paint for mass reduction purposes, but the roll patterns *will* stay in place, since after SRB burnout, they'll be critical to ground-based crosschecks of the guidance telemetry. (They may, however, be reduced--note the simplified roll patterns used on the Skylab and ASTP Saturn Ib boosters compared to those used on the Saturn I and the Apollo 2, 3, 5, and 7 Ibs; it was reduced to just some checkerboard bands on the upper stage instead of alternating white and black tanks in the first stage.)

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I'm not so sure that the giant black rectangles are still necessary for roll monitoring. Look at modern carrier rockets -- the Atlas V and Delta IV, in their single-core SRB-less variants, as well as the Falcon 9 and a bunch of smaller vehicles, don't appear to have roll-distinguishable features beyond the logos. Either they trust the on-board systems more now (probably not) or the ground tracking is good enough to work with rather small markings. I agree with Nibb31 about the patterns being strictly aesthetic.

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Bzzt, wrong. The black and white squares are called Roll Patterns, and are painted on axisymmetric rockets for a very simple reason--they allow the engineers on the ground to track the vehicle's roll attitude independently from its on-board guidance systems. By being able to track roll, you can then also use the measured angle to the horizon to calculate pitch and yaw, again independently--allowing you to get accurate data as to the vehicle's attitude if the guidance system goes ape**** and starts reporting back false data. The white paint is also helpful for cryogenic tankage, as it reflects sunlight and thus helps prevent solar heating of the tanks and boil-off of the contents.

...

"Wrong" is a bit strong here. The examples you cited are very old and may be irrelevant with today's image processing technology. Surely there are ways of cross-checking roll control that don't require sacrificing a few tons of payload. And foam strikes should be less of an issue with nothing bolted on to the side.

Of course, given how many miracles are needed to get this thing off the ground, why not add another: anti-gravity paint. :P

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The ECA (which I assume you were using the numbers of) is a GTO only rocket. For LEO you want the ES

There's no such thing as a "GTO only rocket". Of course you could launch an ECA to LEO. Rockets can be optimized for optimal GTO or LEO performance (basically the mass distribution of the stages will be different), but nothing is stopping you from using a GTO-optimized launcher to put (more obviously) payload to LEO. There Ariane 5 however was optimized for LEO right from the start (Hermes), only in recent years this has been shifted a litte.

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There's no such thing as a "GTO only rocket". Of course you could launch an ECA to LEO. Rockets can be optimized for optimal GTO or LEO performance (basically the mass distribution of the stages will be different), but nothing is stopping you from using a GTO-optimized launcher to put (more obviously) payload to LEO. There Ariane 5 however was optimized for LEO right from the start (Hermes), only in recent years this has been shifted a litte.

The ECA sacrifices a LOT of space to allow it to hit GTO, the thing is that still doesn't change the fact the numbers on the image are wrong no matter how you look at it. I suppose you could make a satellite dense enough to require the ECA to reach LEO but I don't think it would weigh just 10t if you did :P

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Yep, the Ariane should be listed at 21 tons. UR-500 lifts 22 tons (when it works, LOL. ;) )

(No offense to Russian friends intended :) )

It appears that the ECA version of the Ariane does not improve the performance to LEO over the baseline 90s version, and that's why it's not used for the ATV - I guess that the thrust to weight of the hydrolox upper stage is too low?

Edited by thorfinn
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There is a very little difference actually: the Orbiter weighed 70 tons, not much more than the Buran, and it went to orbit too. 100t is the payload of Energija, which was non reusable (there were plans for reusability in the future, kinda like those SpaceX is considering.)

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yes, but the effective payload of Buran was quite a bit smaller. The listing in the graph is wrong there, it lists the payload of Energia as being that of Buran, while listing the payload of the STS as being just that of the orbiter.

http://www.astronautix.com/craft/buran.htm lists an accurate comparison, showing the payload of the Buran orbiter to be about 30 tons, or 20% more than that of the STS Orbiter, seems mostly because the vehicle itself, lacking the SSME of the STS Orbiter, was lighter and therefore a smaller percentage of the payload mass of its launch configuration.

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The ECA sacrifices a LOT of space to allow it to hit GTO, the thing is that still doesn't change the fact the numbers on the image are wrong no matter how you look at it. I suppose you could make a satellite dense enough to require the ECA to reach LEO but I don't think it would weigh just 10t if you did :P

I just asked Mr. Tsiolkovsky, and he told me that the payload-to-LEO capability of the AR5 ECA should be even more than 22t. That is of course by using the exaggerated number from the Ariane 5 User Manual. So something around 20t should be reasonable. :P

Of course, the question of how you can get 20+t under that fairing is an entirely different one. Also, I'm not sure if the structure could withstand the weight of such a payload.

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Of course, the question of how you can get 20+t under that fairing is an entirely different one.

By having a compact payload, I'd say. And for the ATVs, which weigh more or less 20t, I know they use a special reinforced support structure. And looking at the Arianespace site, they say that can put up to 20t in LEO and 10t in GTO. I think those number are reliable, since they are presented in the "commercial offers" section. These numbers are also consistent with those of the french wikipedia page of Ariane 5, except for the liftoff weight, but I suspect that Arianespace accounts for the payload weight, whereas the wikipedia article doesn't, or uses outdated figures from the previous and lighter versions of Ariane 5.

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Did Mr. Tsiolkovsky tell you about gravity losses? The lower thrust is the issue.

The total liftoff thust of the AR5 is about 15000kN. 10t more payload on the vehicle really doesn't matter.

For a payload of 20t I get more than 10km/s of ÃŽâ€v, so yes - including gravity losses.

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The total liftoff thust of the AR5 is about 15000kN. 10t more payload on the vehicle really doesn't matter.

For a payload of 20t I get more than 10km/s of ÃŽâ€v, so yes - including gravity losses.

I think he means gravity losses on the upper stage, where an extra 10t more payload can matter. I think that's why Atlas 5 uses a duel engine centaur when flying to LEO and single engine when flying to GTO.

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There is a very little difference actually: the Orbiter weighed 70 tons, not much more than the Buran, and it went to orbit too. 100t is the payload of Energija, which was non reusable (there were plans for reusability in the future, kinda like those SpaceX is considering.)

Well, the Energia project was just the best and coolest idea if we don't count the R-7 family. Re-usable was one of the main plans, and it was also become not only used for Buran-launches. It was a good rocket (It launched 2 times correct, but Polyus has a failure what cause it was lost) for a low price. And don't forget the Energia-M plan, whats goal was to replace the Proton.

Sadly that the Energia project was in the wrong time, at the wrong place at that moment. If it was in the 70's, or late 90's / early 00's, then it got more chance to be active then in end 80's.

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yes, but the effective payload of Buran was quite a bit smaller. The listing in the graph is wrong there, it lists the payload of Energia as being that of Buran, while listing the payload of the STS as being just that of the orbiter.

http://www.astronautix.com/craft/buran.htm lists an accurate comparison, showing the payload of the Buran orbiter to be about 30 tons, or 20% more than that of the STS Orbiter, seems mostly because the vehicle itself, lacking the SSME of the STS Orbiter, was lighter and therefore a smaller percentage of the payload mass of its launch configuration.

While true that the main page listing for the Buran is technically wrong, the number is correct, since the Energia can (and did, at least for test launching) operate independently, meaning the Energia payload is 100+ tonnes, while the STS system reaches an upper limit of 24. (Plus human payload and supplies, which tend to be discounted when they're relatively consistent between missions and the interesting payload is a separate item)

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