Poll Which NASA plan does the Orbiter community prefer?

[Andy44]

I thought the USA have learned that Operation Paperclip was too expensive for them. They thought they conquer some scientists, instead some scientists conquered them...

I for one would welcome our new brainy overlords.

 

[sunshine135]

I like the Shuttle Derived Launch Vehicle concept along with the Private Space incentives. True exploration and innovation will not come until someone finds some profitability in exploring space and exploiting resources.

In the meantime, the SDLV would provide a good gap filler with proven parts. No one would care if foam fell off the stupid tank.

 

[Ark]

The problem with shuttle-derived launchers is that they preserve the insanely bloated cost of Shuttle operations. Ares I was projected to have the same billion-dollar price tag per launch as the Shuttle did. They were already committed to designing almost entirely new hardware for it, why not ditch that 30-year-old Shuttle crap and take advantage of current technology to do it cheaper?

Is that not the overwhelming question of expansion into space, how to make it cheaper?

 

[Donamy]

SDLV would do it cheaper. Notice there's no shuttle.

 

[Andy44]

The problem with shuttle-derived launchers is that they preserve the insanely bloated cost of Shuttle operations.

No, they don't. The cost of shuttle is driven up by the large crew and long hours needed to turn around the vehicles between flights, and the fact that the launch rate is much slower than the program was meant to do. The slow launch rate and large number of man-hours is driven by the fact that the shuttle is not as safe as it was thought to be.

The SRBs and ET are pretty cheap as far as launch vehicle components go, and if you're using them to launch something that does not have fragile tiles and people on it then it basically becomes just another rocket.

 

[Ark]

No, they don't. The cost of shuttle is driven up by the large crew and long hours needed to turn around the vehicles between flights, and the fact that the launch rate is much slower than the program was meant to do. The slow launch rate and large number of man-hours is driven by the fact that the shuttle is not as safe as it was thought to be.

The SRBs and ET are pretty cheap as far as launch vehicle components go, and if you're using them to launch something that does not have fragile tiles and people on it then it basically becomes just another rocket.

Fair enough, without the complete overhaul following every launch your man-hours go down significantly.

What does a set of three man-rated SSMEs run? Off the top of my head I'd think those things would be the most expensive part of the stack.

 

[Andy44]

Yes, you are correct about SSMEs being too expensive to be expendable.

The tough part of that plan would be to find good replacements. SSMEs being perhaps the best hydrogen-burning engines available, it'd be nice if we had a nice expendable version, but of course that's part of what killed Ares.

 

[Donamy]

Expendable SSME's shouldn't be too much problem, only needing to be used once, no need for expensive recertification inspections.

 

[Ark]

We could always ask the Russians if they have anything good. :lol:

 

[Donamy]

We need the jobs, thankyou.

 

[tblaxland]

We could always ask the Russians if they have anything good. :lol:

They tend to use kerosene first stages, making them unsuitable for an SDLV.

 

[garyw]

Expendable SSME's shouldn't be too much problem, only needing to be used once, no need for expensive recertification inspections.

There are already plans for that. Most of the expensive is in the backups and higher quality parts so if I recalll correctly the plan was to lower the stringent requirements on the parts and remove some of the redundancies.
It brought the cost of the SSME down to just slightly more than other engines.

There is an interesting article on engines here.

 

[Ark]

There are already plans for that. Most of the expensive is in the backups and higher quality parts so if I recalll correctly the plan was to lower the stringent requirements on the parts and remove some of the redundancies.
It brought the cost of the SSME down to just slightly more than other engines.

There is an interesting article on engines here.

Pretty cool article, I hadn't considered the possibility of reactivating the F-1. Imagine how utterly insane watching one of those things light would be, at four times the SSME thrust you'd only need one. :lol:

 

[anemazoso]

I thought the RS-68 was a disposable (and slightly upgraded) version of the SSME?

 

[Urwumpe]

I thought the RS-68 was a disposable (and slightly upgraded) version of the SSME?

No, it is completely unrelated. Different engine cycle and much lower chamber pressure. Which is why it is such a huge beast, compared to the SSME.

 

[T.Neo]

AFAIK RS-68 also has only ablative cooling.

 

[Sky Captain]

I think Russians had expandable H2 engines powering the Energia core which were comparable to SSME`s only much cheaper. Maybe those could be used in place of uber expensive SSME`s.

 

[anemazoso]

AFAIK RS-68 also has only ablative cooling.

I know, that's one of the reasons I thought it was a simpler SSME.

My question is, could the SSME be modified to be cheaper while maintaining it's specific impulse?

 

[Urwumpe]

My question is, could the SSME be modified to be cheaper while maintaining it's specific impulse?

Yes, but not that much. The main costs go into pumping the fuel to the needed 380 bar for injection into the preburners.

Cheaper turbo-machinery would result in lower chamber pressure and lower specific impulse.

 

[Ark]

I know, that's one of the reasons I thought it was a simpler SSME.

My question is, could the SSME be modified to be cheaper while maintaining it's specific impulse?

Let me share a phrase with you that is common among the amateur racing community:

"Speed costs money. How fast do you want to go?"