Zubrin's Ares launch vehicule

[ndiver]

Dear KSP players,

playing KSP helped me to understand better the science behind space launchers.

Recently, i started to read The Case for Mars from Robert Zubrin, that describes why and how we should go to Mars. It's the book summarizing the concept of Mars DIRECT.

Interestingly there is inside a proposal of heavy launch vehicle called Ares, developed by Martin-Marietta, and is a Shuttle-derivative launcher. But I don't get a specific point of the design, that as KSP player, makes no sense for me, and where i couldn't find any explanation : the position of the engines.

http://www.astronautix.com/lvs/areirect.htm

If you look, you can see that the engines are not under, like on the SLS or on Ares V, but aslant on the side (like on the Shuttle). On the Shuttle, i understand that it is to counterbalance the lateral weight, but on this design, it makes for me no sense of why placing the engines like that

Any idea ???

Thanks for your help

[Kryten]

It could be an attempt to reuse the entire thrust structure from the shuttle rather than just the engines. The SSMEs and SRBs probably have enough control authority between them to keep that stable-but I don't inside the cosine losses would be small.

[Navy2k]

Only thing i could think of is a low ascent angle in mid atmosphere. So you could point your craft prograde at a low angle (for example 5°) but also get some lift to pull up apoapsis. So you won't lose any delta-v to drag caused by an angle of attack. Outside of atmosphere it doesn't make any sense at all i guess.

Counter question, why is it that my browser doesn't know the words prograde and apoapsis?

Greetings

Ben

[Bill Phil]

Probably to maximize off the shelf components. Although it does seem ridiculous to me.

[Fuzzy Dunlop]

It's an issue of re-using as much of the shuttle design as possible. Though given the massive redsign of the ET needed to support the payload on top its usefulness is somewhat questionable...

[Chris P. Bacon]

It works in kerbal space program http://imgur.com/a/hZFqE

[ndiver]

Thanks guys for the explanations and ideas ! So yes, the idea of recycling most of the shuttle components was probably good at this time, but is totally outdated nowadays.

[maccollo]

The reason it was done that way was because it was intended to be used alongside the Shuttle. That way new infrastructure wouldn't be required, and the Shuttle could keep flying. Now that the Shuttle is retired the concept seems less appealing.

[billbobjebkirk]

The reason given in The Case For Mars is that the ET was only built to withstamd thrust from the side, so making it all inline would be pointlessly expensive.