SRB specific impulse

[TheBlaster]

Ive felt that the Srbs are underpowered for a while so I decided to calculate the ISP and compare it to real life figures.

Burn time= 30s

Mass-drymass=6

Consumption rate 6/30= .2 kg per second

Thrust=400.

So you throw that in to the ISP equation and you get 400/.2= 2000/9.8= 204s

204 Is a very low number compared to real srbs

Shuttle-269s

Ariane 5-275s

Delta II-278s

Atlas v-275s

It seems odd that the game SRBS would be so underpowered, While the specific impulse of the liquid engines seems right on, maybe a tad high.

[Kosmo-not]

Don\'t forget the small SRB that has a I_sp of 442s.

[TheBlaster]

Yea haha I saw that and figured its just because its an old part but who knows.

[Kosmo-not]

Yea haha I saw that and figured its just because its an old part but who knows.

The old one had a specific impulse of 230s.

[RayneCloud]

Two things,

Placeholders

In Development

Try thinking about that yeah?

[Klopchuck]

Is it OK to talk about improving Placeholders In Development?

Here is a comparison of Propellant Mass Fraction (Propellant Mass / Total Mass):

KSP\'s SRB

• 
  [li]0.800 RT-10 (1.8/.36)[/li]
  [li]0.888 RT-B20 (6.75/.75)[/li]
  

In Production

• 
  [li]0.854 Space Shuttle SRB (503,487/589,670)[/li]
  [li]0.865 EAP (Ariane 5) (238,000/275,000)[/li]
  [li]0.881 Gem-46 (Delta II & III) (37,500/42,520)[/li]
  [li]0.883 Space Shuttle SRB* (503,487/569,893)[/li]
  [li]0.902 GEM-40 (Delta II) (25,801/28,801)[/li]
  [li]0.902 Altas V SRB (36,824/40,824)[/li]
  [li]0.902 GEM-60 (Delta IV) (29,949/33,199)[/li]
  

Looks like Jeb needs to get to work on that RT-10! There should be at least 180 grams of dry mass in that design that could be removed. Has Jeb considered taking off the cup-holder? Hey I just do the maths, not the jokes or snarky moderation.

* Post Challenger-disaster design

(Sources: KSP 0.16; ESA website; and www.astronautix.com for Atlas, Delta, and Shuttle SRB)

[TheBlaster]

Two things,

Placeholders

In Development

Try thinking about that yeah?

I have never understood why people feel the need to say this every time a suggestion for improvement is brought up. Are we not allowed to talk about the game until final release? By then it is too late to affect the features.

Klopchuch thanks for those stats that\'s very interesting. I\'ll use those ratios when making cfg edits haha

[Koschei]

Quite interesting data. I'll check some popular mod SRB's to see how they compare to RL boosters.