SLS 1st stage Vs. Saturn V 1st stage.

[Titan Space Agency]

Now, I have been deciding whether an upgraded Saturn V 1st stage would be better than an SLS 1st stage. The info for the stages so you don’t have to look it up

SLS:

Gross Mass- 979.452 Kg

Dry Mass- 85.270 Kg

Thrust(SL)- 7,440 kN

ISP Sea Lvl.- 363 seconds

(Data is for the Block 1 SLS)

Saturn V:

Gross Mass- 2,300,000 Kg

Dry Mass- 131,000

Thrust(SL)- 33,851 kN

ISP Sea Lvl.- 263 seconds

I have no idea how to calculate delta-v. If someone will be ever so kind to calculate the delta-v of the two stages and post it please do. Thanks. Together we can make a better rocket than the SLS! (If I don't have all the correct info for calculating tell me)

Edited November 29, 2013 by Titan Space Agency

[Kryten]

Delta-V of a rocket stage without payload or upper-stage mass being considered is completely meaningless.

[Titan Space Agency]

Delta-V of a rocket stage without payload or upper-stage mass being considered is completely meaningless.

It is not meaningless because the info can tell you what you need to know to compare first stages, such as what i am doing. You can also use that info to tell you how much mass you can put on that stage.

[goldenpeach]

Calculationg the delta-v is really simple:

∆V=ln(M0/M1)*Isp*9,81

where M0 is the mass before the burn and M1 the mass after the burn(or M0 the mass with the fuel and M0 the mass without the fuel).

ln is the natural logarithm.

[Kryten]

No you can't. Delta-v is purely how fast a specific rocket stage would be going if it was launched, completely empty, in the absence of gravity. Saturn V's own third stage would have a much greater delta-v value than the first stage-if you were right, that'd mean the rocket would have done better assembled the other way up.

[Titan Space Agency]

Calculationg the delta-v is really simple:

∆V=ln(M0/M1)*Isp*9,81

where M0 is the mass before the burn and M1 the mass after the burn(or M0 the mass with the fuel and M0 the mass without the fuel).

ln is the natural logarithm.

Thank you for your help. At least someone is willing to help.

[Kryten]

Would you consider pointing out that you're completely ignoring the SRBs on SLS 'helpful'? Without them the first stage has a loaded thrust-to-weight ratio of less than one-i.e. it wouldn't even be able to leave the ground.

[Titan Space Agency]

Calculationg the delta-v is really simple:

∆V=ln(M0/M1)*Isp*9,81

where M0 is the mass before the burn and M1 the mass after the burn(or M0 the mass with the fuel and M0 the mass without the fuel).

ln is the natural logarithm.

Thank you Mr./Mrs. Goldenpeach. I have used that info (and a scientific calculator) to find the results.

SLS first stage has a delta-v count of 8,693.081 m/s wile the Saturn V has a delta-v count of 7,392.991 m/s. Now the Saturn V might be able to be upgraded to have much more delta-v and match the delta-v of the SLS with boosters.

[dharak1]

I don't see the point of calculating deltaV... By this logic the SLS would be a two stage to orbit if you cadd a stage above it with 1500 deltaV or so. I'm not sure if it is actually 2 stage to orbit. As stated above without boosters the first stage has a TWR <1.

[p3asant]

I don't see the point of calculating deltaV... By this logic the SLS would be a two stage to orbit if you cadd a stage above it with 1500 deltaV or so. I'm not sure if it is actually 2 stage to orbit. As stated above without boosters the first stage has a TWR <1.

Yeah so sls were to be launched without payload? Then we'd have an empty rocket sitting in orbit which is somewhat useless .

If you're calculating first stage dV shouldn't you include the mass of the upper stages also?

Like with saturn first stage mFull=3000 tons and mEmpty 849 tons giving with average 280 isp around 3.5k dV.

[Titan Space Agency]

You know what, I DON'T CARE ANYMORE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ILL CALCULATE WHAT I PLEASE. I DON'T CARE IF IT DOESN'T MAKE ANY POINT!!!!!!!!!!!!!

Also did you know the Sputnick rocket was a single stage with boosters.

At least someone co-oporated. Thank you Goldenpeach for being so kind, unlike the other bozos.

[Psycix]

All you need to do is include the mass of all upper stages and payload in the "dry mass" and your calculation will be valid and meaningful.

[Nibb31]

The SLS core isn't the first stage. The first stage of the SLS is core+boosters.

The delta-V of the core stage standing on the pad is actually zero, because it can't take off without the boosters.

[Shuttle]

I couldn't find any info about SLS size but it seems to be that it is as big as Saturn 5. If so, I don't understand why it uses two side boosters to put 130 tons to orbit while Saturn 5 could put 140 tons without any external boosters at all. The only idea that comes to mind is modularity.

And it looks like there is free space left on the 1st stage, is it possible to use SLS with 4 SRBs?

[Albert VDS]

Here you go, a comparison:

[Nibb31]

I couldn't find any info about SLS size but it seems to be that it is as big as Saturn 5. If so, I don't understand why it uses two side boosters to put 130 tons to orbit while Saturn 5 could put 140 tons without any external boosters at all. The only idea that comes to mind is modularity.

And it looks like there is free space left on the 1st stage, is it possible to use SLS with 4 SRBs?

Because the SLS core uses smaller engines than the Saturn V. The payload of the Saturn V was 120 tons to LEO, but it was far from an optimal design. It was built to be quick and dirty, with whatever parts they had available at the time. The SLS has to built with whatever parts are available now.

What would be the point of making variant with 4 SRBs ? There are still no 100 ton payloads to put on the rocket.