50m starship + 70m booster is essentially a thin and 130m tall wonder of the world.
Take a matchstick with essentially the same length to width ratio and try to keep it standing upright. Pretty hard even without the slightest wind. right?
So why do we actually still launch and land vehicles with thin profile in position that is generally unstable?
More flights mean faster return of investment and bigger chance of becoming multiplanetary civilization before statistically inevitable happens. But here is current 14 pretty strict (no wind over 30mph) weather launch criteria for falcon 9.
Being limited to static launch tower means being limited to weather conditions there too.
It’s not even that hard. We simply need to be more wide than tall. Due to the wonders of engine vectoring we can now be 10m tall (instead of the current 130m) during landing or launch and transition to supersonic upright config anytime.
Weather is definitely the main deciding factor. Making most of the days pretty much no go. And with Climate change, we clearly opened pandora’s box of brutal weather unpredictability and force.
So with tall sticks, we will be sitting ducks a lot of the time. Starships independent from static launch sites and their local limits able to move fast to any place over the sea on earth would allow fast parallel launches from anywhere.
Time and Money Lost Waiting for Good Weather or Bureaucracy is What We Can’t Afford if We Want to Become Multiplanetary.
So. What if we take the current spaceship 50m + booster 70m and slice it instead to 2-3 shorter tubes, put them next to each other with 2 rotatable engine groups on sides and 2 groups on the bottom?
By merging perhaps a significant amount of weight can be now removed. No need for ship booster connection ring and hydraulics 10t?. No need for avionics grid fins and heavy batteries from what was 200-160t booster shaving. 20-40t and another 20-40t? can be shaved by removing what was flaps and heavy batteries from what was the ship.
Hopefully, leaving 50-90t? old budget for side reinforcement beams on a beer can hull between two front rotating 8 motor cluster mounts and two bottom ones with vacuum engines from the ship. Also in case of launch problem, whole 4 clusters of 8 motors are perhaps more easily swapped faster or accessed than 29-32 engine dense plumbing maze. Refueling connects at 1m ground is also a lot less risky than at 70m (space shuttle chunk of ice incident). Front engines could rotate optionally to move to the bottom to reduce thermal stress to the hull.
Maybe SpaceX should try to make their own cheap carbon fiber to expand their material options for some parts if the only price is holding them back from composites.
Considering how efficiently they made iterating steel who knows where carbon composite iteration in parallel would lead them too. Those two are not mutually exclusive. Steel is heavy and not every part makes sense to be made from steel radiation or weight-wise. The simplest way to make carbon nanomaterial even at home is to drop graphite dust on soapy water. Recently one Chinese company found a way to make supercheap carbon nanomaterial batteries.
You can launch 3 ships and chain refuel from 2 at 15km ;D Joking. Or not?
If we are still too heavy to reach orbit we can go back to some parts as composites instead of steel or have a second tube smaller in diameter to form an airfoil shape to use the surface for added lift. That would also help with fuel efficiency until going fully vertical or for two starship tubes in the middle and two returning side boosters config starting and landing in VTOL 10m height config. Two tube starships just to be stable on the moon and Mars dust storms.
At the launch of large loads, we are fighting mostly gravity, not air. Sidewind stability, proper landing legs, wide-area spread failure redundancy is much more important during launch/landing than thin shape for air resistance.
Then in higher altitudes past strong winds we can simply transition to the same supersonic upright flight position as before having engines transition inline with the same engine power. So let’s just slightly reshuffle engines and mfg. pipelines that we already have.
Since the engine can no longer randomly point in random directions in case of sudden computer latency or wind gust, one can argue the biggest points of failure are being removed or reduced.
Vectoring can now be done with simple valves by thrust just like in quadcopters most of the time even manually if a computer fails. Ie. a higher chance to save a vehicle in theory.
The ocean is an incredibly big area and in the quad mode, you are now stable enough to launch from simple and cheap 4 empty used old starship bodies acting as floats below deck you use to catch falcons. It is a great strategic advantage that SpaceX can now manufacture big steel tubes cheap and fast. So perhaps no 100 expensive oil rigs needed to hold 130m tall rockets either. Just 1 ship to pull a chain of starships on floating decks out on the sea.
The whole ship will on landing be essentially one big empty barrel full of air and will float pretty well too.
But maybe the whole idea is stupid too heavy to reach orbit without 2 stages. I don’t know. But that’s me, never afraid to have crazy stupid ideas. I am curious to hear your opinion guys. ;D
Please let me know through your feedback. I am really curious. I asked this question to a few people from SpaceX I found on Linkedin (around 20 :D ?). Curious what their answer will be but I haven’t received a reply so far.
But If there are any open-minded people anywhere willing to take risks and think outside the box to push boundaries of what is possible then it is definitely at SpaceX.
Previously published at https://www.linkedin.com/pulse/what-starship-quadcopter-ladislav-nevery/