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Cost to orbit for a manned craft

Posted by: Andy Hill - Thu Jun 09, 2005 12:52 pm
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Cost to orbit for a manned craft 
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Post Re: Near Term Prospects   Posted on: Fri Jun 10, 2005 4:16 pm
rpspeck wrote:
I have made similar projections:


Using crude rocket motors, the total mass ratio to orbit is about 30, so a reasonable 200 kg orbital mass per person will require 6,000 kg of fuel (about 70% of that is Liquid Oxygen). The 1,800 kg of hydrocarbons (660 gallons of gasoline) is about what is used in an American family car each year. Without “highway taxes”, the cost is less than $1200. Oxygen is much less expensive, and should add less than $800. Efficient flight operations have costs close to twice the fuel costs, giving a $4000 per standard weight passenger ticket price. Note that logging 20,000 air miles (almost around the planet) uses an amount of energy comparable to orbital access (with perhaps ½ the fuel mass, due to greater overall efficiency).

Only decent engineering – WITH NO TECHNOLOGICAL INNOVATION - is necessary to get prices down to the $4000 level.


http://www.boeing.com/commercial/777fam ... nical.html

Boeing 777-300:
Passenger capacity in 3-class configuration: 368
...I'm going to double this number because we're assuming much less luggage in our estimation, right? So we'll say that in "orbital simulation configuration" it will seat 736 people.
Fuel capacity: 45,220 US gallons
Maximum range: 5,995 nmi (7.5 mpg... not too shabby!)

To fly our 736 passengers 20,000 miles: ~150,000 gallons

To fly one passenger 20K miles in this scale: ~204 gallons. (more like 1/4 of the fuel mass than 1/2, and that's FUEL ONLY, not PROPELLANT, of which our estimate says OXIDIZER represents 70% of the mass and nearly 40% of the cost)

Present-day, real-world, everyman cost to fly 20,000 miles on a well-traveled air route:

http://www.fv01.dial.pipex.com/air_calc.shtml
I'll pick LA to Honolulu, round trip (I like Hawaii, its a very nice place) which is 5123 miles.
Yahoo travel has the best fare today at $501 for that trip, which means that we would spend $2000 in logging our 20K air miles.

Thus, our projection on the cost of orbital tourism implies that based on propellant costs alone, and assuming that oxidizer is free, when infrastructure costs and overhead are comperable to present-day air travel, we're looking at something around $6000 to $8000... in 2005 dollars... in something like 70 years from now. (Assuming that inflation over the next 70 years is comperable to what it has been in the last 100, this means in 2075 you will pay about $15K to 20K for that ticket)

SO... how about if we reframe this question to say:

If t/space and SpaceX can BOTH field manned orbital vehicles in the next 10-15 years, how much will an "orbital launch ticket only" cost to anyone wanting to visit ISS or Bigelow's hotel or any other such destination after 7-10 years of such competetive commercial flights? (or, perhaps more to the point, "How much will Pete and Andy have to save to fly in orbit before they have grandchildren?")

...and is it really possible to dock at your station 30 minutes after liftoff? I seem to remember every ISS mission docking THE DAY AFTER launch?


Last edited by SawSS1Jun21 on Fri Jun 10, 2005 5:44 pm, edited 2 times in total.



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Post    Posted on: Fri Jun 10, 2005 4:24 pm
In the thread about Collins' estimation I said today that I have got an answer which I will post next Wednesday latest - until then I will wait for an agreement to post it.

That answer seems to contribute a little bit to the topic of this thread here - and it's interesting.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post Re: Near Term Prospects   Posted on: Fri Jun 10, 2005 5:22 pm
SawSS1Jun21 wrote:
is it really possible to dock at your station 30 minutes after liftoff? I seem to remember every ISS mission docking THE DAY AFTER launch?
NASA is being extra conservative and allowing plenty of time for the crew to reconfigure from launch to cruise, rest, etc., according to an astronaut who spoke to our astronomy club a couple of years ago. Apollo LMs took about 2 hours from takeoff to dock with the CM, so it doesn't have to take all day. 30 minutes may be pushing it though. I would think a minimum of half an orbit (45 minutes) to get up to the station's altitude and circularize your orbit, plus however long it takes to make the final approach and docking, say another 45 minutes minimum. So at least 90 minutes.


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Post    Posted on: Fri Jun 10, 2005 6:16 pm
OK, I like your numbers as much as my back of the envelope ones.

SawSS1Jun21 wrote:
… we're looking at something around $6000 to $8000... in 2005 dollars ... in something like 70 years from now. (Assuming that inflation over the next 70 …


Incidentally, I was offered $7000. last week for a “no advance purchase”, round trip ticket from Denver to Frankfurt (coach). However, inflation is irrelevant – (the big numbers only scare people who can’t imagine earning a million dollars) - the ratio of price to earnings is the key, and will probably either not change, or go down.

I don’t mind being spared “strongly worded skepticism” from DKH. I was around when computers less powerful than those sold bubble packed on wall racks cost a million dollars. It is easy to “prove” that “Man will never fly!”, or that if he does, few will be able to afford it!

Although the ISP of Liquid hydrogen based fuels is attractive, the density of this fuel is so low that its tanks are huge, and this produces its own mass problem, and second, due to extra low temperature as well as low density, it is hard to turbopump and this makes these motor developments much more expensive. The overall size and cost of hydrocarbon based orbital launch systems is virtually identical to those using liquid Hydrogen (which is also far more expensive, for the fuel cost calculation.)


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Post    Posted on: Sat Jun 11, 2005 7:12 am
As soon as I figure out what you just said, I'll give you all the "strongly worded skepticism" I can spare. If you like.

But right now I'm having a hell of a time working out what it is that you're talking about!

DKH

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Post    Posted on: Sat Jun 11, 2005 8:08 pm
rpspeck wrote:
Although the ISP of Liquid hydrogen based fuels is attractive, the density of this fuel is so low that its tanks are huge, and this produces its own mass problem, and second, due to extra low temperature as well as low density, it is hard to turbopump and this makes these motor developments much more expensive. The overall size and cost of hydrocarbon based orbital launch systems is virtually identical to those using liquid Hydrogen (which is also far more expensive, for the fuel cost calculation.)


Excuse my own density here, but are you saying that there is no real advantage of using hydrogen compared to hydrocarbons as a fuel due to the extra costs associated with a motors development and the extra mass and size of fuel tanks. Why then are the launch costs the same for the two types given the cooling problems and the cost of hydrogen fuel being greater? What real advantage is there in using hydrogen if the above problems wipe out most of you Isp gain, would it not be better to develop more efficient cheaper hydrocarbon engines as SpaceX has done?

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Post    Posted on: Tue Jun 14, 2005 12:12 am
That is exactly my observation: the practical problems and costs of the more sophisticated (liquid Hydrogen based) fuels negate their theoretical advantages for ORBITAL flight. Thus the latest Delta (the core system in the Delta “heavy”) is very close to the size, cost and payload of the upgraded Atlas (Five?). Someone with more details can correct this impression – but certainly the Hydrogen will use equal sized tanks to hold a much lower mass of fuel, and development of the Hydrogen engines is a lot more costly.

This observation – if correct – implies that Elon Must made a very good decision, going with the lower development cost fuels. Note that SpaceX continues to talk about reusable components – as well as production efficiencies – when operational experience proves that reused components are safe and reliable. This promises even faster price reductions!

The fuel situation changes with UPPER STAGES, particularly for deep space missions. An upper stage might not be smaller or less expensive, using Hydrogen fuel, compared to a hydrocarbon model – BUT IT IS LOWER IN FUELED MASS – and this reduces the size and mass of the boosters which lift it. The result may or may not help for the second stage of an orbital system, but the advantage grows with each stage needed for interplanetary flight! (Unfortunately, the boil off of the deep cryogenic LH2 makes it impractical (reportedly) for use at the other end of transfer orbits, where it would bring an even larger bonus).

By the way, a launch vehicle which combines 50% or so of bulk supplies (including liquids) with 15 passengers could probably offer much more attractive accommodations for the same “per person” orbital mass. And the “supply” portion does not need reentry and recovery provision.


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Post    Posted on: Wed Jun 15, 2005 12:43 pm
Oomph. The reading's too thick for me.

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