Prompt: You have been tasked with reviewing the selected mission proposals and selecting the one that has the highest probability of success (using tried/tested methods) and is most cost effective. Make your selection and explain it.

After carefully reviewing the eight selected mission proposals for the Mars Sample Return program, I recommend the Rocket Lab proposal led by Richard French as having the highest probability of success while being cost effective. Here’s my analysis:

Key Advantages of the Rocket Lab Proposal:

Demonstrated Experience and Integration Rocket Lab has proven capabilities across all aspects of launch vehicle disciplines, with practical experience in vehicle design, production, logistics, regulatory compliance, and operations. They’ve already demonstrated success with relevant technologies, including:

1. A high delta-V spacecraft (3.2 km/sec) on the NASA CAPSTONE mission in 2022
2. Precision entry system targeting using in-house propulsion in February 2024
3. Active integration of two Mars science orbiters

Cost-Effective Approach The proposal targets a total cost to NASA of less than $2B through:

• Operating as a single management organization under firm fixed price
• Using commercial approaches and vertically integrated capabilities
• Employing a simplified mission architecture

Practical Timeline and Risk Management Their proposal includes:

• A targeted 2028 launch window
• Sample return no later than September 2033
• Clear contingency planning with potential early return in September 2031
• Reduced risk to Perseverance rover lifetime through expedited timeline

Technical Feasibility The two-launch solution using Neutron launch vehicles presents a straightforward approach:

• Launch 1: Earth Return Orbiter (ERO) to Mars orbit
• Launch 2: Mars Lander Vehicle (MLV) with Mars Ascent Vehicle (MAV)
• Proven 7-DOF sampling arm technology
• Demonstrated sterilization and sample transfer capabilities

While other proposals like Lockheed Martin’s offer significant experience and Blue Origin’s Starship concept promises revolutionary capabilities, the Rocket Lab proposal stands out for its balance of proven technology, cost effectiveness, and reasonable timeline. Their vertical integration and commercial approach reduce coordination complexity, while their recent successful demonstrations of key technologies suggest a higher probability of mission success.

The proposal is conservative enough to be reliable but innovative enough to achieve significant cost savings - a crucial balance for a mission of this complexity and importance. The structured approach to science integrity through their Science Advisory Council further strengthens the proposal’s credibility.

In comparison, proposals relying on newer technologies or more complex architectures carry higher risks. For example, Quantum Space’s lunar orbit transfer concept, while innovative, introduces additional complexity and risks. Similarly, while SpaceX’s Starship proposal offers exciting possibilities, it represents a less proven approach for this specific mission profile.

The Rocket Lab proposal represents the optimal balance of proven capability, cost effectiveness, and risk management while still maintaining the core science objectives of returning 30 samples. This balanced approach gives it the highest probability of successful execution within reasonable budget and timeline constraints.