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#376 2014-06-28 22:17:46

RobertDyck
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Re: Yet another Mars architecture

Keep it small so it happens. Big = not happening.

Besides, first you prove technology with something small. Once it works, then scale up to something bigger. The first mission will have to prove it can be done, demonstrate it's safe, and do basic science. Remember, the original Mars Direct had a crew of 4: 2 engineers + 2 scientists. Most work on ISS is maintenance and repairs; the engineers would do that. The movie "Red Planet" called theirs a "Space Janitor", but working life support is rather important. Two scientists with boots on the ground for 14 months? That's a lot of science.

And a lot of engineering experiments on Mars itself. Robert Zubrin's Mars Direct included an inflatable greenhouse. At one Mars Society convention I had a one-on-one conversation with Dr. Penelope Boston. She said there was no known material that could withstand UV at Utah, much less Mars. So I took that as a challenge. Next year I brought samples of Teflon FEP, Tefzel, and PCTFE plastic film. The last one is best for a Mars greenhouse. Ok, so let's do it. Inflatable greenhouse on Mars. The science mission wouldn't depend on the greenhouse, but fresh vegetables are always nice. And make bricks from Mars dirt.

Harveting usable water from Mars ice would demonstrate we can live there. It would be really, really nice if the "pack ice" at Elysium proved to be extant. But even without a frozen lake at the surface, Elysium Planitia has a lot of permafrost. Measured by the neutron/gamma spectrometer on Mars Odyssey.

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#377 2014-06-28 22:24:50

JoshNH4H
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Re: Yet another Mars architecture

Can't say I disagree.  As you saw, I'm arguing for the small mission here.  But GW has been very insistent on the big mission, while never having been really opposed on the matter, so I figure it's about time we had the argument.


-Josh

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#378 2014-06-29 19:02:23

SpaceNut
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Re: Yet another Mars architecture

RobertDyck wrote:

First mission:
- 1 SLS Block 2 for MAV (direct launch from KSC to Mars surface)
- 1 SLS Block 2 for lab & pressurized rover (direct launch)
- 1 Falcon Heavy for ITV
- 1 SLS Block 1 for TMI stage
- 1 Falcon 9 lander & unpressurized rover
- 1 Falcon 9 for Dragon
- 1 Atlas V 402 for Dream Chaser

Keep it small so it happens. Big = not happening.

Looks reasonable until you start adding up the mission costs in launchers and the new R&D for the pieces not developed yet.... and do agree that with that mission costs we will not be going....Agreed it looks like the size of crew and ship are part of the issue when looking at the missions.

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#379 2014-06-29 23:26:54

RobertDyck
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Re: Yet another Mars architecture

I depicted the ITV as single story Mars Direct hab. That's nice, but Falcon Heavy currently only supports a 5 metre diameter fairing. Mars Direct hab is 8 metre diameter, the same as the Ares launch vehicle or SLS. We could use another SLS block 1, which would eliminate Falcon Heavy. Or redesign the ITV to have 2 stories and 5 metre diameter.

And you will notice Option 2 uses Dragon to return crew to Earth from ISS, instead of Dream Chaser. That eliminates Atlas V 402 launch vehicle and Dream Chaser. For the second mission, it replaces Atlas V 402 and Dream Chaser with Falcon 9 and Dragon. Now that Dragon v2 is reusable, that may be the better option.

What is this "new R&D for the pieces not developed yet"? Considering Falcon 9 and Dragon have already flown. And Dragon v2 will fly soon. Atlas V 402 has already flown. And hopefully Dream Chaser won't be too much longer. Congress is determined to complete SLS, both blocks 1 & 2. And life support on ISS will be the basis for life support for Mars. And the SAFE 400 nuclear reactor is already developed, needed for the MAV. And mobility components for Curiosity Rover will be the "light truck" to transport the reactor away from the MAV. And Robert Zubrin's company has completed the brass-board prototype for ISPP; Mars hardware will have to be developed, but the brass-board means much of that work is done. NASA's ADEPT is well underway; that will be the heat shield for aerocapture. What's left?

I keep asserting that simply cancelling Orion and redirecting those funds and those engineers to the Mars mission should be enough. After all, Shuttle was cancelled. But NASA hasn't realized any cost savings. The cost for Shuttle should be enough for Mars. But much of the cost for Shuttle was the NASA centers to support it. Congress doesn't want to shut those centers down, or even reduce staff. That's why they're so paranoid about keeping SLS and Orion: it keeps those centers employed. Mars will need those centers. So simply redirecting funds/engineers from Orion to the Mars mission, should do it. And use SLS. No additional funding. After all, when development of SLS is finished, then costs will be to manufacture/launch SLS. Again that's to keep the NASA centers employed. Those SLS launches will be used for Mars. Isn't that something Congress would accept?

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#380 2014-07-04 01:52:01

Antius
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Re: Yet another Mars architecture

I like this mission architecture.  It would appear to reduce capital costs and technological, although the low-mass lander you are proposing would appear to offer less duration on the Martian surface.

Perhaps a 'Phobos-first' approach could be used to enhance the architecture still further.  You could then refuel the SSTO in orbit and would not need any hydrogen or methane from Earth.  Presumably, an initial mission to Phobos could use ion propulsion all the way from Earth orbit.  With such low surface gravity, landing would be easy.  Only after we had built up a sizable colony of Phobos would we need to carry out development of Mars landing vehicles.  A phobos colony could then serve as a staging post for exploration of the entire planet in relatively short duration missions using SSTOs.

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#381 2014-07-04 02:17:45

louis
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Re: Yet another Mars architecture

SpaceNut wrote:
RobertDyck wrote:

First mission:
- 1 SLS Block 2 for MAV (direct launch from KSC to Mars surface)
- 1 SLS Block 2 for lab & pressurized rover (direct launch)
- 1 Falcon Heavy for ITV
- 1 SLS Block 1 for TMI stage
- 1 Falcon 9 lander & unpressurized rover
- 1 Falcon 9 for Dragon
- 1 Atlas V 402 for Dream Chaser

Keep it small so it happens. Big = not happening.

Looks reasonable until you start adding up the mission costs in launchers and the new R&D for the pieces not developed yet.... and do agree that with that mission costs we will not be going....Agreed it looks like the size of crew and ship are part of the issue when looking at the missions.

I think you'll find it you break down the mission into smaller parts it ends up being cheaper than you think.  I looked into this before. We already have the technology to land substantial items on Mars e.g. Polar lander at half a ton. Much of the cost of the robot landers has related to the development of the robots.  In terms of landing supplies, these missions would be relatively cheap, in the context of what people claim should be at least a $40 billion price tag for a human mission to Mars.

I've always felt a Mission based on six people in two separate landing craft, and with about 8 support missions landing supplies, hab, and energy generation in maybe two to three tonne loads are what is required.  Make the human landers as Apollo Lunar module like as feasible i.e. short duration vehicles.

The Mars Polar lander, according to NASA, cost "$110 million for spacecraft development, $10 million mission operations; total $120 million (not includding launch vehicle or Deep Space 2 microprobes)".

Even if you quadruple that for 2 tonne supply loads, you are still talking about only $0.5 billion per landing mission.   For 8 missions over an 8 year period building up to a human landing that would be a total of $4 billion (10% of a $40billion price tag), or $500 million per annum (last time I looked NASA's overall budget was something like $25billion pa).

So - eminently affordable.

I think you could do the whole of a 6 man mission for under $20 billion.

Launch costs are small change in this context.


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

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#382 2014-07-04 08:23:07

RobS
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Re: Yet another Mars architecture

In terms of development costs, Musk developed the Falcon and Dragon for about a billion dollars. So inexpensive development is possible. If the Dragon and Falcon landing systems work--we'll know in two years--we'll have a way to land capsules and cargo on Mars. The Dragon's canted retrorocket system seems well suited for Mars.

A Falcon Heavy can push 14 tonnes of payload to trans-Mars injection, exclusive of empty stage. Zubrin assumed a hydrogen-oxygen trans-Mars injection stage --say, an enlarged Centaur--able to push 17 tonnes to trans-Mars injection and land 14 tonnes on Mars (this was in his Mars semi-direct proposal, using Dragon and Falcon Heavy). If we used two Heavies that docked together--one with a propulsion stage--we'd have a reasonably simple system able to push 28-30 tonnes of payload to Mars. That's close to the range of Mars Direct.

So I would design a system using Falcon Heavies if possible, since they appear to be large and cheap. Again, we'll be more certain in another year, when a Falcon is (hopefully) soft landed successfully, and a Falcon Heavy will have flown.

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#383 2014-07-04 10:08:37

louis
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Re: Yet another Mars architecture

RobS wrote:

In terms of development costs, Musk developed the Falcon and Dragon for about a billion dollars. So inexpensive development is possible. If the Dragon and Falcon landing systems work--we'll know in two years--we'll have a way to land capsules and cargo on Mars. The Dragon's canted retrorocket system seems well suited for Mars.

A Falcon Heavy can push 14 tonnes of payload to trans-Mars injection, exclusive of empty stage. Zubrin assumed a hydrogen-oxygen trans-Mars injection stage --say, an enlarged Centaur--able to push 17 tonnes to trans-Mars injection and land 14 tonnes on Mars (this was in his Mars semi-direct proposal, using Dragon and Falcon Heavy). If we used two Heavies that docked together--one with a propulsion stage--we'd have a reasonably simple system able to push 28-30 tonnes of payload to Mars. That's close to the range of Mars Direct.

So I would design a system using Falcon Heavies if possible, since they appear to be large and cheap. Again, we'll be more certain in another year, when a Falcon is (hopefully) soft landed successfully, and a Falcon Heavy will have flown.

I agree entirely: use what is already there. If we can land 14 tonnes safely, well - job done. But I think we could probably do it more cheaply if we had the political will.

IN any case it is clear to me that for Musk Space X remains principally a way of getting humans established on Mars within his own lifetime. His eyes on the prize. If Musk becomes the man to get humans on to Mars he will be remembered for all time by the greater part of humanity. If he is simply a man who got stuff into orbit cheaply he will be of renown for only a few decades. The way he talks about getting to Mars being the biggest advance for humans since the neolithic revolution shows how big he thinks.


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

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#384 2014-07-04 10:23:00

RobS
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Re: Yet another Mars architecture

And Musk has already started developing the Methane-Oxygen Raptor engine of his "Mars Colonial Transport" which, if it is a triple barrel vehicle like the Falcon Heavy, will be able to launch 400-500 tonnes to low Earth orbit and land 100 tonnes on Mars. THAT'S a commitment! It'd be a nine-engine first stage, 1-engine second stage vehicle and would be reusable using the same system as the Falcon. Apparently he told NASA he could develop it for 2 or 3 billion and would even absorb the cost overruns. But they (or the Senate, to be exact) prefered the pork barrel 10-12 billion dollars SLS instead, wich will launch much less mass for a much higher cost per launch.

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#385 2014-12-25 16:25:40

RobertDyck
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Re: Yet another Mars architecture

Option 4: Maximize assets currently favoured by Congress - return crew with CST-100, and another SLS instead of Falcon Heavy.

First mission:
- 1 SLS Block 2 for MAV (direct launch from KSC to Mars surface)
- 1 SLS Block 2 for lab & pressurized rover (direct launch)
- 1 SLS Block 1 for ITV
- 1 SLS Block 1 for TMI stage
- 1 Falcon 9 lander & unpressurized rover
- 1 Atlas V or Falcon 9 for CST-100

Second mission:
- 1 SLS Block 2 for MAV
- 1 SLS Block 2 for lab & pressurized rover
- 1 SLS Block 1 for TMI stage
- 1 Falcon 9 lander & unpressurized rover
- 1 Atlas V or Falcon 9 for CST-100

Third mission:
- 1 SLS Block 2 for MAV
- 1 SLS Block 1 for TMI stage
- 1 Falcon 9 lander & unpressurized rover
- 1 Atlas V or Falcon 9 for CST-100

Note: This would require modifying CST-100 to have a PICA-X heat shield like Dragon, instead of Avcoat.

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#386 2015-01-19 13:40:25

RobertDyck
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Re: Yet another Mars architecture

In the first version of my plan, I said the ITV would be about the size of Zvezda. That's the module of ISS that Russia calls the core module, and NASA calls the Russian Service Module. It has life support, living quarters, and exercise equipment for 3 crew. We should be able to design one that can accomodate 4 crew. This was launched by a single Proton-K, and thrusters and radar onboard Zvezda rendezvoused with Zarya and docked. Zvezda has launch mass of 20,295kg, and Proton-K is able to lift 19,760kg to 186km orbit @ 51.6° inclination. That's the same inclination as ISS, but why was it able to lift Zvezda to the higher orbit? Proton-K (8K82K) configuration 398-01 lifted it to 332km apogee, 179km perigee. Then Zvezda used onboard thrusters to raise orbit to 288 x 357km. It then became a passive docking target. At that time ISS was just Zarya/Unity. Zarya with Unity attached then rendezvoused with Zvezda and docked. That configuration of Proton-K appears to not have any sort of upper stage. Was the initial launch with higher payload mass achieved simply by inserting into eliptical orbit with lower perigee?

Anyway, the point was to achieve the same thing with the ITV, but using an American launch vehicle. The radar and OMS/RCS thrusters could be used to re-dock with ISS after returning from Mars. Falcon 9 is only able to lift 10,450kg to 200km orbit @ 28°. Falcon Heavy can lift 28,000kg to the same orbit. Atlas V 552 is rated to lift 20,520kg to 185km circular orbit @ 28.5° inclination. Delta IV Heavy is rated to lift 22,977kg to 185km @ 28.5°.

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#387 2015-01-19 15:56:59

RobS
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Re: Yet another Mars architecture

My understanding, Robert, is that Falcon 9 can lift 13 tonnes to LEO and Falcon Heavy can lift 53 tonnes.

http://en.wikipedia.org/wiki/Falcon_9

http://en.wikipedia.org/wiki/Falcon_Heavy

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#388 2015-01-19 16:27:41

RobertDyck
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Re: Yet another Mars architecture

Ok. I quoted data from Encyclopedia Astronautica. Checking the SpaceX website, to get data directly from the horse's mouth:
Payload to LEO: 53,000kg (116,845 lb)
Payload to GTO: 21,200kg (46,738 lb)
Payload to Mars: 13,200kg (29,101 lb)
Status: Expected Launch in 2015

So now the relevant question: what is the price of Falcon Heavy, Altas V 552, and Delta IV Heavy? The Wikipedia page you linked cites

The published prices for Falcon Heavy launches have moved some from year to year, with announced prices for the various versions of Falcon Heavy priced at US$80-125 million in 2011, US$83-128 million in 2012, US$77.1-135 million in 2013, and US$85 million for up to 6,400 kg to GTO (with no published price for heavier GTO or any LEO payload) in 2014.

And Wikipedia for the other launch vehicles:

In 2013, the cost for an Atlas V 541 launch to GTO (including launch services, payload processing, launch vehicle integration mission, unique launch site ground support and tracking, data and telemetry services) was about $223 million (inflation adjusted $226 million in 2015). In 2014 the ESA contracted ULA to launch the Solar Orbiter for around $173 million. Since about 2005 Atlas V has not been cost-competitive for most commercial launches, where launch costs were about $100 million per satellite to GTO in 2013.

Delta IV Heavy: Cost per launch $375 million (2014)

With that lift mass, one launch of Falcon Heavy might be able to lift both the ITV and Mars lander with unpressurized rover (open rover). That would eliminate one Falcon 9 launch for the first mission. Subsequent missions would reuse the ITV, so launch the lander with rover on Falcon 9.

It may be interesting to work out the exactly mass, so we can calculate the exact TMI stage mass. Could we get it small enough for a single Falcon Heavy? To replace the SLS Block 1. Or would splitting the TMI stage into two work? To replace one SLS Block 1 with two Falcon Heavy. Which would have the lower total cost?

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#389 2015-01-19 16:42:11

RobS
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Re: Yet another Mars architecture

Of course, no one known how much an SLS launch will cost. But what I have seen is that the launches of the Block 2 will be so expensive, NASA will be able to afford only one every year or two. That's why the test launch is 2018 but the first launch with a crewed vehicle is three years later. If we're talking about a billion dollars to put 140 tonnes into LEO, and three Falcon Heavy launches can put 159 tonnes into LEO for less than $400 million, there simply is no comparison. And later this year, Musk will almost certainly manage to land and reuse a first stage. Three of them make up a Falcon Heavy. If he brings back two of the three, the mass to LEO will be diminished somewhat (perhaps to 40 tonnes to LEO) but the launch cost will be cut in half. The stuff I have read is that the 13 tonnes to LEO mass for the Falcon 9 includes returning the first stage! If Space X can put 40 tonnes into LEO for, say, $60 million with reused stages, I'd design the Mars mission with those masses and prices in mind.

Recently, Musk said that by the end of this year, he will unveil his Mars architecture. He also said that they are looking at various sizes for the Raptor engine, and  a 500 tonne thrust engine (or maybe he said a half million pound thrust engine; I can't remember which) seems to be optimum, because mass production means they can make more engines, and he's confident they can fly multiple-engine rockets.

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#390 2015-01-20 04:56:25

louis
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Re: Yet another Mars architecture

RobertDyck wrote:

Ok. I quoted data from Encyclopedia Astronautica. Checking the SpaceX website, to get data directly from the horse's mouth:
Payload to LEO: 53,000kg (116,845 lb)
Payload to GTO: 21,200kg (46,738 lb)
Payload to Mars: 13,200kg (29,101 lb)
Status: Expected Launch in 2015

So now the relevant question: what is the price of Falcon Heavy, Altas V 552, and Delta IV Heavy? The Wikipedia page you linked cites

The published prices for Falcon Heavy launches have moved some from year to year, with announced prices for the various versions of Falcon Heavy priced at US$80-125 million in 2011, US$83-128 million in 2012, US$77.1-135 million in 2013, and US$85 million for up to 6,400 kg to GTO (with no published price for heavier GTO or any LEO payload) in 2014.

And Wikipedia for the other launch vehicles:

In 2013, the cost for an Atlas V 541 launch to GTO (including launch services, payload processing, launch vehicle integration mission, unique launch site ground support and tracking, data and telemetry services) was about $223 million (inflation adjusted $226 million in 2015). In 2014 the ESA contracted ULA to launch the Solar Orbiter for around $173 million. Since about 2005 Atlas V has not been cost-competitive for most commercial launches, where launch costs were about $100 million per satellite to GTO in 2013.

Delta IV Heavy: Cost per launch $375 million (2014)

With that lift mass, one launch of Falcon Heavy might be able to lift both the ITV and Mars lander with unpressurized rover (open rover). That would eliminate one Falcon 9 launch for the first mission. Subsequent missions would reuse the ITV, so launch the lander with rover on Falcon 9.

It may be interesting to work out the exactly mass, so we can calculate the exact TMI stage mass. Could we get it small enough for a single Falcon Heavy? To replace the SLS Block 1. Or would splitting the TMI stage into two work? To replace one SLS Block 1 with two Falcon Heavy. Which would have the lower total cost?

I have always tended to multiply the launch costs to get a Mars mission. I did that based on some published project costs as against launch costs.

Obviously, even if you are using rockets and some other equipment that have been through the development phase, you are still going to have development, planning and mission control costs.  On billion dollars might pay for 5,000 people for ONE year (engineers and scientists being pretty highly paid, and there being lots of on costs - pensions, health care and so on). Or 500 for ten years.  500 people is not so many on the payroll.   Once you start thinking in terms of 24/7 cover at a mission control, well you have to divide the number of people by four (three shifts and other cover) - so if your mission control had 50 people, you would need 200 on the payroll.

I think we probably need something like 20-40 tonnes on the Mars surface, for a return mission.   I would hazard the total costs would be much higher than perhaps you are suggesting - a minimum of several billion, but I'd like to see maybe $20billion invested over 20 years to do it right - with plenty of pre-missions. That's only $2 billion per anum - a joint enterprise of NASA, ESA, JAXA and others should easily be able to handle that funding. What's lacking is the political will (Obama in particular doesn't do space - he's a Chicago street activist and they were always complaining about the space budget not being spent on the poor).


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

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#391 2015-01-20 15:56:11

RobertDyck
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Re: Yet another Mars architecture

louis wrote:

I would hazard the total costs would be much higher than perhaps you are suggesting - a minimum of several billion, but I'd like to see maybe $20billion invested over 20 years to do it right - with plenty of pre-missions. That's only $2 billion per anum - a joint enterprise of NASA, ESA, JAXA and others should easily be able to handle that funding. What's lacking is the political will (Obama in particular doesn't do space - he's a Chicago street activist and they were always complaining about the space budget not being spent on the poor).

I believe once Orion development is complete, they're going to have to use it. So expenses for Orion are ongoing. If you redirect those annual funds into a Mars mission, then you have enough. And use SLS to launch the Mars mission, instead of launching Orion on some stupid justification for Orion. Is Congress going to send Orion on a fly-by around the far side of the Moon, with no lunar module so no ability to land, simply to justify Orion? I would rather that SLS launch, and that money, be used for a Mars mission.

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#392 2015-01-20 20:12:27

SpaceNut
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Re: Yet another Mars architecture

SLS cost depend on how you fudge the numbers for what is considered developement to steady state launch em costs and for how long....
As we could look at the money spent on constellation, orion and its only launch for demonstration as a 10 billion shot as that has been all that has happened and that was not even on the Da' stick (Ares I).

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#393 2015-01-21 17:49:02

kbd512
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Re: Yet another Mars architecture

SpaceNut wrote:

SLS cost depend on how you fudge the numbers for what is considered developement to steady state launch em costs and for how long....
As we could look at the money spent on constellation, orion and its only launch for demonstration as a 10 billion shot as that has been all that has happened and that was not even on the Da' stick (Ares I).

I rather liked the Roman candle.

I don't buy the argument that Ares I would not have been ready for a manned flight until 2017 or cost as much as SLS.  Orion development may have held up a manned flight until then, but not Ares I.

I also have a hard time believing that Ares I would cost more than the STS to fly if one per year were launched.

Last but not least, if the marginal cost for additional launches was really $138M or anything close to it, that's a bargain.

They could probably have deleted that expensive and heavy launch abort system, too.

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#394 2015-01-21 18:39:35

RobertDyck
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Re: Yet another Mars architecture

kbd512 wrote:

I rather liked the Roman candle.

Excessive vibration made Da' Stick unsafe for human space flight. No way to resolve it. One design decision for Orion was to make it excessively heavy in the hope that the waight would dampen vibrations from Da' Stick. They had to add a large liquid fuel upper stage to help dampen vibrations. They still hadn't solved it. It can't be solved. Flying a human spacecraft on a giant solid rocket always was a bad idea. ATK argued that their rocket (Ares I) was safer than either EELV because it was based on an SRB; the same SRB as Shuttle. But Shuttle had a 104 tonne (landing weight) orbiter, plus a giant liquid fuel external tank to dampen vibrations. Putting a capsule on one of those things would never work. Altas V or Delta IV was always safer.

kbd512 wrote:

They could probably have deleted that expensive and heavy launch abort system, too.

Um, what? Are you kidding? Every human spacecraft has a launch abort system of some sort. Gemini had ejection seats, like a fighter jet. The engineers who designed it were fighter jet engineers, including the engineering team lead. Dragon has Draco thrusters in capsule sides. They double as landing rockets. If used for abort, Dragon must use its parachute. CST-100 will use main thrusters of its service module for launch abort. Orion needs a launch abort system of some sort.

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#395 2015-01-21 21:23:42

Impaler
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Re: Yet another Mars architecture

kbd512:  Your pro-Roman-Candle and anti Launch-Abort system, are you Evel Knievel??

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#396 2015-01-22 10:31:55

kbd512
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Re: Yet another Mars architecture

RobertDyck wrote:

Excessive vibration made Da' Stick unsafe for human space flight. No way to resolve it. One design decision for Orion was to make it excessively heavy in the hope that the waight would dampen vibrations from Da' Stick. They had to add a large liquid fuel upper stage to help dampen vibrations. They still hadn't solved it. It can't be solved. Flying a human spacecraft on a giant solid rocket always was a bad idea. ATK argued that their rocket (Ares I) was safer than either EELV because it was based on an SRB; the same SRB as Shuttle. But Shuttle had a 104 tonne (landing weight) orbiter, plus a giant liquid fuel external tank to dampen vibrations. Putting a capsule on one of those things would never work. Altas V or Delta IV was always safer.

Can't be solved?  Can't is a pretty strong word.  Yes, the orbiter and ET were mighty hefty whereas Orion is svelte by way of comparison.  Rather than even worry about dampening vibrations, why not design the capsule to accommodate vibration?  My understanding is that someone had the bright idea to strobe the instrument displays at the same frequency as the vibrations by attaching an accelerometer to the seats to sync the display with the vibrations.  Isn't that useful in other ways?

RobertDyck wrote:

Um, what? Are you kidding? Every human spacecraft has a launch abort system of some sort. Gemini had ejection seats, like a fighter jet. The engineers who designed it were fighter jet engineers, including the engineering team lead. Dragon has Draco thrusters in capsule sides. They double as landing rockets. If used for abort, Dragon must use its parachute. CST-100 will use main thrusters of its service module for launch abort. Orion needs a launch abort system of some sort.

No, I'm not kidding.  Abort into what?  Burning propellant?

- The Apollo abort system was never used.  One of the Apollo astronauts actually stated that he moved his hand off the abort controller and would rather have died than accidentally hit the button.
- The Apollo I capsule killed the crew with fire.  No abort system would have saved them.
- The only Space Shuttle lost during ascent was utterly destroyed in less than a second, but according to some at NASA the crew survived the explosion and died on impact with the ocean.  All of the training they received teaching them how to bailout didn't help.

The idea of being able to escape from a malfunctioning rocket is quaint and maybe it's some sort of psychological aid to the people inside, but it's also a bit unrealistic.  Riding atop millions of pounds of propellant is inherently dangerous.  You either accept the danger and move forward or you don't get in the cockpit.

On the topic of man-rated systems, if you put me atop a Delta IV H in an Orion capsule after the second or third flight, presuming all unmanned test flights were successful, I'd have no issue with that, even though the Delta IV H is not "man-rated" and the capsule has no launch abort system.  I understand the risks and I understand the inevitable outcome if the rocket malfunctions during ascent.

Reality says your chances of escaping from a malfunctioning rocket are slim, with or without an abort system.  Only one successful launch abort has been made in the history of manned space flight and it wasn't from an American rocket.

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#397 2015-01-22 11:33:28

kbd512
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Registered: 2015-01-02
Posts: 7,859

Re: Yet another Mars architecture

Impaler wrote:

kbd512:  Your pro-Roman-Candle and anti Launch-Abort system, are you Evel Knievel??

No, I'm simply willing to accept that some situations aren't survivable and that there are degrees of risk involved in any rocket launch.  After the engineers have done what they can to make a system reliable, it's time to accept that the only way to discover whether or not something works is to test it.

A launch abort system merely serves to further complicate an already enormously complex launch system.  I'd feel better about not having it.  It reinforces the requirement to perform operations correctly.

There's a difference between being stupid or careless and accepting risk.  I don't drive like a maniac because I have a SUV with a V8 and I look both ways before I cross the street.  However, I accept that once I cross the street there's the possibility of being run over.  I routinely cross the street and have no intention of stopping, whether I'm run over or not.

I have two small children, one is seven and the other two.  I pay for life insurance so that if I die they have the financial means to continue forward with their own lives.  That's all I can realistically do because I don't have a crystal ball.  People die every day.  The world will keep on turning with or without me in it.

If NASA needed people to "man-rate" their capsule and wasn't willing to risk the life of an astronaut to do it, I would gladly perform the task to move the program forward.  I've never had any desire to be an astronaut or even a pilot, but every time someone says something can't be done I have an overwhelming urge to prove them wrong.  No one would need to see my face or know my name, so if I died there wouldn't be any ridiculous self flagellation and no expensive, highly trained astronaut with a triple PhD in rocket surgery would have been lost.

I think it's an overwhelming fear of failure.  No matter how hard you try, sometimes you won't succeed.  The entire point behind testing things is to discover what works, what doesn't, and why.  The idiotic notion that every launch test, or any other test for that matter, has to succeed kills both the incentive to try new things and any measure of creativity.

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#398 2015-01-22 12:23:14

Terraformer
Member
From: The Fortunate Isles
Registered: 2007-08-27
Posts: 3,907
Website

Re: Yet another Mars architecture

Valar dohaeris.

Still, we're not intending to keep spaceflight niche, are we? A 2% risk is too high. Would air travel have taken off, if every time a plane flew it stood a 2% chance of being destroyed? Even if you had a perfect abort system to save everyone - which you've decided you wouldn't have - getting only 50 flights on average out of a plane before needing to replace it would make in non-viable.


Use what is abundant and build to last

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#399 2015-01-22 15:09:45

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,859

Re: Yet another Mars architecture

There's this problem that's infected the thinking of virtually everyone at NASA with any authority to do anything and, to an even greater extent, the contractors that NASA uses.

I call the problem technosis.  Yes, I just made that up.

Technosis is characterized by a burning desire to create magnificently complicated systems that take technology to and often times over the bleeding edge.  Though the system may be perfectly designed to do whatever task it's designed to do, it will fail spectacularly if someone so much as farts in the wrong direction.  The notion that every solution to a simple problem has to embody perfection or demonstrate an absurd degree of technical complexity is just stupid.

Let's use Orion as an example.  When it was designed, nobody knew exactly how much it would weigh, but they did know that it would be pretty hefty for a capsule.  Instead of waiting until the craft was somewhere near a baseline design, development of Ares I proceeded absent sufficiently detailed information about the weight of the capsule.  What was the predictable result?  The capsule's service module had to be redesigned to the point that it was useless for its originally intended purpose, the upper stage of the Ares I had to be redesigned to save weight and increase performance, and at the end of the day a lot of money was spent without result.

The precious launch abort system that everyone is purring about weighs north of 7t.  That capsule couldn't possibly use the extra propellant for more dV, could it?  I have another term I use for the abort system- dead weight.  The rocket either works or it doesn't.

Let's fast forward to the best part.  Now that Ares I has been cancelled, NASA intends to launch Orion on SLS, a rocket that's even more complicated than Ares I.  It's projected to have flight costs in excess of a billion dollars per launch.  In other words, Orion/SLS will be every bit as affordable and sustainable as STS.  If the primary problem with STS was the cost of operations, anyone care to hazard a guess as to where our "new" manned space program is headed?

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#400 2015-01-22 19:46:06

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,433

Re: Yet another Mars architecture

The risk assessment for a rocket flies even in the face of the shuttle as after columbia was destroyed astronauts were ready to fly the Hubble rescue mission even without a chance of a safe haven if it had recieved damage.

As for the SRB resonance with fuel burn think changing the harmonic by creating a fret ( think Guitar) inside the chamber for the pitch to change to as the fuel burns. Had a sliding sleeve inside that moves up or down the walls of the chamber to make the change...

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