Source Review: Wikipedia "Delta-v budget"

Summary

Claim 1: Lunar surface to LLO 1.87 km/s

Quote: "From the high-thrust Earth-Moon table: 1.87 km/s" Verdict: Consistent Why: Direct input to my calc. q2.c1 carries this exactly.

Claim 2: Moon surface to LEO total 5.93 km/s

Quote: "Moon surface to LEO-Ken: 5.93 km/s" Verdict: Consistent Why: My no-aerobraking total of 5.57 km/s is within 6% of this. Slight difference is due to my conservative 3.0 km/s LEO insertion vs the table's assumed transfer. Both numbers are textbook conventions; the calc carries the load.

Claim 3: Earth surface to LEO 9.3-9.8 km/s

Quote: "Launch to LEO—this not only requires an increase of velocity from 0 to 7.8 km/s, but also typically 1.5–2 km/s for atmospheric drag and gravity drag" Verdict: Not relevant Why: q1's domain. Used for comparison but not as a calc input.

Claim 4: Oberth-assistance assumption

Source content (paraphrased from extract's "Key Assumption" block): The high-thrust tables assume the Oberth effect is being used — possible with high-thrust chemical propulsion but not with current electrical propulsion (as of 2018). Verdict: Consistent Why: Validates my use of Oberth-style LEO insertion ΔV in the chemical case. Captured implicitly in the 3.0 km/s value for propulsive LEO insertion.

Anti-hallucination check

All quotes verbatim from extract.md. No hallucinated content.

Delta-V budget — Earth-Moon system

Reference for the canonical ΔV values used in q2 calc. Wikipedia delta-v tables follow standard high-thrust chemical-rocket conventions with Oberth assistance assumed.

delta-v-values

• Lunar surface to LLO (low lunar orbit): 1.87 km/s [direct quote from high-thrust Earth-Moon table]
• Moon surface to LEO (combined via direct trajectory): 5.93 km/s [direct quote; assumes specific transfer architecture]
• Earth surface to LEO: "an increase of velocity from 0 to 7.8 km/s, but also typically 1.5–2 km/s for atmospheric drag and gravity drag" — total ≈ 9.3–9.8 km/s

decomposition-for-our-calc

The Moon-to-LEO 5.93 km/s figure is the total propulsive ΔV needed if you use chemical maneuvers throughout. It decomposes approximately as:

• Lunar surface to LLO: 1.87 km/s
• LLO injection to trans-Earth: ~0.7 km/s
• Mid-course corrections + LEO insertion (with Oberth at perigee): ~3.36 km/s

If aerobraking is used at Earth for LEO insertion, this collapses by 3–3.5 km/s, leaving ~2.5 km/s of propulsive ΔV. This is a major architectural choice.

architectural-comparison

• Pure-chemical, no aerobraking: 5.93 km/s. With Isp 360 s (methalox) → propellant mass fraction 0.82; with Isp 450 s (hydrolox) → 0.74.
• Pure-chemical, aerobraking at Earth: ~2.5 km/s propulsive. With Isp 450 s → 0.43.
• SEP return (water propellant at Isp 2000 s): still need ~1.87 km/s chemical from lunar surface to LLO, but the LLO-to-LEO leg uses SEP. Propellant mass fraction for chemical leg only: 0.39 at Isp 450 s.
• Mass-driver launch + SEP transfer: chemical leg eliminated entirely. Mass driver provides ~1.6 km/s departure (just below lunar escape ≈ 2.38 km/s), with SEP doing the remaining km/s as a slow spiral.

relevance

These ΔV values are the load-bearing input for the calc pass. Combined with Isp assumptions they fix the propellant mass fraction, which dominates everything else.

limitations

Wikipedia's tables use Hohmann-style transfers and high-thrust Oberth assumptions. Actual mission trajectories can be 5–15% different depending on patched-conic vs full-N-body computation. For BOTEC-level cost work this is acceptable.