Join Space Engine Systems @ IAC Milan Oct 14-18:Booth MN1-A02d L1 & Paper Presentation - Combined Air-Breathing and Rocket Propulsion System Trajectory Analysis for Delivering Payload to Space

https://www.iac2024.org/

Abstract: An opportunity exists for small payload launchers to utilize a combination of air-breathing and rocket engines. Incentives for a combined turbojet-ramjet-rocket engine mode strategy include leveraging the engine type with the highest specific impulse during the ascent and configuring a reusable spaceplane with horizontal and landing capability to enable quick turn-around. This paper provides advice to size vehicles for a given payload and introduces a trajectory optimization methodology using the Dymos library built onto OpenMDAO where inputs include lift- and drag- coefficients from CFD and thrust coefficients from pyCycle. Using higher-fidelity CFD data differentiates this study from prior analyses where it is noted that complex flow features associated with inlet performance are difficult to predict empirically. This framework will be beneficial towards the operational planning of Space Engine Systems two-stage-to-orbit Hello-1 launch vehicle.

The mission objective analyzed in this paper was for a three-stage-to-orbit mission whose airbreathing first stage achieves Mach 5 at 30 km altitude and reusable rocket-boosted second stage that ascends to 100 km apogee, releases a third stage capable of delivering a 550 kg (1213 lbm) payload to 600 km sun-synchronous orbit, and has a glide descent. Hydrogen fuel was specified for the ramjet and rocket phases. Preliminary results found that the take-off mass was 30,300 kg and 10,050 kg fuel was required. A 60% increase in payload fraction and 60% reduction in fuel cost per kg-payload were identified relative to the evaluated lowest cost small payload vertical spacecraft launcher that uses less environmentally favourable LOX/kerosene fuel.