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Author Topic: Re-purposing SpaceX hardware for near term exploration of Mars  (Read 9471 times)

Offline Russel

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I was going to use the title "Re-purposing SpaceX hardware for a manned landing on Mars in the near term with limited crew and pure science and exploration objectives and without consideration of colonisation".

But, that wouldn't fit :-)

Some predictions:

- NASA will abandon further development of SLS in favour of commercial tender
- SpaceX will use this as as a means to develop a scaled version of BFR
- SpaceX will continue sub-scale testing of technology relevant to BFS but will eventually concede that there is no business case for BFS and the inherent problems in this architecture are too great (including mining of Mars).

We are still left with some very useful technology, including reusable boosters and a much better understanding of how to build high lift re-entry vehicles. We may also end up with a booster that is more capable than Falcon Heavy but still not actually BFR.

What can we do with it?

Let me make some concrete suggestions. The BFS concept is still very useful and adaptable. In fact you could still use a scaled down version (remember we are talking a small crew, exploration only) and still use it in a reusable fashion.

You can use BFS style technology to land people on Mars and as an ascent vehicle from Mars into low Mars orbit. We are only talking 4-6 people here so the pressurised volume is tiny. Full reusability is an option but I'm not sure that stacks up. It is after all only a small proportion of the mass you are sending to Mars.

Like the BFS it would glide and then land propulsively on its tail. It would refuel with locally sourced oxygen. Methane would be imported. One option is to import the methane with the vehicle itself.

The big advantage of doing this over a direct entry is that with enough surface area and low mass (crew only) you can arrange for a relatively low g force landing (I'm not sure, I'm guessing around 2.5). This compares to the 4-6 estimated for BFS.

Of course you need to send cargo to Mars surface. This can be done with a conventional (blunt body) vehicle with movable center of mass and a late-lifting (high g force) trajectory. This can be accomplished with either one or two Falcon Heavy flights or a larger vehicle which may be a scaled down version of BFR.

You may also need to send fuel (or a complete booster) into Mars orbit. This would be done similarly except you would use a modest amount of fuel for orbital capture and then slow multi-pass aerobraking.

What you then use to send humans to and from Earth orbit and Mars orbit is another topic. As explained in another topic, I'd be happy to build a symmetric vehicle that can spin. Again, assembly in orbit through docking and multiple launches, but there's nothing here we don't already know how to do.

The whole point is that SpaceX has done us a big favour by developing reusable boosters. They may build a bigger reusable booster for the sake of NASA and they may develop further technology in the pursuit of an ultimately unbuilt BFS.

One further point. A limited manned Mars exploration mission may well be the work of multiple nations. It may even be instigated by some other agency than NASA. But it may as well build on what SpaceX has done (and utilise NASA expertise in various technologies).

Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

Offline kevinof

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Good post but I see a couple of major issues

1) SLS will keep going. It will continue to be funded by the politicians for years to come because it's what they do.  For Nasa, SLS is the only game in town for BEO.

2) Nasa would never accept a "taxi ride" solution. They will want their sticky fingers over every aspect of the design,
specs, features and endless paperwork. It's in their DNA, it's all they know and it's hard to change that.  I know the Nasa administrator has gone on about everything re-usable but I don't see it happening for a long, long time. (if ever).

3) Because of #2, SpaceX will never work with Nasa on a manned BEO platform. It would kill their creativity and speed.


Offline su27k

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Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

You need to clarify which SpaceX technology we can and cannot use, since you assumed BFR would fail, this means one or more of the near term SpaceX technology used by BFR wouldn't work.

Offline TripleSeven

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I was going to use the title "Re-purposing SpaceX hardware for a manned landing on Mars in the near term with limited crew and pure science and exploration objectives and without consideration of colonisation".

But, that wouldn't fit :-)

Some predictions:

- NASA will abandon further development of SLS in favour of commercial tender
- SpaceX will use this as as a means to develop a scaled version of BFR
- SpaceX will continue sub-scale testing of technology relevant to BFS but will eventually concede that there is no business case for BFS and the inherent problems in this architecture are too great (including mining of Mars).

We are still left with some very useful technology, including reusable boosters and a much better understanding of how to build high lift re-entry vehicles. We may also end up with a booster that is more capable than Falcon Heavy but still not actually BFR.

What can we do with it?

Let me make some concrete suggestions. The BFS concept is still very useful and adaptable. In fact you could still use a scaled down version (remember we are talking a small crew, exploration only) and still use it in a reusable fashion.

You can use BFS style technology to land people on Mars and as an ascent vehicle from Mars into low Mars orbit. We are only talking 4-6 people here so the pressurised volume is tiny. Full reusability is an option but I'm not sure that stacks up. It is after all only a small proportion of the mass you are sending to Mars.

Like the BFS it would glide and then land propulsively on its tail. It would refuel with locally sourced oxygen. Methane would be imported. One option is to import the methane with the vehicle itself.

The big advantage of doing this over a direct entry is that with enough surface area and low mass (crew only) you can arrange for a relatively low g force landing (I'm not sure, I'm guessing around 2.5). This compares to the 4-6 estimated for BFS.

Of course you need to send cargo to Mars surface. This can be done with a conventional (blunt body) vehicle with movable center of mass and a late-lifting (high g force) trajectory. This can be accomplished with either one or two Falcon Heavy flights or a larger vehicle which may be a scaled down version of BFR.

You may also need to send fuel (or a complete booster) into Mars orbit. This would be done similarly except you would use a modest amount of fuel for orbital capture and then slow multi-pass aerobraking.

What you then use to send humans to and from Earth orbit and Mars orbit is another topic. As explained in another topic, I'd be happy to build a symmetric vehicle that can spin. Again, assembly in orbit through docking and multiple launches, but there's nothing here we don't already know how to do.

The whole point is that SpaceX has done us a big favour by developing reusable boosters. They may build a bigger reusable booster for the sake of NASA and they may develop further technology in the pursuit of an ultimately unbuilt BFS.

One further point. A limited manned Mars exploration mission may well be the work of multiple nations. It may even be instigated by some other agency than NASA. But it may as well build on what SpaceX has done (and utilise NASA expertise in various technologies).

Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

I agree with your three statements....I dont know the time frame that they all happen in, and they are all triggered by SLS collapsing...but SLS Will collapse in my view. 

I would add a fourth one.  AT some point NASA and American space policy are going to embrace "Boston Dynamics" type robotics...and the bulk of Mars (as well as initial lunar exploration) is going to be advanced robotics...AND will take advantage of increased automation and robotics to do initial stages of exploration on all the inner planets as a precursor to someday human involvement at a "closer point in the loop" level.

The main thing that "rocket companies" can contribute to this...is the ability to lift larger and larger "shake and bake" Payloads to places like Mars (although the atmosphere of Venus is another place) that are heavenly automated and very dynamic in terms of their capabilites.

I agree as well that reuse is not all that important for the payloads that are sent or the vehicles that send them

It is to bad Red Dragon did not work out.  It would have been a near leapfrog in Martian activity and could have been the first "shake and bake" payload that really changed the NASA dynamics.


Offline speedevil

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I note the posts BFS - how bad can it be and get to Mars with little delay.
Much of BFS does not have to work at all in order for it to be orders of magnitude cheaper than NASA offerings.
I note that launching five BFS/BFB totally expendably is likely to get you a hundred tons or so on Mars. You only need the heatshield to work once, and at a peak velocity similar to LEO.

Offline Lar

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I'm with Speedevil, I reject the entire premise of this post and think it's not that interesting to speculate about counterfactuals.

We have seen lots of evidence of 9 meter tooling. Scaling down would completely waste that tooling.
« Last Edit: 11/29/2018 09:28 am by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline Russel

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Good post but I see a couple of major issues

1) SLS will keep going. It will continue to be funded by the politicians for years to come because it's what they do.  For Nasa, SLS is the only game in town for BEO.

2) Nasa would never accept a "taxi ride" solution. They will want their sticky fingers over every aspect of the design,
specs, features and endless paperwork. It's in their DNA, it's all they know and it's hard to change that.  I know the Nasa administrator has gone on about everything re-usable but I don't see it happening for a long, long time. (if ever).

3) Because of #2, SpaceX will never work with Nasa on a manned BEO platform. It would kill their creativity and speed.

There have been a number of articles recently to the effect that NASA will retire SLS in favour of commercial launches. I'm speculating that SpaceX will take the opportunity and get a NASA contract to develop what is a scaled down version of BFR.

For example:

https://www.inverse.com/article/51026-nasa-might-retire-sls
https://www.businessinsider.com.au/nasa-sls-replacement-spacex-bfr-blue-origin-new-glenn-2018-11?r=US&IR=T
https://www.nextbigfuture.com/2018/11/nasa-may-try-to-kill-sls-around-2022-and-another-16-billion-is-spent.html

Offline kevinof

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I know - I saw those quotes also.

But doing ANYTHING with Nasa brings a load of pain. I just don't see SpaceX having the appetite to engage on this when they can do so on their own and I certainly don't see them downsizing BFR/BFS.

SpaceX has a plan and they are charging ahead with that plan. If Nasa want's a ride then pay up and step back. If Nasa want's their own toy then they can engage with another supplier.

Good post but I see a couple of major issues

1) SLS will keep going. It will continue to be funded by the politicians for years to come because it's what they do.  For Nasa, SLS is the only game in town for BEO.

2) Nasa would never accept a "taxi ride" solution. They will want their sticky fingers over every aspect of the design,
specs, features and endless paperwork. It's in their DNA, it's all they know and it's hard to change that.  I know the Nasa administrator has gone on about everything re-usable but I don't see it happening for a long, long time. (if ever).

3) Because of #2, SpaceX will never work with Nasa on a manned BEO platform. It would kill their creativity and speed.

There have been a number of articles recently to the effect that NASA will retire SLS in favour of commercial launches. I'm speculating that SpaceX will take the opportunity and get a NASA contract to develop what is a scaled down version of BFR.

For example:

https://www.inverse.com/article/51026-nasa-might-retire-sls
https://www.businessinsider.com.au/nasa-sls-replacement-spacex-bfr-blue-origin-new-glenn-2018-11?r=US&IR=T
https://www.nextbigfuture.com/2018/11/nasa-may-try-to-kill-sls-around-2022-and-another-16-billion-is-spent.html

Offline Russel

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Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

You need to clarify which SpaceX technology we can and cannot use, since you assumed BFR would fail, this means one or more of the near term SpaceX technology used by BFR wouldn't work.

I think I made it clear but let me reiterate this.

Its pretty clear that some of the technology relevant to BFS can and will be tested. That should be obvious from the fact that I said that this technology could find a use - for example as a Mars surface to Mars orbit shuttle but that's just one possibility.

I have said pretty clearly that BFS has no business case. It doesn't really matter if its "in development". I'm ruling out BFS ever being built in its currently proposed form.

I'm not ruling out the possibility of BFR (at full scale) being built and flown. Even at full scale one can easily imagine uses for it that don't involve BFS. What I've said though is that it is far more likely that we'll see a scaled down version of BFR.

My problem with BFS is not that the technology wouldn't work. Its simply that its economics are broken.

Offline Russel

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I'm with Speedevil, I reject the entire premise of this post and think it's not that interesting to speculate about counterfactuals.

We have seen lots of evidence of 9 meter tooling. Scaling down would completely waste that tooling.

The tooling you need for things this size aren't cheap. But they are only a small fraction of the overall cost of development. I'm not saying that BFR itself won't fly at full scale (it might). I'm saying a) it may eventually be realised as something smaller because that's what NASA may wish to contract for and b) even if it is built at full scale, it will be for a purpose other than flying BFS.

Offline Russel

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I know - I saw those quotes also.

But doing ANYTHING with Nasa brings a load of pain. I just don't see SpaceX having the appetite to engage on this when they can do so on their own and I certainly don't see them downsizing BFR/BFS.

SpaceX has a plan and they are charging ahead with that plan. If Nasa want's a ride then pay up and step back. If Nasa want's their own toy then they can engage with another supplier.

Good post but I see a couple of major issues

1) SLS will keep going. It will continue to be funded by the politicians for years to come because it's what they do.  For Nasa, SLS is the only game in town for BEO.

2) Nasa would never accept a "taxi ride" solution. They will want their sticky fingers over every aspect of the design,
specs, features and endless paperwork. It's in their DNA, it's all they know and it's hard to change that.  I know the Nasa administrator has gone on about everything re-usable but I don't see it happening for a long, long time. (if ever).

3) Because of #2, SpaceX will never work with Nasa on a manned BEO platform. It would kill their creativity and speed.

There have been a number of articles recently to the effect that NASA will retire SLS in favour of commercial launches. I'm speculating that SpaceX will take the opportunity and get a NASA contract to develop what is a scaled down version of BFR.

For example:

https://www.inverse.com/article/51026-nasa-might-retire-sls
https://www.businessinsider.com.au/nasa-sls-replacement-spacex-bfr-blue-origin-new-glenn-2018-11?r=US&IR=T
https://www.nextbigfuture.com/2018/11/nasa-may-try-to-kill-sls-around-2022-and-another-16-billion-is-spent.html

SpaceX has a history of piggybacking its development work off NASA contracts. It somehow manages to deal with NASA quite well. The problem with BFR is that its has very limited use commercially. Elon might be a billionaire but he cannot fund BFR out of his own pocket. Eventually the most expedient thing for him to do is to sell BFR (or a scaled down version of BFR) to NASA as a way to get out of building the later versions of SLS.

Offline TripleSeven

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Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

You need to clarify which SpaceX technology we can and cannot use, since you assumed BFR would fail, this means one or more of the near term SpaceX technology used by BFR wouldn't work.

I think I made it clear but let me reiterate this.

Its pretty clear that some of the technology relevant to BFS can and will be tested. That should be obvious from the fact that I said that this technology could find a use - for example as a Mars surface to Mars orbit shuttle but that's just one possibility.

I have said pretty clearly that BFS has no business case. It doesn't really matter if its "in development". I'm ruling out BFS ever being built in its currently proposed form.

I'm not ruling out the possibility of BFR (at full scale) being built and flown. Even at full scale one can easily imagine uses for it that don't involve BFS. What I've said though is that it is far more likely that we'll see a scaled down version of BFR.

My problem with BFS is not that the technology wouldn't work. Its simply that its economics are broken.

A couple of great post...in my view the last sentence nails it. 

As I said in an earlier reply it is to bad red dragon did not fly.  Had it flown, at the cost level that seemed to be advertised it is one of the first things in the space manufactoring business that could have "broken" the NASA monopoly on payloads to the planets.  But what I dont know about it is if 1) it was technically possible and or 2) the economics were broken.

Anyway a nice discussion. 

Offline kevinof

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Yes, when they were starting F9 and Dragon development. It made sense.

With BFS there is no business case. Musk/SpaceX want to get to mars whether it makes money for them or not. It's not a commercial undertaking.  If they can do P2P on Earth and make money then great. If they can launch a 1000 Starlink sats in one go then great.

They might lease a BFS to Nasa but I can't see them doing a custom build. And even if they did sell/lease one to Nasa, it wouldn't be acceptable to Nasa as it wouldn't meet their specifications. Then you are into a new development program. I don't see a chance in hell of them doing a smaller version just for Nasa. It doesn't make sense to re-allocate resources, new tooling, new pads and all the other stuff.

You can wish for it all you want but I don't see any of this happening.

...
SpaceX has a history of piggybacking its development work off NASA contracts. It somehow manages to deal with NASA quite well. The problem with BFR is that its has very limited use commercially. Elon might be a billionaire but he cannot fund BFR out of his own pocket. Eventually the most expedient thing for him to do is to sell BFR (or a scaled down version of BFR) to NASA as a way to get out of building the later versions of SLS.

Offline rpapo

As I said in an earlier reply it is too bad Red Dragon did not fly.  Had it flown, at the cost level that seemed to be advertised it is one of the first things in the space manufacturing business that could have "broken" the NASA monopoly on payloads to the planets.
Hasn't ISRU already done this with their Mars Orbiter Mission (Mangalyaan)?  It wasn't a lander, but still...
An Apollo fanboy . . . fifty years ago.

Offline TripleSeven

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As I said in an earlier reply it is too bad Red Dragon did not fly.  Had it flown, at the cost level that seemed to be advertised it is one of the first things in the space manufacturing business that could have "broken" the NASA monopoly on payloads to the planets.
Hasn't ISRU already done this with their Mars Orbiter Mission (Mangalyaan)?  It wasn't a lander, but still...

Yes and I haad not thought of that...but yes to a small level...but they did start it.  If other countries or groups of countries start routinely flying payloads to Mars orbit (and maybe with the Europeans or eventually the Chinese landing) at some point the folks who really do the payloads...the universities will try and find funding to "get on those".  But there has to be the space/payload mass/ and chance of success.

I know an Aussie who is working on getting some penetrators (and is having some surprising success) on the European rover payload...

The thing about REd Dragon is that it would have been massive payload...and power (assuming they could figure that out) which would have been a "buffet" for the science community probaby one to big for them not to go for federal funding in some way on

I dont know for sure what killed it...the technology would not have worked or the money...I am guessing both...

Offline zodiacchris

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What is the point of this thread? Why would we assume that BFS should fail and SpaceX develops a scaled down version with NASA money??? BFS can work because it is large, scaling down is actually taking away the business case and would not make it easier to develop. Where would the sudden onrush of common sense in Congress come from, for them to realise that SLS is a dead horse?

Congress is not enamoured with commercial space, see the recent political decission to do an entirely pointless workplace review at SpaceX and Boeing.

So why not a thread on hardware available from all commercial providers suitable to land humans on Mars, but only left handed Astronauts, and only on Wednesdays or Fridays?  :o

Offline TripleSeven

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What is the point of this thread? Why would we assume that BFS should fail and SpaceX develops a scaled down version with NASA money??? BFS can work because it is large, scaling down is actually taking away the business case and would not make it easier to develop. Where would the sudden onrush of common sense in Congress come from, for them to realise that SLS is a dead horse?

Congress is not enamoured with commercial space, see the recent political decission to do an entirely pointless workplace review at SpaceX and Boeing.

So why not a thread on hardware available from all commercial providers suitable to land humans on Mars, but only left handed Astronauts, and only on Wednesdays or Fridays?  :o
.

Congress is not who did the safety review.  The [edit: snark removed] administrator did that
« Last Edit: 12/02/2018 01:37 pm by gongora »

Offline MATTBLAK

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I'm currently writing an 'alternate future' (as opposed to alternate history) novella set in the late 2020s about a manned, 'Red Dragon' mission to Mars. The architecture uses a mixture of largely off-the-shelf hardware and technology plus some custom built hardware. Two person crew, flags and footprints mission plus some rock & regolith collection. Short stay on the Martian surface. Retired, ex-Astronauts are the crew. Reason for mission? SpaceX experiences some annoying delays to it's BFR/BFS program, due to technology and financial glitches - so a trio of eccentric billionaires cough up for the mission; using soon to be retired Falcon boosters and Dragons - some of which are modified and upgraded.

Spoiler Alert:








...Mission mostly goes okay, but several things break down and make the Astronaut's lives difficult. Why do the mission? Because they can, and it furnishes some promotion for the idea of 'Man On Mars' to alleviate some public skepticism as the big scale mission proves harder to do than expected. Much like Falcon Heavy was. Some 'hand waving' is required to buy into the story... But probably not as much as aspects of the film version of Andy Weir's 'The Martian'.
« Last Edit: 11/29/2018 10:56 am by MATTBLAK »
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Offline su27k

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Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

You need to clarify which SpaceX technology we can and cannot use, since you assumed BFR would fail, this means one or more of the near term SpaceX technology used by BFR wouldn't work.

I think I made it clear but let me reiterate this.

Its pretty clear that some of the technology relevant to BFS can and will be tested. That should be obvious from the fact that I said that this technology could find a use - for example as a Mars surface to Mars orbit shuttle but that's just one possibility.

I have said pretty clearly that BFS has no business case. It doesn't really matter if its "in development". I'm ruling out BFS ever being built in its currently proposed form.

I'm not ruling out the possibility of BFR (at full scale) being built and flown. Even at full scale one can easily imagine uses for it that don't involve BFS. What I've said though is that it is far more likely that we'll see a scaled down version of BFR.

My problem with BFS is not that the technology wouldn't work. Its simply that its economics are broken.

If BFS technology works, SpaceX will have a launcher that can send 100t+ to LEO for $7M, plus a spaceship capable of landing 100t+ on the Moon and Mars, how can the economics of this possibly be broken? The launch cost is lower than some of the small satellite launchers. Just replace F9/FH with BFR would save them bunch of money, that's not even considering their constellation, and new markets such as space tourism, missions to Moon/Mars, etc.

I don't understand this obsession regarding BFR's size. BFR is only 3 times the size of Falcon Heavy, if you think that's too large, what is the size you can accept? 2 times the size of FH? Because it's obvious they don't need another FH sized rocket since they already have FH. Then the question becomes: What's the difference between 2x FH size and 3x FH size that is so critical such that one size can make it work, while the other size can sink it?

Finally, I don't see any reason NASA would abandon SLS unless SpaceX can build something bigger. If you shrink BFR, you automatically give up any hope of stealing SLS' underpants.

Offline Russel

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What is the point of this thread? Why would we assume that BFS should fail and SpaceX develops a scaled down version with NASA money??? BFS can work because it is large, scaling down is actually taking away the business case and would not make it easier to develop. Where would the sudden onrush of common sense in Congress come from, for them to realise that SLS is a dead horse?

Congress is not enamoured with commercial space, see the recent political decission to do an entirely pointless workplace review at SpaceX and Boeing.

So why not a thread on hardware available from all commercial providers suitable to land humans on Mars, but only left handed Astronauts, and only on Wednesdays or Fridays?  :o

You know, not so long ago, discussion about Mars missions involved fairly unexciting hardware. And lots of discussion about IMLEO. Then came Elon and suddenly the entire conversation is about BFS and nothing else matters.

The purpose of this thread is to put the BFS aside and instead ask the question, how would you build a Mars architecture for limited exploration, but in the light of technology developed by SpaceX. Its a perfectly legitimate focus.

There is no business case for BFS (it doesn't matter what scale it has) and I really don't care to go into that on this thread. If you want to start a new thread where the gloves are off and we can discuss the "underpants gnomes" issues behind BFS, please do.


Offline Russel

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I'm currently writing an 'alternate future' (as opposed to alternate history) novella set in the late 2020s about a manned, 'Red Dragon' mission to Mars. The architecture uses a mixture of largely off-the-shelf hardware and technology plus some custom built hardware. Two person crew, flags and footprints mission plus some rock & regolith collection. Short stay on the Martian surface. Retired, ex-Astronauts are the crew. Reason for mission? SpaceX experiences some annoying delays to it's BFR/BFS program, due to technology and financial glitches - so a trio of eccentric billionaires cough up for the mission; using soon to be retired Falcon boosters and Dragons - some of which are modified and upgraded.

I thought you had pretty much locked in your architecture a while back?

Offline Russel

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Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

You need to clarify which SpaceX technology we can and cannot use, since you assumed BFR would fail, this means one or more of the near term SpaceX technology used by BFR wouldn't work.

I think I made it clear but let me reiterate this.

Its pretty clear that some of the technology relevant to BFS can and will be tested. That should be obvious from the fact that I said that this technology could find a use - for example as a Mars surface to Mars orbit shuttle but that's just one possibility.

I have said pretty clearly that BFS has no business case. It doesn't really matter if its "in development". I'm ruling out BFS ever being built in its currently proposed form.

I'm not ruling out the possibility of BFR (at full scale) being built and flown. Even at full scale one can easily imagine uses for it that don't involve BFS. What I've said though is that it is far more likely that we'll see a scaled down version of BFR.

My problem with BFS is not that the technology wouldn't work. Its simply that its economics are broken.

If BFS technology works, SpaceX will have a launcher that can send 100t+ to LEO for $7M, plus a spaceship capable of landing 100t+ on the Moon and Mars, how can the economics of this possibly be broken? The launch cost is lower than some of the small satellite launchers. Just replace F9/FH with BFR would save them bunch of money, that's not even considering their constellation, and new markets such as space tourism, missions to Moon/Mars, etc.

I don't understand this obsession regarding BFR's size. BFR is only 3 times the size of Falcon Heavy, if you think that's too large, what is the size you can accept? 2 times the size of FH? Because it's obvious they don't need another FH sized rocket since they already have FH. Then the question becomes: What's the difference between 2x FH size and 3x FH size that is so critical such that one size can make it work, while the other size can sink it?

Finally, I don't see any reason NASA would abandon SLS unless SpaceX can build something bigger. If you shrink BFR, you automatically give up any hope of stealing SLS' underpants.


Once again, I have no problem with the size of BFR. It may get built. But in order for it to get built it may get built first in a smaller version. My real issue is with BFS. BFS only really has one purpose and that's mass colonisation. Again, I'm not going to speak my mind about that issue on this thread. I just assert that BFS is not what we are going to be using for initial exploratory missions to Mars.

So.. on topic please?

Offline TripleSeven

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What is the point of this thread? Why would we assume that BFS should fail and SpaceX develops a scaled down version with NASA money??? BFS can work because it is large, scaling down is actually taking away the business case and would not make it easier to develop. Where would the sudden onrush of common sense in Congress come from, for them to realise that SLS is a dead horse?

Congress is not enamoured with commercial space, see the recent political decission to do an entirely pointless workplace review at SpaceX and Boeing.

So why not a thread on hardware available from all commercial providers suitable to land humans on Mars, but only left handed Astronauts, and only on Wednesdays or Fridays?  :o

You know, not so long ago, discussion about Mars missions involved fairly unexciting hardware. And lots of discussion about IMLEO. Then came Elon and suddenly the entire conversation is about BFS and nothing else matters.

The purpose of this thread is to put the BFS aside and instead ask the question, how would you build a Mars architecture for limited exploration, but in the light of technology developed by SpaceX. Its a perfectly legitimate focus.

There is no business case for BFS (it doesn't matter what scale it has) and I really don't care to go into that on this thread. If you want to start a new thread where the gloves are off and we can discuss the "underpants gnomes" issues behind BFS, please do.

If one has affordable FH, BO, NG to name the most likely three but ULA works as well to spread around the 'pork". Its not hard to figure out how to do affordable Mars, Moon and really Venus exploration...in thos launch sized packets.

There are three big decisions points

The first is where to assemble the hardware.  I like ISS its there, the big issue is the inclination but thats not aa terrible loss in terms of payload for these vehicles.

The second is what kind of architecture one is going to use...I like cyclers that lead to "stations" in orbit around the planet (or moons in the case of Mars).  The cyclers are robust have plenty of power and can keep the crew sae and with gravity which is not hard the the ISS Nautilus effort...that includes shuttle ships (both people and cargo) that are FalconH and BO "bites"" ...the ships meet the Cycler, the crew hangs out and then uses atmospheric braking to get into the planet orbit.

The stations (or moons) around the planet allow the crew to do serious uncrewed exploration (I think LOckmart is correct in this) not tying the entire expedition to one place on the planet...which will get science non interesting fast...and eventually move on to week or two crewed visits...it also has the opprutnity to do both crewed and uncrewed resource use and that includes in the case of Mars the moons

The third thing you have to do is freee up the resources for all this by 1) cancelling programs that dont work and 2) empowering private industry by 1) keeping them busy and 2) coming up with a contactor service arraingment that works (commercial crew might not be the best template) ...

The advantages of this program is that 1) something happens every year which keeps the program in the eye of the public, 2) spreads the federal wealth around empowering contractors who should be able to prosper on this and 3) opens the door for expansion as cost come down

Its not 400 people to Mars but its something that in my view is doable.
« Last Edit: 11/29/2018 01:51 pm by TripleSeven »

Offline Slarty1080

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I'm with Speedevil, I reject the entire premise of this post and think it's not that interesting to speculate about counterfactuals.

We have seen lots of evidence of 9 meter tooling. Scaling down would completely waste that tooling.

The tooling you need for things this size aren't cheap. But they are only a small fraction of the overall cost of development. I'm not saying that BFR itself won't fly at full scale (it might). I'm saying a) it may eventually be realised as something smaller because that's what NASA may wish to contract for and b) even if it is built at full scale, it will be for a purpose other than flying BFS.

The reason why Starship / Superheavy are the size and design they are is because a) Musk wants to send humans to Mars and b) development costs. It is certainly not the most efficient way to do things, but it's a good compromise. If development costs were not an issue it would be better to have dedicated vehicles - orbiters, cyclers and landers each optimised for its own role, but it is just too expensive and will take too long (Musk is in a real hurry) so Starhip / Superheavy is a jack of all trades. Compromises have to be made but it should eventually be able to cover all the tasks required for it at an acceptable efficiency.

The real master stroke is what is actually going to make the SS/SH pay. I think that SpaceX will struggle for a few years as the development cost escalate but I'm hopeful it will be able to get the basic SS/SH version 1 flying in the early 2020's. SS/SH's (course the re-naming!) very first job will be lunching thousands of starlink satellites. This may well be started with F9 or FH but SS/SH should be on line to do most of the heavy lifting.

Starlink will be very profitable - banks and high frequency traders will pay a fortune to shave a few milli-seconds of the transatlantic communication time - to name but one use. While Starlink is being launched SpaceX will be gaining experience with SS/SH and increasing income. The profits from Starlink will pay for the final development stages of SS/SH v2 for Mars.

Musk may well continue to be very encouraging to NASA and will probably continue his praise for whatever NASA does as they have bought a lot of SpaceX services and he won't want to alienate them. But as Starlink becomes operational and income increases SpaceX will be well placed. NASA will be encouraged to join in, but I can't see Musk agreeing to any boatymcboatfaced-jobs-for-the-boys nonsensical Mars plan unless a) SpaceX is paid handsomely for it and b) he can continue his own plans on the side.

NASA might well want to use SpaceX to launch heavy cargos but why scale down SS/SH, why not just use FH?

As for NASA calling the shots, one day sometime in the not too distant future there will be a day of reckoning with NASA. I don't know how it will happen or how long it will take, but the current insane arrangement with SLS will become a news story and it will unravel. For example: #Dearmoon flies and returns a lot of stunning images (like the Apollo 8 view of Earth rise) before SLS has done anything worthwhile, prompting public curiosity in the Space program and what NASA is actually doing. The next administration may simply cancel SLS as too expensive and tells NASA to use a commercial launcher.
« Last Edit: 11/29/2018 03:49 pm by Slarty1080 »
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline Slarty1080

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"Re-purposing SpaceX hardware for a manned landing on Mars in the near term with limited crew and pure science and exploration objectives and without consideration of colonisation"

I would have thought that limited crew, pure science and exploration objectives would have been an absolute requirement for the first mission (first two or three even). Even Musk has to walk before he can run. One concession I think there will be a place for some applied science experiments looking at extraction of water, ISRU etc. 

Given the current state of development there are still a number of issues that might cause a lot of problems for a Mars mission that would encourage initial exploration missions first. One in particular is the availability of water. Although water appears to be relatively plentiful and many people assume that water availability is a done deal, it is not.

There are many technical challenges that will need to be overcome before water extraction technology can be relied on, such as drilling (what depth, what rock types and particle sizes?), large scale material handling equipment and the exact nature of the water baring substrate (does it come as a frozen brine? as frozen mud? Mixed with large rocks? As a hydrate? Is milling required before processing? How much water is available? How close to the landing site? Will the landing site be destabilised by extracting hundreds of tons of material from below the surface? And so on.

Due to these reasons the first mission will almost certainly not have access to Martian water for ISRU other than on an experimental scale. But in order to make the mission possible at all it may well have access to oxygen extracted from the atmosphere 2C02 > 2CO + O2 process, experimental versions of which I believe will be included in a near term Mars mission (Exomars?).

What this means is there will be a lot less payload available on initial missions than people think due to the need to cart fuel down to the surface. In fact a very large amount of payload will also be taken up by things like ECCLSS, oxygen, water, food, spares etc etc so mass saving will be of paramount importance.

IMO this means the first crew will be limited to four (not six) and the first Mars bound Starship might have a cut down habitation module of 3-4 decks rather than 7-8, (less shell, less decks and fittings). Another possible alteration would be a docking port at the front allowing greater flexibility in mission profiles allowing other Starships or other modules to dock. Maybe a high performance booster provided by A.N. Other launched on an SLS, SH, FH or NG to give them more dV.

Another alternative approach to minimise risk might be taking the Mars crew into LEO on return, and returning them and their samples to Earth in a dragon. This would minimise the danger of using the heatshield after all the time spent on Mars (it could then be refuelled and landed autonomously).
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline SteveKelsey

As someone has already pointed out on another thread, even if the Musk plan works out as planned there will still be plenty of spare capacity for using the BFR once the fleet is on its way every synod. I agree that, for space access, the booster is probably the most  transformational component of the BFS/BFR design and it can launch a lot of tonnage very cheaply. It opens up a lot of scope for those too expensive to realise projects and redefines the parameters of payload design for any LEO project. I liken it to the internet. Before the internet there was no market for social networks or global collaborative spaces, and DARPA was interested in nuke proof communications, not Google. So we really can't tell what those markets might be today, but having that sort of capability will stimulate a lot of invention.
2001 is running a little late, but we are getting there.

Offline speedevil

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I'm not ruling out the possibility of BFR (at full scale) being built and flown. Even at full scale one can easily imagine uses for it that don't involve BFS. What I've said though is that it is far more likely that we'll see a scaled down version of BFR.

My problem with BFS is not that the technology wouldn't work. Its simply that its economics are broken.

Arguing 'economics are broken' runs into several problems - first that you seem to be ignoring the projections on cost - if BFS fails in such a way so as to make the economics broken, that means it is costing $50M or so per launch. (for a vehicle that is proposed in the future to be able to launch for a fixed cost excluding fuel an amortisation of $300K, and a total near-term cost of $5M)

Secondly, it assumes that these problems can be fixed by shrinking the vehicle more easily than fixing the technology, which implies developing and testing a whole nother vehicle with new tooling is cheaper.

I've noted in the thread I mentioned above that excessive scale is what makes BFS systemically reliable.

Everything overweight by 150% - still works.
TPS only works to half LEO velocity - still works.
Raptor only works as well as SL Merlin - still works.

If you are going to argue that BFS is not possible, but subscale BFS is, you are implicitly saying that a launcher with much narrower margins than BFS works, built largely of BFS components, when BFS does not.

Which raises the obvious issue that if all the bits work for something subscale, ...
It is reasonable to say that BFS may be delayed. It is not reasonable to state that it will certainly fail to achieve its goals without specifying in detail how.

This is TESS - mass 360kg encapsulate in a F9 fairing.


Offline MATTBLAK

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I'm currently writing an 'alternate future' (as opposed to alternate history) novella set in the late 2020s about a manned, 'Red Dragon' mission to Mars. The architecture uses a mixture of largely off-the-shelf hardware and technology plus some custom built hardware. Two person crew, flags and footprints mission plus some rock & regolith collection. Short stay on the Martian surface. Retired, ex-Astronauts are the crew. Reason for mission? SpaceX experiences some annoying delays to it's BFR/BFS program, due to technology and financial glitches - so a trio of eccentric billionaires cough up for the mission; using soon to be retired Falcon boosters and Dragons - some of which are modified and upgraded.

I thought you had pretty much locked in your architecture a while back?
Yes. And nothing in my most recent post quoted above suggests otherwise. Modular, ISRU is important, etc. I'm 23,000 words into it.
« Last Edit: 11/29/2018 11:06 pm by MATTBLAK »
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Offline Russel

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I'm not ruling out the possibility of BFR (at full scale) being built and flown. Even at full scale one can easily imagine uses for it that don't involve BFS. What I've said though is that it is far more likely that we'll see a scaled down version of BFR.

My problem with BFS is not that the technology wouldn't work. Its simply that its economics are broken.

Arguing 'economics are broken' runs into several problems - first that you seem to be ignoring the projections on cost - if BFS fails in such a way so as to make the economics broken, that means it is costing $50M or so per launch. (for a vehicle that is proposed in the future to be able to launch for a fixed cost excluding fuel an amortisation of $300K, and a total near-term cost of $5M)

Secondly, it assumes that these problems can be fixed by shrinking the vehicle more easily than fixing the technology, which implies developing and testing a whole nother vehicle with new tooling is cheaper.

I've noted in the thread I mentioned above that excessive scale is what makes BFS systemically reliable.

Everything overweight by 150% - still works.
TPS only works to half LEO velocity - still works.
Raptor only works as well as SL Merlin - still works.

If you are going to argue that BFS is not possible, but subscale BFS is, you are implicitly saying that a launcher with much narrower margins than BFS works, built largely of BFS components, when BFS does not.

Which raises the obvious issue that if all the bits work for something subscale, ...
It is reasonable to say that BFS may be delayed. It is not reasonable to state that it will certainly fail to achieve its goals without specifying in detail how.


You've missed my point entirely..

BFS only works if you've got tens of thousands of willing customers. And that's even if you hold your nose and close your eyes about the other issues like mining of Mars or the supply chain that's actually needed for colonisation.  In short, its business case is entirely broken.

To the extent that the technology for BFS is tested, the knowledge can be reapplied. I'm not suggesting BFS is sub scaled. I'm suggesting that the technology may be re-applied to something more practical in the short term and for exploration purposes. hence the idea of a Mars lander/ascent vehicle (to and from Mars orbit) that is based on the same principles.

As for BFR. It may or may not get built at full scale. I'd like to see it built at full scale since this simplifies the process of getting large amounts of fuel into Earth orbit. But if it doesn't then you can still arrange the same thing with FH. To me, the question of whether BFR actually gets built at full scale has nothing to do with BFS (which isn't going to fly) and everything to do with whether BFR is either going to be useful to NASA at full scale, or useful as a commercial launch vehicle, again at full scale. Maybe it will.

Offline Russel

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As someone has already pointed out on another thread, even if the Musk plan works out as planned there will still be plenty of spare capacity for using the BFR once the fleet is on its way every synod. I agree that, for space access, the booster is probably the most  transformational component of the BFS/BFR design and it can launch a lot of tonnage very cheaply. It opens up a lot of scope for those too expensive to realise projects and redefines the parameters of payload design for any LEO project. I liken it to the internet. Before the internet there was no market for social networks or global collaborative spaces, and DARPA was interested in nuke proof communications, not Google. So we really can't tell what those markets might be today, but having that sort of capability will stimulate a lot of invention.

The transformational component is the reusability. And I'll bet you good money that Elon's competitors will attempt to copy this feature and that's probably not a bad thing.

Being able to re-fly a rocket quickly is more important I think than the economy of scale that comes with larger and larger rockets. Yes you do get economy of scale, but you also get bigger and more expensive facilities too, to the point where its a game of diminishing returns.

I actually like the idea of using the BFS as a tanker, but its not necessary to develop something that complex, or even something reusable if your only purpose is to get a large amount of fuel into orbit. Indeed if you're not using BFS as a tanker and instead just sending a big (and expendable) aluminium can, then you get more fuel up there for a given sized booster. After all, the expensive bit is the engines.

Offline Russel

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"Re-purposing SpaceX hardware for a manned landing on Mars in the near term with limited crew and pure science and exploration objectives and without consideration of colonisation"

I would have thought that limited crew, pure science and exploration objectives would have been an absolute requirement for the first mission (first two or three even). Even Musk has to walk before he can run. One concession I think there will be a place for some applied science experiments looking at extraction of water, ISRU etc.

Agreed. And I often have to wonder what is going through Elon's head with regards to this issue. Even if you think colonisation is a good thing (I don't) then you still need a knowledge base that can only come from taking those baby steps and doing limited missions.

Quote
Given the current state of development there are still a number of issues that might cause a lot of problems for a Mars mission that would encourage initial exploration missions first. One in particular is the availability of water. Although water appears to be relatively plentiful and many people assume that water availability is a done deal, it is not.

There are many technical challenges that will need to be overcome before water extraction technology can be relied on, such as drilling (what depth, what rock types and particle sizes?), large scale material handling equipment and the exact nature of the water baring substrate (does it come as a frozen brine? as frozen mud? Mixed with large rocks? As a hydrate? Is milling required before processing? How much water is available? How close to the landing site? Will the landing site be destabilised by extracting hundreds of tons of material from below the surface? And so on.

Agreed. All of this means you have to get there first and try some of this stuff out. And there may well be surprises. Personally I think the water issue will be solved with serendipity. Again, a limited mission first.

Quote
Due to these reasons the first mission will almost certainly not have access to Martian water for ISRU other than on an experimental scale. But in order to make the mission possible at all it may well have access to oxygen extracted from the atmosphere 2C02 > 2CO + O2 process, experimental versions of which I believe will be included in a near term Mars mission (Exomars?).

Which is why I've been working on the assumption that to the extent you can use ISRU for propellant you should only count on being able to generate oxygen. Hence imported methane. Also, the scale limits you to a non-direct return. In other words you need to think seriously about going to Mars orbit first, then return to Earth. Even a mini BFS (one capable of going back to Earth but with only 6 people) is unthinkable unless and until we've landed on Mars first and we are ready to do ISRU on a large scale.

Quote
What this means is there will be a lot less payload available on initial missions than people think due to the need to cart fuel down to the surface. In fact a very large amount of payload will also be taken up by things like ECCLSS, oxygen, water, food, spares etc etc so mass saving will be of paramount importance.

While I partly agree here, I do think that the mass of imported methane needed could be as little as a few tonnes. In other words a small fraction of the overall one-way cargo. I can't imagine you doing this with less than 50 tonnes of cargo once you include the surface hab, rovers and all that.

Quote
IMO this means the first crew will be limited to four (not six) and the first Mars bound Starship might have a cut down habitation module of 3-4 decks rather than 7-8, (less shell, less decks and fittings). Another possible alteration would be a docking port at the front allowing greater flexibility in mission profiles allowing other Starships or other modules to dock. Maybe a high performance booster provided by A.N. Other launched on an SLS, SH, FH or NG to give them more dV.

Firstly on crew size. I'm just going on what has been written that indicated 6 to 8 people. If it really matters then you could do with 4 people, at least on the surface. Its easy to imagine missions where 1 or 2 people remain in Mars orbit (wouldn't you hate that job). I'm not fond of a space vehicle become a surface hab.


Quote
Another alternative approach to minimise risk might be taking the Mars crew into LEO on return, and returning them and their samples to Earth in a dragon. This would minimise the danger of using the heatshield after all the time spent on Mars (it could then be refuelled and landed autonomously).

In my preferred architecture you'd be doing this on both ends. A Mars lander/ascent vehicle for the trip to and from Mars orbit and fairly off the shelf hardware to get to and from Earth orbit. And a space-only vehicle in between.

Offline woods170

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You've missed my point entirely..

BFS only works if you've got tens of thousands of willing customers. And that's even if you hold your nose and close your eyes about the other issues like mining of Mars or the supply chain that's actually needed for colonisation.  In short, its business case is entirely broken.

You forgot to add "IMO".

Because the only ones who can actually tell if BFS is financially viable (or not) are Elon and Gwynne.

And you are neither of them.

Issuing statement the way you do makes you sound like that (former) ULA guy who used an Excel spreadsheet to "prove" that first stage reusability for Falcon 9 was cost ineffective.
Time proved him wrong on every assumption he had made to support his "proof".


IMO the one thing you keep overlooking is that BFS is not intended for Mars flights ONLY. It's a one-size-fits-all vehicle to do everything.
Point-To-Point transportation of cargo and passengers. Launch of commercial payloads. Launch of institutional payloads. Launch of military payloads.
IMO the number of missions where BFS actually flies to Mars will be small compared to the number of missions that will be flown as PTP, to Earth-bound orbits or to Lunar space.
« Last Edit: 11/30/2018 10:53 am by woods170 »

Offline su27k

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Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

You need to clarify which SpaceX technology we can and cannot use, since you assumed BFR would fail, this means one or more of the near term SpaceX technology used by BFR wouldn't work.

I think I made it clear but let me reiterate this.

Its pretty clear that some of the technology relevant to BFS can and will be tested. That should be obvious from the fact that I said that this technology could find a use - for example as a Mars surface to Mars orbit shuttle but that's just one possibility.

I have said pretty clearly that BFS has no business case. It doesn't really matter if its "in development". I'm ruling out BFS ever being built in its currently proposed form.

I'm not ruling out the possibility of BFR (at full scale) being built and flown. Even at full scale one can easily imagine uses for it that don't involve BFS. What I've said though is that it is far more likely that we'll see a scaled down version of BFR.

My problem with BFS is not that the technology wouldn't work. Its simply that its economics are broken.

If BFS technology works, SpaceX will have a launcher that can send 100t+ to LEO for $7M, plus a spaceship capable of landing 100t+ on the Moon and Mars, how can the economics of this possibly be broken? The launch cost is lower than some of the small satellite launchers. Just replace F9/FH with BFR would save them bunch of money, that's not even considering their constellation, and new markets such as space tourism, missions to Moon/Mars, etc.

I don't understand this obsession regarding BFR's size. BFR is only 3 times the size of Falcon Heavy, if you think that's too large, what is the size you can accept? 2 times the size of FH? Because it's obvious they don't need another FH sized rocket since they already have FH. Then the question becomes: What's the difference between 2x FH size and 3x FH size that is so critical such that one size can make it work, while the other size can sink it?

Finally, I don't see any reason NASA would abandon SLS unless SpaceX can build something bigger. If you shrink BFR, you automatically give up any hope of stealing SLS' underpants.


Once again, I have no problem with the size of BFR. It may get built. But in order for it to get built it may get built first in a smaller version. My real issue is with BFS. BFS only really has one purpose and that's mass colonisation. Again, I'm not going to speak my mind about that issue on this thread. I just assert that BFS is not what we are going to be using for initial exploratory missions to Mars.

No that's incorrect, see the attached image, this is the BFS (2017 configuration), it is not being used in mass colonization, but being used to launch a satellite.

Offline Russel

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You've missed my point entirely..

BFS only works if you've got tens of thousands of willing customers. And that's even if you hold your nose and close your eyes about the other issues like mining of Mars or the supply chain that's actually needed for colonisation.  In short, its business case is entirely broken.

You forgot to add "IMO".

Because the only ones who can actually tell if BFS is financially viable (or not) are Elon and Gwynne.

And you are neither of them.

Issuing statement the way you do makes you sound like that (former) ULA guy who used an Excel spreadsheet to "prove" that first stage reusability for Falcon 9 was cost ineffective.
Time proved him wrong on every assumption he had made to support his "proof".


IMO the one thing you keep overlooking is that BFS is not intended for Mars flights ONLY. It's a one-size-fits-all vehicle to do everything.
Point-To-Point transportation of cargo and passengers. Launch of commercial payloads. Launch of institutional payloads. Launch of military payloads.
IMO the number of missions where BFS actually flies to Mars will be small compared to the number of missions that will be flown as PTP, to Earth-bound orbits or to Lunar space.

Are we confusing two things?

The BFR is a reusable booster. The BFS is a reusable spaceship.

You don't need the BFS to launch satellites. That task is easily served by hardware we already have. What do you gain from putting a BFS on top of a BFR, then putting a satellite inside the BFS and then launching the whole thing? The mass of the BFS itself is just dead weight if you're only sending something one way.
« Last Edit: 11/30/2018 11:44 am by Russel »

Offline Russel

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Does anyone else want to suggest how SpaceX technology either present or near term can be creatively reused for a practical near term Mars mission?

You need to clarify which SpaceX technology we can and cannot use, since you assumed BFR would fail, this means one or more of the near term SpaceX technology used by BFR wouldn't work.

I think I made it clear but let me reiterate this.

Its pretty clear that some of the technology relevant to BFS can and will be tested. That should be obvious from the fact that I said that this technology could find a use - for example as a Mars surface to Mars orbit shuttle but that's just one possibility.

I have said pretty clearly that BFS has no business case. It doesn't really matter if its "in development". I'm ruling out BFS ever being built in its currently proposed form.

I'm not ruling out the possibility of BFR (at full scale) being built and flown. Even at full scale one can easily imagine uses for it that don't involve BFS. What I've said though is that it is far more likely that we'll see a scaled down version of BFR.

My problem with BFS is not that the technology wouldn't work. Its simply that its economics are broken.

If BFS technology works, SpaceX will have a launcher that can send 100t+ to LEO for $7M, plus a spaceship capable of landing 100t+ on the Moon and Mars, how can the economics of this possibly be broken? The launch cost is lower than some of the small satellite launchers. Just replace F9/FH with BFR would save them bunch of money, that's not even considering their constellation, and new markets such as space tourism, missions to Moon/Mars, etc.

I don't understand this obsession regarding BFR's size. BFR is only 3 times the size of Falcon Heavy, if you think that's too large, what is the size you can accept? 2 times the size of FH? Because it's obvious they don't need another FH sized rocket since they already have FH. Then the question becomes: What's the difference between 2x FH size and 3x FH size that is so critical such that one size can make it work, while the other size can sink it?

Finally, I don't see any reason NASA would abandon SLS unless SpaceX can build something bigger. If you shrink BFR, you automatically give up any hope of stealing SLS' underpants.


Once again, I have no problem with the size of BFR. It may get built. But in order for it to get built it may get built first in a smaller version. My real issue is with BFS. BFS only really has one purpose and that's mass colonisation. Again, I'm not going to speak my mind about that issue on this thread. I just assert that BFS is not what we are going to be using for initial exploratory missions to Mars.

No that's incorrect, see the attached image, this is the BFS (2017 configuration), it is not being used in mass colonization, but being used to launch a satellite.

As I alluded to in the previous post, this illustration is pure marketing spin.

You don't need a BFS to launch a satellite. You gain nothing. It just adds more mass and then you have to land the BFS and re-cycle it.

And now you're going to tell me that the BFS is effectively an upper stage. Well, it can be, but its also an enormous development cost which you have to recover from a limited market when you could have used a conventional upper stage and still have people willing to pay for it.

Where is the customer that is willing to pay more for a satellite launch using a BFS as an upper stage?

Offline TripleSeven

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Because the only ones who can actually tell if BFS is financially viable (or not) are Elon and Gwynne.

there are other people who can make as good a judgment as those two.  I'll name two.  the first is the money people and the second is the USAF.

both have a pretty good idea of the economic "possibilities" of BFR/BFS or whatever it is called



Quote
Issuing statement the way you do makes you sound like that (former) ULA guy who used an Excel spreadsheet to "prove" that first stage reusability for Falcon 9 was cost ineffective.
Time proved him wrong on every assumption he had made to support his "proof".

I dont know about that either...I have not seen the spreadsheet...but the reusability and economics behind the first stage reuse are still "in work"
Quote
It's a one-size-fits-all vehicle to do everything.
Point-To-Point transportation of cargo and passengers. Launch of commercial payloads. Launch of institutional payloads. Launch of military payloads.

the history of "onse size fits all vehicles that can do anything is not promising


Offline Russel

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I'll also add that the BFS is a quite large vehicle as currently proposed. Way too large to be commercial for things like satellite launch. I know you're about to say that they will go on to develop a Falcon H/SH with a reusable second stage that has BFS features-in-testing. Sure.

But then what they'll end up with (maybe) is a darn good reusable second stage that still isn't a BFS. A BFS is a very large and very expensive development project. They can test a bunch of technology related to BFS using a mini version of it for commercial purposes, but what then? The BFS was always going to be scaled for Mars colonisation. And that's where the story ends.

And that's where this thread begins. Absent of a BFS, but given the technology, how then do you propose to explore Mars.

And I do wish you guys would get back on topic.

Offline TripleSeven

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Everything overweight by 150% - still works.
TPS only works to half LEO velocity - still works.
Raptor only works as well as SL Merlin - still works.


I dont know that I agree with either your points.  the one above or the one that if it cannot work larger it cannot work smaller

First the point above seems to say "it cannot fail" thats not true.  you are essentially making the same arguments that were made for the shuttle system (in fact this seems to me to be turning into a shuttle redux)

the thing can fail technically, it can fail economically, it can fail from a reliability standpoint, it can fail from "no customers"|

the underlying assumptions are very aggressive...ie a 7 million (is that the latest number) launch, the notion of turnaround time, the notion of how frequently things are reusable

there is a reason the USAF rejected funding the system...they looked at all these things and did not come to the same conclusion you do

as for smaller...thats another kettle of fish

Offline TripleSeven

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And that's where this thread begins. Absent of a BFS, but given the technology, how then do you propose to explore Mars.

And I do wish you guys would get back on topic.

my take on it is that SpaceX, NG (maybe I dont know the economics of their vehicle), Blue and yes ULA are all positioned to start playing a role in first a lunar "surge" and than next a Mars up tick in exploration.

but people will go to the Moon first...and that will be a proving ground for the "methods" that are used for Mars exploration (and maybe Venus atmosphere) ...the key is going to develop an architecture that works...


Offline woods170

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You've missed my point entirely..

BFS only works if you've got tens of thousands of willing customers. And that's even if you hold your nose and close your eyes about the other issues like mining of Mars or the supply chain that's actually needed for colonisation.  In short, its business case is entirely broken.

You forgot to add "IMO".

Because the only ones who can actually tell if BFS is financially viable (or not) are Elon and Gwynne.

And you are neither of them.

Issuing statement the way you do makes you sound like that (former) ULA guy who used an Excel spreadsheet to "prove" that first stage reusability for Falcon 9 was cost ineffective.
Time proved him wrong on every assumption he had made to support his "proof".


IMO the one thing you keep overlooking is that BFS is not intended for Mars flights ONLY. It's a one-size-fits-all vehicle to do everything.
Point-To-Point transportation of cargo and passengers. Launch of commercial payloads. Launch of institutional payloads. Launch of military payloads.
IMO the number of missions where BFS actually flies to Mars will be small compared to the number of missions that will be flown as PTP, to Earth-bound orbits or to Lunar space.

Are we confusing two things?

The BFR is a reusable booster. The BFS is a reusable spaceship.

You don't need the BFS to launch satellites. That task is easily served by hardware we already have. What do you gain from putting a BFS on top of a BFR, then putting a satellite inside the BFS and then launching the whole thing? The mass of the BFS itself is just dead weight if you're only sending something one way.

I am not confusing things. But you certainly are.

I suggest you let go of the "dead weight" argument. BFS is not dead weight. For example: in the case of deploying a satellite to orbit the BFS acts as the second stage AND fairing in one package. A reusable package I might add because after delivering the satellite to orbit BFS returns to Earth for another round of flying stuff to orbit.

Weight optimization is NOT a factor in the design of BFS.

Offline woods170

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No that's incorrect, see the attached image, this is the BFS (2017 configuration), it is not being used in mass colonization, but being used to launch a satellite.

As I alluded to in the previous post, this illustration is pure marketing spin.

You don't need a BFS to launch a satellite. You gain nothing. It just adds more mass and then you have to land the BFS and re-cycle it.

And now you're going to tell me that the BFS is effectively an upper stage. Well, it can be, but its also an enormous development cost which you have to recover from a limited market when you could have used a conventional upper stage and still have people willing to pay for it.

Where is the customer that is willing to pay more for a satellite launch using a BFS as an upper stage?

That's the whole point of BFS: By being fully reusable the cost of launching BFS to deploy a payload to orbit (such as the satellite in the picture) drops well below that of (partially) expendable systems such as Vulcan, Ariane and even F9 and FH.

But from your repeated posts it is rapidly becoming clear that you are incapable of getting your head around the concept of reusability and the cost savings that come along. You are just as much in denial as the CEO's of ULA and Arianespace were two years ago.

Offline Russel

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And that's where this thread begins. Absent of a BFS, but given the technology, how then do you propose to explore Mars.

And I do wish you guys would get back on topic.

my take on it is that SpaceX, NG (maybe I dont know the economics of their vehicle), Blue and yes ULA are all positioned to start playing a role in first a lunar "surge" and than next a Mars up tick in exploration.

but people will go to the Moon first...and that will be a proving ground for the "methods" that are used for Mars exploration (and maybe Venus atmosphere) ...the key is going to develop an architecture that works...

I'm not particularly bothered by the "moon first" approach. Its really unnecessary to getting to Mars but if someone want to then why not, we will learn things from it.

What I do have a problem with is Elon and his fans getting distracted from the fact that getting to Mars is hard. Colonisation is a couple of orders of magnitude harder. If we are going to get there in the near term to actually explore then we are going to need an architecture that doesn't involve large scale ISRU and therefore doesn't involve a direct to Mars surface and then direct to Earth approach. I also have a problem with NASA wasting a lot of money on something (SLS) when it could get the same thing cheaper from commercial providers and instead concentrate on doing the really hard stuff.

Offline Russel

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No that's incorrect, see the attached image, this is the BFS (2017 configuration), it is not being used in mass colonization, but being used to launch a satellite.

As I alluded to in the previous post, this illustration is pure marketing spin.

You don't need a BFS to launch a satellite. You gain nothing. It just adds more mass and then you have to land the BFS and re-cycle it.

And now you're going to tell me that the BFS is effectively an upper stage. Well, it can be, but its also an enormous development cost which you have to recover from a limited market when you could have used a conventional upper stage and still have people willing to pay for it.

Where is the customer that is willing to pay more for a satellite launch using a BFS as an upper stage?

That's the whole point of BFS: By being fully reusable the cost of launching BFS to deploy a payload to orbit (such as the satellite in the picture) drops well below that of (partially) expendable systems such as Vulcan, Ariane and even F9 and FH.

But from your repeated posts it is rapidly becoming clear that you are incapable of getting your head around the concept of reusability and the cost savings that come along. You are just as much in denial as the CEO's of ULA and Arianespace were two years ago.

You're now being uncivil.

I've made it clear I have no problem with the idea of reusability, but how many times do I need to repeat that BFS as it is presented (a very large Mars colonisation vehicle) is non-commercial. Its not needed at the scale its presented as. Not for commercial uses.

That doesn't mean that they won't test BFS related technology and that that won't result in a reusable upper stage for commercial use.

But that does not mean that we should expect that a full scale BFS will be the first to land on Mars. For one thing, it won't be going anywhere without fuel.

We need to be sensible and pragmatic about this.
« Last Edit: 11/30/2018 12:16 pm by Russel »

Offline Russel

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I will also add that despite all the talk about the BFS, this thread was created to specifically exclude discussion of the BFS. Discussion of the BFS is off topic.

So would you guys kindly stay on topic?

Moderators. Can you please enforce this?
« Last Edit: 11/30/2018 12:20 pm by Russel »

Offline woods170

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Because the only ones who can actually tell if BFS is financially viable (or not) are Elon and Gwynne.

there are other people who can make as good a judgment as those two.  I'll name two.  the first is the money people and the second is the USAF.

both have a pretty good idea of the economic "possibilities" of BFR/BFS or whatever it is called

You state an assumption here. Ample proof for your assumption being a bad one can be found in the fact that those same money people are still very much willing to invest in SpaceX. And USAF is actively funding the development of the BFR/BFS engine: Raptor.

Issuing statement the way you do makes you sound like that (former) ULA guy who used an Excel spreadsheet to "prove" that first stage reusability for Falcon 9 was cost ineffective.
Time proved him wrong on every assumption he had made to support his "proof".

I dont know about that either...I have not seen the spreadsheet...but the reusability and economics behind the first stage reuse are still "in work"
No, they are not. The savings SpaceX is getting from reusing F9 first stages have already begun to pay back significant chunks of the reusability-development investments. It is only a matter of time (and less time than you might think) before every single reuse of an F9 first stage is adding very significant profits to every single launch, above and beyond the profits they are already making now.

It's a one-size-fits-all vehicle to do everything.
Point-To-Point transportation of cargo and passengers. Launch of commercial payloads. Launch of institutional payloads. Launch of military payloads.
The history of "onse size fits all vehicles that can do anything is not promising

And yet that is where everyone is heading for.
See: https://spacenews.com/launch-companies-reduce-vehicle-options-to-lower-costs/

On a more personal note. I can understand that you, being a hardcore fan of Boeing, have a tendency to react strongly to every post concerning SpaceX. After all, SpaceX and Boeing are not exactly friends.
But I suggest you remember what happened the last time you over-reacted in similar discussions.

Offline woods170

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You're now being uncivil.
No. I'm pointing out a pattern that is beginning to emerge from your recent posts.
« Last Edit: 11/30/2018 12:24 pm by woods170 »

Offline woods170

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I will also add that despite all the talk about the BFS, this thread was created to specifically exclude discussion of the BFS. Discussion of the BFS is off topic.

So would you guys kindly stay on topic?

Moderators. Can you please enforce this?

If discussion of the BFS is off topic than why did you bother to mention BFR/BFS no less than half a dozen times in your opening post?
By doing that you very much made BFR/BFS on-topic.


Also: if you wish to address the moderators: there is a "Report to moderator"  link underneath every single post. Use that in stead of addressing them in the open thread. It's much more efficient.
« Last Edit: 11/30/2018 07:07 pm by woods170 »

Offline TripleSeven

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And that's where this thread begins. Absent of a BFS, but given the technology, how then do you propose to explore Mars.

And I do wish you guys would get back on topic.

my take on it is that SpaceX, NG (maybe I dont know the economics of their vehicle), Blue and yes ULA are all positioned to start playing a role in first a lunar "surge" and than next a Mars up tick in exploration.

but people will go to the Moon first...and that will be a proving ground for the "methods" that are used for Mars exploration (and maybe Venus atmosphere) ...the key is going to develop an architecture that works...

I'm not particularly bothered by the "moon first" approach. Its really unnecessary to getting to Mars but if someone want to then why not, we will learn things from it.

What I do have a problem with is Elon and his fans getting distracted from the fact that getting to Mars is hard. Colonisation is a couple of orders of magnitude harder. If we are going to get there in the near term to actually explore then we are going to need an architecture that doesn't involve large scale ISRU and therefore doesn't involve a direct to Mars surface and then direct to Earth approach. I also have a problem with NASA wasting a lot of money on something (SLS) when it could get the same thing cheaper from commercial providers and instead concentrate on doing the really hard stuff.

SLS (and to some extent the gateway) are a function of next to zero political leadership from the executive office ie the office of the president

All presidents come into office and eventually get into "space policy".  in the process of getting "into it" they go from "lets do something different because my administration is doing everything different from the last one" to the reality of "wow its expensive to do things in space and worse NASA is not very good at it anymore and Idont want to have a Challenger or Columbia on my watch"

so what do they do?  give money to build things.  building things is fine because they take forever, keep certain pols happy and never fly.

The notion of changing how human spaceflight is done is not that appealing because it offers now so little reward.  no politician (ormost of them anyway) thinks that sending people to the moon would get them any "creds" with the American people

The loss in TX 7 where the guy had brought home the space pork and his rival ridiculed it...its not a single event

As for Musk and Mars...

you and I are I guess two of the skeptics.  I think Musk balked on Red Dragon 1) because NASA wouldnt pay the money to make the powered landing stuff work and 2) he got worried that Dragon would not last the trip to mars.

right now he has the best ofboth worlds...he is slowly but surely developing a solid product that probably has lower cost to orbit (real lower cost to orbit) then the competition and might be on the verge of some real break throughs in refurbishment/reusability

and the day of "every person access to space" is pushed back yet again...

But I predict that Musk like Blue and ULA and other groups wont get to far from where federal money is going...and tht is to the Moon.  he needs the money  the federal government pays primo dollars

EDIT...one more thing

I really dont think most Americans say 98 or 99 percent CARE about what goes on in space with humans.

« Last Edit: 11/30/2018 12:39 pm by TripleSeven »

Offline su27k

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Once again, I have no problem with the size of BFR. It may get built. But in order for it to get built it may get built first in a smaller version. My real issue is with BFS. BFS only really has one purpose and that's mass colonisation. Again, I'm not going to speak my mind about that issue on this thread. I just assert that BFS is not what we are going to be using for initial exploratory missions to Mars.

No that's incorrect, see the attached image, this is the BFS (2017 configuration), it is not being used in mass colonization, but being used to launch a satellite.

As I alluded to in the previous post, this illustration is pure marketing spin.

No, it's not, they already got a billionaire customer for a non-Mars related mission using BFS.

Quote
You don't need a BFS to launch a satellite. You gain nothing. It just adds more mass and then you have to land the BFS and re-cycle it.

Of course you gain something: lower launch cost, as already explained multiple times above. Yes it adds more mass and need to be landed and reused, but that's the same for F9 first stage too, are you telling me you think F9 first stage reuse gains nothing either? After all you don't need reusable first stage to launch a satellite either.

Quote
And now you're going to tell me that the BFS is effectively an upper stage.

Not just "effectively", it is an upper stage with integrated fairing.

Quote
Well, it can be, but its also an enormous development cost which you have to recover from a limited market when you could have used a conventional upper stage and still have people willing to pay for it.

Assuming BFR launch cost is $7M, and reusable F9 launch cost is $30M, then for each launch BFR can save $23M. To payback $5B of development cost, it needs ~200 launches. Assuming 20 launches per year, it needs ~10 years to pay back the development cost, not great but not bad either.

But once you adds Starlink the savings provided by BFR went through the roof, SpaceX has 11,000 satellites to launch, assuming 25 satellites per F9, that's 440 F9 launches or $13B in launch cost. Now assume BFR can launch 100 satellites per launch, then they only need 110 BFR launches or $770M in launch cost, an order of magnitude reduction in cost and a saving of $10B+, more than enough to pay back the BFR development cost.

And this doesn't even consider the fact that BFS opens up additional markets that conventional upper stage can never dream of. For example, SpaceX already signed up a customer willing to pay hundreds of millions for one BFS mission.

Quote
Where is the customer that is willing to pay more for a satellite launch using a BFS as an upper stage?

Customer doesn't need to pay more, they pay less since BFR is designed to be cheaper than F9/FH due to full reusability.
« Last Edit: 11/30/2018 12:40 pm by su27k »

Offline TripleSeven

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You state an assumption here. Ample proof for your assumption being a bad one can be found in the fact that those same money people are still very much willing to invest in SpaceX. And USAF is actively funding the development of the BFR/BFS engine: Raptor.

the USAF balked on any funds for BFR  the engine survives (and goes onto Falcon upper stage) if BFR or whatever it is called fails

but the USAF knows the money issue well


Quote
No, they are not. The savings SpaceX is getting from reusing F9 first stages have already begun to pay back significant chunks of the reusability-development investments. It is only a matter of time (and less time than you might think) before every single reuse of an F9 first stage is adding very significant profits to every single launch, above and beyond the profits they are already making now.

that is your opinion, one which is not universally held

Quote
And yet that is where everyone is heading for.

no not really.  Most are headed toward a vehicle which will deliver 15 tons to lunar orbit and more mass to LEO...almost no one is really working on point to point, a mars vehicle etc...  thats a SpaceX thing alone.




 

Offline Chris Bergin

Is this thread going anywhere? Seems to be an awful lot of "my idea" and "nope" style Q&A.

And people are going to get frustrated with lines like "What I do have a problem with is Elon and his fans getting distracted from the fact that getting to Mars is hard. "

That's patronizing in the style of "Elon should stop thinking about landing boosters as he'll lose focus on actually being able to launch satellites of any decent mass".

Let's give this thread 24 hours to prove itself. :)

Offline Russel

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Is this thread going anywhere? Seems to be an awful lot of "my idea" and "nope" style Q&A.

And people are going to get frustrated with lines like "What I do have a problem with is Elon and his fans getting distracted from the fact that getting to Mars is hard. "

That's patronizing in the style of "Elon should stop thinking about landing boosters as he'll lose focus on actually being able to launch satellites of any decent mass".

Let's give this thread 24 hours to prove itself. :)

What about just asking people to post on topic.
Its an interesting topic and I certainly don't have all the answers, which is why I asked.
If they're not interested in posting on the actual topic then the thread will die a natural death.

However I actually would like to see what good ideas there are about getting to Mars in the near term, on a limited scale, not involving the BFS (at least not the 100 people at a time version) and certainly not involving the scale of ISRU implied in the BFS.

That's what the thread is for. I would rather separate thread to debate the BFS.
Also telling people they haven't paid attention/listened/whatever is uncivil. I've tolerated the off topic stuff but the interesting stuff (and why this thread exists) is actual problem solving.

Offline Chris Bergin

Great.

Problem is, no one (including and especially yourself) has reported any of the uncivil posts, as you should do (otherwise you have no reason to complain). And I only ended up here because people were complaining about your posts. So there you go. :)

Offline Russel

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Great.

Problem is, no one (including and especially yourself) has reported any of the uncivil posts, as you should do (otherwise you have no reason to complain). And I only ended up here because people were complaining about your posts. So there you go. :)

Well all I'm asking is that this forum maintains the one basic rule of all forums - relevance.
I set this thread up making it very clear it was not about discussion of BFS.
I also politely suggested on several occasions that I wasn't interested in BFS related discussion but was happy to take it elsehwere.

If people don't think the actual topic is worth talking about they can choose not to comment.
If people continue to post off topic then I'll make a point of simply referring it to you.

Offline Slarty1080

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I think part of the trouble is that Starship / Superheavy are very logical choices for a Mars mission even if they do need to be modified in the near term as I mentioned up post), so it's hard to exclude them from a discussion concerning repurposing SpaceX hardware for Mars.

Unless you meant repurposing SpaceX hardware that has already flown in which case all SS/SH and  raptor discussion is off topic and it comes down to designing a Mars mission using F9, FH, Dragon and perhaps a few mods. So is discussion of modification to SS/SH for Mars on topic for this post? Also what constitutes near term? How many years?


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Offline MATTBLAK

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If we are not talking about BFS then I was strongly assuming we were talking about 'Red Dragon' and Falcon Heavies at the very least? I've even seen some papers and videos around where it is postulated that Dragon 2's and Falcon Heavies; coupled with add-on Habitation and Propulsion Modules (likely storable) could accomplish either 'Inspiration Mars' style missions with 2x Astronauts or a mission to Phobos with a crew of three, for a short stay with some basic EVA's in Stickney Crater. These two classes of missions would not interfere with any stated plans for SpaceX's BFR/BFS architecture and might even be good missions in their own right.

The Habitation/Mission Module for the 'Inspiration' and Phobos mission could be a stretched, 4-segment version of Cygnus that has been proposed by Orbital Science Corp. Cover it with kevlar and mylar for insulation and meteroid protection. An efficient life support and recycling system could be in the Cygnus; trialing efficiency and miniaturization of such systems. For The Phobos mission the spacecraft 'stack' could be an enhanced Dragon 2 for Command, Control and Earth Return, the Cygnus and another Module similar to an ISS Node, which would act as the Airlock and Equipment Module. I would see the need for Propulsion Modules - either one or two, depending on propellant load - that would have hypergolic propellants and engines - either of a cluster of Dracos or a single Super Draco with a large expansion nozzle.

The flight plan would be a long coast either to or fro from Mars with a Venus swing by being necessary. One of the legs would be shorter. This would be a classical Opposition class mission where the stay at Phobos could be as little as three weeks or as much as 40 days depending on the launch window and the delta-v requirements. Much more propellants than an economic, long stay Conjunction class mission, but an overall much shorter mission duration, paid for with a lot of fuel. But an extra Falcon Heavy launch in the architecture could provide those propellants. I'm remembering Robert Zubrin's 2011 idea for a mission design similar to 'Red Dragon' but with only two people aboard. The basic ideas were sound, but there was a bit of 'hand waving' done at the time. I've been trying to close the gaps and loopholes in the ideas, and have adopted a roughly similar concept to Zubrin's for my story.
« Last Edit: 11/30/2018 02:04 pm by MATTBLAK »
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Offline Lar

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Great.

Problem is, no one (including and especially yourself) has reported any of the uncivil posts, as you should do (otherwise you have no reason to complain). And I only ended up here because people were complaining about your posts. So there you go. :)

Well all I'm asking is that this forum maintains the one basic rule of all forums - relevance.
I set this thread up making it very clear it was not about discussion of BFS.
I also politely suggested on several occasions that I wasn't interested in BFS related discussion but was happy to take it elsehwere.

If people don't think the actual topic is worth talking about they can choose not to comment.
If people continue to post off topic then I'll make a point of simply referring it to you.

Arguing with the owner is usually not going to work out well for you, trust me.

My judgement is that you misunderstand the basic idea behind BFS/BFR, have decided that you know better than SpaceX how the economics work, and have a pet project that you want to push for which makes no economic sense whatever.

You've been refuted 9 ways from Sunday but you aren't listening. You're grasping at the claim that people are off topic because they don't want to debate your exact scenario.. it already got rebutted.

24 hours. If that.
« Last Edit: 11/30/2018 03:56 pm by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline Russel

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I think part of the trouble is that Starship / Superheavy are very logical choices for a Mars mission even if they do need to be modified in the near term as I mentioned up post), so it's hard to exclude them from a discussion concerning repurposing SpaceX hardware for Mars.

Unless you meant repurposing SpaceX hardware that has already flown in which case all SS/SH and  raptor discussion is off topic and it comes down to designing a Mars mission using F9, FH, Dragon and perhaps a few mods. So is discussion of modification to SS/SH for Mars on topic for this post? Also what constitutes near term? How many years?

The topic is very clear. Its about SpaceX hardware and technology already built and likely to be tested in the near future. The near future meaning roughly the next 5-10 years. Evolution of present SpaceX vehicles is on topic. BFS is not on topic. Technologies that may be developed in pursuit of BFS are on topic.

"Near term" means a mission planned in the 20s and executed in the 30s.

Offline Russel

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If we are not talking about BFS then I was strongly assuming we were talking about 'Red Dragon' and Falcon Heavies at the very least? I've even seen some papers and videos around where it is postulated that Dragon 2's and Falcon Heavies; coupled with add-on Habitation and Propulsion Modules (likely storable) could accomplish either 'Inspiration Mars' style missions with 2x Astronauts or a mission to Phobos with a crew of three, for a short stay with some basic EVA's in Stickney Crater. These two classes of missions would not interfere with any stated plans for SpaceX's BFR/BFS architecture and might even be good missions in their own right.

The Habitation/Mission Module for the 'Inspiration' and Phobos mission could be a stretched, 4-segment version of Cygnus that has been proposed by Orbital Science Corp. Cover it with kevlar and mylar for insulation and meteroid protection. An efficient life support and recycling system could be in the Cygnus; trialing efficiency and miniaturization of such systems. For The Phobos mission the spacecraft 'stack' could be an enhanced Dragon 2 for Command, Control and Earth Return, the Cygnus and another Module similar to an ISS Node, which would act as the Airlock and Equipment Module. I would see the need for Propulsion Modules - either one or two, depending on propellant load - that would have hypergolic propellants and engines - either of a cluster of Dracos or a single Super Draco with a large expansion nozzle.

The flight plan would be a long coast either to or fro from Mars with a Venus swing by being necessary. One of the legs would be shorter. This would be a classical Opposition class mission where the stay at Phobos could be as little as three weeks or as much as 40 days depending on the launch window and the delta-v requirements. Much more propellants than an economic, long stay Conjunction class mission, but an overall much shorter mission duration, paid for with a lot of fuel. But an extra Falcon Heavy launch in the architecture could provide those propellants. I'm remembering Robert Zubrin's 2011 idea for a mission design similar to 'Red Dragon' but with only two people aboard. The basic ideas were sound, but there was a bit of 'hand waving' done at the time. I've been trying to close the gaps and loopholes in the ideas, and have adopted a roughly similar concept to Zubrin's for my story.

I'd originally thought that the "Red Dragon" might make a good Mars lander/ascent vehicle and it would be worth hanging on to on the flight back as an Earth re-entry vehicle. Of course this would involve fuel being sent to Mars orbit.

There is a lot that can be made of a FH class vehicle if you use Earth orbit assembly (docking) and fuel transfer. So a habitat like you've pictured is a real possibility.

The nice thing about SpaceX technology is that with (relatively) cheap launches and in orbit fuel transfer its possible to contemplate a fast transit to Mars which to my mind is the best defense against radiation issues (apart from using fuel/other consumables and personal protection vests).

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The topic is very clear. Its about SpaceX hardware and technology already built and likely to be tested in ... roughly the next 5-10 years. (...)BFS is not on topic.
Which is it? Make up your mind.
« Last Edit: 11/30/2018 11:39 pm by rakaydos »

Offline MATTBLAK

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We've said before that it's not going to happen - and I was tempted to use it in my fiction - but if the Falcon Heavy had it's upper stage upgraded to a single Raptor engine and diameter increased to 5.2 meters to match the payload fairing, and running methane instead of kerosene; this version of that rocket would be an SLS Block 1 killer, performance and price wise, even in expendable. But Elon wont do it, because he's committed to the BFR and 'Starship'. Such an enhanced F.H. would have been an interesting rocket and could have done some pretty good 'Red Dragon' missions...

...I would hope this is deemed on-topic to the "Re-purposing SpaceX hardware for near term exploration of Mars". I'm assuming that this thread is in large part hypothetical?
« Last Edit: 12/02/2018 07:04 am by MATTBLAK »
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Offline zodiacchris

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If we‘re just talking Lalaland rockets and hardware not in development, like Red Dragon (no propulsive landing in development, no extended interplanetary lifespan) or FH with new Raptor upper stage (not gonna happen, with F9 family on the way out mid term) then this thread is to a large part hypocritical...

Offline MATTBLAK

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Yes. I'm not using FH/Raptor in my novella because the Falcon family being used in the story have had their 'careers' extended one last time anyway, so they would be used as-is, according to their final versions after the early 2020s. The idea for the one-off mission would be that most of the Falcons in the story were being used in expendable mode on one last flight and to maximize the payloads. One or two of the Falcons are landed on drone ships when there is any surplus capacity on their launches. A couple flown stages for museums, then! I also use Vulcan launchers in the story.
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Offline MATTBLAK

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Yes. If an FH Raptor upper stage was made refuelable, as ACES wants to be; it would give exceptional capability.
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Offline Cinder

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Maybe that separate thread getting everyone on the same page as to the premise of a non BFS BFR is unavoidable.  Why stifle the very people you want contributing here; it'll be just a small fraction of the discussion without them.

 It sounds like you already know what the issues are and can demonstrate the infeasibility of some of the solutions (SpaceX's)  - so show that work there as a premise to this thread here?  It'd be a shame to have only a locked thread, instead of a two-part discussion with all of the dissent actually hashed out and then a development of whatever consensuses result.
« Last Edit: 12/03/2018 01:48 pm by Cinder »
Warning - while you were reading 86 new replies have been posted. You may wish to review your post.

Offline Slarty1080

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Maybe that separate thread getting everyone on the same page as to the premise of a non BFS BFR is unavoidable.  Why stifle the very people you want contributing here; it'll be just a small fraction of the discussion without them.

 It sounds like you already know what the issues are and can demonstrate the infeasibility of some of the solutions (SpaceX's)  - so show that work there as a premise to this thread here?  It'd be a shame to have only a locked thread, instead of a two-part discussion with all of the dissent actually hashed out and then a development of whatever consensuses result.
Yes that's a good idea. This thread is "Re-purposing SpaceX hardware for near term exploration of Mars", I think excluding Starship/Superheavy on the near term grounds. I will start a separate thread including Starship/Superheavy (medium terms perhaps). Both threads should be complementary and there are a number of issues with the Starship to Mars scenario that could be explored.
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

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The big thing here is that Starlink doesnt actually need a chomper, just a deployment mechanisim that pushes them out the side door.

That massively improves the commonality with a mars lander design.

Offline Russel

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Would you mind explaining what a "chomper" is?

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Would you mind explaining what a "chomper" is?
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Offline Russel

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The "chomper" is the whole ship (pictured) or?

Offline hopalong

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The "chomper" is the whole ship (pictured) or?

Yes the whole ship.
The satellite carrying version of the BFS.
Carries the satellite(s) to their final or transfer orbit, releases them and then returns to the launch site.

Offline BeamRider

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The essence of the Chomper is the wide-open “mouth” capable of deploying very large satellites. The point being made is that Spacex’s low-orbit net sats will be small enough to deploy out of the smaller hatch in the side of the ship, obviating the need for the Chomper version (for Spacex’s purposes), which is not very design-compatible with the crewed Spaceship version.

I suspect a Chomper is inevitable though. Somebody with deep pockets will be willing to pay a premium to launch really (dimensionally) large payloads. I think their initials would be USAF. The Terrestrial Planet Finder (-type) telescope community would also probably like to have the elbow room for big mirrors that did not have to fold up to quite so tiny a package, presumably allowing them to attain more performance for the same engineering dollar.

Offline Russel

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What I see from this is that any mirror large than 8m is going to be flown as a constellation.

http://spie.org/newsroom/0250-nasa-defines-mirror-technology-needs-for-future-space-telescopes?SSO=1

Offline speedevil

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What I see from this is that any mirror large than 8m is going to be flown as a constellation.

http://spie.org/newsroom/0250-nasa-defines-mirror-technology-needs-for-future-space-telescopes?SSO=1

I'm not sure where you're getting that from.
It's a report from 2006, and constellations are only mentioned for x-ray telescopes.
It's from a time when there was no realistic prospect of large launchers.
And this isn't really very on topic at all whatsoever for this thread.

Offline Russel

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The point made still applies today. Go beyond 8m and it becomes almost impossible to build a suitable mirror, regardless of the size of your fairing. A terrestrial planet finder is likely to end up as a constellation of mirrors.

It doesn't really matter actually if its a TPF or just any kind of optical instrument. its going to come in smaller pieces. So the argument that you need huge fairings for that kind of mission doesn't hold water.

Why is it relevant to topic? Because I don't see the demand for the flip top version of chomper. In fact I don't see anything that large as particularly relevant to a practical near term mission to Mars. You can easily get to Mars based purely on Falcon Heavy if your design around its limitations.

Offline Tulse

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I didn't think the chomper was intended for Mars, but instead for deploying large payloads in earth orbit (and possibly for lunar missions).

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I didn't think the chomper was intended for Mars, but instead for deploying large payloads in earth orbit (and possibly for lunar missions).
indeed- one of the complaints about the chomper design is that the hatch is poorly suited for dropping off cargos in gravity.

Offline KelvinZero

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Hey this thread got into trouble because it became to much about why not bfs.  IMO you should just have a clear hypothesis such as "stick to F9 and FH first stages for launch" and keep it purely technical.. just like with spin gravity threads where we don't actually know what gravity we need for health.

Anyway, to fix this someone created an identically named thread, but now there are BFS comparisons again and two identically named threads.

I think you guys should agree to lock one thread. I don't know which one because I have not been following closely.

Only think I can think to say on the subject is you probably end up with either
* Something like Zubrin's FH plan
* Or a mini BFS launched on a FH.

..and also, though it seems really tough to get to mars I just wanted to note the awesome moon missions you could do with just F9 and in orbit refueling. You get a moon lander pretty much the size of an F9 upper stage with cargo docked around the base. You could land whole moon bases in a single flight.
« Last Edit: 12/12/2018 11:48 pm by KelvinZero »

Offline Slarty1080

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Hey this thread got into trouble because it became to much about why not bfs.  IMO you should just have a clear hypothesis such as "stick to F9 and FH first stages for launch" and keep it purely technical.. just like with spin gravity threads where we don't actually know what gravity we need for health.

Anyway, to fix this someone created an identically named thread, but now there are BFS comparisons again and two identically named threads.

I think you guys should agree to lock one thread. I don't know which one because I have not been following closely.

Only think I can think to say on the subject is you probably end up with either
* Something like Zubrin's FH plan
* Or a mini BFS launched on a FH.

..and also, though it seems really tough to get to mars I just wanted to note the awesome moon missions you could do with just F9 and in orbit refueling. You get a moon lander pretty much the size of an F9 upper stage with cargo docked around the base. You could land whole moon bases in a single flight.
As you say you have not been following closely. In fact there are not two identicaly named threads.
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Offline KelvinZero

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I stand corrected.
Re-purposing SpaceX hardware for mid term exploration of Mars
Re-purposing SpaceX hardware for near term exploration of Mars

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The problem is that the thread OP does not agree with the rest of the forum as to what "near term SpaceX hardware" means. Red Dragon, canceled years back, is "near term", but the ship that will begin testing in 2019 "will never happen" (though we've gotten past that statement, at least)

The fact is, there is only one manned mars lander that's left the powerpoint stage. We arnt going to mars until we can get back off of it, something Red Dragon isnt capable of. The ONLY near term mars exploration option is BFS/Starship, because it's the only way home.

Offline mikelepage

I'm with Speedevil, I reject the entire premise of this post and think it's not that interesting to speculate about counterfactuals.

We have seen lots of evidence of 9 meter tooling. Scaling down would completely waste that tooling.

The problem is that the thread OP does not agree with the rest of the forum as to what "near term SpaceX hardware" means. Red Dragon, canceled years back, is "near term", but the ship that will begin testing in 2019 "will never happen" (though we've gotten past that statement, at least)

The fact is, there is only one manned mars lander that's left the powerpoint stage. We arnt going to mars until we can get back off of it, something Red Dragon isnt capable of. The ONLY near term mars exploration option is BFS/Starship, because it's the only way home.

Can I suggest to the moderators that both of the "re-purposing SpaceX hardware" threads actually belong in the SpaceX section of the forums, where there are numerous similar threads?  I enjoy talking about SpaceX as much as the next guy, but that's why I go to the SpaceX section  ::)





Offline zodiacchris

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I would prefer to not have this thread in the SpaceX section, it would really not add anything given it’s messed up premise...🙄
« Last Edit: 12/13/2018 07:01 am by zodiacchris »

Offline Lar

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I stand corrected.
Re-purposing SpaceX hardware for mid term exploration of Mars
Re-purposing SpaceX hardware for near term exploration of Mars
Those titles are so wildly different that I don't really see how any one could be confused.
Those titles are so wildly similar that I don't really see how any one could NOT be confused.

One of those statements is correct.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline Lar

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Can I suggest to the moderators that both of the "re-purposing SpaceX hardware" threads actually belong in the SpaceX section of the forums, where there are numerous similar threads?  I enjoy talking about SpaceX as much as the next guy, but that's why I go to the SpaceX section  ::)
You certainly can suggest it. Use the report to mod function to do so rather than starting (or continuing) metadiscussion.
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Offline Chris Bergin

Report to mods suggesting different options. Temp poll added so we can go with the majority ;)

Offline Lar

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Poll is closed. 14 votes is not a lot,  but a pretty wide margin to move it to SpaceX section. Moving it.

The discussion seems to have died down though. Could it be that the relevance of this has been overcome by events, with a boilerplate hopper already under construction in Boca Chica?
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>
You've missed my point entirely..

BFS only works if you've got tens of thousands of willing customers.

SH/SS may well pay for itself simply by enabling the faster mass deployment (of v2+) and replacenent/upgrading (20%/yr) of StarLink.

Some published projections show StarLink having a revenue stream of $20-$30 billion a year.

Additional revenues would be sauce for the goose.
« Last Edit: 12/23/2018 02:17 am by docmordrid »
DM

Offline Lar

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>
You've missed my point entirely..

BFS only works if you've got tens of thousands of willing customers.

SH/SS may well pay for itself simply by enabling the faster mass deployment (of v2+) and replacenent/upgrading (20%/yr) of StarLink.

Some published projections show StarLink having a revenue stream of $20-$30 billion a year.

Additional revenues would be sauce for the goose.
That's just one customer. Imagine if there were tens of thousands of willing customers each with that demand level.

If BFS hits its cost numbers, it changes everything. Those numbers are not much more than FedEx prices per KG to the other side of the US.

There are two kinds of people, those that understand this and don't bother with the "it needs lots of launches to work" because that's kind of a given, and those that don't and tediously point it out over and over as if it was an argument worth mentioning.

If you build it, they will come.
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Offline colbourne

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The fact is, there is only one manned mars lander that's left the powerpoint stage. We arnt going to mars until we can get back off of it, something Red Dragon isnt capable of. The ONLY near term mars exploration option is BFS/Starship, because it's the only way home.
Is this really the only option. I expect there would be many people willing to carry out a one way trip to Mars (at least with no option of return in the first 4 years). I would not expect a NASA mission to carry out a one way mission, but is there anything stopping volunteers from doing this. It makes more sense as the risk of the return trip is cut out, return trip fuel does not need to be made , the extra mass can be used to make surviving on Mars much more comfortable and safe with hundreds of extra tonnes of supplies.
Having a crew on Mars would make setting up the base much easier as robots are likely to have malfunctions caused by very minor problems easily fixed by an on-site engineer.

Offline Lar

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With a one way you've committed to resupply for .. 50 years or more... It's like getting a pet, you don't just stop feeding it when you're bored.
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Offline colbourne

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As we will probably have to stay on Mars for at least two years anyway for the first mission, I think that just staying alive should be the top priority at first.
Provisions for a crew of four to last four years would be quite light, assuming water is available. If the budget is limited, I am sure many astronauts would prefer more provisions, equipment and living space than the extra weight and work of generating fuel.
I dont mean to force the crew to stay on Mars for 50 years, but removing the short term plan of return in two years will allow more capacity to increase the safety of the base, which I feel should always be the top priority.
Also I feel if the craft has to be refueled for return to Earth, the chance of people ever landing on Mars is probably much reduced. The probability of a person staying alive is probably much higher staying on Mars than attempting to return for the same budget.

Offline Lar

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As we will probably have to stay on Mars for at least two years anyway for the first mission, I think that just staying alive should be the top priority at first.
Provisions for a crew of four to last four years would be quite light, assuming water is available. If the budget is limited, I am sure many astronauts would prefer more provisions, equipment and living space than the extra weight and work of generating fuel.
I dont mean to force the crew to stay on Mars for 50 years, but removing the short term plan of return in two years will allow more capacity to increase the safety of the base, which I feel should always be the top priority.
Also I feel if the craft has to be refueled for return to Earth, the chance of people ever landing on Mars is probably much reduced. The probability of a person staying alive is probably much higher staying on Mars than attempting to return for the same budget.

Not sure I follow you.

Once ISRU is working, instead of one expendable(and expended) ship landing with supplies per synod, there will be an ever increasing swarm of traffic on both directions. More stuff sent means better survival chances (first aid to clinic to full blown hospital, for example) even if one stays.

I don't think you get the big picture, not completely.
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Offline Slarty1080

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As we will probably have to stay on Mars for at least two years anyway for the first mission, I think that just staying alive should be the top priority at first.
Provisions for a crew of four to last four years would be quite light, assuming water is available. If the budget is limited, I am sure many astronauts would prefer more provisions, equipment and living space than the extra weight and work of generating fuel.
I dont mean to force the crew to stay on Mars for 50 years, but removing the short term plan of return in two years will allow more capacity to increase the safety of the base, which I feel should always be the top priority.
Also I feel if the craft has to be refueled for return to Earth, the chance of people ever landing on Mars is probably much reduced. The probability of a person staying alive is probably much higher staying on Mars than attempting to return for the same budget.

Not sure I follow you.

Once ISRU is working, instead of one expendable(and expended) ship landing with supplies per synod, there will be an ever increasing swarm of traffic on both directions. More stuff sent means better survival chances (first aid to clinic to full blown hospital, for example) even if one stays.

I don't think you get the big picture, not completely.
I think the diference between you is is baked into the difference between first mission and subsequent missions as well as "once ISRU is working"
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline Lar

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On the notional time line, first unmanned landings in 22, (2 ships) and manned landings in 24 (4 ships) ... ISRU will be *known to work* sometime in mid/late 22, well before the launch in 24. It will be *working* shortly after the landing in 24.

Adjust the dates as necessary for slips but... second landing and a few months == working. First mission.
« Last Edit: 01/02/2019 05:08 pm by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline DecoLV

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It occurs to me that some of this, e.g. mining, could be done with Red Dragon. A small drill setup could fit inside a cargo Dragon, with robotics to open the side hatch and extend arms out the door, couldn't it? Maybe if it hadn't been cancelled in 2018, a Red Dragon could be probing for methane deposits right now!

Offline Yaotzin

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It occurs to me that some of this, e.g. mining, could be done with Red Dragon. A small drill setup could fit inside a cargo Dragon, with robotics to open the side hatch and extend arms out the door, couldn't it? Maybe if it hadn't been cancelled in 2018, a Red Dragon could be probing for methane deposits right now!
Would methane really help?

Offline Lar

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It occurs to me that some of this, e.g. mining, could be done with Red Dragon. A small drill setup could fit inside a cargo Dragon, with robotics to open the side hatch and extend arms out the door, couldn't it? Maybe if it hadn't been cancelled in 2018, a Red Dragon could be probing for methane deposits right now!
Would methane really help?
I don't think so. There would still remain oxygen generation, which would probably be from CO2. So you have avoided some things but not all (you still have to gather CO2 in either case)
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

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