Are shuttles uneconomical?

[MarvinKitFox]

So you have a shuttle that drops two S1 SRB, and one orange tank, on the way up?

Then drops off a satellite in orbit, and recovers the shuttle on runway...

The economy should work out very similar to the real-life shuttle's economy.

i.e. ruinously expensive.

Now if you could manage it without dropping that orange, or the srb's.... that would be economical. Maybe.

Lugging a dozen tons into orbit, for each ton of actual payload, doesn't ever make sense unless you can trim the overhead a lot, by not dropping *anything*. and preferably something better than rocket engines.

[zekes]

In most cases, mabye. If done right (IE boosters can be recovered), they are a cheap way of getting small payloads to orbit. however, due to KSP being limited to 2.5km load range (although there are mods for that), it kind of defeats the purpose of a shuttle - none of the fuel tanks or SRBs are recoverable.

As for my case, OF COURSE NOT. Mine puts 33 tonnes into orbit, but only after throwing 2400 tonnes of junk up with it

[Giggleplex777]

Not in KSP. It also won't work right because KSP physics aren't real-world physics.

Really, what you need is something akin to the saturn-shuttle, which is a Shuttle stuck atop a Saturn V lower stage.

And what would be the advantages of that over a conventional shuttle?

[Kesa]

I can put ~6t in LKO with a full orange fuel tank and two BACC SRBs, so unless your probes are anything near 5t (which I really doubt since you can send them for 5000), your shuttle is way over powered. If you don't use jet engines, a shuttle will always be less fuel efficient than a rocket, because they use similar engines but carry more than the playload. If you use jet engines, fully recoverable SSTOs are so easy and fuel so cheap that a shuttle will be less competitive.

In real life, fuel cost nothing, but there is nothing like a 100% fund recovery. A spacecraft mostly cost in engineering, which means building simple and expandable booster for rocket, and designing and maintenance of a though and reentry capable plane for shuttle, hence the difference of cost, reguardless the reusability.

Also, real life shuttle have a higher safety standards, which make them more reliable for manned mission.

[GoSlash27]

I can put ~6t in LKO with a full orange fuel tank and two BACC SRBs, so unless your probes are anything near 5t (which I really doubt since you can send them for 5000), your shuttle is way over powered. If you don't use jet engines, a shuttle will always be less fuel efficient than a rocket, because they use similar engines but carry more than the playload. If you use jet engines, fully recoverable SSTOs are so easy and fuel so cheap that a shuttle will be less competitive.

http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/Lifter-Ception/Flight

noob

Yeah, just messin' with ya...

Best,

-Slashy

[kujuman]

Let's not derail this thread, but you can't argue that it was economical and (needlessly) expensive - those are directly contradictory terms. As for comparing the 1970s era design with modern ones - the costs for the NASA stuff have been scaled for inflation. That is, it would cost about the same as those figures if it were done now instead. Development costs are very relevant - if it costs more to develop a design than you will save by using it, it's a terrible idea. In the case of the shuttle, the development costs dwarfed even the usage costs, never mind savings.

Why can't one argue that the NASA shuttle was both economical and needlessly expensive? Economics is about allocating resources; a single, partly reusable multipurpose launcher may take less development time and capital than a few dedicated lifter types and have lower operating costs. Based on what is public information, the NASA shuttle never did many of the missions it was designed to do, but it would have been able to do them rather than requiring a new space vehicle. It's similar to buying a multifunction printer rather than buying a scanner, a fax machine, and a printer as separate items; it makes sense if you actually use all of its functions, but if you just use it to scan documents, you were probably better off with a scanner. But if you need to print something right away, having the capability is worth something. That's the economic decision of value. (high value items are economical)

Cost is a different thing. Paying more for the same capability makes something needlessly more expensive.

I do agree with the gist though: the shuttle was a terrible compromise from an organization that was so unsure of its purpose that it allowed outside actors to heavily influence a vehicle it would have to live with for 30 years. Mission creep and relying on first generation technology made the shuttle cost far more than it could have. A 1/2 size experimental shuttle would have probably given NASA a great idea of the true difficulty in developing that type of vehicle.

In KSP, shuttles can be economic decisions, but I find them to require too much testing (mostly because of restricted gimbal range) to make sense the way I play, and I spend most of my time in LKO building space stations. I bet a interplanetary ship build from shuttle payloads would be fun, but awesomely more challenging than using custom lifters each time.

[GoSlash27]

I do agree with the gist though: the shuttle was a terrible compromise from an organization that was so unsure of its purpose that it allowed outside actors to heavily influence a vehicle it would have to live with for 30 years. Mission creep and relying on first generation technology made the shuttle cost far more than it could have.

All true.

The STS was originally designed to be a complete transportation infrastructure, not just a mostly- reusable launcher.

When the funding for STS got axed, the launcher remained. Then reasoning that it would only fly 100 missions, they made a balance between initial cost and cost of operation and came up with a design that wasn't cheap to build *or* operate.

That's how we ended up with the shuttle; a vehicle that was never really well- suited or economical for the jobs it wound up doing.

Best,

-Slashy

[LethalDose]

I think the space shuttle was wildly charismatic and had tons of development behind it, but it failed to live up to the hype (huh, that sounds like some video games). It wasn't able perform it's mission profile efficiently because it had a too many mission profiles to perform, and there were some problems (like the heat tiles) that just never got properly sorted.

Refurbish time and development cost aren't an issue with KSP: we can turn around a spacecraft in a couple seconds flat.

Eh, I kinda disagree with this. In KSP, the development cost is the time it takes to get the cursed things to work right and start to break even economically. I think there's way better ways to spend your time in the game or in real life.

[Anquietas314]

Why can't one argue that the NASA shuttle was both economical and needlessly expensive?

Ahem... the definition of economical:

adjective

giving good value or return in relation to the money, time, or effort expended.

synonyms: cheap, inexpensive, low-cost, low-price, low-budget, [...]

antonyms: expensive

(of a person or lifestyle) careful not to waste money or resources.

That's why. Economics is about allocating resources efficiently; if you're wasting resources, you're obviously not being efficient with them. Your analogy doesn't work though if you don't actually have a use for the scanning and fax capabilities of your multifunction printer; if you pay for features you don't need or at least foresee a need for, that's not being economical. This is of course assuming those features come with extra cost, which these days isn't really true any more - you can get a decent multifunction printer for under £20, and a single-purpose inkjet printer for about the same price - actually some are more expensive.

n KSP, shuttles can be economic decisions, but I find them to require too much testing (mostly because of restricted gimbal range) to make sense the way I play, and I spend most of my time in LKO building space stations. I bet a interplanetary ship build from shuttle payloads would be fun, but awesomely more challenging than using custom lifters each time.

SSTO spaceplanes that take off from the runway are much cheaper than shuttles, and considerably easier to make

[Pecan]

...SSTO spaceplanes that take off from the runway are much cheaper than shuttles, and considerably easier to make

But not as cheap or simple as 'tail-sitter' jets (your preference).

A thing which is 'economical' may be cheaper than the alternative but, nevertheless, needlessly more expensive than it could be - ie; 'better' but not 'best' because there was waste or under-utilisation. You ain't going to win - low-price isn't the same as lowest-price.

When it comes to spending even 'lowest' has different meanings - I worked at one company that decided it was cheaper to re-wire the entire head-office building twice (at more than twice the cost) because they could write-off the expenditure in different tax years that way.

[Anquietas314]

But not as cheap or simple as 'tail-sitter' jets (your preference).

In my experience, tail sitters are way more trouble than they're worth; it's easier to just pull up to 90 degrees (or as close to it as you can) as soon as you come off the runway. Plus you need more thrust to make a tail-sitter viable.

As for economical, maybe it really was cheaper for the company because of the tax stuff? In any case, one company misusing a word doesn't change the meaning of that word; that only happens if the majority of people who use the word use it to mean something different.

[King Arthur]

I believe that, even with differences in opinions regarding the Space Shuttle's effectiveness, most of us can agree that the Space Shuttle remains a crowning achievement in space exploration and aeronautics that many of us consider to be simply badass even in spite of its various downfalls. The Space Shuttle is more often than not one of the first things that people want to try building and/or flying in KSP and other space sims, it's become iconic of manned space exploration second-only to the Saturn V and Apollo.

We definitely should discuss about and learn from the Space Shuttle's problems, but credit should be given where credit is given due and the Space Shuttle has most definitely advanced science and technology and performed missions that simply no other spacecraft, neither before it nor after (for the foreseeable future), could have or will perform.

As far as Space Shuttles in KSP, they certainly aren't the most economical nor effective way to complete missions. That said, they look awesome, are fun to design and fly, and give a very nice feeling of satisfaction when you wrap up the mission and return to KSC for a glamorous landing.

Edited December 29, 2014 by King Arthur
Typo fix. Derp. :(

[Pecan]

...most of us can agree that the Space Shuttle remains a crowning achievement in space exploration and aeronautics...

It's only because of KSP that I'm at all impressed with the US shuttle as it happens. Until a similar thread came up several months ago I'd sort of written it off as a failure because of how long it took and how much it cost between flights. THEN I looked-up the mission-logs and wow! I didn't know just how many times each one of those things flew! That's cool :-)

So's Apollo, of course, and that's a REALLY bad way to visit Mun, in KSP!

[GoSlash27]

^ This is all true.

The STS did everything it was called upon to do; probably more in terms of raw tonnage and numbers than most other launch systems combined.

Not the most economical or efficient system, but it was definitely effective and admired.

Best,

-Slashy

[panzer1b]

In real life the main savings of any SSTo, especially shuttles are reusable engines. Engines if im not mistaken are very expensive (much more then any fuel tanks), contrary to KSP's more or less engine is nothing and fuel tanks seem to cost alot more (+ no ability to recover the boosters without mods), shuttles or anything for that matter that isnt 100% SSTO will not be logical.

If you want to make the best cost/mass craft, SSTO is the best method. The only cost is the payload and fuel, and fuel while still a cost, is peanuts compared to the entire craft (unless u happen to have some brute-force rocket thats more or less nothing but fuel tanks apon fuel tansk with engines strapped everywhere).

Anyways, shuttles in KSP are more or less a sandboxy design as is, theyre cool, its nice to recreate real lift craft, but in terms of the way KSP works, and its current economy (subject to change in later updates id guess), the only truly good method to get something into orbit cheap is SSTo, second by a rocket thats as small and efficient as possible for teh given payload (extra dV, extra mass you dont need, all it does is exponentially increase entire things cost).

[numerobis]

Apollo is a great way to go to Mun in 6.4x -- in stock KSP, return from Mun is so cheap there isn't a big enough benefit to merit all the complication.

[Pecan]

Apollo is a great way to go to Mun in 6.4x -- in stock KSP, return from Mun is so cheap there isn't a big enough benefit to merit all the complication.

Yes; I should perhaps have said 'stock' KSP. With mods, of course, the physics and economy can be anything.

Apollo was/is a good Earth-design (if you believe in that mythical planet where people have different names and all those silly stories ^^).

[Captain Sierra]

In KSP, the theoretical 'best' design economically is one where you recover as much as possible.

There seems to be a bit of debate over whether VTOL "tail-sitter" SSTOs are better than SSTO spaceplanes.

[table][tr][td]Pros:[/td][/tr]

[tr][td]

"Tail Sitter:"

• Often unmanned, less plane parts (which are expensive)
  
• Expandable design
  
• Larger payload potential size-wise
  
• Generally simpler to build
  
• Lower skill requirement for piloting
  

[/td][td]

Spaceplane:

• Can take off with TWR <1
  
• Can use less engines overall
  
• Wings for lift reduce need for vertical thrust
  
• Less fuel needed
  
• Have considerably higher badass factor and/or prestige (especially with payload capacity)
  
• Large cross-range capability
  

[/td][/tr]

[tr][td]Cons:[/td][/tr]

[tr][td]

"Tail-Sitter":

• Requires more engines
  
• Requires TWR >1
  
• More fuel needed
  
• No aerodynamic lift, only vertical thrust
  
• Limited cross-range capability
  

[/td][td]

Spaceplane:

• Limited payload size
  
• Higher piloting skill required
  
• More complex engineering/testing involved
  
• Cannot be expanded on without creating wholly new design
  
• Uses large quantities of expensive plane parts
  

[/td][/tr][/table]

Analyzing this, the bundle of jets, tanks, and intakes that make up most tail-sitters are great economically when you need a lot of mass in orbit very quickly, however when the payload requirement is smaller (or if you have an absurdly large payload-capable spaceplane), then an SSTO spaceplane is a more efficient option IF you can build and fly one, this being a major inhibitor for lots of people.

Correct me if I missed anything major in my listing.

[King Arthur]

Personally, as far as STS-style shuttles and SSTOs in KSP, I've managed to pull off the best of both worlds:

Javascript is disabled. View full album

SSTO carrier shuttle made of B9 S3, S2, and S2W parts and powered by eight RX-25 SSMEs from the Klockheed Martian space shuttle engine pack. The Mk2 shuttle is piggybacked to orbit similarly to most space shuttle designs. Per-launch cost is approximately 16,000 funds at most assuming a safe landing back at KSC. The album is that of an inaugural test flight, so I carried the Mk2 shuttle back down still piggybacked to stress test the carrier shuttle; normally the Mk2 shuttle undocks and goes off on its own merry way.

Sometimes, one can have their cake and eat it too.

[Anquietas314]

http://imgur.com/a/APSAi

--snip--

Sometimes, one can have their cake and eat it too.

That's.... wow, very nice

[GoSlash27]

Correct me if I missed anything major in my listing.

One major factor:

Spaceplanes have a large safety factor in the event that something goes wrong during the launch/ climbout.

A spaceplane can usually fly (or at least glide) to dry land, thus recovering most of the funds and *very importantly* not killing Kerbals.

A vertical lifter... you can separate the cargo and recover the launcher, but the payload itself is a write- off.

[Pecan]

Correct me if I missed anything major in my listing.

Broadly, I'd agree - especially that a spaceplane is the better choice IF you can build and fly it BUT can't land accurately without wings.

I do not believe that spaceplanes need less fuel than jet tail-sitters - it's a matter of engines vs wings. Either certainly need a lot less than rockets.

Given that you need TWR > 1 to lift-off in the first place with a tail-sitter the lack of aerodynamic lift is not a 'con' - you launch vertical so don't need wings, by the time you're at 2km+ you follow exactly the same flight profile as a spaceplane and during the most critical parts of the flight the atmosphere is so thin wings wouldn't generate much lift anyway.

Although Hodo and Wanderfound assure me that TWR < 1 is useful for a spaceplane I've always just wondered how such low-thrust designs accelerate for horizontal speed at altitude.

Changes to stock (parts and aerodynamics) may well change the balance of the argument considerably.

Ultimately, I think if this were one of those things that had a single, clear winner none of us would be happy - because introducing huge wings, etc. to make large spaceplanes practical without huge laggy part-counts would make it 'too easy'. All the spaceplanes would look identical too - Helloo Mk2 cockpit - we know how the ARM engines argument went.

ETA: My heavy-lift tail-sitters don't kill Kerbals by virtue of not carrying any! When the payload is only crew I use a spaceplane.

[Anquietas314]

Although Hodo and Wanderfound assure me that TWR < 1 is useful for a spaceplane I've always just wondered how such low-thrust designs accelerate for horizontal speed at altitude.

Lots of intakes to get higher up in the atmosphere to overcome drag

ETA: My heavy-lift tail-sitters don't kill Kerbals by virtue of not carrying any! When the payload is only crew I use a spaceplane.

What if you're launching a station hab module (not for contracts)? You could launch it empty then fill it later, but that means two launches, one of which isn't necessary