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#1 2019-09-19 09:22:41

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Top ten things Space X have to get right for the first Mars Mission

Here are my top ten things Space X have to get right for the first Mars Mission:

1. Starship/Super-Heavy development.   

This is undoubtedly going well at the moment but the prototype is at least six months from orbital flight. There needs to be a test programme for both cargo and human flights.

Space X clearly have a lot of transferable skills now that they have learned with Falcon 9 and Falcon 9H which they can apply to Starship. That will speed up development. For instance, they seem now to have very reliable control systems for accurate vertical landing.

2. EDL plus 

(a) Entry, descent and landing for Mars, with very accurate landing  (b) maintenance for return (c) Mars launch, return and re-entry.

For me this implies a test run on the Moon.

3. Coms. 

Mars is a long way off.  Space X will, in my view, largely depend on NASA's coms experience. However - here's a thought...could Starlink act like a huge communications antenna for messages from Mars?

4. Mars Hab 

Looks like Bigelow might have a ready-made solution to this issue.

5. Energy system on Mars

Musk can supply a lot of scientific know-how about solar energy for a system based on solar power. 

Space X could also buy in ATK systems.

6. Water Sourcing and Propellant production plant.   

As far as I know, a big unknown at the moment. What are the challenges of running a plant in such a cold environment? Do you basically need a hab in which you put your propellant production plant? If so, then I am not sure Bigelow has a solution as yet. Presumably if you can keep the plant in a more Earth like environment, we can apply Earth-based experience to the production process.

Can the propellant be "stored" in the return Starship?

[Edited to add in water sourcing...water sourcing is only a requirement for propellant production - but for that is absolutely essential. Otherwise, with six Starship craft and advanced water recycling, water sourcing is not required.]

6. Health of crew 

This will include radiation protection en route and on Mars, exercise regime and space medicine to ensure no bone or muscle loss (now doable), and further investigation of eyesight and immunity reduction.

7.  Build Robot Rovers and Pressurised Human Passenger Rovers   

Personally I would call on NASA's expertise in this area.

8. Ensure life support systems for the Starship and on Mars are all in good order 

Space X will need to call on the expertise of NASA and its contractors.

9.  Offloading of cargo

We haven't yet seen a persuasive illustration of how Space X intends to offload cargo from 100 ft or more up.  This has never been attempted before in the history of space missions. It will require some innovative thinking. With less gravity on Mars, there may well be more stability issues, especially where you have craft with virtually empty fuel tanks...

10.  Mars Pioneers Selection 

Selection and training of crew for Mars Mission One will be a huge undertaking.  For a crew of 6 you'll probably need a pool of 20. Selection and training could easily take 5 years.

The 20 are going to be exceptional individuals. Using ex NASA crew might be one route might reduce training requirements. But personally I would favour starting from scratch.

Last edited by louis (2019-09-19 12:33:57)


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#2 2019-09-21 09:34:07

Oldfart1939
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Registered: 2016-11-26
Posts: 2,384

Re: Top ten things Space X have to get right for the first Mars Mission

Louis-

For the most part, I can say I agree with you. Health also includes food supply and management, making sure there is adequate caloric content and palitability that doesn't drive the crews bonkers by being too much same-old-same-old slop. My major complaint with the movie The Martian was the inadequacy of food provided to the crews; should have been enough in reserve to feed entire crew in case of a missed Hohmann Transfer window. I would support bringing enough to feed everyone for TWO missed transfer windows! In Britain, I believe this is called a "belts and braces" approach to problems.

In terms of energy requirements, we need a mixture of sources, and that includes BOTH solar AND nuclear. There needs to be system
redundancy--to extent of 200%. Again, a massive oversupply of an essential resource.

I suspect that Tesla could cooperate with NASA to design a great set of rovers. An exploration rover as well as a work-rover with a front loader and auger attachment for drilling holes in regolith. Bring in a company like Bobcat to cooperate with BOTH Tesla and NASA!

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#3 2019-09-21 09:58:29

louis
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From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Top ten things Space X have to get right for the first Mars Mission

Yes, I was taking food as a given, since so much knowledge about food in space has been built up over the last 60 years, though you would be right in saying this is all new to Space X.

My view has been that for Mission One you would have a mix of fresh food (apples for instance can be kept "fresh" at low temperatures for probably 9 months), vaccuum packed meals, frozen meals and foods, dry or dried foods (flours, spaghetti, eggs and so on), nuts, snacks, chocolate bars, energy bars and so on.  The mission can also take a wide variety of tinned foods as well. Items like tinned peaches and tinned potatoes aren't too bad. Salted butter can be kept frozen for at least a year.  They can take a bread maker machine with them for fresh bread. Make good use of oils like olive oil which have v. high calorific value to mass ratio. Once on Mars, the pioneers could operate a small salad vegetable farm to provide fresh lettuces, beanshoots and so on which I am sure will be much appreciated.

I would certainly agree with taking enough food for one missed window. Two? Well that is being pessimistic I would say, since a rescue Starship should at least be able to land with enough food for another missed window.

I think there is definitely a need for a pressurised human passenger rover. Whether one model will serve for both exploration and movement around the base is open to question but the answer is probably yes, since I don't think exploration on Mission One will be a huge priority. Again there is the issue of redundancy. Probably will need to be 2 pressurised rovers, in case anything happens to one of them.

In addition I would say we might need up to 3 robot rovers. You might want a couple working in tandem at a water source - one drilling maybe, while another clears away rock and debris.  Again, you probably need another rover for failsafeness. You might need carts for holding water ice/icy regolith that can be pulled by the rovers back to the propellant production facility.

These rovers are going to be undertaking some heavy duty work on the surface, so will have to be more robust than we have seen to date. Yes, it would be nice to see Tesla work with NASA.



Oldfart1939 wrote:

Louis-

For the most part, I can say I agree with you. Health also includes food supply and management, making sure there is adequate caloric content and palitability that doesn't drive the crews bonkers by being too much same-old-same-old slop. My major complaint with the movie The Martian was the inadequacy of food provided to the crews; should have been enough in reserve to feed entire crew in case of a missed Hohmann Transfer window. I would support bringing enough to feed everyone for TWO missed transfer windows! In Britain, I believe this is called a "belts and braces" approach to problems.

In terms of energy requirements, we need a mixture of sources, and that includes BOTH solar AND nuclear. There needs to be system
redundancy--to extent of 200%. Again, a massive oversupply of an essential resource.

I suspect that Tesla could cooperate with NASA to design a great set of rovers. An exploration rover as well as a work-rover with a front loader and auger attachment for drilling holes in regolith. Bring in a company like Bobcat to cooperate with BOTH Tesla and NASA!


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

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#4 2019-09-21 11:36:53

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,459
Website

Re: Top ten things Space X have to get right for the first Mars Mission

Louis:

I think your list is pretty good.  The most critical item is in-situ propellant production,  without which the trip is one-way,  period.  Musk is not developing this,  he will carry it as payload.  I am not aware of any concerted effort to develop a production plant.  NASA lab experiments will not serve this function.

I'm not as worried about unloading with a crane,  as you seem to be.  It depends upon the crane capacity,  which must be limited to masses whose weights do not cause the net center of gravity vertical vector line-of-action to fall outside the landing pad footprint (as determined by pad centroids not the extreme dimensions).  If the surface slopes a bit,  this problem gets worse if the cargo door happens to be on the downslope side. But it is still only a static stability problem. Tripod stance does make this problem more sensitive to crane load limits than a quadruped stance.

GW


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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#5 2019-09-21 11:55:01

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,384

Re: Top ten things Space X have to get right for the first Mars Mission

Louis-
I make my assertions based on worst possible case scenarios. A lot depends on continued funding by SpaceX and Elon's health. There are more than technical sources for mission delays or failures. Having a huge stockpile of food is only a desperate emergency fallback plan in place. As GW correctly pointed out--having a viable source for fuel resupply through both Sabatier reactor and Moxie units are absolutely essential; otherwise this becomes a one-way mission. I wouldn't be quick to count on a rescue mission, especially if there is any significant change in the political or economic bases in the USA. So--a 5 year food supply for the entire crew is essential. In that time, there will undoubtedly be some accidents or deaths due to illness. Having a small clinic included is essential.

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#6 2019-09-21 15:45:32

kbd512
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Registered: 2015-01-02
Posts: 7,430

Re: Top ten things Space X have to get right for the first Mars Mission

We obviously have to solve EDL with massive vehicles and extended duration space flight before we can even think about going there.  I think the two major hurdles to obtaining a government-sanctioned exploration flight will be providing enough power for propellant production to return home, developing and then integrating a propellant production plant into a cargo variant of Starship that's light and reliable enough for the task, and finding a local source of water that's accessible from wherever Starship was landed.  The mental and physical health of the crew is another major concern.  Beyond that, everything else is just an engineering or logistics problem, rather than a basic research and development type of problem.

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#7 2019-09-21 16:08:14

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Top ten things Space X have to get right for the first Mars Mission

I think it's just when I've researched cranes that can handled loads maybe in the 1 - 2 ton range at height, they seem pretty heavy duty.

You can break down a lot of items into smaller masses, but not a Bigelow hab...and maybe some of the propellant plant elements will be large as well.

On the propellant plant, my thinking is that everything becomes easier if it is contained in a hab, or even better a series of habs (to increase failsafeness) where humans can access the equipment and monitor it easily. Storing the propellant is another issue. Can it simply be stored within the Starship?

GW Johnson wrote:

Louis:

I think your list is pretty good.  The most critical item is in-situ propellant production,  without which the trip is one-way,  period.  Musk is not developing this,  he will carry it as payload.  I am not aware of any concerted effort to develop a production plant.  NASA lab experiments will not serve this function.

I'm not as worried about unloading with a crane,  as you seem to be.  It depends upon the crane capacity,  which must be limited to masses whose weights do not cause the net center of gravity vertical vector line-of-action to fall outside the landing pad footprint (as determined by pad centroids not the extreme dimensions).  If the surface slopes a bit,  this problem gets worse if the cargo door happens to be on the downslope side. But it is still only a static stability problem. Tripod stance does make this problem more sensitive to crane load limits than a quadruped stance.

GW


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#8 2019-09-21 16:09:49

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Top ten things Space X have to get right for the first Mars Mission

Well it might make sense to run with a 5 year food supply on the basis it would not take up too much room if a lot of it was in the form of dried foods.

Oldfart1939 wrote:

Louis-
I make my assertions based on worst possible case scenarios. A lot depends on continued funding by SpaceX and Elon's health. There are more than technical sources for mission delays or failures. Having a huge stockpile of food is only a desperate emergency fallback plan in place. As GW correctly pointed out--having a viable source for fuel resupply through both Sabatier reactor and Moxie units are absolutely essential; otherwise this becomes a one-way mission. I wouldn't be quick to count on a rescue mission, especially if there is any significant change in the political or economic bases in the USA. So--a 5 year food supply for the entire crew is essential. In that time, there will undoubtedly be some accidents or deaths due to illness. Having a small clinic included is essential.

Last edited by louis (2019-09-21 17:40:24)


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#9 2019-09-21 17:23:52

SpaceNut
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Registered: 2004-07-22
Posts: 28,866

Re: Top ten things Space X have to get right for the first Mars Mission

Dry foods tend to have less nutrients and will require more water utilization to be able to eat them.

Heavy duty cranes mean increase mass that we wanted for other items....

The EDL is fairly well mapped out once the heat shielding and retro engines are made for the martian atmospheric environment as its not all that different than landings for earth.

The issue of scale for the insitu makes it a major problem for Space x as no company is going to give that away and the same will be true for the power supply that is needed or the crews survival.

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#10 2019-09-21 17:43:01

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Top ten things Space X have to get right for the first Mars Mission

I think there would be efficient water recycling at the base and the Mission would bring substanstial water supplies, so I wouldn't see that as a problem re dried foods. It's true dried foods may be less nutritious but vitamin and mineral supplements will guard against any major deterioration in health.


SpaceNut wrote:

Dry foods tend to have less nutrients and will require more water utilization to be able to eat them.

Heavy duty cranes mean increase mass that we wanted for other items....

The EDL is fairly well mapped out once the heat shielding and retro engines are made for the martian atmospheric environment as its not all that different than landings for earth.

The issue of scale for the insitu makes it a major problem for Space x as no company is going to give that away and the same will be true for the power supply that is needed or the crews survival.


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

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#11 2019-09-21 18:32:58

kbd512
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Registered: 2015-01-02
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Re: Top ten things Space X have to get right for the first Mars Mission

For many centuries before there were rockets capable of reaching space, there were these fairly well-known and simple devices capable of hoisting incredible weight that we know as ropes and pulleys.  Modern materials have made these things a light weight, durable, and viable alternative to cranes for infrequent light duty usage.  A 2 ton pulley weighs less than 4 pounds.  A 12.5 ton working load snatch block weighs 6 pounds.  25 ton tensile strength 3/4" Technora is about 20 pounds per 100 foot of rope.  Bigelow BEAM is ~1,400kg.  We can put the snatch blocks around the base of the landing gear and crane off the heavier payloads that way.  All that is stupid simple stuff most rednecks knew before our scientists were old enough to shave, but would rather show how clever they are, rather than how practical their solutions can be.

Anyway, most of the weight of that solution would actually be in the ropes and winches used to lower cargo to the surface.  These devices can be constructed such that human muscle power alone is sufficient to safely lower the cargo to the surface, although I suspect some sort of motorized winch will be used just to complicate matters.  We could also use counter-weighting and guy wires strung from the nose of Starship on the opposite side to stabilize it prior to unloading operations.  This operation might last a few days at most, provided that most of the cargo was packaged into human transportable containers.  I suspect that 250kg of cargo handling equipment (ropes, winches, and pulleys), not including a battery powered tracked light cargo carrier, would be required to crane the cargo off the ship.  Thereafter most of that equipment would be dual use type stuff that's also suitable for transportation and erection of permanent surface habitation.

If engineers want to show how clever they are, then they can demonstrate their intelligence through designing everything to be multi-purpose and simple.  Apart from the cargo carrier, their solution should be 100% hand-operated equipment.

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#12 2019-09-22 08:06:51

louis
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From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Top ten things Space X have to get right for the first Mars Mission

Working on unloading of cargo will, as far as Space X illustrations indicate, involved working in the Mars atmosphere. That in turn means that humans will have to engage in EVAs. That is an immediate drawback I would say, requiring the pioneers to don space suits relatively soon after arrival after possibly six months' of weighlessness.

I would certainly favour an automated system.  Ideally the first humans on Mars should come out of the Starship in a pressurised vehicle that can be brought to the surface.


kbd512 wrote:

For many centuries before there were rockets capable of reaching space, there were these fairly well-known and simple devices capable of hoisting incredible weight that we know as ropes and pulleys.  Modern materials have made these things a light weight, durable, and viable alternative to cranes for infrequent light duty usage.  A 2 ton pulley weighs less than 4 pounds.  A 12.5 ton working load snatch block weighs 6 pounds.  25 ton tensile strength 3/4" Technora is about 20 pounds per 100 foot of rope.  Bigelow BEAM is ~1,400kg.  We can put the snatch blocks around the base of the landing gear and crane off the heavier payloads that way.  All that is stupid simple stuff most rednecks knew before our scientists were old enough to shave, but would rather show how clever they are, rather than how practical their solutions can be.

Anyway, most of the weight of that solution would actually be in the ropes and winches used to lower cargo to the surface.  These devices can be constructed such that human muscle power alone is sufficient to safely lower the cargo to the surface, although I suspect some sort of motorized winch will be used just to complicate matters.  We could also use counter-weighting and guy wires strung from the nose of Starship on the opposite side to stabilize it prior to unloading operations.  This operation might last a few days at most, provided that most of the cargo was packaged into human transportable containers.  I suspect that 250kg of cargo handling equipment (ropes, winches, and pulleys), not including a battery powered tracked light cargo carrier, would be required to crane the cargo off the ship.  Thereafter most of that equipment would be dual use type stuff that's also suitable for transportation and erection of permanent surface habitation.

If engineers want to show how clever they are, then they can demonstrate their intelligence through designing everything to be multi-purpose and simple.  Apart from the cargo carrier, their solution should be 100% hand-operated equipment.

Last edited by louis (2019-09-22 08:21:55)


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#13 2019-09-22 14:22:16

kbd512
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Posts: 7,430

Re: Top ten things Space X have to get right for the first Mars Mission

Louis,

People who have never designed automated systems always tend to favor having an "easy button" that they can press.  Those of us who have designed software for automated systems know how difficult it is to make such systems function reliably, or at all in many cases.  A lightweight and simple design that does not require sophisticated technology to function, never mind function well on the very first flight and all subsequent flights, tends to be a better solution.

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#14 2019-09-22 14:43:53

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,866

Re: Top ten things Space X have to get right for the first Mars Mission

That said you would need a payout cable monitor sensor and a sensor to detect ground approaching plus contact to it once down. The sensor for the payout could do double duty for the return but ultimately you will still need a top sensor stop if automated. The approaching ground and ground detection would require payout cables for power for these to work which adds another layer of difficulty to the design as now the cable for the power could be stretched breaking it on each use as it may not move the same distance as the crane cable....it may be possible to optic sensing but with the dust its likely to mess up over time and conditions....I would think that the crane cable length would be 50% greater than the hieght of the rocket to the surface to ensure we can go a bit further if the rocket is near a hole or depression.

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#15 2019-09-22 16:56:15

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,459
Website

Re: Top ten things Space X have to get right for the first Mars Mission

Half a century ago,  when I was an engineering student at UT Austin,  Memorial Stadium received an expansion by the addition of an upper deck on the west side.  This was done with T-head cranes well over 200 feet tall,  and with a boom nearly 100 feet long,  same as a lot of construction all over the country today. 

The largest of the objects these cranes lifted half a century ago were the stadium light standard columns,  cast reinforced concrete items,  at 52,000 lb each.  That's 26 US tons,  or just under 24 metric tons.  The T-head cranes used tons of ballast on their backsides to compensate for the loads applied way out on those booms. 

Kbd512 is exactly right:  we have known how to lift hundreds of tons at a time,  with very simple steel truss and cable/pulley technology.  And for a VERY long time indeed!  There is ABSOLUTELY NO reason this cannot be done on Mars to unload a "Starship",  even with a crane that is part of the "Starship" itself.  This is "freshman engineering statics 101" not to topple the ship doing it. 

As for the Memorial Stadium expansion at UT half a century ago,  there was an accident with a collapsed boom that nearly toppled the T-head crane.  Had the wind been higher,  it would have toppled over.  This accident happened NOT because of anything fundamental,  but because somebody tried to be too cheap and used boom-mounting shear pins one size too small. 

This thing would have fallen upon a neighboring dorm to mine at the time.  There was an all-night crisis until the biggest dragline crane I have ever seen arrived from Houston,  and took down the wreckage. 

Louis,  we already KNOW how to handle giant loads with cranes (far larger than what "Starship" can carry),  and how not to topple over doing this kind of work.  The problem isn't technical,  it's just greed getting in the way.

GW

Last edited by GW Johnson (2019-09-22 16:58:25)


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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#16 2019-09-22 19:08:36

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,866

Re: Top ten things Space X have to get right for the first Mars Mission

https://en.wikipedia.org/wiki/Counterweight

Only 1 door makes for an issue for this type as a fulcrum would be setup inside the ship and a second exit door would be used to make the counter balance device.

https://pdfs.semanticscholar.org/b259/6 … 44db6c.pdf

https://www.cranecrews.com/crane-blog/t … ne-anatomy

330_orig.jpg

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#17 2019-09-22 20:05:30

tahanson43206
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Registered: 2018-04-27
Posts: 17,144

Re: Top ten things Space X have to get right for the first Mars Mission

For SpaceNut re #16 ...

If this were FaceBook I'd give this post a "Like"

Hopefully it will inspire those in the forum with drafting talents to show Starships equipped with something along these lines.

However, this post is an opportunity to pick up on the exchange earlier about using ropes which are light in weight and strong.

The risk of a vertical Starship lander toppling over would be reduced if lines were run to a tripod of anchors shortly after landing.

In addition, such lines can be used as inclined planes (well, lines) to facilitate off loading or loading.

(th)

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#18 2019-09-23 02:57:43

louis
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From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Top ten things Space X have to get right for the first Mars Mission

It's not simple having to don a space suit - takes about 3 hours. The difference between Mars and Earth is that humans can operate freely in most parts of the planet. On Mars our ability to engage in complex physical manouevres will be extremely restricted

We have landed spacecraft automatically on Mars. We have deployed Rovers automatically. We have operated Rovers automatically on Mars and they have undertaken various actions like drilling and so on under our direction from Earth.

When I say automated, I mean under direction of the Starship crew and Earth ground control.

I wouldn't disagree with some form of manual backstop for cargo unload but we should be looking to an automated system in the first place.


kbd512 wrote:

Louis,

People who have never designed automated systems always tend to favor having an "easy button" that they can press.  Those of us who have designed software for automated systems know how difficult it is to make such systems function reliably, or at all in many cases.  A lightweight and simple design that does not require sophisticated technology to function, never mind function well on the very first flight and all subsequent flights, tends to be a better solution.


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

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#19 2019-09-23 03:02:37

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Top ten things Space X have to get right for the first Mars Mission

Yes, the issue is: how do you deploy the crane.  If it's going to be people on the ground, then how do you get the people on to the ground...

I think an automated crane tower is a possibility that should be looked at...or maybe it could be something like a rail system similar to mountain rail systems. I'm thinking of something that protrudes beyond the open cargo door and then unfolds in sections until it meets the ground. It's a hell of a challenge I think...

Another possiblity is soimething like a Bigelow inflatable but to operate as an inflatable chute, down which equipment can be lowered at an angle on a winch.


SpaceNut wrote:

https://en.wikipedia.org/wiki/Counterweight

Only 1 door makes for an issue for this type as a fulcrum would be setup inside the ship and a second exit door would be used to make the counter balance device.

https://pdfs.semanticscholar.org/b259/6 … 44db6c.pdf

https://www.cranecrews.com/crane-blog/t … ne-anatomy

https://www.cranecrews.com/uploads/1/5/ … 0_orig.jpg


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

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#20 2019-09-23 03:12:38

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Top ten things Space X have to get right for the first Mars Mission

We've had a couple of fatal crane tower collapses in London in recent years.

I am very pleased to hear that we can lift off large loads on pulley systems...but the first question is how do you get people (in space suits) on to the ground to operate these systems?


GW Johnson wrote:

Half a century ago,  when I was an engineering student at UT Austin,  Memorial Stadium received an expansion by the addition of an upper deck on the west side.  This was done with T-head cranes well over 200 feet tall,  and with a boom nearly 100 feet long,  same as a lot of construction all over the country today. 

The largest of the objects these cranes lifted half a century ago were the stadium light standard columns,  cast reinforced concrete items,  at 52,000 lb each.  That's 26 US tons,  or just under 24 metric tons.  The T-head cranes used tons of ballast on their backsides to compensate for the loads applied way out on those booms. 

Kbd512 is exactly right:  we have known how to lift hundreds of tons at a time,  with very simple steel truss and cable/pulley technology.  And for a VERY long time indeed!  There is ABSOLUTELY NO reason this cannot be done on Mars to unload a "Starship",  even with a crane that is part of the "Starship" itself.  This is "freshman engineering statics 101" not to topple the ship doing it. 

As for the Memorial Stadium expansion at UT half a century ago,  there was an accident with a collapsed boom that nearly toppled the T-head crane.  Had the wind been higher,  it would have toppled over.  This accident happened NOT because of anything fundamental,  but because somebody tried to be too cheap and used boom-mounting shear pins one size too small. 

This thing would have fallen upon a neighboring dorm to mine at the time.  There was an all-night crisis until the biggest dragline crane I have ever seen arrived from Houston,  and took down the wreckage. 

Louis,  we already KNOW how to handle giant loads with cranes (far larger than what "Starship" can carry),  and how not to topple over doing this kind of work.  The problem isn't technical,  it's just greed getting in the way.

GW


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

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#21 2019-09-23 11:44:09

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,459
Website

Re: Top ten things Space X have to get right for the first Mars Mission

Louis:

Yeah,  the T-head crane collapses are rare,  and usually traceable to unusually high winds.

I would expect there will be an extendible-boom crane that protrudes out the cargo door on "Starship".  Extension is push-button hydraulic, with a simple operator's station. "Out",  "in",  and "stop" buttons. Once extended,  this thing will have another (or maybe the same) operator's station,  with "up",  "down",  and "stop" buttons to push.  Positioning the load is unimportant,  you are just lowering stuff to the ground on a platform bed,  to be rolled off once on the ground.  Loading is the reverse,  although it will be a long time before that is an issue. 

Pushing big fat buttons is something a human could do even wearing once of those incredibly-clumsy NASA-designed spacesuits.  That's not the issue.  The issue is seeing what's going on with the load on the cable.  That could be mirrors,  TV cameras,  or probably some of both.  And remember,  any freight "elevator" can transport people. 

What you might add to your top-ten list is a supple space suit.  To me it seems more likely that a successful supple design would have to be MCP.  Not the way the gal from MIT did it,  the way Dr. Webb originally did it half a century ago:  essentially as vacuum-protective underwear that you couple with whatever unpressurized outerwear you need for the job at hand. 

GW

Last edited by GW Johnson (2019-09-23 11:46:16)


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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#22 2023-12-29 06:47:01

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 9,267

Re: Top ten things Space X have to get right for the first Mars Mission

Land robots with a reactor, build a farm with moss, plants, animals or some Biofuel factory before humans arrive?

back on Earth with shipping

'NYK Line to trial long-term biofuel use'

https://www.marinelog.com/news/nyk-line … ofuel-use/


Not sure what's happening Bigelow, they were doing something spooky UFO ghost like tv programs about 'SkinwalkerRanch' he might have helped get that UAP or UFO public release thing moving


as for Coms

What is laser space communication and what does it give us?
https://ccm.net/computing/networks/1187 … it-brings/

Last edited by Mars_B4_Moon (2023-12-29 06:53:36)

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