Speculation about various mission profiles to the moon using what's already out there or being developed

If Starship lander doesn't work on the moon, what could take its place, while still using its massive capabilities? This is what I speculated upon with the AI vetting my ideas. The best response seemed to be in using the Blue Origin lander inside of the Starship.

Blue Origin also wants to go to the moon. Would a moon lander fit inside of the Starship cargo area?

Yes, an entire Blue Origin lunar lander—specifically their Blue Moon architecture (such as the MK1 cargo variant or the larger MK2 human-landing system being developed for NASA's Artemis V mission)—could fit inside the Starship cargo area, provided it is engineered to respect the dimensional limits of the bay.

Blue Origin's Moon Landers vs. Starship's Cargo Bay

Blue Origin has two primary lunar lander concepts in development:

1. Blue Moon MK1 (Cargo Variant): Designed to deliver up to 3 metric tonnes of payload to the lunar surface. It has a diameter of roughly 7 meters and stands around 10 to 12 meters tall.

- Fit Test: Because its diameter is around 7 meters (fitting within Starship's 8-meter dynamic envelope) and its height is well under the 17–22 meter length of the cargo bay, the MK1 lander can easily fit entirely inside Starship's cargo hold.

2. Blue Moon MK2 (Human Landing System / Artemis): This is a much larger vehicle designed for crewed descents. It utilizes a BE-7 engine powered by liquid hydrogen and liquid oxygen. While its exact fully-outfitted dimensions are tightly guarded, the descent stage diameter and height are tailored to fit inside traditional commercial heavy fairings (like New Glenn's 7-meter fairing).

- Fit Test: If a MK2 lander (or a scaled version of it) is designed with a diameter under 7.5 to 8 meters and a length under 15 meters, it could be packed into Starship's cargo bay and deployed in Low Earth Orbit or lunar orbit. However, because hydrogen tanks are notoriously voluminous (due to hydrogen's low density), a fully assembled human-class hydrogen lander might push right up against the absolute limit of Starship's volumetric capacity.

The Irony of Competitors Utilizing Starship

While Blue Origin and SpaceX are fierce commercial rivals in the new space race, the math of heavy-lift logistics creates a fascinating scenario: SpaceX's Starship is essentially the only vehicle currently operating or in development with a cargo bay large enough to swallow a competing company's heavy lunar lander whole.

If an agency or private entity wanted to launch a Blue Origin-style lander into Earth orbit or onto a trans-lunar trajectory using a vehicle other than New Glenn or SLS, Starship's 1,000-cubic-meter volume and 150-tonne capacity make it the ultimate universal heavy-lift delivery truck. Instead of building a custom, multi-billion-dollar rocket to launch their lander, a competitor could theoretically buy a Starship ride, pop the lander out of the side-door "PEZ dispenser" in LEO, and send it on its way to the Moon.

Here's another idea: What about the Falcon 9 and Dragon? What is the masses and dimensions of the second stage Falcon 9 rocket and dragon capsule?

If a second stage of Falcon 9 and Dragon were to be launched on a Starship, what could that combination do? Could it get to the moon?

Launching a Falcon 9 second stage and a Dragon spacecraft inside of Starship’s cargo bay as a secondary payload combo sounds like a wild sci-fi concept, but purely from a rocketing and delta-V perspective, it opens up some fascinating orbital mechanics.

The Setup: What You're Deploying

If you eject the Falcon 9 second stage and the Dragon capsule out of Starship's cargo door in Low Earth Orbit (LEO), you essentially have a completely independent, highly capable orbital stack.

- The Falcon 9 Second Stage brings its single Vacuum Merlin engine and roughly 111.5 tonnes of RP-1/LOX propellant.

- The Dragon 2 brings its own Draco thrusters, SuperDraco abort engines, life support systems, avionics, and a pressurized cabin.

Could It Get to the Moon?

Short answer: Yes, but with some heavy modifications and severe operational caveats.

If the Falcon 9 second stage were fully fueled in LEO (which would require Starship to act as a gas station to pump propellants into it, or launching the stage pre-fueled inside a pressurized/safe Starship bay), let's look at the delta-V math:

1. Delta-V Budget: The Falcon 9 second stage with a lightweight payload like Dragon has a massive vacuum specific impulse ($I_{sp} \approx 348\text{ seconds}$) and a great mass ratio. Unloaded from Earth's deep gravity well (since Starship did the heavy lifting to LEO), that second stage sitting in orbit possesses roughly 4,000 to 5,000 m/s of delta-V.

2. Trans-Lunar Injection (TLI): To get from LEO to a lunar intercept requires roughly 3,100 to 3,200 m/s of delta-V. Mathematically, the F9 second stage has more than enough energy to push Dragon out of Earth orbit and onto a trajectory toward the Moon.

The Massive Engineering Hurdles

While the raw math works out, executing this in reality would be an engineering nightmare for several reasons:

- Propellant Boil-Off and Compatibility: Falcon 9 uses RP-1 (refined kerosene) and Liquid Oxygen (LOX). While LOX requires cryogenic cooling, RP-1 is stable at room temperature, which is nice. However, the Falcon 9 upper stage avionics, batteries, and pressurization systems (helium tanks) are not designed for long-duration coast phases in deep space. Falcon 9 upper stages typically burn out within hours of launch; keeping one alive and functional for a multi-day lunar transit would require completely rewriting its electrical and thermal control systems.

- Thermal Protection for Lunar Reentry: Dragon is engineered to survive reentry from Low Earth Orbit (returning from the ISS at roughly 7.8 km/s). If Dragon is sent to the Moon and comes back, it will hit Earth's atmosphere at trans-lunar return speeds of roughly 11 km/s. Dragon's PICA-X heat shield is fundamentally not designed or certified to handle the extreme thermal and radiative flux of a lunar return without burning through.

- Redundancy: Dragon lacks a deep-space habitation environment, heavy radiation shielding, and long-duration life support for a crew to travel to the Moon and back safely outside of Earth's magnetosphere.

Why Do It When Starship is Already There?

The ultimate irony of this thought experiment is that Starship itself is already a vastly superior vehicle for the job.

If Starship has already hauled the Falcon 9 stage and Dragon up to LEO, Starship itself has 1,000 cubic meters of volume, life-support capabilities, and with orbital refueling, enough delta-V to land on the Moon and come back directly (as seen in the Artemis HLS contract). Using a Falcon 9 second stage as a makeshift lunar kick-stage for a Dragon capsule would be like packing a smart car inside the back of a semi-truck, only to hitch a lawnmower engine to the smart car to finish the trip.

Still, it highlights the sheer scalability of Starship—the fact that you can fit an entire traditional orbital launch vehicle inside of another rocket's payload bay proves just how much the paradigm of spaceflight has shifted.

How much payload could it land on the Moon?

If you were to use a fully fueled Falcon 9 second stage as a lunar kick-stage to push a Dragon capsule toward the Moon, how much payload could it actually land on the lunar surface?

The short answer is: Zero, because neither the Falcon 9 second stage nor the Dragon capsule is designed to land on the Moon.

Unlike Starship (which has its own heat shield and massive Raptor engines for a propulsive touchdown) or a dedicated lunar lander, neither piece of this hardware has landing legs, surface engines, or a descent guidance system.

However, if we adjust the thought experiment—turning the Falcon 9 second stage into a lunar orbital insertion and landing stage, or assuming we strap a makeshift landing frame to it—let’s look at what the math says about its mass limits on the lunar surface.

1. The Mass Budget in LEO

Once delivered to Low Earth Orbit by Starship, your stack looks like this: - Falcon 9 Second Stage (Dry): ~4,000 kg - Falcon 9 Second Stage Propellant (RP-1/LOX): ~111,500 kg - Dragon 2 Capsule + Trunk (or equivalent payload): ~12,000 kg (max) - Total Stack Mass in LEO: ~127,500 kg (~127.5 tonnes)

2. The Delta-V Journey to the Moon

To take that entire 127.5-tonne stack from LEO, inject it to the Moon (TLI), capture into lunar orbit, and de-orbit/land, you need a staggering amount of delta-V:

1. Trans-Lunar Injection (TLI): ~3,150 m/s

2. Lunar Orbit Insertion (LOI): ~900 m/s (assuming you go into orbit first)

3. Powered Descent & Landing: ~2,000 m/s (since the F9 engine cannot throttle down low enough to hover a heavy vehicle on the Moon, you would need an entirely different landing engine, but let's assume ideal rocket math).

Total required delta-V from LEO to the lunar surface is roughly 6,050 to 6,500 m/s.

3. Running the Tsiolkovsky Rocket Equation

The Falcon 9 second stage's single Vacuum Merlin engine has a specific impulse ($I_{sp}$) of about 348 seconds in a vacuum.

If you burn the entire 111,500 kg of propellant available in the second stage to push the dry stage (4,000 kg) and a payload all the way to a lunar landing:

- With a total initial mass of 127.5 tonnes and a total delta-V requirement of ~6,200 m/s, the exponential mass ratio eats away at your capacity very quickly.

- By the time the second stage performs TLI and decelerates into a lunar landing trajectory, the remaining payload mass you could safely set down on the lunar surface is roughly 2 to 4 metric tonnes—assuming you added landing legs, guidance computers, and a secondary low-thrust landing engine to handle the final touchdown.

The Ultimate Reality Check

While you could theoretically squeeze 2 to 4 tonnes onto the Moon using a hacked-together F9 upper stage, it highlights why this approach is completely impractical:

1. Dragon Can't Land There: Dragon relies entirely on Earth's atmosphere for parachutes and a water landing. On the Moon, it's a dead brick with no air.

2. Merlin Can't Hover: The Merlin 1D Vacuum engine is optimized for high-thrust space burns; it cannot throttle down low enough to soft-land a vehicle on the lunar regolith without digging a crater and destroying itself.

3. Starship Does It Better: Starship HLS (Human Landing System) is designed to land 100 metric tonnes directly on the Moon and lift crew back off, all using a single vehicle that launched from Earth (with orbital refueling).

So, while putting an F9 upper stage and a Dragon inside Starship is a fun geometry puzzle, trying to turn them into a lunar lander is like trying to turn a speedboat into a submarine—it's the wrong tool for an entirely different ocean!

What if we add landing legs and engines?

Isn't the Dragon used as an escape stage if something goes wrong with the launch? If that's true, then how does dragon land?

You are thinking of the Launch Abort System (LAS), which is a critical safety feature for crewed spacecraft. However, how the Dragon handles aborts and how it lands are two different mechanisms, and there is a unique twist with how SpaceX designed the Dragon 2.

How Dragon's Abort System Works

Unlike older spacecraft (like Apollo or Orion) that use a giant tower with solid-propellant rockets on top of the capsule to pull it away from danger, SpaceX’s Crew Dragon does things differently.

- Integrated SuperDraco Thrusters: Crew Dragon has 16 SuperDraco engines built directly into the side walls of the spacecraft's hull.

- The Abort Sequence: If the Falcon 9 rocket suffers a catastrophic failure on the pad or during ascent, the SuperDracos instantly fire with immense thrust (pushing the capsule away at over 400 miles per hour in seconds) to tear the Dragon clean away from the exploding booster.

- The Trunk Separation: Once the capsule is safely clear of the danger zone, the unpressurized "trunk" (which houses the solar panels and grid fins) is jettisoned, and the capsule orients itself for a safe parachute descent.

How Dragon Lands

Despite early plans by SpaceX to have Dragon land propulsively on solid ground using those same SuperDraco thrusters and deployable landing legs, that concept was scrapped.

- Water Landings: Today, every operational Crew Dragon and Cargo Dragon lands exclusively in the ocean (the Atlantic Ocean or Gulf of Mexico off the coast of Florida).

- The Parachute Sequence: After reentering Earth's atmosphere, the capsule deploys two drogue parachutes to stabilize itself, followed by four massive main parachutes to slow its terminal velocity down to about 16 to 18 mph (25 to 29 km/h).

- Splashdown: The capsule splashes down into the water, where recovery ships scoop it up. The water acts as the ultimate shock absorber, eliminating the need for heavy landing legs or propulsive landing engines.

What About Cargo Dragon?

It is also worth noting that Cargo Dragon (Dragon 2)—the version used to resupply the International Space Station—does not even have SuperDraco abort engines. Because there are no humans on board, it doesn't need a launch abort system. It relies purely on the Falcon 9's normal flight safety systems during launch, and it returns to Earth using the exact same parachute and ocean-splashdown method as the Crew Dragon.

Why was propulsive landing scrapped?

SpaceX’s decision to scrap propulsive landing for the Crew Dragon capsule—originally designed to touch down on solid ground using its SuperDraco thrusters and deployable landing legs—was one of the toughest engineering pivots in the company's history.

Elon Musk announced the cancellation in 2017, and it came down to a combination of regulatory roadblocks, engineering complexity, and the realization that the juice simply wasn't worth the squeeze.

Here are the primary reasons why propulsive landing was dropped:

1. NASA’s Certification and Safety Requirements

When SpaceX signed its Commercial Crew contract with NASA to ferry astronauts to the International Space Station, safety was the absolute non-negotiable priority.

- Unproven Tech for Human Return: Landing a capsule propulsively on land had never been done before in human spaceflight (the Soviet/Russian Soyuz uses parachutes and soft-landing solid retrorockets right at the ground, but it still lands under a canopy; Apollo splashed down in the ocean).

- The "Factor of Safety": NASA's safety panels were deeply skeptical. Proving that a propulsive landing system would work with a 100% success rate under every conceivable failure mode (such as an engine failing to ignite, guidance software glitches, or high crosswinds at touchdown) required mountains of paperwork, testing, and risk analysis that threatened to delay the program for years.

2. Qualification of the Landing Legs

Designing structural landing legs that can fold tightly into the aerodynamic contour of a spacecraft, survive the blistering heat of atmospheric reentry (up to 1,600°C), and then successfully deploy and lock in place right before touchdown proved to be a brutal engineering challenge.

If the legs failed to deploy, the capsule would essentially crash onto its side, risking the lives of the crew. Qualifying those mechanisms to NASA's standards was a massive hurdle.

3. The Path of Least Resistance (Parachutes Already Worked)

SpaceX had decades of historical precedent and existing data showing that parachutes and ocean splashdowns work reliably.

- While parachutes require naval recovery teams, ships, and a bit more logistical turnaround time than touching down on a concrete pad at Cape Canaveral, they are fundamentally simpler and have a predictable physics profile.

- By dropping the propulsive landing requirement for Dragon, SpaceX could focus its engineering talent and capital entirely on perfecting Falcon 9 and Starship booster landings (where propulsive landing does make immense economic sense).

The Ultimate Irony

While propulsive landing was scrapped for Dragon, the lessons learned from trying to make it work directly fed into Starship.

SpaceX took the core concept—using heavy retro-propulsion to land a spacecraft vertically without runways or parachutes—and scaled it up to the massive Starship vehicle. So, while Dragon settled for a traditional ocean splashdown, the ghost of propulsive landing lives on in every Starship test flight today.

Two launches versus up to 16. Which would you prefer?

There's a criticism of the Artemis configuaration as Starship HLS module would require a large number of launches. Is there a way around this? There just might be, but will that be the way it goes? Let's explore that with an AI dialogue...

Let's discuss SpaceX's Starship once again... Do you have the specifications of the Starship? That is, how much of the interior volume is reserved for cargo and crew? Is it possible to draw that in a schematic which would show how much of the ship's length is available for cargo and crew?



Yes, SpaceX’s Starship is an absolute engineering marvel, designed from the ground up to completely transform humanity's access to space and enable deep-space colonization.

Starship Specifications & Internal Volume

When looking at the overall vehicle dimensions, the Starship upper stage stands approximately 50 meters (164 feet) tall with a diameter of 9 meters (30 feet).

Within that upper stage, the total internal volume—often referred to as the payload bay or combined crew/cargo volume—is roughly 1,000 cubic meters (though some older or more conservative estimates place the pressurized/usable volume around 614 to 825 cubic meters depending on the specific block configuration and whether it's outfitted for cargo or crew). For comparison, that is roughly equivalent to the total pressurized volume of an entire wide-body commercial airliner like an Airbus A380.

- Cargo Configuration: Features a massive payload bay that is roughly 17 to 22 meters in length (with an 8-meter dynamic envelope diameter), capable of hauling up to 150 metric tonnes to Low Earth Orbit in a fully reusable mode (and over 200 tonnes if expended).

- Crew Configuration: Replaces or integrates the cargo space with a pressurized section designed to hold up to 100 passengers, complete with private cabins, large communal areas, centralized storage, solar storm shelters, and life-support systems that recycle air and water.

Length Schematic Representation

While I cannot directly output an image file, we can visualize the breakdown of the Starship upper stage's 50-meter length through a text-based structural schematic.



+-------------------------------------------------------+ <- Nose Cone / Tip (0m) | | | FORWARD FLAPS / AERODYNAMICS | | | +-------------------------------------------------------+ <- Approx. 10m - 12m mark | | | | | CARGO BAY / CREW SECTION | | (~1,000 m³ Total Volume) | | Length available: ~17 to 20 meters | | | | | +-------------------------------------------------------+ <- Approx. 28m - 32m mark | | | COMMON BULKHEAD / LIQUID METHANE (CH4) | | | +-------------------------------------------------------+ <- Liquid Oxygen (LOX) Tank | | | COMMON BULKHEAD / LIQUID OXYGEN | | | +-------------------------------------------------------+ <- Approx. 44m mark | | | ENGINE BAY & RAPTOR ENGINES | | (3 Sea-Level + 3 Vacuum Raptors) | +-------------------------------------------------------+ <- Aft Heat Shield / Base (50m)



As you can see from the breakdown, roughly one-third to two-fifths of the upper stage's total height is dedicated entirely to the payload and crew zone at the top, sitting cleanly above the massive propellant tanks (liquid methane and liquid oxygen) and the heavy Raptor engine bay at the base. This layout keeps the center of mass optimized for atmospheric reentry and landing maneuvers.



Looking at the text based schematic you provided, it looks like the nose cone/tip along with the forward flaps and aerodynamics take up about 10 meters of the total length. What would happen if the cargo/area was moved here, and the aerodynamics/ flaps were moved down? I am thinking of the possibility of making this a 3 stage vehicle, which would separate from each other after attaining orbit. The lower stage would return to the ground as usual. The upper stage would be outfitted with its own engines and control surfaces for returning to Earth.



Rearranging the layout of Starship by moving the cargo bay up into the nose cone and shifting the forward flaps and control surfaces down presents some fascinating aerodynamic and structural trade-offs. While exploring novel staging concepts is a hallmark of aerospace innovation, doing this to turn Starship into a 3-stage orbital vehicle introduces severe engineering hurdles.

1. Moving the Cargo to the Nose Cone (Mass and Center of Gravity)

If you relocate the cargo or crew compartment all the way up into the forward tip of the nose cone, you are shifting the dry mass center of gravity (CoG) significantly forward.

- Atmospheric Reentry and Skydive: Starship relies heavily on a precise center of mass during its supersonic "skydive" descent. It enters the atmosphere belly-first at a high angle of attack, using the forward and aft flaps to control its pitch, roll, and yaw. If the heaviest components (cargo/crew or a dedicated upper-stage propulsion system) are packed into the extreme nose, the aerodynamic moment arm changes drastically. The vehicle would tend to want to "dart" nose-first rather than stabilize in its flat, drag-inducing belly-flop posture.

- Structural Loads: The extreme tip of a rocket experiences immense aerodynamic bending moments during Max-Q (maximum dynamic pressure). Placing a heavy payload volume right at the apex would require reinforcing the nose cone with much heavier, thicker materials, eating directly into your payload capacity.

2. Moving the Aerodynamic Flaps Down

Shifting the forward flaps downward—closer to the middle or lower section of the ship—disrupts their primary aerodynamic function.

- Control Authority: The forward flaps act as canards to keep the nose pitched up during descent. If you move them too far down toward the middle of the vehicle, they lose their leverage over the pitch axis.

- Thermal Protection: The lower half of the Starship experiences the most intense plasma heating during reentry. Putting delicate actuation mechanisms, hinges, and control surfaces further down means they would be subjected to harsher thermal environments, requiring even heavier heat-shield tiles and active cooling.

3. Turning Starship into a 3-Stage Vehicle

Your idea of a 3-stage vehicle—where the booster (Super Heavy) launches, and the upper stage splits into two separate orbital sub-stages—changes the operational paradigm completely. Currently, Starship is a 2-stage-to-orbit (2STO) architecture (Super Heavy + Starship).

- The Staging Penalty: Every time you add a stage, you add another set of interstage hardware, separation mechanisms, pneumatic pushers, and an entirely new engine ignition sequence in the vacuum of space. While staging helps maximize delta-V for deep space missions, the dry mass penalty for a third stage on a vehicle this size can quickly outweigh the performance gains.

- Operational Complexity: SpaceX's entire philosophy revolves around rapid reusability and minimizing points of failure. Managing three separate returning vehicles from a single launch (the booster, a mid-stage/upper-stage 1, and an upper-stage 2) would multiply the logistical and recovery complexity exponentially.

That said, looking at alternative configurations is how aerospace engineers test the boundaries of what is possible. If you were designing this 3-stage variant, how would you handle the propellant distribution across those separated segments once they are in orbit?



Let's set that 3 stage idea aside. Let's look at what could be put inside of the cargo area and deployed to space after reaching orbit. It looks to me that the cargo area may be limited to how big of an object can be placed there. How much of that cargo area can be utilized if the doors are limited in how wide it can open? Can an object close to the full size of the cargo area be deployed into space, or would something need to be downsized a bit in order to deal with the limitations?



You have hit on one of the most critical real-world design constraints of the current Starship cargo architecture. While the interior volume of the cargo bay is roughly 1,000 cubic meters, what you can actually fit and deploy is strictly governed by the "dynamic envelope" and the physical geometry of the payload door.

The Starship Cargo Door Limitation

Unlike a traditional rocket fairing that splits entirely in half and falls away (exposing the entire circumference of the payload), Starship uses a longitudinal "peel-back" clamshell-style cargo door that runs along one side of the cylinder.

- Door Dimensions: The opening is roughly 8 meters in diameter and about 17 to 22 meters long, but because it is a side-opening hatch rather than a full separation fairing, payloads cannot simply be pushed straight out radially without clearance, nor can they match the full 9-meter outer diameter of the ship's hull.

- The Dynamic Envelope: SpaceX specifies a payload envelope diameter of roughly 8 meters to account for structural walls, internal mechanisms, and clearance during deployment.

Can You Fit an Object Close to the Full Size?

The short answer is no, you cannot deploy an object that fills 100% of the cargo bay's internal dimensions. You always have to downsize or segment payloads to deal with several hard geometric and mechanical limitations:

1. Clearance and Translation: To eject a large satellite, telescope, or habitat module out of the side-opening door, the object must be translated (pushed out) using a mechanical deployment arm, pneumatic pushers, or a specialized rail system. If an object completely fills the cross-section of the bay, it will jam against the edges of the door frame as it tilts or moves outward.

2. Length vs. Turning Radius: If a payload is close to the maximum 17 to 22-meter length of the bay, clearing the door is an even bigger geometric challenge. The object has to pivot or slide out linearly without clipping the lips of the hatch.

3. Internal Infrastructure: A portion of that 1,000 cubic meters is taken up by mounting points, deployment mechanisms, avionics, and plumbing.

How Large Payloads Are Handled

To get massive structures into space using Starship without hitting these door and volume bottlenecks, engineers rely on a few specific strategies:

- Modular Assembly: Instead of one monolithic object that fills the entire bay, payloads are built as interlocking modules that are deployed separately and assembled in orbit (using robotic arms or EVAs).

- Deployable/Inflatable Structures: Just like the James Webb Space Telescope had to fold up to fit inside an Ariane 5 fairing, Starships will rely heavily on unfurlable solar arrays, telescoping trusses, and inflatable habitat modules that expand exponentially after clearing the cargo door.

- The "Gateway" Evolution: There have been continuous discussions within the aerospace community about whether future iterations of Starship might need a full nose-cone separation or a wider-opening mechanism for truly out-of-spec deep space infrastructure, but the current side-door layout remains the baseline for operational efficiency and structural integrity during reentry.

Given your answer above with regards to the largest sized object that Starship could deliver to space, what would that look like in terms of dimensions and mass possibilities? I am thinking of delivering separate modules that could be assembled in space for deep space missions-- like the Moon or Mars.

Delivering large, modular components to build deep-space infrastructure for the Moon or Mars is precisely the mission profile Starship was built for. Because you cannot deploy a monolithic structure that completely fills the internal dimensions of the cargo bay, any deep-space module must be engineered around the ship's practical deployment limits.

Maximum Practical Dimensions of a Single Module

To ensure a module can safely clear the side-opening "PEZ dispenser" style door without jamming against the hull or the doorframe, the absolute maximum practical dimensions for a single deployable unit are:

- Maximum Diameter / Width: 7.5 to 8 meters. (Leaving a small clearance buffer inside the 9-meter hull and 8-meter dynamic envelope).

- Maximum Length: 15 to 17 meters. (Leaving enough margin at the top and bottom of the roughly 17 to 22-meter bay for deployment rails, pusher mechanisms, and clearance as the module pivots or slides out).

- Usable Volume per Module: Roughly 500 to 700 cubic meters per single launch, leaving room for the deployment hardware.

Maximum Mass Possibilities

In terms of mass, the limits are defined by Starship's performance envelope rather than volume:

- To Low Earth Orbit (LEO) - Reusable: Up to 150 metric tonnes. This is your baseline for heavy cargo heading to an orbital staging depot or assembly node.

- To LEO - Expendable: Up to 250+ metric tonnes, if you decide not to recover the ship (though this is rare for standard operations).

- To Deep Space (Trans-Lunar Injection or Mars Transfer): If Starship is refueled in LEO by tanker flights, it can deliver that entire 100 to 150-tonne payload capacity directly to the lunar surface (as seen with the Artemis HLS variant) or inject it onto a direct Mars transfer trajectory.

What These Assembled Deep-Space Modules Look Like

If you are designing a deep-space habitat or a surface base for Mars or the Moon using Starship as the delivery truck, the strategy relies on a "Lego-brick" approach utilizing these maximal dimensions:

1. Rigid Cylindrical Segments: A single Starship launch can carry a rigid habitat cylinder roughly 8 meters wide and 15 meters long—weighing upwards of 80 to 100 tonnes fully outfitted with internal decks, life support, and shielding. Multiple ships can land these on Mars or the Moon, where robotic cranes or astronauts link them end-to-end or side-by-side using standardized docking collars.

2. Expandable/Inflatable Hybrid Modules: To maximize the internal living space once on the surface, engineers often pair an 8-meter rigid structural core (housing the heavy avionics, airlocks, and life support) with outer layers that inflate or telescope outward. This turns a single 1,000-cubic-meter cargo delivery into a much larger multi-room surface habitat.

3. Truss and Power Infrastructure: For solar farms, nuclear surface reactors, or communication arrays, components are packed flat or folded radially against a central support spine, pulled out of the cargo bay via robotic winches, and unfolded in zero-G or on the regolith.



What were the dimensions of the SIV-B rocket stage of the Saturn V rocket that carried astronauts to the moon?

The S-IVB (Stage IV-B) was the third stage of the Saturn V rocket, and it played a critical dual role: it fired to push the Apollo spacecraft out of Low Earth Orbit and onto a Trans-Lunar Injection (TLI) trajectory, and its instrument unit and forward area also housed the Lunar Module adapter (SLA) during launch.

Here are the exact physical dimensions of the S-IVB stage:

- Diameter: 6.60 meters (21.6 feet)

- Length / Height: 17.81 meters (58.4 feet)

- Empty Mass: Approximately 13,300 kg (29,300 lbs)

- Loaded Mass (Propellant): Approximately 123,000 kg (271,000 lbs) of liquid oxygen and liquid hydrogen.

- Engine: A single J-2 engine producing about 103,300 pounds-force (459 kN) of thrust in a vacuum.

Comparison to Starship's Cargo Bay

Putting the S-IVB's dimensions side-by-side with what we just discussed regarding Starship's cargo capabilities reveals a fascinating historical parallel:

- S-IVB Dimensions: 6.6m diameter × 17.8m length

- Starship Practical Cargo Envelope: ~7.5m to 8m diameter × ~15m to 17m length

The S-IVB stage is actually remarkably close in length to Starship's cargo bay limit, and its diameter is only slightly smaller than the 8-meter dynamic envelope of Starship. This means an entire Saturn V upper stage—complete with its massive propellant tanks and rocket engine—could fit entirely inside Starship's cargo bay with room to spare.

It highlights just how massive SpaceX's vehicle is; a single Starship can haul a payload volume and mass class that rival or exceed the upper stages of the greatest heavy-lift rocket of the 20th century.



Along the same lines as above, could a second Starship launch fill in the rest? It doesn't look big enough to house the command module and lunar module. Could those two modules fit into a second Starship launch?

You have hit on the exact scaling difference between 1960s architecture and modern heavy-lift capability. You are entirely correct: the Apollo Command/Service Module (CSM) and the Lunar Module (LM) together with the S-IVB stage could not all fit inside a single Starship cargo bay at the same time.

However, looking at this through the lens of a second Starship launch changes the equation entirely, and it reveals why Starship is such a disruptive paradigm shift.

What Apollo Packed into a Single Launch

On the Saturn V, the entire Apollo stack—the S-IVB stage, the Lunar Module (tucked into the SLA adapter), the Service Module, and the Command Module—was launched together in one monumental stack, standing about 111 meters tall.

Can a Second Starship Launch Fit the Rest?

If we use Launch #1 to deliver a massive structural component, propellant depot element, or a precursor habitat (like a heavy-lift payload comparable to or larger than an S-IVB stage), what can Launch #2 carry?

A second Starship launch gives you an entirely separate 1,000 cubic meter volume and up to 150 metric tonnes of payload capacity.

- Fitting the CSM and LM: Absolutely, yes. The Apollo Command/Service Module combined was about 11 meters long and 3.9 meters wide. The Lunar Module in its deployed landing configuration was about 7 meters wide and 7 meters tall (though it folded up tightly to fit in the 6.6m SLA). Both of these spacecraft together could easily fit inside a single Starship cargo bay, with plenty of room left over for extra supplies, rovers, or scientific equipment.

- Mass vs. Volume: While the Apollo CSM and LM combined weighed only about 45 metric tonnes fully fueled, Starship's 150-tonne capacity means you wouldn't just be launching a replica of Apollo—you could launch a spacecraft three times as massive, completely fully fueled, with heavy radiation shielding and vastly superior life support.

The Modern Deep-Space Playbook

Instead of trying to cram an entire moon mission into one fragile, highly complex single-launch stack like the Saturn V, SpaceX's architecture allows for orbital assembly and refueled modularity:

1. Launch 1: Send up a massive infrastructure element, propellant node, or a heavy cargo lander variant.

2. Launch 2: Send up the crew, habitat modules, or the equivalent of the CSM/LM stack (or use the Starship HLS variant directly, which eliminates the need for separate CSM/LM architectures entirely by landing the massive Starship cabin straight onto the lunar surface).

3. Refueling: Use a series of Starship tanker flights in Low Earth Orbit to top off the main vehicles before they burn for the Moon or Mars.

So, while a single Starship cargo bay can't swallow a whole 1969 Apollo stack in one go, a second Starship launch doesn't just "fill in the rest"—it provides an entirely redundant, heavy-lift powerhouse that dwarfs the entire capability of the Saturn V system.

Starship critique (AI -generated)

  Comment:

  The answer to the question was not exactly what I expected. Indeed, it would take a complete redesign of the spacecraft.

  What would I suggest? A partial redesign. The booster is okay, leave it alone. Instead, the effort should be made to redesign the Starship itself.

  The ship as it stands can deliver 100+ tons in its present configuration. If the redesign can improve upon that, then why not?

  An idea presented itself to me. On my trip out to the area a couple of months ago for flight 12, I had the opportunity to touch the TPS tiles. The impression I got was that they were rather robust. They aren't fragile.

  Could these tiles be used as part of the skin, while minimizing the use of the heavy stainless steel?

  The empty weight of the Starship is over 100 tons. It will carry about 1200 tons of fuel. Therefore, the ratio between the empty weight and the full weight is much lower than for the booster. This is inefficient.

  If the tiles could replace the stainless steel skin, wouldn't that reduce the weight? It should seem so. That's because there's a duplication in having the TPS when there is already a skin.

  But what would hold it together? Perhaps a way could be found to connect the tiles that would allow such a substitution to work. Indeed, the current design requires that the TPS be impervious to the environment. If that is so, then the only other requirement is that it be strong enough to deal with the forces that would be working against it during the mission.

  So my thinking was to run the stainless steel through the TPS and then connect the individual tiles that way. It would use less steel, and eliminate some of the duplication. If enough steel was used, it may even be strong enough to do what is required of it with regards to strength.

  The current design requires sheets of steel. Instead of doing that, the sheets could be manufactured out of a constructed and interlocking set of heat tiles.

  Such could be stacked in a similar way that they're being stacked now.

  The only question then is the strength of the tiles thusly arranged.

  A second suggestion would be to have the crew area and cargo area SEPARATE from the second stage. The second stage could return as it already does. The third stage could be a space only vehicle. But how to get home? Perhaps with a large capsule-like device. This design would also incorporate a propulsion capability that would enable it to launch from the surface of the Moon.

  Mars may require another solution.

  Yet another idea presents itself. Why do much of a redesign at all? Make the third stage as the redesign, and leave the second stage as it is, with some minor modifications. That is to say, it would have the cargo and crew area as a completely separate part of the spacecraft, with an enlarged capsule like design. The heat shield will be on the bottom of the spacecraft, as opposed to what it is now.

What are the main criticisms of SpaceX's Starship's design, and what would be improved upon in order to make it better?

Answer:

This is a great engineering question. I’ll give you the main technical criticisms of Starship’s current design, followed by the improvements that would address them. I’ll be clear about what is a legitimate trade-off versus what may be a genuine flaw.

Main Criticisms of Starship’s Design

1. Stainless Steel Construction (Weight Penalty)

SpaceX uses 304L stainless steel for the hull. Stainless is cheap, strong at high temperatures, and easy to weld, but it is significantly heavier than carbon composites or aluminum-lithium alloys. This directly reduces the payload mass fraction. For a reusable vehicle, the dry mass penalty is a serious disadvantage.

2. The “Belly Flop” Reentry Profile

Starship reenters broadside with a massive frontal area, then flips at the last moment. This is aerodynamically inefficient and subjects the vehicle to extreme lateral heating. The control surfaces (forward and aft flaps) are heavy, add complexity, and experience some of the most severe thermal loads. If the flap actuators fail, the vehicle is unrecoverable.

3. Heat Shield Tile Attachment

The TPS uses hexagonal ceramic tiles bonded directly to the stainless steel. This is similar to the Space Shuttle’s system, which had a persistent problem with tile shedding. Starship has already lost tiles during test flights. If a tile is missing in a critical area, the underlying steel could be compromised. The adhesive bond line is a single-point-of-failure for the entire vehicle.

4. Raptor Engine Complexity

The Raptor 3 is a full-flow staged combustion cycle engine. It is extraordinarily complex, with extreme chamber pressures (~350 bar) and high turbine inlet temperatures. This has led to turbopump failures, combustion instability, and a high rate of engine swaps. The number of engines (33 on Super Heavy, 6 on Starship) multiplies the risk of a single-engine failure cascading.

5. No Crew Escape System

Starship has no launch abort system beyond the vehicle’s own ability to separate. If the Super Heavy booster fails catastrophically, the crew cannot escape. For a vehicle intended to carry 100 people, this is a fundamental safety issue. NASA’s HLS contract requires an abort capability, but the current design relies on the engines to push the ship away, which is unproven at high dynamic pressure.

6. Orbital Propellant Transfer (Unproven)

Starship’s deep space architecture depends on on-orbit refueling. This requires transferring super-chilled propellant between two large vehicles in microgravity, with no ullage. The boil-off rate, settling, and docking loads are unresolved. The entire Mars and lunar mission plan hinges on this capability.

7. Landing Leg Design

The current landing legs are internal, deployed at the last moment. They are small, have a narrow footprint, and are vulnerable to hard landings. The vehicle is top-heavy, and a leg failure on touchdown would be catastrophic.

8. Cargo Door and Payload Deployment

The large forward payload door (the “pez dispenser”) is a complex mechanism that must open and close in space with no backup. If it jams, the mission is lost. The door’s seals and thermal protection are also a concern.

Improvements That Would Make It Better

1. Replace Stainless with a Heat-Resistant Composite

A carbon-carbon or carbon-ceramic composite skin would save mass and improve structural performance. The trade-off is cost and manufacturing complexity. If SpaceX could develop a reusable composite hull that withstands reentry, the dry mass reduction would be substantial.

2. Use a More Conventional Reentry Profile

Adding small deployable wings or a lifting body shape would reduce heating, improve cross-range, and simplify the control system. The trade-off is added mass and complexity for the wings. But the belly flop is a high-risk maneuver that puts enormous stress on the vehicle.

3. Mechanically Attached TPS

Move from adhesive bonding to a mechanical attachment system (like pins or rails) with a redundant backing. This would prevent tile shedding and allow for easier inspection and replacement. The Shuttle’s bonding was a known failure mode; Starship should not repeat it.

4. Simplified Engine Architecture

Reducing chamber pressure or switching to a simpler oxygen-rich staged combustion cycle (like the RD-180) would improve reliability at the cost of specific impulse. Alternatively, developing a more robust turbopump with a larger margin to failure would reduce the engine swap rate.

5. Add a Tractor-Tower Abort System

For crewed missions, a tower-based launch abort system (like the one on Dragon 2) would provide a reliable escape path from pad to Mach 1. The extra mass and complexity are justified for human safety.

6. Prove Propellant Transfer with a Dedicated Testbed

Before relying on it for mission-critical operations, SpaceX should fly a dedicated tanker mission that demonstrates multiple transfer cycles, settling, and low-boil-off storage. The current plan to “figure it out during the mission” is not engineering best practice.

7. Larger, Wider Landing Legs

Deployable legs with a wider footprint would improve stability and tolerate rougher landings. The legs should be tested with a high safety margin on both terrestrial and extraterrestrial surfaces.

8. Redundant, Mechanically Locked Payload Doors

The cargo door should have a mechanical backup (e.g., a secondary latch system) and a manual override. The door should be tested in a thermal-vacuum environment with the full thermal cycle.

Summary

Starship is a revolutionary vehicle, but it is also a vehicle of compromises. The design prioritizes low cost, rapid iteration, and exotic performance over robustness, safety, and simplicity. The improvements I listed would make it more reliable and safer, but they would also increase its cost and development time. Whether that trade-off is worth it depends on whether you believe the mission is to get to Mars soon or to get there safely.

How SpaceX is making America uncatchable

Here's somebody saying what I've been saying for the last 15 years.

Another example of saying it in a way in which people may LISTEN.

Are you sure you want to put Elon out of business? Only if you don't care about the people you represent. My question is this: Why would you support somebody who doesn't have your best interest in mind?

Talk given at TEAC11 a few years ago

James Conca has a few words to say about his experiences giving talks about radioactivity.

I can relate to this somewhat. He says that you have to make it fun, or people won't listen. What I was told was that my writing on this blog was "too dry". You can complain about all these kinds of things, but it does no good. So you just work with it.

JP Aerospace tests their home-made submarine

7/12/26:

Here's a list of update videos that JP has made recently. Do not be discouraged that the one shown first is from 4 years ago. You need to scroll through the list to find the most recent one, which was just days ago.

Given that SpaceX wants to colonize Mars, these airships that JP builds could come in handy on Mars. The requirements to get to orbit from the Martian surface are much less. Maybe Mach 10 or 11 would get you from the surface to Mars orbit. That may be feasible for his airships on Mars.

In other words, another way to get back and forth between the surface and Mars orbit without having to use the Starship.

5/17/25: The original post follows below:

 

The video below was published just prior to a test of the sub...

... and afterwards a post on the blog about it. Not many details, but those may be forthcoming.

Ellie in Space, Flight 13 video

Good job.

Coding skills for what?

7/10/26:

I'm juggling all these blogs. No wonder I haven't got much time.

1/12/26: The original post follows:

  Update:

  New blog. Details over there. Anyway, no more blogging on this blog about my coding. All coding issues will be blogged on the new coding blog.

  There is a league at w3schools, where you can compete with others for points. Points are awarded for completed lessons and challenges and so forth.

  This may be bragging, but I tend to finish near the top every week.

  But the competition is not very fierce. It did start that way, but I got suspicious that it wasn't for real. I don't know if I've changed my mind on that or not.

  At this point, there's not much left to do. Perhaps I could go for a certificate, but that means more money spent. I'm not going to spend more money on this. Not that it was all that much anyway.

  The question now is what to do with this. I don't want a job at a company. It may be a marketable skill, but my working career is over. If I could find something that didn't require punching a clock, I'd consider it.

  I don't want to keep posting on this either. So here I am. What to do with this?

Financial roadmap for LPPFusion

Disclosure: I own shares ( originally 1 share, but there was a split, so now it is ??).

Comment: This is what you call "risk-capital". That is to say, it won't be ruinous for me to lose all of my investment, because $200 investment that goes kaput won't kill me. Read on to see the large potential payoff.

A copy of an email is shown below:

Ivy here with the financial roadmap and exit strategy.

Most investors want to know:

When do I see returns?

What's the exit path?

What's the projected valuation growth?

Let me break it down.

Timeline to Liquidity:

2025-2026 (Current Phase):

Raise $4-5M (this round)

Achieve net energy by end of 2026 (more energy out than in)

Surpass China's hydrogen-boron fusion record

Expected share price increase when net energy achieved

2027-2030 (Prototype Development):

Demonstrate working commercial prototype

Begin licensing discussions with manufacturers (GE, Siemens, Samsung)

Raise additional capital (likely at higher valuation)

Expected share price increases as prototype milestones hit

2030-2031 (Commercialization & Exit):

Execute licensing deals (revenue begins)

IPO / Acquisition (liquidity event for investors)

Projected valuation: 10-100x current ($83.9M - $800M-8B+)

Exit Options:

Option 1: IPO (Most Likely)

Timeline: 2030-2031

Once we demonstrate working prototype and secure licensing deals

Comparable: Helion Energy (projected $3B+ valuation pre-IPO)

LPPFusion advantage: Published results (not just promises)

Option 2: Acquisition

Potential acquirers: GE, Siemens, Samsung, Energy companies

Strategic value: Patents, know-how, team expertise

Precedent: Many fusion startups acquired by larger players

Option 3: Secondary Market (Available Now)

Some investors already selling shares to each other

Liquidity available before IPO (though limited market)

Price: Negotiated between buyer/seller

Financial Projections:

Revenue Model:

Licensing fees: $10-50M per manufacturer

Ongoing royalties: 3-5% of generator sales

Target: 10-20 licensing deals by 2035

Market Capture:

Goal: 25% of global energy market by 2040

100,000 generators deployed globally

Each generator: $5-10M manufacturing cost, powers 4-5K homes

Investor Returns (Hypothetical):

Scenario 1 (Conservative):

IPO valuation: $800M (10x current)

Your $50K investment @ $25/share = 2,000 shares

At 10x: $500K value = 10x return

Scenario 2 (Moderate):

IPO valuation: $4B (50x current)

Your $50K = $2.5M value = 50x return

Scenario 3 (Aggressive):

IPO valuation: $8B+ (100x current)

Your $50K = $5M+ value = 100x return

Disclaimers:

Projections are estimates, not guarantees

High-risk investment (R and D company, technical execution risk)

Past performance (10x share price growth since 2003) doesn't guarantee future results

But here's what we DO guarantee:

Published, peer-reviewed science

Transparent financial audits (SEC-required)

Mission-driven team (refused VC control)

Capital efficiency (proven track record)

Ready to discuss your investment strategy?

Book a call to explore:

Detailed financial projections (Excel model)

Risk factors and mitigation strategies

Large investor perks ($100K+: advisory board seat, lab tours, etc.)

Timing your investment (now vs. waiting for milestones)

BUTTON: deleted

Or invest now:

BUTTON: deleted

The math works. The science works. Let's build it together.

Ivy

P.S. - Investors $100K+ can negotiate custom terms (board seats, advisory roles, preferred reporting). Book a call to discuss.

SpaceX is betting its future on this

Farzad youtube



Comment:

The golden goose keeps laying the golden eggs, but some folks want to cook the goose because it is "too fat". But if you try to extract their essense from them, you kill the goose. Not real smart.