Cost Modeling

• Primary: Phase A (ROM for proposal and feasibility), Phase B (refined estimate for confirmation)
• Supporting: Phase C (cost tracking against baseline), Phase D (actual vs. estimate comparison)

Ownership Boundary

Cost Estimation Methods

1. Parametric (CER-based)

Cost Estimating Relationships express cost as a function of technical parameters:

• General form: $Cost = a \cdot X^b$ where $X$ is a driver (mass, power, data rate, etc.)
• Common CER sources:
  • USCM (Unmanned Spacecraft Cost Model): Subsystem-level CERs for unmanned missions
  • SSCM (Small Satellite Cost Model): Tuned for <500 kg spacecraft
  • PCEC (Project Cost Estimating Capability): NASA's integrated cost tool
  • NICM (NASA Instrument Cost Model): For science instruments/payloads
• Typical cost drivers by subsystem:
  • Structure: dry mass (kg)
  • Thermal: radiator area (m²), heater power (W)
  • Propulsion: propellant mass (kg), Isp class
  • EPS: solar array area (m²), battery capacity (Wh)
  • C&DH/FSW: SLOC (lines of code), processor class
  • Communications: data rate (Mbps), antenna diameter (m)

2. Analogy-Based

• Select a reference mission with known cost and similar scope.
• Adjust for differences in complexity, mass, heritage, and technology maturity.
• Best used when CER databases are unavailable or the mission is highly novel.

3. Multi-Unit Production

• Learning curve: $C_n = C_1 \cdot n^{\log_2(s)}$ where $s$ is the learning rate (typically 85-95% for spacecraft).
• Non-recurring vs. recurring: NRE (design, tooling, qualification) amortized over production quantity.
• Constellation economics: Per-unit cost drops significantly at quantities >10.

Cost Categories (WBS-Aligned)

Cost Risk & Uncertainty

• Phase A: ±50-100% (order of magnitude). State as a range, not a point estimate.
• Phase B: ±25-50%.
• Phase C/D: ±15-25%.
• S-curve / Monte Carlo: If probabilistic analysis is needed, recommend tools (e.g., @RISK, Crystal Ball) rather than attempting it with napkin math.
• Cost growth: Historical average is 20-50% above initial estimate for government programs. Flag this.

Launch Cost Reference

Note: Rideshare can reduce launch cost to $5k-15k/kg for small satellites.

Output Format

1. Cost Estimate Report (cost_estimate.md): WBS-level cost breakdown, methodology, assumptions, reference year, and uncertainty range.
2. Cost Summary Table: One-line-per-subsystem with NRE + recurring + total.
3. Lifecycle Cost Profile: Year-by-year spending curve if operations phase is significant.
4. 🟢 / 🟡 / 🔴 status: Cost feasibility vs. stated budget constraints.

Interface

• Reads from: /requirements/, /analysis/systems-engineering-assessment/ (mass/power budgets), /analysis/propulsion-assessment/ (propellant mass), all subsystem outputs for CER inputs
• Writes to: /analysis/cost-modeling/
• Consumed by: trade-study-manager (cost as FoM), systems-engineering-assessment (cost summary)