Lecture Notes: Skyroot Aerospace Factory Tour

Introduction

Speaker visited Skyroot Aerospace for a factory tour.
Skyroot Aerospace, an Indian private space startup founded by Pawan and Bharat in 2018, both ex-ISRO.
Currently working on Vikram 1, an orbital class rocket with four stages (three solid, one liquid).
Previous suborbital test with Vikram S (VKS).

Height: 22 meters, equivalent to a 7-story building.
Stages:
- Stage 1, Stage 2, and Stage 3: Solid motors.
- Stage 4: Liquid stage.
Structural: Highly composite structure, very lightweight, uses carbon fiber throughout.
Challenges: Separation Systems
- Horizontal and vertical separation needing rigorous testing and good design.
Changes in Design
- Transition from conical to cylindrical shape for better center of pressure and control.
- Adjustments in nozzle angle for controlling the rocket.

Design Complexity: Involves both horizontal and vertical separation.
Seal and Venting: Needs to maintain a clean environment for the satellite and release pressure gradually.

Used for thrust vector control (TVC).
Composed of layers of rubber and metal, allowing the nozzle to flex and steer the rocket.
High-pressure tests to ensure survival under operational conditions.

Houses roll control systems and thrusters.
Modular design to separate and reconnect various sections.
Complex wiring and plumbing for control systems, ensuring no collision during separation.
Pneumatic separation mechanisms over pyros for reliability.

Uses two actuators positioned at 90 degrees for pitch and yaw control.
Mirror imaging sensors to mirror actuator movements and manage flex seal pressures.

Filament Winding: Uses a 4-axis robot to achieve directional strength in carbon fiber components.
Tooling: Each stage requires specific tooling; complexity increases with size.
Prototyping: Initial stages tested with smaller models, scaling up step-by-step.
Challenges: Ensuring no-slip during winding, managing manufacturing precision, and lightweight structures.
Integration: Complex assembly processes for aligning large components.

Pressure Testing: Extensive pressure tests to verify structural integrity and performance.
Static Fire Tests: Scheduled static fire tests for various stages, particularly new designs like Kalam 250 (second stage, 250 kN thrust).
Separation Tests: Testing separation dynamics and mechanisms, including fairing separation.

Real-time simulations for aerodynamic and thermal aspects.
Ensuring dynamic control during all phases of flight.
Handling residual thrust in solid motors and using retro motors for immediate stage separation.

Payload Capacity: Expected to exceed 400 kg to low inclination orbits.
Optimization: Continuous design refinements based on early flight data.
New Technologies: Exploring liner-less cryogenic tanks and advanced manufacturing methods.
Central Thruster for Upper Stages: Using 3D-printed engines with regenerative cooling for improved control.
Wind Tunnel Testing: Validated aerodynamics for accurate coefficient measurements.

Speaker's personal experience: Spent 4 hours on the tour, learned a lot about rocket manufacturing and engineering challenges.
Highlighted the growth of Indian private space startups and their advancements.

Note: The speaker acknowledged financial supporters for making the tour and video possible.