#2570 New Glenn Rocket; Alternatives to MASS-ive First Stage Structure

#2570 New Glenn rocket

The New Glenn rocket, developed by Blue Origin, is a massive heavy-lift launch vehicle designed for both crewed and uncrewed missions to low Earth orbit and beyond. Named after astronaut John Glenn, this two-stage rocket stands at over 320 feet (98 meters) tall and boasts a reusable first stage, designed to land vertically on a droneship named "Jacklyn" after liftoff. This reusable design mirrors aspects of SpaceX’s Falcon 9, although New Glenn features some distinct aerodynamic additions, such as four adjustable fins and two stabilizing strakes to control airflow during descent, enhancing its reusability and stability.

Powered by seven BE-4 engines in the first stage (using liquid methane and liquid oxygen), the rocket generates significant thrust and can carry payloads of up to 45 metric tons to low Earth orbit or 6.8 metric tons to lunar orbit. The second stage, equipped with two BE-3U engines running on liquid hydrogen and liquid oxygen, is designed for high-energy orbital missions, enabling flexibility for varied mission profiles.

New Glenn's initial launch has seen multiple delays, but Blue Origin now aims for a debut mission by the end of 2024 or early 2025. This mission is expected to carry the company's "Blue Ring" platform, focusing on satellite operations and orbital adjustments. The rocket’s development has positioned it as a key player among heavy-lift vehicles, with a commitment to enabling reusable, sustainable access to space for commercial, scientific, and governmental payloads.

For further details, you can read more at Blue Origin's website and on recent industry reports.

Unfueled, what does the first stage weigh?

The unfueled weight (dry mass) of New Glenn’s first stage is estimated to be over 200 metric tons. This robust build supports its reusable design, where it’s powered by seven BE-4 engines running on liquefied natural gas and liquid oxygen. This configuration allows the first stage to generate significant thrust (about 3.8 million pounds-force) and enables vertical landings on the droneship Jacklyn after separation. The first stage’s dry mass is optimized using techniques like friction stir welding to reduce parasitic weight, making it more efficient without compromising strength.

If you're looking for more detailed specifications, including projected payload capacities, Blue Origin’s website provides an in-depth overview of New Glenn’s design and operational goals.

Theoretically, how much fuel is required to lift the first stage vehicle alone, no cargo?

Theoretically, calculating the fuel needed to lift the New Glenn first stage alone (with no cargo) involves understanding the mass of the stage, the type of fuel, and the delta-v required for reaching the edge of space (or a specific altitude). Here’s a simplified outline of the fuel calculation:

Mass of the First Stage (Dry): As noted, the dry mass of the New Glenn’s first stage is approximately 200 metric tons.
Full Mass with Fuel: While Blue Origin has not provided the exact fuel mass, the total mass of the New Glenn first stage with fuel is expected to be around 1,000 metric tons based on industry estimates for similar heavy-lift rockets. This suggests a fuel load of roughly 800 metric tons.
Type of Fuel and Specific Impulse: The BE-4 engines use liquid oxygen (LOX) and liquefied natural gas (LNG), with a specific impulse of approximately 330 seconds at sea level. Specific impulse indicates the engine efficiency; higher values mean more thrust per unit of fuel.
Delta-V Requirement: The delta-v (change in velocity) for the first stage to reach an altitude where stage separation would occur (around 40-70 km) is typically in the range of 2,500–3,000 m/s.
Tsiolkovsky Rocket Equation: The equation, $Δ v = I_{s p} \times g \times \ln (\frac{m_{0}}{m_{f}})$ , where $m_{0}$ is the full mass, $m_{f}$ is the dry mass, $I_{s p}$ is specific impulse, and $g$ is gravitational acceleration (9.81 m/s²), helps estimate the fuel mass.

Plugging in the values:

$m_{0} \approx 1, 000$ metric tons
$m_{f} \approx 200$ metric tons
$I_{s p} = 330 s$

Assuming the target delta-v is 2,500–3,000 m/s, calculations show that approximately 800 metric tons of LOX/LNG fuel would be needed. This aligns with typical figures for similar reusable rocket first stages, like SpaceX’s Falcon 9.

This theoretical figure would cover lifting the first stage to an altitude sufficient for booster separation and descent. For precise estimates, fuel requirements would also account for aerodynamic drag, gravitational losses, and other mission-specific variables.

From <https://chatgpt.com/>

Be serious but think innovatively. I want to design a rocket first stage that gets its propellant from an external source not attached to the vehicle. The goals is to provide the necessary propellant to get the vehicle off the pad, but not add to the vehicle's initial mass.

For a first-stage rocket design that uses an external propellant source without adding mass to the vehicle, the main innovative solution revolves around creating an infrastructure to supply fuel and oxidizer remotely. Here are feasible ideas based on established propulsion technology:

1. Ground-Based Propellant Injection System

Concept: Design a system on the ground to inject fuel and oxidizer directly into the rocket’s first-stage engines while it remains on the launch pad.
Implementation: Equip the pad with fuel and oxidizer lines that lock onto the rocket’s engines or propellant intake manifolds, similar to a refueling probe but optimized for high flow rates and pressure. High-speed injectors would pulse fuel and oxidizer into the engine, providing thrust without adding vehicle mass.
Key Challenge: As the rocket lifts off, disengaging the connection reliably and safely at the precise moment requires precision engineering. Additionally, pressure management and flow rate control must ensure that the rocket receives consistent thrust without fluctuation until it achieves a height where it can switch to internal tanks.

2. Vertical Cable-Propellant Feed System

Concept: A flexible but high-strength, pressurized hose or tube system attached to the rocket’s base would supply propellant from the ground up to a specified height.
Implementation: The propellant hose would retract or break away as the vehicle ascends to reduce drag, which allows propellant feed without the need to carry significant quantities of propellant onboard initially.
Key Challenge: Engineering a rapid-detach, high-pressure, and heat-resistant system that can maintain flexibility yet withstand launch-induced vibrations. Additionally, the system must safely break or disconnect to avoid entanglement or risk of damage to the rocket.

3. Electromagnetic or Laser Ignition and Propellant Heating

Concept: Use ground-based lasers or microwave beams to ignite and maintain the rocket’s engines during the first few seconds of flight.
Implementation: The rocket contains only the engine and minimal start-up fuel, while intense beams provide thermal energy to heat a specially designed propellant or gas stream, generating initial thrust. The vehicle could transition to internal propellant tanks once the altitude or speed threshold is met.
Key Challenge: Developing a suitable ignition material or a reaction that responds consistently to remote energy input is complex. High-precision aiming and control of the energy source would be essential to avoid efficiency losses and ensure adequate thrust output during the initial phase.

4. Launch Assisted by Ground-Based Thrusters

Concept: Integrate ground-based thrusters directly under the launch pad or via thrust vectors that feed into the rocket’s base, creating lift.
Implementation: The rocket lifts off using high-thrust ground-based boosters that guide it for the initial phase, effectively pushing it until it reaches a velocity where onboard systems take over. This works similarly to assisted takeoff systems but is focused solely on the first stage.
Key Challenge: Coordinating the timing and thrust direction to avoid disrupting the vehicle’s trajectory, as well as ensuring safe transition to internal engines.

Each of these ideas requires advances in precision engineering, high-speed propellant flow management, and seamless transition systems.

What about a core tank that the vehicle encloses but does not have to lift, or, probably better yet, a surrounding tank that is protected from rocket flames but does not have to be lifted at launch?

Utilizing a stationary external tank—either a core or surrounding tank—offers a highly innovative solution for reducing vehicle launch mass. Here's how both configurations could be practically implemented:

1. Central Core Tank Configuration

Concept: The rocket’s engines draw fuel and oxidizer from a stationary core tank that is vertically aligned within the rocket but remains on the ground. This tank would be enclosed by the vehicle structure, providing it with protection and alignment without requiring the vehicle to lift it.
Implementation:
- The core tank is built into a reinforced section of the launch pad and extends vertically into the rocket’s first stage.
- The rocket structure encloses this central tank, allowing propellant to feed directly into the engines through a telescoping feed mechanism or retractable connectors.
- The core tank remains anchored to the ground, providing fuel and oxidizer during the initial lift-off phase until the vehicle reaches a specified altitude and engages its onboard tanks.
Advantages: The central tank approach simplifies propellant handling and minimizes mass penalties for the rocket. Additionally, the tank could be highly insulated and pressurized since it doesn't need to consider weight constraints.
Key Challenge: The disengagement mechanism between the core tank and rocket structure would need precise engineering to ensure a clean and safe detachment. A seal that can withstand both extreme pressure and temperatures while reliably detaching is critical.

2. Surrounding Tank Configuration (Tank Shroud)

Concept: The rocket lifts off surrounded by a ring-like external tank that encircles the vehicle’s lower section but remains stationary on the ground. This tank would feed propellant to the rocket engines via flexible feed lines during launch and would disengage or retract once the rocket gains initial altitude.
Implementation:
- The surrounding tank could be designed as a sturdy, thermally insulated ring that encircles the vehicle just above the flame trench, protected by heat shielding to prevent damage from the exhaust.
- High-flow, retractable connectors provide a fuel and oxidizer supply directly to the engines, and as the rocket ascends, the connectors automatically detach, allowing the rocket to continue on its internal fuel tanks.
Advantages: The surrounding tank configuration is highly versatile. The ring structure remains stationary, does not add lift-off weight, and can hold significant amounts of propellant, extending the vehicle’s effective range without impacting the weight lifted.
Key Challenge: Designing robust, flexible fuel connectors that can sustain the stress and vibration of lift-off yet detach seamlessly at the right moment is a major engineering hurdle. Additionally, ensuring the surrounding tank structure does not interfere with the rocket’s aerodynamics or thrust flow requires precise structural planning.

Potential Benefits and Applications

Reduced Mass at Lift-Off: Both designs eliminate the need to lift large propellant tanks, reducing the vehicle’s initial mass and potentially enabling heavier payloads or extending range.
Cost Efficiency: By reducing onboard fuel requirements, the vehicle may achieve better cost efficiency due to the lowered mass.
Safety and Reliability: Ground-based propellant sources can be better insulated, pressure-managed, and controlled than those onboard, leading to potentially safer initial ignition and lift-off stages.

Final Considerations

While either configuration would need rigorous testing and development, each presents a viable pathway for achieving efficient launches with reduced initial mass requirements.

From <https://chatgpt.com/>

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