Exponential Rocket Equation

[DarkenedOne]

Something that has been bothering me about NASA rockets is their development costs.

Let's examine the medium size rockets. At the low end of the scale the Falcon 9 was developed for around $400 million. On the high end of the scale the Atlas V was developed for something like $1.6 billion.

Both rockets in their simple form only carry about 10 Mg to orbit.

Now lets compare that to the Ares I rocket, which was estimated as of 2009 to cost $40 billion to develop. Now the Ares I is only able to carry 25 Mg to orbit. That is about 2.5 times what the Falcon 9 and the Atlas V cost. Yet it was going to cost 100 times as much as the Falcon and 25 times as much as an Atlas V. Now I understand that manned rockets cost more than unmanned rockets, but I do not understand why it would cost that much more.

It seems like there is some kind of exponential equation regarding rocket development.

 

[SteveCNC]

Basically the difference I see is the difference between private enterprise developing something vs the government developing something . Cost plus at it's finest . Did you ever have a job that you knew when you finished that job you would need to find new work cause the paychecks would stop rolling in ? Kinda like that , it dosen't inspire for greatness in speed .

Now to man rate an atlas V might cost another billion but it's still cheaper than government run by far . Did they change the motor on the atlas V lately or are they still using the russian motor ? I haven't worked on atlas V in about 4 years but I used to make the mount beams for the russian motor for Lockheed/Martin . From what I'm told the russian motors are never pushed beyond about 75% , I guess they have more thrust than needed but are very reliable so should be easy enough to man rate with mostly an escape system development .

However as always I'm a huge fan of private space and my hopes lie with them :!:

 

[pathfinder_01]

Another factor is politically motivated engineering. To sell ARES 1 NASA had to claim it wouldn’t require much new development which in this day and age tring to tell that big a lie isn’t going to work.

It made me lose faith that the people who were supposed to be experts chose such a bad design. They choose a solid rocket first stage and topped it with an engine that can not be air started!

No rocket the size of ARES has ever used a first stage that was solid and having a solid rocket for a first stage means your performance is fixed. With a liquid fueled rocket you could increase tank size, change engines, and have much more to tinker with to get the performace you need.

In the end ARES 1 went from being shuttle derived a completely new rocket with little in common with the shuttle. It would have a five segment booster with different propellant than the shuttle. It would us the J2X and engine that needed to be developed! And using a solid for a first stage is a very questionable way to safetly send a crew into space.

 

[MeteorWayne]

Just to point out, the Falcon is NOT a NASA project...