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#1 2007-09-05 19:53:06

TwinBeam
Member
From: Chandler, AZ
Registered: 2004-01-14
Posts: 144

Re: Relative cost - manned vs un-manned launches

Due to the need to reduce risks, manned launches should cost substantially more than un-manned.

How much more?

We can't fairly compare the mixed-payload shuttle to anything.  So how about the relative costs of the up-coming "back to the moon" architecture?  Two rockets, one manned, one un-manned, both developed in the same time frame with access to the same technologies.   

Of course, even that is likely skewed - NASA will continue to focus on maximum performance at the expense of both cost and reliability, and attempt to make up for it with an army of inspector/technicians for both.

Suppose we could tolerate losing 1 (expendible) cargo rocket and payload every 20 launches, with no more than 10% increase in average launch cost.  I.e. assume the cargo is on average equal in cost to the rocket and other launch costs.  If we start shipping fuel/O2 into space for space tugs and such, that's likely an over-estimate.

How much cheaper might commercial cargo launch costs get in that case, through making the rocket simpler (if somewhat lower performance) and eliminating most of the army of technicians?

For manned launches, on the other hand, we'd really like no more than 1 in 1000 to fail, and there's no way NASA will drop the army there.  Does a 50x better launch survival rate equate to a 50x higher cost?  5x?  2x?

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#2 2007-09-06 04:09:20

cIclops
Member
Registered: 2005-06-16
Posts: 3,230

Re: Relative cost - manned vs un-manned launches

Old accountants joke: how much would you like it to be?

Yes human rating launchers means making them safer by adding redundancy to critical systems and that means more cost per vehicle and more mass and therefore less payload. As all human rated launch vehicles so far have been produced by governments, costs are very difficult to establish. Soyuz is probably the easiest example to use because it flies in both crew and cargo modes, yet  there are no publically available figures for its actual costs.

NASA have said their new architecture Ares V, the 131 mT cargo launcher, will have a marginal cost of $200 to $300m. Ares I, the six person crew launcher, will probably be about $100m marginal cost. These numbers do not include fixed costs, such as launch pad and mission control. The Ares vehicles are being designed with cost as well as safety and reliability as drivers. Performance has to meet requirements otherwise the system will fail, the trade between all these factors is what engineering is about. The good news is that Ares I is meeting its requirements.

Onorbit fuel depots are not currently competitive. When the technology for storage and transfer of cryogenic fuels is developed as well as much cheaper launchers, then they may happen.

One thing is for sure, launching payloads to LEO is and will be very expensive for many years and launching crew will cost even more.


[color=darkred]Let's go to Mars and far beyond -  triple NASA's budget ![/color] [url=irc://freenode#space]  #space channel !! [/url] [url=http://www.youtube.com/user/c1cl0ps]   - videos !!![/url]

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#3 2007-09-06 05:45:41

Yang Liwei Rocket
Member
Registered: 2004-03-03
Posts: 993

Re: Relative cost - manned vs un-manned launches

The good news is that Ares I is meeting its requirements.

We will see, while I agree that NASA needed a new vision and putting men on Mars would be a great thing - you cIclops, have decided to put a lot of happy-clappy positive spin behind the CLV or 'TheStick'. EELVs could have welcome solutions for certain payloads, there are some big doubters about TheStick and with good reason, the timetable hasn't been running so smoothly, they had to extend contracts and pump in millions more.


'first steps are not for cheap, think about it...
did China build a great Wall in a day ?' ( Y L R newmars forum member )

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#4 2007-09-06 06:34:31

cIclops
Member
Registered: 2005-06-16
Posts: 3,230

Re: Relative cost - manned vs un-manned launches

We will see, while I agree that NASA needed a new vision and putting men on Mars would be a great thing - you cIclops, have decided to put a lot of happy-clappy positive spin behind the CLV or 'TheStick'. EELVs could have welcome solutions for certain payloads, there are some big doubters about TheStick and with good reason, the timetable hasn't been running so smoothly, they had to extend contracts and pump in millions more.

What positive spin? All the spin seems to be coming from people who seem determined to prove that Ares I won't work and they do not have one piece of evidence to support that claim. Surely we all want to know the truth and AFAIK Ares I is on schedule and on budget and meeting its requirements. The timetable has been delayed because Congress have not fully funded NASA.

Which Ares I contract has been extended or had more money added?


[color=darkred]Let's go to Mars and far beyond -  triple NASA's budget ![/color] [url=irc://freenode#space]  #space channel !! [/url] [url=http://www.youtube.com/user/c1cl0ps]   - videos !!![/url]

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