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#101 2018-06-07 19:02:16

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
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Re: NASA's planning for Mars human missions - interesting stuff.

So assuming ISPP and propellant depot on Mars so BFS is reusable, and assuming 100 one-way settlers, what is the cost per passenger and how much luggage per passenger?

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#102 2018-06-07 19:12:47

kbd512
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Re: NASA's planning for Mars human missions - interesting stuff.

Void,

I should have said, the interceptors will fly between the Sun and Mars, not Earth and Mars.  To use the Gen 2 ITV, the vehicle must fly into the Sun and then fly away from the Sun about midway between the Earth and the Sun.  That said, your maximum transit duration when Earth and Mars are furthest from each other is 7 days at 1g acceleration.  No spinning wheel section is required.  You're always at 1g.  This works in orbit around the Earth, in Earth's ionosphere, and in deep space.  It's possible to accelerate cargo to get to Mars overnight, a sort of overnight delivery service if you will, but the acceleration would crush humans.

As far as tanking is concerned, the proper way to do this is with refueling probes and single tanking operations.  An OPD in LEO would be the way to do this if we're absolutely insistent upon using such an expensive mission architecture.  Again, the use of these novel chemical propulsion related technologies are an act of desperation to try to get around the fact that chemical propulsion is so inefficient.  Energy is plentiful, but resources are few and far between.

Hanging out in the Van Allen belts in a vehicle that has to be as lightly constructed as possible because it's an upper rocket stage is not my idea of a good plan.  The ITV is not a rocket stage.  It's an artificial gravity space station that has the radiation protection, power, and thus propulsion required to go to other places of interest in a fuel efficient manner.  My intent was also that ITV technology replaces ISS, except that it stays in LEO.

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#103 2018-06-07 19:56:32

kbd512
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Re: NASA's planning for Mars human missions - interesting stuff.

RobertDyck wrote:

So assuming ISPP and propellant depot on Mars so BFS is reusable, and assuming 100 one-way settlers, what is the cost per passenger and how much luggage per passenger?

Rob,

After the initial infrastructure is in place on Mars for ISPP and tunnel boring, the cost to transport is as follows:

100 = $500K / person
1,000 = $50K / person (requires a special type of seating arrangement, but everyone will fit)
1,000+ = $50K / person*

* SpaceX ITS needed to further reduce transportation costs to Mars because BFS is too small
* Larger ITV required to transport 10,000 people, or multiple ITV's per 1,000 people
* My design limit for the ITV was 1,000 people
* All BFS will be permanently reassigned to Venus colonization detail when ITS is required

All Martian colonists will be housed in tunnels dug by 3m 500kWe electric TBM's like the ones Robinson makes.  The cutter / powerhead is about 25t.  No idea how much the muck train units weigh.  I know it's less than that, but don't know the exact figure.  I need some of those HIAD or ADEPT units to land them and a tracked transporter / crane to lower the TBM into the hole.

Personal effects are limited to your space suit, jewelry, pictures, a cell phone, and a tablet.  A data center will collect internet data transmitted from Earth to Mars via laser communications.  The electronics are present for communication, work, learning, and recreation.  Every two years, you'll receive new devices.

The Mars colony makes the clothes you wear, the food you eat, and the water you drink aboard the ITV on the transit to Mars.  Their ability to make these things for future colonists' use is proof positive that they can support more people on Mars.  If you can't make the clothes, bedding, toiletries, food, and water, then you're not ready for more colonists.  It may seem unfair, but it's a way of ensuring the ability to produce and it builds a sense of community.

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#104 2018-06-07 20:29:59

RobertDyck
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From: Winnipeg, Canada
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Re: NASA's planning for Mars human missions - interesting stuff.

The business plan was a ticket would cost you life savings. Sell your house, car, liquidate you life insurance and pension. Now how much could a typical American family raise, how many family members, how much could they raise per person? Say successful professionals, not blue collar workers. And with 100 people per trip, with Elon's plan, with cabins. How much luggage?

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#105 2018-06-08 05:03:50

louis
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From: UK
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Re: NASA's planning for Mars human missions - interesting stuff.

I agree with your general point that we need to find alternatives to chemical propulsion, particularly for getting off planetary surfaces and into orbit. One of the issues which might well come to fore as earthbound transport is increasingly powered by "green energy" is the issue of pollution by rocket propellant. It would be odd if we have non-polluting energy used in all transport modes except rockets.  I favour laser or microwave beam propulsion for getting people into orbit. That seems a promising route.

However, that is all a few decades in the future I think.

I don't agree that a Mars settlement programme is dependent on "capturing the public's attention" as with Apollo.  The Apollo mission was entirely dependent on public funding which was why the issue of public attention and support was so important. All Americans were paying for Apollo through taxation, so they all (or at least most of them) needed to be interested and supportive. Space X's mission is private, no public funding required and - though we may differ on this - Mars settlement can I believe be funded by Mars ISRU, Mars trading  with Earth and other revenue streams such as sponsorship. You just need a substantial number of institutions and people on Earth to be interested in Mars to sustain it.

Your estimate of $50 million per flight is way out of line with this estimate (based on detailed analysis) of $7 million per flight:

https://www.nextbigfuture.com/2017/10/s … aunch.html

That sounds much more in line with Space X's claim that they can compete with top end prices for airline tickets on long haul flights.

That's something you perhaps overlooked - that BFR is going to be used in multiple roles, so spreading the costs of development and achieving economies of scale across the board.


kbd512 wrote:

Louis,

I was tired when I watched it, so 5 tanker flights it is.  GW says 6, I thought I counted 4.  Either way, we're still proving my point.  12 BFR launches to send 2 vehicles to Mars is unsustainable.  Absent real interplanetary transport vehicles that use electric propulsion and artificial gravity, this sort of mission architecture is already flags and footprints.  STS was unsustainable as a function of the program cost.  SLS has simply been entirely unaffordable from the word "go".  The continual use of chemical propulsion for in-space transportation is less affordable on a per mission basis than STS was.  The excitement won't capture public attention for more than the first few missions.  Apollo proved that beyond any reasonable doubt.

The cost of launching doesn't go away because you have a reusable rocket.  It's more affordable than expendable rockets in certain cases, but still solidly within the realm of the extravagantly wealthy and governments.  If BFR was flown in expendable mode, then you'd get enough tonnage in LEO to fly a single mission.  Doing that also defeats the purpose of reusable space launch vehicles.

It's not about the cost of the propellant even though that quickly adds up.  The maintenance forever and always costs real money.  The $50M for each flight means each flight of BFR costs $50M, not $50M to send 1 BFS to Mars.  That's $600M for a single mission to Mars.  I'm trying to lower the operational costs to roughly double that of a two hour 747 flight, on a per person basis.  Normal people can afford to pay those prices and normal people are your recurring revenue stream.  IIRC, 747's cost $24K to $27K per flight hour.  You can think of this BFR and ITV enabled architecture in terms of cost per mission instead of cost per flight hour.  My full mission architecture has a recurring cost of $50K to send a person to Mars when the number of people sent is 1K per mission.  For every hour that a 747 flies, you have tens of hours of associated maintenance that must be performed, roughly on the order of the costs stated, or the jet stops working.  The same is true for launch vehicles.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#106 2018-06-08 08:55:33

Void
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Registered: 2011-12-29
Posts: 3,776

Re: NASA's planning for Mars human missions - interesting stuff.

Without ignoring you Louis or RobertDyke,

Kbd512,

The idea of using better propulsion is indeed sensible.  Perhaps electric propulsion to send a propulsive depot storage device to a location desired.

But for now I am going to work with the items that SpaceX apparently intends to produce, and also perhaps borrow from Vulcan.

1) BFR.  As far as I can tell this will be a relatively standardized device, but I would expect it to receive upgrades for some time.  It will likely become larger and more efficient.

2) BFS(s).  This will be a plurality of specialized versions, which you have listed in a prior post.

3) A device called a "Depot", which has not otherwise been technically specified.

I will make a suggestion.  While it could just be some tankage built in orbit, orbital construction is troublesome.  Better to stay simple.
Why not make it a daisy chain of BFS(s). 

This version would have removable engines which could be brought down to the Earths surface in the cargo bay of another BFS.  Or the engines could be stored in orbit.

The Depot BFS(s) could be daisy chained together.

And a Cargo or Passenger BFS could couple to such a daisy chained depot assembly of depot BFS(s) like a tug with barges on a river.

https://www.bing.com/images/search?q=ri … &FORM=IGRE

......

As for the Depot BFS(s) they might have a heat shield so that the engines could be reconnected at some point so it could land (It might only need one engine?).

Or it could be throw away without a heat shield.  Probably throw away if going to Mars, but then maybe not necessarily.  Perhaps some of them would return to Earth depending on how your mission propulsion was scripted.

Going to some other place where you are not going to do an aeroburn on arrival, then have the type you want.

......

Another possible option is to have the Depot BFS(s) have one landing engine, escort the Mars bound BFS to a high Earth orbit, and then they would disconnect, and return to Earth, or Earth orbit.

It is like Lego's very flexible.

And then indeed throw in other methods of propulsion, and you might really get things done.

Done.

Last edited by Void (2018-06-08 09:10:44)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#107 2018-06-08 12:12:38

kbd512
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Re: NASA's planning for Mars human missions - interesting stuff.

Louis,

Here's another article making wild assumptions about things we know nothing about:

The Space Review - Estimating the cost of BFR by Sam Dinkin

The aspirational target prices for ITS per Mars mission (6 booster flights, 5 tanker ship flights, 1 passenger or cargo flight) were $11M for the booster, $8M for the tanker, and $43 million for the ship.  The ITS didn't require a separate cargo flight to Mars.

From the article you posted a link to: "Spacex should be able to profitably get into the cost per flight of $20-40 million."

$40M / flight = so much better than we've ever done in the past that nothing else is remotely comparable
$20M / flight = absolutely jaw-dropping
$7M / flight = miracle of epic proportions

Why would anyone assume that some vehicle that's never flown that's based upon a concept that's never worked as well as intended in the past will automatically be an order of magnitude less costly than anything else that's ever flown?

A Mars mission is not a per-flight proposition.  A minimum of 6 launches is required to get 1 BFS to Mars, realistically 2 BFS to Mars for them to do much of anything while they're on Mars.  At today's prices, The propellants for the 6 upper stages alone are $2,328,000.  Just double that number for the boosters' propellants, even though it's slightly more than that.  Finally, add the propellant costs for the cargo flight to that number since the colonists can't build anything without the cargo.  We're starting from scratch.  Like he said, Mars is a fixer-upper planet.

I'll simply grant "absolutely jaw-dropping" to your line of reasoning, but not "miracle of epic proportions" until someone actually flies something and we figure out exactly how much transportation and maintenance costs will be.  That's $240M per Mars mission and approximately half of a Space Shuttle mission.  To simply pay for the mission, that's $2.4M per person at maximum capacity.

The mass margins for this stupendously high performance BFS are already well below that of a commercial airliner.  It's improbable at best that it could be flown twice a day without an unacceptably high risk of catastrophic failure, but let's wait until one actually flies before we assume something that nobody without a crystal ball knows until testing begins.

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#108 2018-06-08 12:35:03

louis
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From: UK
Registered: 2008-03-24
Posts: 6,713

Re: NASA's planning for Mars human missions - interesting stuff.

If it really was $240 million per Mars mission that would be chicken feed! smile

I think you are wrong to keep dividing mission costs by 100 as though ticket prices are going to cover the cost of travel (even if that is how Musk presented it to begin with).  For many years Australian government advertised £10 tickets for passage to Australia by would be migrants from the UK. I'd guess that was probably about 3% of the real cost at the time.

It's much more likely that the super-profitable Mars community will subsidise the passage of migrants.

I was just reading that the development cost of the Falcon 9 was a mere $2 billion which compares v. favourably with other rockets and airliners.  I suspect the BFR costs will be similarly  on the low side.

kbd512 wrote:

Louis,

Here's another article making wild assumptions about things we know nothing about:

The Space Review - Estimating the cost of BFR by Sam Dinkin

The aspirational target prices for ITS per Mars mission (6 booster flights, 5 tanker ship flights, 1 passenger or cargo flight) were $11M for the booster, $8M for the tanker, and $43 million for the ship.  The ITS didn't require a separate cargo flight to Mars.

From the article you posted a link to: "Spacex should be able to profitably get into the cost per flight of $20-40 million."

$40M / flight = so much better than we've ever done in the past that nothing else is remotely comparable
$20M / flight = absolutely jaw-dropping
$7M / flight = miracle of epic proportions

Why would anyone assume that some vehicle that's never flown that's based upon a concept that's never worked as well as intended in the past will automatically be an order of magnitude less costly than anything else that's ever flown?

A Mars mission is not a per-flight proposition.  A minimum of 6 launches is required to get 1 BFS to Mars, realistically 2 BFS to Mars for them to do much of anything while they're on Mars.  At today's prices, The propellants for the 6 upper stages alone are $2,328,000.  Just double that number for the boosters' propellants, even though it's slightly more than that.  Finally, add the propellant costs for the cargo flight to that number since the colonists can't build anything without the cargo.  We're starting from scratch.  Like he said, Mars is a fixer-upper planet.

I'll simply grant "absolutely jaw-dropping" to your line of reasoning, but not "miracle of epic proportions" until someone actually flies something and we figure out exactly how much transportation and maintenance costs will be.  That's $240M per Mars mission and approximately half of a Space Shuttle mission.  To simply pay for the mission, that's $2.4M per person at maximum capacity.

The mass margins for this stupendously high performance BFS are already well below that of a commercial airliner.  It's improbable at best that it could be flown twice a day without an unacceptably high risk of catastrophic failure, but let's wait until one actually flies before we assume something that nobody without a crystal ball knows until testing begins.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#109 2018-06-08 15:32:35

GW Johnson
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From: McGregor, Texas USA
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Re: NASA's planning for Mars human missions - interesting stuff.

This debate is all "angels on the head of a pin" until the BFR/BFS system begins flying after its checkout. 

I think all your numbers are bogus until then.

BTW,  they will not fly "grasshopper" missions with BFS at the McGregor test site.  That will be either at Brownsville,  or Vandenburg,  or Canaveral.  Nobody can ship things that big to McGregor. 

GW

Last edited by GW Johnson (2018-06-08 15:33:11)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#110 2018-06-08 16:18:23

kbd512
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Posts: 4,432

Re: NASA's planning for Mars human missions - interesting stuff.

Louis,

$240M may be chicken feed for NASA, but not a company that has to turn a profit.  That's the difference between tax payer funding and private funding.  Someone has to make money off it or eventually the business goes out of business.  When's the last time you've spent $1M on anything?

On that note, $2.4M is not chicken feed for John Q. Public since he's subsidizing the cost of transporting his fellow Americans to another planet when they don't really need to go there in order to lead productive lives.  This is a pipe dream that people like us fantasize about because we're science and technology nerds and to us it's pretty cool.  Any plan that requires tax money has to be sold to the tax paying public.

If the US government is covering the transportation costs, then it's propping up a business that isn't profitable or so expensive for the service it provides that it requires a constant flow of large sums of tax money.  That was Elon Musk's critique of ULA when he testified before Congress about competitively bidding on launch contracts for the US Air Force.  Now he's taking USAF funding for the development of BFR.  I'm not complaining about that, just pointing out the hypocrisy.  I think it'll be some of the best money they've spent in recent years since SpaceX is so serious about delivery of product, even if it's a little bit later than intended.  It still gets done and "the doing" is what matters most.

Subsidization of the future colonists by the colony was exactly what I proposed as the measure by which the ability to accept more colonists should be judged.  If the Mars colony's own production can load the ITV with all the food, water, fuel, and other consumables required, that means you're ready to support more colonists on Mars because you have a surplus of production and need more people to expand the colony.

The use of the ITV is a mission enabler because it drastically simplifies the transportation logistics, reduces risks from potentially lethal activities like reentries at interplanetary velocities, and eliminates the need to constantly refuel ships to send them from Earth to Mars and back again.  This is the kind of development work that NASA should undertake because the agency has the resources available and it has a vested interest in technologies that can take them anywhere they want to go at economical prices.

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#111 2018-06-08 19:53:01

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 22,652

Re: NASA's planning for Mars human missions - interesting stuff.

It would seem that another means to have joe public get funding for mars to be able to live and work there is going to come from those that do go as they will be indebt for eternity in order to pay off the trips cost. Of course that will mean that some business will be requesting you to work in order for you to payoff your bill for the trip. The first will be science that will pay that bill but whats after to allow for more people to go as the science will be all done that they will want. So how will more people keep going to grow the colonies that mars will have?

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#112 2018-06-09 05:43:30

elderflower
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Registered: 2016-06-19
Posts: 1,262

Re: NASA's planning for Mars human missions - interesting stuff.

In the early days it won't be Joe P or Uncle Sam that pays, well not directly. It will be richly endowed foundations, large publicity seeking corporations and well heeled science departments.

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#113 2018-06-09 06:46:51

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
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Re: NASA's planning for Mars human missions - interesting stuff.

CNN - August 5, 2014: America's middle class: Poorer than you think

The numbers seem to back it up. Americans' average wealth tops $301,000 per adult, enough to rank us fourth on the latest Credit Suisse Global Wealth report.

But that figure doesn't tell you how the middle class American is doing.

Americans' median wealth is a mere $44,900 per adult -- half have more, half have less. That's only good enough for 19th place, below Japan, Canada, Australia and much of Western Europe.

Forget about "median" wealth, let's look at successful professionals.

Average number of people per family in the United States from 1960 to 2017
Quote from Google preview, not the article itself. That comes from the HTML header for this page.

As of 2016, the U.S. Census Bureau counted about 82.18 million families in the United States. The average family consists of 3.14 persons in 2017, down from 3.7 in the sixties.

So a family with 2 adults and 1 child can afford $100,000 per person. That's not a lot, as rockets go. Can BFR/BFS transport settlers to Mars for that? Using Elon Musk's design with 100 settlers per BFS with cabins? That means $10 million per flight. Millions, not billions. Even with reusable rockets, somehow I doubt that will work. Elon said a different arrangement could carry 200 or 300 settlers at a time. Earlier in this discussion thread, kbd512 posted...

kbd512 wrote:

100 = $500K / person
1,000 = $50K / person (requires a special type of seating arrangement, but everyone will fit)
1,000+ = $50K / person*

That sounds like wishful thinking. Elon did claim BFS would transit to Mars in 4 months, not 6 like Mars Direct. But BFS would not have artificial gravity. Packing 1,000 people into one ship requires life support and food for the entire trip. Even with aircraft seating, is there room for that many people with life support and food? And that means no luggage, just carry-on. An economy seat for an aircraft has space beneath the seat in front of you, plus the overhead compartment. You could change that to under your own seat, to avoid the problem with bulkheads (no seat in front of you). But can you survive a trip in an aircraft seat for 4 months? Even if it's equivalent to business class instead of economy class? Some long-haul aircraft now have "suites", so you can lie down. Is there really enough room on BFS for 1,000 "suites" plus life support and food? I would have to see details to believe that.

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#114 2018-06-09 08:01:35

Oldfart1939
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Registered: 2016-11-26
Posts: 2,157

Re: NASA's planning for Mars human missions - interesting stuff.

I've been fairly silent on this thread ever since the discussion devolved or deteriorated to talking about costs and number of passengers per flight. GW was quite observant in his comments about angels dancing on the head of a pin. Until I even see some real hardware standing on either a test stand or launch pad, I'll not comment about whether the angels are (1) ballroom dancing, (2) ballet dancing, or (3) tap dancing. I've not commented about electric propulsion, either. We need to go ASAP, or NOW, with the technology available. Everything for the first 10 years of the actual flight program must be somehow underwritten by a private-public partnership, or IT AIN'T GONNA HAPPEN! The first people going to Mars will be some combination of scientists and construction workers/engineers. Not for any other reason than those are the necessary human resources for further growth and expansion. All the grandiose dreams and plans are just DREAMS and PLANS until the first BFR primary stage fires up it's engines. My prediction is in 5 to 8 years for the first suborbital test flights. I fervently hope it's sooner and more in line with Elon's more aggressive timeline.

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#115 2018-06-09 09:04:23

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,453
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Re: NASA's planning for Mars human missions - interesting stuff.

I have a launch costs comparison posted over at "exrocketman",  complete with a list of sources for my data.  It includes some launchers that have been retired,  and includes best projections for Falcon-Heavy,  but not BFR/BFS.  There are no hard data for BFR/BFS yet,  because there is as yet no assembled hardware to fly.  It's titled "Launch Costs Comparison 2018",  and dated Feb 9,  2018.  Click on "feb" under 2018,  then the title,  and you're there. 

I think Kbd512 underestimates the cost of a shuttle launch in his comparisons.  The source I used dates to the end of the program,  and shows closer to $1500 million per launch than his $500 million.  That's factor 3 higher.  With discrepancies like that folded into the discussion,  you can see why I said this cost per passenger debate on BFR/BFS to Mars is really still "angels dancing on the head of a pin". 

Have patience,  in a handful of years the thing will most likely be flying,  and those numbers will begin to surface. 

Also have patience.  After the thing is flying,  perhaps we'll begin to get fielded very high power electric propulsion.  THAT really would be a breakthrough,  as you could send lots of stuff to Mars without all those tanker flights.  BFR/BFS really might be a very cost-effective mass transport to LEO,  and a specialty type transport elsewhere.  The breakthrough with BFR/BFS is an inherently reusable second stage to LEO,  large enough to carry serious amounts of payload.

Yeah,  by flying lots of tankers,  you can go to Mars with it,  and it will be a good thing until a better deal comes along.  Whether it's 4,  5, or 6 tankers remains to be seen.  That's why the video is vague about that.  If the launch cost per vehicle is low enough,  a handful of tankers won't matter so much. 

What you have to remember here is that Musk's vision is not about what he himself can do.  Others are going to have to help.  He's focused on the transportation,  coming from where he is now,  which is chemical rocketry (not electric propulsion,  or nuclear propulsion).  Others will have to help fund the building of the city,  and perhaps some of the transport cost.  But it's chicken-and-egg:  nobody will want to belly up to the bar until the first one already has.  That is what his first few missions is really all about. 

GW

Last edited by GW Johnson (2018-06-09 09:09:14)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#116 2018-06-09 09:06:25

louis
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From: UK
Registered: 2008-03-24
Posts: 6,713

Re: NASA's planning for Mars human missions - interesting stuff.

Falcon 9 went from announcement to launch in four years (2005-2009).  That was quite a leap for Space X back then.

We know they had their problems with the Falcon 9 Heavy but Musk admits now that they didn't appreciate the complexities that would result from basically strapping together 3 rockets in a row.

But with BFR they are back in single rocket mode.

The announcement of what is now the BFR can be traced back to 2012 (although they were already working on the Raptor engines). So that is really the start line.  7 years to get to a test hop launch in 2019 does not to me seem beyond the bounds of possiblity.

So I remain optimistic, if not wildly so.

As to the issue of cost of flights and per person travel, I think these are highly relevant to the goal of colonisation and I think we can relate something like the BFR to other rockets and aircraft like the Airbus and make educated guesses about cost of development and flights.

Oldfart1939 wrote:

I've been fairly silent on this thread ever since the discussion devolved or deteriorated to talking about costs and number of passengers per flight. GW was quite observant in his comments about angels dancing on the head of a pin. Until I even see some real hardware standing on either a test stand or launch pad, I'll not comment about whether the angels are (1) ballroom dancing, (2) ballet dancing, or (3) tap dancing. I've not commented about electric propulsion, either. We need to go ASAP, or NOW, with the technology available. Everything for the first 10 years of the actual flight program must be somehow underwritten by a private-public partnership, or IT AIN'T GONNA HAPPEN! The first people going to Mars will be some combination of scientists and construction workers/engineers. Not for any other reason than those are the necessary human resources for further growth and expansion. All the grandiose dreams and plans are just DREAMS and PLANS until the first BFR primary stage fires up it's engines. My prediction is in 5 to 8 years for the first suborbital test flights. I fervently hope it's sooner and more in line with Elon's more aggressive timeline.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#117 2018-06-09 09:13:25

louis
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From: UK
Registered: 2008-03-24
Posts: 6,713

Re: NASA's planning for Mars human missions - interesting stuff.

I think the first Mars Mission is going to cost a lot more than $240 million because it will have to pay its share of the BFR development costs, because there will have to be several pilot missions around and on the Moon, and because there will be a lot of first time inventing (e.g. the Mars-rated propellant plant, surface habs and so on).  But further down the road, I think your $240 million is a gross over-estimate. The BFR development costs will have been sunk, we'll know how to get to and survive on Mars and there will be no need for test flights. I think a medium term of $50 million to get one BFR to Mars seems plausible to me, with possibly as many as 100 people on board. If so, the "ticket" price would be $500,000 and many corporations, universities, TV companies and space agencies wouldn't blink an eye at spending that sort of money on sending one of their own to Mars.


kbd512 wrote:

Louis,

$240M may be chicken feed for NASA, but not a company that has to turn a profit.  That's the difference between tax payer funding and private funding.  Someone has to make money off it or eventually the business goes out of business.  When's the last time you've spent $1M on anything?

On that note, $2.4M is not chicken feed for John Q. Public since he's subsidizing the cost of transporting his fellow Americans to another planet when they don't really need to go there in order to lead productive lives.  This is a pipe dream that people like us fantasize about because we're science and technology nerds and to us it's pretty cool.  Any plan that requires tax money has to be sold to the tax paying public.

If the US government is covering the transportation costs, then it's propping up a business that isn't profitable or so expensive for the service it provides that it requires a constant flow of large sums of tax money.  That was Elon Musk's critique of ULA when he testified before Congress about competitively bidding on launch contracts for the US Air Force.  Now he's taking USAF funding for the development of BFR.  I'm not complaining about that, just pointing out the hypocrisy.  I think it'll be some of the best money they've spent in recent years since SpaceX is so serious about delivery of product, even if it's a little bit later than intended.  It still gets done and "the doing" is what matters most.

Subsidization of the future colonists by the colony was exactly what I proposed as the measure by which the ability to accept more colonists should be judged.  If the Mars colony's own production can load the ITV with all the food, water, fuel, and other consumables required, that means you're ready to support more colonists on Mars because you have a surplus of production and need more people to expand the colony.

The use of the ITV is a mission enabler because it drastically simplifies the transportation logistics, reduces risks from potentially lethal activities like reentries at interplanetary velocities, and eliminates the need to constantly refuel ships to send them from Earth to Mars and back again.  This is the kind of development work that NASA should undertake because the agency has the resources available and it has a vested interest in technologies that can take them anywhere they want to go at economical prices.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#118 2018-06-09 09:18:13

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,453
Website

Re: NASA's planning for Mars human missions - interesting stuff.

Even Spacex's Glynne Shotwell acknowledges the frustrations of dream vs reality and over-optimistic timelines.  She has learned how to deal with Musk,  and how to do the picking and choosing of what is most important,  to make his wishes come true.  That conundrum is simply an artifact of Spacex's founder's personality.  It is why there is time,  and then there is Elon-time.  However,  it has been getting a little better. 

Louis says Falcon-9 flew in 4 years.  Yes,  but NOT the version that turned out to be practical!  That took several more years,  and block 4 is only an approximation:  Spacex won't refly that one but twice.  It's this years' block 5 that might actually be practical.  In comparison to that timeline,  getting around the teething troubles with Falcon-Heavy really is a tad shorter,  if more difficult technically.  And the two problems are related,  and solved together,  which is a beneficial synergy.  They will use Block 5 Falcon stages in the next Heavy,  I read somewhere.

GW

Last edited by GW Johnson (2018-06-09 09:21:19)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#119 2018-06-09 09:42:34

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,713

Re: NASA's planning for Mars human missions - interesting stuff.

I think the Elon Time thing is overdone...in 16 years Space X has gone from nothing to launching a Heavy rocket - something no other private company has done. I call that stupendous progress. I think people are a little confused because (a) the F9H ended up being a bit of an unnecessary detour (b) Space X has had to satisfy NASA, rather than themselves, on a lot of things and (c) a lot of the work on the BFR has been taking place somewhat out of the limelight, while the focus has been on the F9 and F9H (so people don't realise how much progress has already been made).

I think Musk's timetable is an  "if everything goes right" timeline, which is definitely the correct one to aim for in my view (build in contingencies for cashflow but not timeflow).  Of course we know things don't always go right, but there is some give in the timeline and I think Space X now have a solid store of knowledge they can draw on re landing, life support, engine design, propellant tank design etc, which was not the case in 2002 (they had nobody then and Musk, not a rocket engineer himself, had to step in to work on a lot of the original rocket design).

GW Johnson wrote:

Even Spacex's Glynne Shotwell acknowledges the frustrations of dream vs reality and over-optimistic timelines.  She has learned how to deal with Musk,  and how to do the picking and choosing of what is most important,  to make his wishes come true.  That conundrum is simply an artifact of Spacex's founder's personality.  It is why there is time,  and then there is Elon-time.  However,  it has been getting a little better. 

Louis says Falcon-9 flew in 4 years.  Yes,  but NOT the version that turned out to be practical!  That took several more years,  and block 4 is only an approximation:  Spacex won't refly that one but twice.  It's this years' block 5 that might actually be practical.  In comparison to that timeline,  getting around the teething troubles with Falcon-Heavy really is a tad shorter,  if more difficult technically.  And the two problems are related,  and solved together,  which is a beneficial synergy.  They will use Block 5 Falcon stages in the next Heavy,  I read somewhere.

GW


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#120 2018-06-09 10:48:55

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,432

Re: NASA's planning for Mars human missions - interesting stuff.

GW and Louis,

I'm not proposing holding anything up for electric propulsion.  The first few missions can still be accomplished with chemical propulsion, if required.  The cost of the initial infrastructure setup on Mars has to be written off by governments for exploration purposes.  For this to be a profitable continuous commercial operation, the transportation costs must be severely restricted.  That is only achievable using high powered electric propulsion.  Strict limits on acceleration loads must also be achieved so that ordinary civilians, with a modicum of training, can make the transit.  That is also only achievable with electric propulsion transport vehicles with artificial gravity followed by reentry at orbital velocity.

X3 is done with testing this year.  It's time to turn it into something more than an expensive science project.  ATK is working on a PMAD architecture that scales from 300kWe to 1MWe+.  Again, time to turn it into something.  This is the sort of development work that should receive funding.  A vehicle using thin film arrays could be deployed from a F9 or F9H.  Electrodynamic tethers can also be tested for orbit raising and gyro systems can be tested for fine attitude control.  Boeing already has all-electric satellites in orbit.  Take Orbital ATK's LEOStar bus, currently being worked on to support X3 and MegaFlex, and start serious design and testing work now.  The high power MPD thrusters are in continuous testing at various universities like Princeton.  Propulsion technologies that work this well are not simply scientifically interesting anymore.  We finally have solar arrays with the power density and mass ranges favorable for the intended use case.

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#121 2018-06-09 18:12:45

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,713

Re: NASA's planning for Mars human missions - interesting stuff.

I simply don't accept this.  Nowhere has Musk said the initial propellant plant needs to be written off by government and there will simply be huge (billions of dollars) amounts of sponsorship and other investment available for the early missions which will set up the initial infrastructure.

kbd512 wrote:

The cost of the initial infrastructure setup on Mars has to be written off by governments for exploration purposes.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#122 2018-06-09 19:27:01

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 22,652

Re: NASA's planning for Mars human missions - interesting stuff.

So far its looking like just for the cost of rides to mars even with all the recycled rockets that we are well over 2 billion of costs for a mission and thats not even with any discusion of what we need to bring for science, equipment, food, and lots of other stuff needed.

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#123 2021-05-28 12:24:17

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 742

Re: NASA's planning for Mars human missions - interesting stuff.

Bernie Sanders speask on space. United States Senator from Vermont and Liberal Democrat US Presidential Candidate
https://observer.com/2021/05/bernie-san … n-project/
'Bezos and Musk Should Pay for NASA’s Moon Mission', Says Bernie Sanders

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#124 2021-05-28 12:43:48

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 22,652

Re: NASA's planning for Mars human missions - interesting stuff.

well if each pays for there ship to be used then its the one with the bigger wallet that wins....

Each will and does have a competitive vehicle for use for the moon but its still got to be seen if one can do mars...

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