There is a relationship between delta-v and orbital speed, but there's another factor: The delta-v to reach an orbit doesn't just include the velocity of that orbit, but also the potential energy required. Given that geosynchronous orbit is 35,785 km up there, the potential energy is enough that in spite of the lower final velocity, it still takes about 13 km/s to get there from Earth's surface. This gravitational potential energy also has to be accounted for in launches to LEO, but because you're only going up about 200 km or so, the effects are smaller--a couple km/s (a total of more like 9 km/s would be closer to correct than 8 km/s). This is why the delta-v to LEO is fairly close to the orbital velocity, but the delta-v to get to a geosynchronous orbit is not close to the velocity of a geosynch orbit--there's a lot more potential energy you have to store up to get to GEO.
Also, to answer your specific question, you need to subtract the delta-v performed by any lower stage (which is essentially what your "super-booster" is, a low-performance first stage). For instance, if the payload needs 9.4 km/s to reach LEO, and it's already going 400 m/s, then the rocket doesn't need to do 9.8 m/s, but rather the remaining 9 km/s. This results in a lower mass ratio required for the upper stage, which implies that more of the vehicle's fueled mass can be structure and payload as opposed to fuel.QuoteOk. To be sure I understand, you are saying that a certain delta-V invested at launch counts the same as the same delta-V achieved at any other point in flight, yes? Even though the energy required to accelerate the fully loaded rocket is more than the energy to accelerate the almost empty rocket?Does this help you understand what you need to in order to ask your question?
Ok. To be sure I understand, you are saying that a certain delta-V invested at launch counts the same as the same delta-V achieved at any other point in flight, yes? Even though the energy required to accelerate the fully loaded rocket is more than the energy to accelerate the almost empty rocket?
I have a question that may be is for advanced concepts, but let's see if I got the general concepts right.Let's say that you want to do a sun escape mission. And let's say that your last stage is a SEP stage. Could you launch towards the sun without delta-v penalty (i.e. passing closer to the Sun than Earth's orbit?This would give you plenty of power, but the main argument is how would the Oberth Effect work there? I understand that the SEP would be running for a long time (months), but it would be closer to the Sun than Earth. And since it is a Sun escape mission, it should give some extra boost.Of course the thermal requirements might be ugly, but the P/W of the solar system would improve. But I don't want to digress. The important part are the delta-v questions.
I know that S-V generated obout 4-5 G on lift off
I was watching a small clip about the sprint missile as being the fastest Accelerating rocket ever build. (as far as I know)
This info transformed in my mind to the following question.I know that S-V generated obout 4-5 G on lift off and shuttle even less. But what is the slowest accelerating orbital reaching rocket ever build?
Don't know any which have as much a 2 gees of thrust at point of launch.
Quote from: gbaikie on 07/09/2013 05:08 amDon't know any which have as much a 2 gees of thrust at point of launch.Solid LVs like Scout and M-V.
Solid rockets are good at providing a lot of thrust.
Quote from: gbaikie on 07/09/2013 06:36 amSolid rockets are good at providing a lot of thrust.Indeed. The Sprint ABM is just crazy, see the video how friction makes missile skin go white hot within seconds from launching.Solid LVs compensate for lower Isp with higher T/W. Less time boosting = less gravity loss, obviously drag losses increase to some extent, but solid LVs can cope with much higher drag because structurally they are much sturdier than liquid LVs.
Each kernel of popcorn contains a certain amount of moisture and oil. Unlike most other grains, the outer hull of the popcorn kernel is both strong and impervious to moisture, and the starch inside consists almost entirely of a hard, dense type....The pressure continues to increase until the breaking point of the hull is reached: a pressure of about 135 psi (930 kPa)[8] and a temperature of 180 °C (356 °F).
I'd wager that seemingly nothing would happen.http://en.wikipedia.org/wiki/PopcornQuoteEach kernel of popcorn contains a certain amount of moisture and oil. Unlike most other grains, the outer hull of the popcorn kernel is both strong and impervious to moisture, and the starch inside consists almost entirely of a hard, dense type....The pressure continues to increase until the breaking point of the hull is reached: a pressure of about 135 psi (930 kPa)[8] and a temperature of 180 °C (356 °F).It seems to be a very sturdy pressure vessel, just vacuum outside would be way below it's breaking point. The kernel would only slowly dry up.
So in Earth low orbit, you throw a dried cob popcorn so it de-orbits to Earth surface. And you toss [superman tosses] another cob of popcornso it's at hohmann transfer and intersects Mars and hits Mars surface.What happens to the popcorn on the cob?It seems to me the popcorn would arrive to Earth and Mars, without popping and cob which hits Mars surface is going near supersonic [not a lot kernels would survive intact] and cob hitting earth surface would be much slower and more would survive intact. And those intact kernels could be popped or grown.if in suitable environment [Mars is not suitable environment].
Quote from: gbaikie on 07/14/2013 12:22 pmSo in Earth low orbit, you throw a dried cob popcorn so it de-orbits to Earth surface. And you toss [superman tosses] another cob of popcornso it's at hohmann transfer and intersects Mars and hits Mars surface.What happens to the popcorn on the cob?It seems to me the popcorn would arrive to Earth and Mars, without popping and cob which hits Mars surface is going near supersonic [not a lot kernels would survive intact] and cob hitting earth surface would be much slower and more would survive intact. And those intact kernels could be popped or grown.if in suitable environment [Mars is not suitable environment].Depends on how fast Superman throws it. Seriously gbaikie, there'd be nothing left of the corn on the cob, it would be completed disintegrated upon impact.