Elon Musk IAC Mars Speech - Sept. 27, 2016 - DISCUSSION THREAD

[Rocket Science]

So I guess we are in agreement then that there is only "one" failure mode abort "if" the S2 engines and gear are not damaged and that is "abort to orbit". Any CRS-7 or AMOS-6 type event, for sake of discussion are impossible or "iffy" at best... Inline staging is not fool proof and the Shuttle side mount was not the only risky type architecture which is why Orion, Dragon 2 and CST-100 all have a dedicated LES...

How many flights do you need to be confident enough not to have an abort strategy?
How do you get that flight count on a brand new engine and launch system?

I guess you have to retire the risk on each system then the vehicle as a whole and Elon makes the call on what is acceptable since he is running his own space agency here. Now if you ask in light of the recent failures color me a bit skeptical at this point... This vehicle has the potential explosive energy of a small nuclear device even more than a Saturn V...
(Written by a good friend here on NSF)
http://www.thespacereview.com/article/591/1

[savuporo]

- What magic will keep both propellant in tanks for several months
- Spark ignited, strung out turbopumped deep space propulsion ? What kind of redundancy and whats the testing regime for this ?

[Llian Rhydderch]

Do we have any hard data that the Tankers would definitely have/use legs?

If landing on a cradle is modus operandi for the Booster, then perhaps is also for the Tankers.  In which case, leave off the legs, and carry more propellant.

 

Wait - if the booster comes back and lands in the cradle, why won't the tanker too?

Because why make redundant systems for landing on a vehicle when the legs only works for Mars/Earth tanker/crew/cargo?

The tanker is already a variant.

It flies 5x more often.

Legs add weight.

If you can make the cradle work (which they clearly are planning to) it's less hassle to process the vehicle.  No need to lift, fold legs, place on launch pad, etc.

They are talking about several hours turn around...  Cradle is the right choice here.

[yg1968]

I haven't read all the comments in this thread. But I sort of wonder what is the best way to describe the spacecraft, it seems like a cross between a capsule and a lifting body. It has a black heatshield on one side.

Seriously, up-thread, someone suggested that it is basically a biconic lifting body but I'll leave that one to the experts.

Blue's commercial crew spacecraft was also described as biconic. Both companies use methane, both companies use a biconic spacecraft. It's interesting that they tend to make similar choices.

http://www.space.com/15406-blue-origin-private-spacecraft-infographic.html

[AncientU]

- What magic will keep both propellant in tanks for several months
- Spark ignited, strung out turbopumped deep space propulsion ? What kind of redundancy and whats the testing regime for this ?

Radiators, narrow aspect to the sun(engines toward the sun), cryo-coolers... some combination of these low grade technologies.

Testing in Cis-Lunar space -- the proving ground.

... 'magic' and 'strung out' are pure snark.

[pobermanns]

I was disappointed. Musk seems to subscribe to the idea that space colonization (of whatever sort) is basically a transportation problem and his presentation was virtually all about transportation. I think that kind of narrow focus is a huge mistake which will become more obvious as time goes on.

Maybe. I think transportation is his first priority. The overall planning of how a Mars colony could develop is critical, and he must have outlines of how it can come together, problems to be overcome etc, because private enterprise and the competitive aspect he wants needs a structure to build from.

But he is hoping for collaboration. And he may plan on handing that over to another company. Perhaps MarsX, but he may hope for NASA too.

So a reason to not say much about it?

EM's analogy to the Union-Pacific seems spot-on. He's trying to make it possible for other companies to risk their assets, and for individuals to commit part of their lives, for the opportunity to start a grand adventure.

It's been over 50 years since I learned about that railroad in school (so feel free to correct my version of history), but it and the later ones were heavily subsidized by the federal government - the railroad companies were outright given all of the land on either side of the right-of-way, out to 50 miles. Initially there was nothing between the endpoints. However, this was coincident with arrival of huge numbers of immigrants to the US, and lots of them took the chance to move into the wilderness and farm that same land. The crops produced had to be shipped out, which increased the justification for the railroad. Et cetera. More people, more economic activity, more innovation, gradually less rugged conditions. Took a long time, but now we have all of those excellent cities, roads, businesses, and farms.

But none of that would have happened if the railroad hadn't been built. So yeah, EM is pushing a transportation system. I would be surprised if his people haven't been working on solutions to all of these other problems, too, but making it practical to get there is positively Job #1.

[jpo234]

- What magic will keep both propellant in tanks for several months

Look at the schematics on slide 26: there are smaller tanks inside the main tanks.

[rsdavis9]

- What magic will keep both propellant in tanks for several months
- Spark ignited, strung out turbopumped deep space propulsion ? What kind of redundancy and whats the testing regime for this ?

Solar powered liquefaction pumps that take boil off and re-condense? Maybe just some sub cooling so there is no boil off. refrigerators are easy.

[robert_d]

Probably worth repeating... on The Space Show, 21st March 2014, Gwynne Shotwell was talking about a lot of launch sites in 2025.

“In that timeframe (10-11 years) we should have really great progress on our Mars vehicles.
What are the challenges there? Probably similar to what we’re working here.
Turning those R&D vehicles into production vehicles.
Finding enough launch sites where you can get a lot of people moving, or at least planning for the launch sites to get a lot of people moving and launching"
(45m30)

"You’ll end up seeing a lot of launch sites in order to meet the future demand that we anticipate”
(50m20)

Puerto Rico could use the economic boost this could bring if it became reality.

[AncientU]

I was disappointed. Musk seems to subscribe to the idea that space colonization (of whatever sort) is basically a transportation problem and his presentation was virtually all about transportation. I think that kind of narrow focus is a huge mistake which will become more obvious as time goes on.

Maybe. I think transportation is his first priority. The overall planning of how a Mars colony could develop is critical, and he must have outlines of how it can come together, problems to be overcome etc, because private enterprise and the competitive aspect he wants needs a structure to build from.

But he is hoping for collaboration. And he may plan on handing that over to another company. Perhaps MarsX, but he may hope for NASA too.

So a reason to not say much about it?

EM's analogy to the Union-Pacific seems spot-on. He's trying to make it possible for other companies to risk their assets, and for individuals to commit part of their lives, for the opportunity to start a grand adventure.

It's been over 50 years since I learned about that railroad in school (so feel free to correct my version of history), but it and the later ones were heavily subsidized by the federal government - the railroad companies were outright given all of the land on either side of the right-of-way, out to 50 miles. Initially there was nothing between the endpoints. However, this was coincident with arrival of huge numbers of immigrants to the US, and lots of them took the chance to move into the wilderness and farm that same land. The crops produced had to be shipped out, which increased the justification for the railroad. Et cetera. More people, more economic activity, more innovation, gradually less rugged conditions. Took a long time, but now we have all of those excellent cities, roads, businesses, and farms.

But none of that would have happened if the railroad hadn't been built. So yeah, EM is pushing a transportation system. I would be surprised if his people haven't been working on solutions to all of these other problems, too, but making it practical to get there is positively Job #1.

Getting out of the gravity well of Earth is like railroads where you cannot get out of the station.  Space therefore is a double barrier -- gravity well plus expanse of empty space between endpoints.  Challenge is exponentially more difficult than railroads, so has confounded our society for 50 years.

[Star One]

That is an entirely different beast than the base financial investment required to get the first people to Mars, which presumably would be quite a bit less than the $10b total. 

The actual amount Elon seems to expect SpaceX to spend over the next 8-10yrs  is something on the order of ~$1.2-$2.4b, based on his assertion that he would ramp up spending to ~$200-$300m/yr starting in a couple of years. 

That isn't going to happen if his current cash flow is interrupted yearly.  Musk said they'd do what they can, which in my mind implies that he was planning on saying more before events intervened.  Even assuming SX was running 10% margins and spending half of that on Raptor dev, another 9+ month shutdown is going to erase a lot more than 10%.  There are some lean years ahead imho.  FH test is put off until a redundant pad exists because you can't risk your only pad.  Some of those customers walk.  Musk said that schedule was for if everything went right.  It already hasn't.  I suspect a full assess is waiting on finding what went wrong.  I don't expect there'll be 9 figures of free cash flow in a couple of years, sadly.

Well as he mentioned when he sells Tesla that will generate quite a bit of cash to be invested in this.

[ThereIWas3]

I was wondering about the property values in Titusville and Cocoa Beach, with a lot of these things launching every day even without un-scheduled booms.  The window replacement people will get a lot of business, replacing glass with polycarbonate.   And a new trend toward using something other than sheetrock for walls.

Still, you can get used to a lot of things.   People live near Air Force bases.   Back in the SAC days those were very noisy places.  Japan has 3 earthquakes a day, but most are underwater and so small you barely feel them.

Those towns might actually see a big influx of people, due to all the jobs this project will create, especially when you include all the other manufacturers that will be on board.  I remember in the Red Mars books, the hydrazine-powered bulldozer they used for initial construction was made by Volvo...

[Llian Rhydderch]

I haven't read all the comments in this thread. But I sort of wonder what is the best way to describe the spacecraft, it seems like a cross between a capsule and a lifting body. It has a black heatshield on one side.

Yes, it seems to me to be a new class of spaceflight vehicle:  it is a sort of integrated second-stage and spacecraft rolled into one.  Not something we've seen much of (if any) before.

The on-orbit re-propellanting for the BEO missions allows the spacecraft itself to also fulfill the role that a second stage usually fulfills in the LV design.

[rsdavis9]

- What magic will keep both propellant in tanks for several months

Look at the schematics on slide 26: there are smaller tanks inside the main tanks.

Ok, So what are the tanks holding? I bet they are holding gaseous ch4 and o2. They need a rcs that works with no tank settling. They need gases for pressurization. Etc. The big tanks hold the liquid.

[AncientU]

Probably worth repeating... on The Space Show, 21st March 2014, Gwynne Shotwell was talking about a lot of launch sites in 2025.

“In that timeframe (10-11 years) we should have really great progress on our Mars vehicles.
What are the challenges there? Probably similar to what we’re working here.
Turning those R&D vehicles into production vehicles.
Finding enough launch sites where you can get a lot of people moving, or at least planning for the launch sites to get a lot of people moving and launching"
(45m30)

"You’ll end up seeing a lot of launch sites in order to meet the future demand that we anticipate”
(50m20)

Puerto Rico could use the economic boost this could bring if it became reality.

Lots of launch sites probably means more than heavily populated coastal areas can bear.

I suspect the answer for this mutiplicity will be either bottom-mounted offshore platforms or interior/remote/desert  launch sites.  If reliability is high enough to forego launch abort systems and the vehicle isn't leaving a debris trail along its flight path (as current tech continues to do), then the interior becomes an excellent option.

[Rocket Science]

I was disappointed. Musk seems to subscribe to the idea that space colonization (of whatever sort) is basically a transportation problem and his presentation was virtually all about transportation. I think that kind of narrow focus is a huge mistake which will become more obvious as time goes on.

Maybe. I think transportation is his first priority. The overall planning of how a Mars colony could develop is critical, and he must have outlines of how it can come together, problems to be overcome etc, because private enterprise and the competitive aspect he wants needs a structure to build from.

But he is hoping for collaboration. And he may plan on handing that over to another company. Perhaps MarsX, but he may hope for NASA too.

So a reason to not say much about it?

EM's analogy to the Union-Pacific seems spot-on. He's trying to make it possible for other companies to risk their assets, and for individuals to commit part of their lives, for the opportunity to start a grand adventure.

It's been over 50 years since I learned about that railroad in school (so feel free to correct my version of history), but it and the later ones were heavily subsidized by the federal government - the railroad companies were outright given all of the land on either side of the right-of-way, out to 50 miles. Initially there was nothing between the endpoints. However, this was coincident with arrival of huge numbers of immigrants to the US, and lots of them took the chance to move into the wilderness and farm that same land. The crops produced had to be shipped out, which increased the justification for the railroad. Et cetera. More people, more economic activity, more innovation, gradually less rugged conditions. Took a long time, but now we have all of those excellent cities, roads, businesses, and farms.

But none of that would have happened if the railroad hadn't been built. So yeah, EM is pushing a transportation system. I would be surprised if his people haven't been working on solutions to all of these other problems, too, but making it practical to get there is positively Job #1.

IIRC those railroad companies got subsidies and grants and the nation benefited by having a transcontinental RR to transport it's citizens and moving goods to markets. Where in the nation's benefit in dong this for Mars?

[ThereIWas3]

People who really did well during the Westward expansion in North America wre the shopkeepers and provisioners.  I can see similar industries starting up around this.   Travel/Hotel people will outfit the spacecraft interiors with modular units just like they do on cruise ships (though not made out of steel obviously).    They will take care of provisioning, entertainment, all that stuff.  Like Norwegian Cruise Lines, adapted for much smaller volumes and lighter weight.   Selling tickets, housing people nearby before the ship spacecraft departs...

[AncientU]

I haven't read all the comments in this thread. But I sort of wonder what is the best way to describe the spacecraft, it seems like a cross between a capsule and a lifting body. It has a black heatshield on one side.

Yes, it seems to me to be a new class of spaceflight vehicle:  it is a sort of integrated second-stage and spacecraft rolled into one.  Not something we've seen much of (if any) before.

The on-orbit re-propellanting for the BEO missions allows the spacecraft itself to also fulfill the role that a second stage usually fulfills in the LV design.

This is the first true Spaceship.  Apollo and all previous spacecraft were payloads.

[Archibald]

I can't help but thinking about Ray Bradbury Martian chronicles, with their rockets carrying all those Mars pilgrims away from (a doomed) Earth
Bradbury had 1999 as the first year of Mars colonization but AFAIK he moved it by 20 years in later editions of the novel.

[Dante80]

I was disappointed. Musk seems to subscribe to the idea that space colonization (of whatever sort) is basically a transportation problem and his presentation was virtually all about transportation. I think that kind of narrow focus is a huge mistake which will become more obvious as time goes on.

Maybe. I think transportation is his first priority. The overall planning of how a Mars colony could develop is critical, and he must have outlines of how it can come together, problems to be overcome etc, because private enterprise and the competitive aspect he wants needs a structure to build from.

But he is hoping for collaboration. And he may plan on handing that over to another company. Perhaps MarsX, but he may hope for NASA too.

So a reason to not say much about it?

EM's analogy to the Union-Pacific seems spot-on. He's trying to make it possible for other companies to risk their assets, and for individuals to commit part of their lives, for the opportunity to start a grand adventure.

It's been over 50 years since I learned about that railroad in school (so feel free to correct my version of history), but it and the later ones were heavily subsidized by the federal government - the railroad companies were outright given all of the land on either side of the right-of-way, out to 50 miles. Initially there was nothing between the endpoints. However, this was coincident with arrival of huge numbers of immigrants to the US, and lots of them took the chance to move into the wilderness and farm that same land. The crops produced had to be shipped out, which increased the justification for the railroad. Et cetera. More people, more economic activity, more innovation, gradually less rugged conditions. Took a long time, but now we have all of those excellent cities, roads, businesses, and farms.

But none of that would have happened if the railroad hadn't been built. So yeah, EM is pushing a transportation system. I would be surprised if his people haven't been working on solutions to all of these other problems, too, but making it practical to get there is positively Job #1.

IIRC those railroad companies got subsidies and grants and the nation benefited by having a transcontinental RR to transport it's citizens and moving goods to markets. Where in the nation's benefit in dong this for Mars?

You cannot think of a benefit from an American company developing a Mars Transportation System that can put people and cargo on another planet for peanuts?