Wiki Super Heavy/Starship - General Development Discussion

[FoverM]

Are you not planning on going to Mars? Limiting yourself to a return capsule only?

Yes, I'm limiting myself to capsule return. It's relatively simple, proven, and safe. Its payload is just a few hundred pounds.

FH has max LEO payload of 70 tons, less than half of Starship. So twice the flights. Plus needing to reintegrate after each launch. It also runs on more expensive fuel and pressurization gas.

Not FH, Starship Heavy (the first stage/booster for Starship). SpaceX could make it smaller because it won't be lifting a bunch of mass that'll return to Earth. Starship is well over 100 mT dry weight.

I want us to focus on in-space hardware. We've been stuck on going from Earth to LEO and back for too long. SpaceX has solved that problem with reusable boosters. Now we should focus on actually doing something up there!

 

[PhantomX]

Yes, I'm limiting myself to capsule return. It's relatively simple, proven, and safe. Its payload is just a few hundred pounds.


Not FH, Starship Heavy (the first stage/booster for Starship). SpaceX could make it smaller because it won't be lifting a bunch of mass that'll return to Earth. Starship is well over 100 mT dry weight.

I want us to focus on in-space hardware. We've been stuck on going from Earth to LEO and back for too long. SpaceX has solved that problem with reusable boosters. Now we should focus on actually doing something up there!

Yup. The further away from LEO, the more sense a capsule makes. Why bring extra mass when it's essentially dead weight except for the little cross range capability at landing? And you can't really use that wing on Mars anyway, so why bother?

 

[mongo]

Yup. The further away from LEO, the more sense a capsule makes. Why bring extra mass when it's essentially dead weight except for the little cross range capability at landing? And you can't really use that wing on Mars anyway, so why bother?

Those are not wings, those are aero brakes. They are needed on Mars to slow down and control the ship on reentry. Watch the slightly dated old landing simulation:
https://www.spacex.com/sites/spacex/files/mars-entry.mp4

Alternative is a one way, few hundred pound, parachute/ retropropulsive capsule.

 

[mongo]

Not FH, Starship Heavy (the first stage/booster for Starship). SpaceX could make it smaller because it won't be lifting a bunch of mass that'll return to Earth. Starship is well over 100 mT dry weight.

Whoops, my bad in the misread.
They will be using a Tanker version of Starship for refueling.

Yes, I'm limiting myself to capsule return. It's relatively simple, proven, and safe. Its payload is just a few hundred pounds.

I want us to focus on in-space hardware. We've been stuck on going from Earth to LEO and back for too long. SpaceX has solved that problem with reusable boosters. Now we should focus on actually doing something up there!

Up there as in LEO? Why is doing something in LEO better than doing something on the moon or Mars?
With only a few hundred pounds of re-entry mass, what is the point beyond the current ISS research?

If you want a > 150 ton single piece object in LEO, they'll also make a bulk payload version (the satellite launcher with actuated fairing). And expendable is still an (expensive) option.

Is the current setup a limiting factor for any planned launch?

Is a 2 ton return mass a limiting factor for any planned mission?

 

[ecarfan]

Launch tower is higher because of the exhaust from launch.
Lifting crane on tower as seen in earlier videos - yes

Okay thanks. I’m not aware of any other rocket launch site that takes that approach, and it caught my eye because it seemed so different than what we had seen in past Elon presentations on Starship.

Always vertical. No horizontal at all.

So SpaceX is going to be constructing some very tall VABs! And then they need some huge ground transport vehicles to get the Super Heavy/Starship from their VAB to the launch site.

How about the spiral building design in the future - very cool. Definite improvement too.

Are you referring to the briefly shown image of the Martian colony? I need to replay the webcast and do some screen captures so I can study that image.

 

[mongo]

Okay thanks. I’m not aware of any other rocket launch site that takes that approach, and it caught my eye because it seemed so different than what we had seen in past Elon presentations on Starship.

This makes a lot of sense. The system stays vertical and there is no mobile crane that can stack a Starship on a Superheavy (Liebherr LTM 11200-9.1 only has 100m boom). So land or transport the next module to the loading zone and lift it into place. Having only the launch mount elevated allows most of the surrounding area to be landing site versus a huge elevated launch pad.

Tim Dodd also hypothesized using oil rig type platforms as the launch sites. So basically an evelated platform.

So SpaceX is going to be constructing some very tall VABs! And then they need some huge ground transport vehicles to get the Super Heavy/Starship from their VAB to the launch site.

VAB only needs to be the height of SH since they can stack at the launch mount. Too bad water table is so high, a shaft/ elevator into the ground would be great for stack and weld operations.

Or they build horizontally. Starship for sure can handle side loading.

High capacity moving equipment is common in the construction business. SpaceX will be moving the Cocoa Starship via such things.

 

[ecarfan]

VAB only needs to be the height of SH since they can stack at the launch mount... Or they build horizontally. Starship for sure can handle side loading.

Yes, we really don’t know for sure yet how SpaceX is going to handle that. I do wonder what the cost of such a launch pad/tower/crane structure is going to be. It looks pricey.

 

[ecarfan]

Logically I know this is true, but it still blows my mind!

On the right is the first stage of a Falcon 1. 11 years ago that is what SpaceX built and launched. Now SpaceX is about to launch the first Starship test flight. That rate of progress is almost incomprehensible to me.

Think about what SpaceX will be doing 11 years from now. I predict there will be crewed Starship launches every 26 months (window of opportunity for Hohmann Transfer Orbits to Mars) as well as uncrewed Starship cargo missions.

I also predict that in 11 years NASA still will not have made a single crewed mission to Mars. NASA may get humans back to the Moon. But suspect it will be done using SpaceX Starships.

 

[EVCollies]

Can that be seen? Or will it be private?

On the livestream...

The Q and A was interesting, they are already refining the construction process hoping to use a single sheet for an entire Starship ring, saving weight and money.

Also his description of the design process, less is better, if you are struggling too hard to design it is probably the wrong design, any meeting that removes part of the design is success...

 

[Cosmacelf]

The Q and A was interesting, they are already refining the construction process hoping to use a single sheet for an entire Starship ring, saving weight and money.

Also his description of the design process, less is better, if you are struggling too hard to design it is probably the wrong design, any meeting that removes part of the design is success...

Yes, most companies do not focus on manufacturing speed optimization. If fact, you are taught, actually taught, “quality, cost, speed, pick two”, meaning that rushing things will result in extra cost or reduced quality.

Obviously Elon thinks that is bullshit, and he is apparently proving it.

 

[dhanson865]

Yes, most companies do not focus on manufacturing speed optimization. If fact, you are taught, actually taught, “quality, cost, speed, pick two”, meaning that rushing things will result in extra cost or reduced quality.

Obviously Elon thinks that is bullshit, and he is apparently proving it.

I think it's more that he is pivoting between pairs and is smart enough to do so when needed.

If phase 1 can be speed + quality and he can afford it he does.

If phase 2 needs to be quality + cost and he can't avoid the time delay he does that instead.

But as soon as he sees the chance to pivot he'll go back to speed + quality.

And he is pouring a lot of money into this so just because the cost is lower than prior designs doesn't mean cost isn't part of the "here's 3, pick 2" conundrum.

 

[mongo]

Yes, we really don’t know for sure yet how SpaceX is going to handle that. I do wonder what the cost of such a launch pad/tower/crane structure is going to be. It looks pricey.

Is it pricey? Steel core with stainless for protection on the tower where needed. Concrete pad for the mount. Seems fairly common. 50? story building with a small parking multistory deck.

 

[FoverM]

Up there as in LEO? Why is doing something in LEO better than doing something on the moon or Mars?

Up there as in the Moon, Mars, etc. LEO isn't the final destination, it's the staging area for missions to other places. So, we optimize the Earth-to-LEO part first by placing a depot or depots in LEO. You use a small man-rated rocket like Falcon 9 to send crews from Earth to the depot, a medium or large dumb (not man-rated) rocket for mission hardware to the depot, and finally a big, dumb rocket for propellant to depot. The last two items could use the same large dumb rocket if that works best. Think of these things as "transportation services" provided to the mission rather than an integral part of the mission. NASA says, "I need 50 mT of hardware and 100 mT of methalox at the LEO depot".

Musk, last night, used an analogy with flying when promoting the reusability of Starship: "you don't fly on a plane somewhere and throw away the jet when you get there, you use it to fly back". That's true, of course, but only because flying somewhere and flying back are identical (it doesn't matter which way you fly). Going to space and back is asymmetrical, with totally different physics involved on each leg. It would be like requiring your plane to fly somewhere then act as a submarine on the return. How complicated would your "plane" have to be to handle those requirements?

Anyway, none of what I'm saying is new. You can read endless arguments for the various space strategies in the forum at nasaspaceflight.com ( NASASpaceFlight.com Forum - Index ). I like the segmented approach because it lets engineers optimize each segment ... and it enables routine Earth-to-LEO trips in between missions, which could open up LEO tourism.

 

[ecarfan]

Going to space and back is asymmetrical, with totally different physics involved on each leg.

I think the same physical principles apply in both directions. The gravity wells of course are different, as are the atmospheres, or lack thereof.

 

[mongo]

Up there as in the Moon, Mars, etc. LEO isn't the final destination, it's the staging area for missions to other places. So, we optimize the Earth-to-LEO part first by placing a depot or depots in LEO. You use a small man-rated rocket like Falcon 9 to send crews from Earth to the depot, a medium or large dumb (not man-rated) rocket for mission hardware to the depot, and finally a big, dumb rocket for propellant to depot. The last two items could use the same large dumb rocket if that works best. Think of these things as "transportation services" provided to the mission rather than an integral part of the mission. NASA says, "I need 50 mT of hardware and 100 mT of methalox at the LEO depot".

Musk, last night, used an analogy with flying when promoting the reusability of Starship: "you don't fly on a plane somewhere and throw away the jet when you get there, you use it to fly back". That's true, of course, but only because flying somewhere and flying back are identical (it doesn't matter which way you fly). Going to space and back is asymmetrical, with totally different physics involved on each leg. It would be like requiring your plane to fly somewhere then act as a submarine on the return. How complicated would your "plane" have to be to handle those requirements?

Anyway, none of what I'm saying is new. You can read endless arguments for the various space strategies in the forum at nasaspaceflight.com ( NASASpaceFlight.com Forum - Index ). I like the segmented approach because it lets engineers optimize each segment ... and it enables routine Earth-to-LEO trips in between missions, which could open up LEO tourism.

Ok, so you're a proponent of the Atremis approach?

No need to rehash I suppose, but I still don't get how a rocket that can do Earth to Earth, Earth to Moon, Moon to Earth, Earth to Mars, Mars to Earth, Mars/ Earth to outer planets/ moons (and back) with zero support infrastructure outher than minir variants of itself is a bad idea just because it has control surfaces.

Looking back on your orignal posts:

I hate to be a negative Nelly ... and I'm not a rocket scientist ... but I don't like the evolution of Starship. It's veering towards an Orbiter II, with the large canards, chines, winglets/flaplets, etc. The final design will probably merge all those into delta wings! It's the
classic trap of combining astronautics and aeronautics.

Which you've stated was incorrect since they are not wings.

I thought the Shuttle taught everyone that reusable second stages were a bad idea and that all that matters is usable mass in orbit.

Starship is planned to have the most usable mass to orbit of any rocket ever (150 tons). What's the problem? If you want to pay hundreds of million a lauch more, fly it expendable in a cargo varient.

SLS's final block 2 is planned for only 130-143 tons to LEO. How much do you criticize their design?

Earth to LEO trips without reusability are not fiscally viable for most of the population.

Mars has an atmosphere, we want to get pople from there back to Earth. Is that really a submarine vs the Earth to Mars airplane?
For Mars, does that mean building a Martian Gateway in Martian orbit with landers to get to/from the surface?
And why does each segment need such optimization anyway? (If you can even make them more capable than Starship).

 

[e-FTW]

Too bad water table is so high, a shaft/ elevator into the ground would be great for stack and weld operations.

That probably also plays into the elevated launch mount V flame-trench decision.

 

[e-FTW]

Posting some of the 1:1 interviews Elon did after the presentation and Q&A.

Source: Elon Musk, Man of Steel, reveals his stainless Starship — Ars Technica

After the event, as the hour approached 11pm local time, Musk offered some additional insight during an interview with Ars. Seated alongside the company's principal Mars development engineer, Paul Wooster, Musk expounded upon his timeline for going to the Moon and Mars.

"It depends on whether development remains exponential. If it remains exponential, it could be like two years," Musk said of landing on the Moon. A cargo trip to Mars could happen by 2022, due to the availability of launch windows, he added. "I mean these are just total guesses, as opposed to checking a train schedule."

SpaceX is funding the Starship project with its own money. Some of that comes from positive cash flow from satellite launches. The company has also raised nearly $1 billion from private investors in recent months, and it has also received an undisclosed payment from Japanese Billionaire Yusaku Maezawa as the first customer for a mission to lunar orbit and back.

"I think we're able to see a path to getting the ship to orbit, and maybe even doing a loop around the Moon," Musk said. "Maybe we need to raise some more money to go to the Moon or landing on Mars. But at least getting the Starship to an operational level in low Earth orbit, or around the Moon, I feel like we're in good shape for that."

A common question about Starship is how the company plans to keep people alive on board the vehicle when it is flying crew instead of cargo missions. SpaceX has some experience with life support after developing the Crew Dragon spacecraft for NASA.

"We definitely have learnt a lot, and we would do it differently," Musk said. "The Dragon life support system is not really all that renewable. It's basically mostly expendable."

For example, Dragon uses lithium hydroxide as a "scrubber" to remove carbon dioxide exhaled by humans, producing lithium carbonate and water as byproducts. This is perfectly adequate for four people for four days, and perhaps could even be used for short missions around, and to the surface of the Moon.

But using Starship to go to Mars would require six months for a journey there, and up to 2.5 years for a roundtrip mission. With as many as 100 people on board the vehicle, that would require a regenerative life support system that will, Musk acknowledged, "take a bit of work."

 

[e-FTW]

The CNN Business interview: Elon Musk: Starship could take people to orbit within a year - CNN Video

This it the one where he really responds to Jim Bridenstine:

Did he mean Commercial Crew or SLS?

Mic drop!

 

[e-FTW]

One interesting quote in this NYT article: SpaceX Unveils Silvery Vision to Mars: ‘It’s Basically an I.C.B.M. That Lands’

He said SpaceX was continuing to study using Starship as a speedy — likely expensive — way to travel around the world, New York to Tokyo in 30 minutes.

“It’s basically an I.C.B.M. that lands,” Mr. Musk said. “Nothing gets there faster than a I.C.B.M. It’s just minus the nuclear bomb and add landing.”

Quite the sales pitch! Would love to hear reactions from the major airlines.

 

[FoverM]

Ok, so you're a proponent of the Atremis approach?

Artemis? I don't even follow the government plans anymore because they'll change again (and never be completed). Might as well read SciFi novels in PowerPoint format.

No need to rehash I suppose, but I still don't get how a rocket that can do Earth to Earth, Earth to Moon, Moon to Earth, Earth to Mars, Mars to Earth, Mars/ Earth to outer planets/ moons (and back) with zero support infrastructure outher than minir variants of itself is a bad idea just because it has control surfaces.

Not control surfaces, it's returning the large mass to Earth ... which requires a larger booster, larger heat shields, large control surfaces, many failure points, etc, etc. You *really* think that a Mars-capable Starship will be a minor variant of a cargo or even Moon-capable Starship??? I guess we'll see.

Looking back on your orignal posts:
Which you've stated was incorrect since they are not wings.

That was a joke/exaggeration (note the '!').

SLS's final block 2 is planned for only 130-143 tons to LEO. How much do you criticize their design

Do I even need to criticize SLS??? It's a ridiculous waste of taxpayer money and violates several of the lessons learned from STS: no crew with payload (i.e. no manrating of heavy lift), no large solids, etc. SLS will fly once or twice then be quietly canned. There won't be a Block II. I'd say, "give that money to SpaceX", but then that risks SX getting fat and lazy rather than staying lean and mean. I think, overall, the best approach is for NASA to eventually buy services from commercial providers (e.g. "we need you to transport seven people to XYZ and back") and not design launchers.

Earth to LEO trips without reusability are not fiscally viable for most of the population.

It'll never be fiscally viable for most of the population.

Mars has an atmosphere, we want to get pople from there back to Earth. Is that really a submarine vs the Earth to Mars airplane?
For Mars, does that mean building a Martian Gateway in Martian orbit with landers to get to/from the surface?
And why does each segment need such optimization anyway? (If you can even make them more capable than Starship).

Yes, I do think we/they need landers specifically designed for their environment. Sending a large mass down and back up requires huge amounts of propellant ... which feeds back into needing a much larger launcher from Earth and numerous refueling stops in LEO, etc. Well, we're right back to the idea of a depot in LEO. And if we're going to blow that much propellant anyway, why not make a spacecraft that propulsively brakes back into LEO to dock with the depot (the crew can reenter in a simple capsule) and reuse it. It never lands anywhere, it simply goes from one orbit to another.