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Free Engineering Tools

Systems Engineering Calculators

Free, instant-answer calculators for aerospace mission concepts and defense program control. No signup required. Full spreadsheet export, mission saves, traceability, and 118+ additional calculators are in the industry packs.

Aerospace — mission concept

Orbit, RF, power and imaging trade studies for early mission design.

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Link Budget Calculator

RF link analysis for spacecraft comms. EIRP, path loss, G/T, C/N₀, margin — live as you type.

EIRPpath lossX-bandS-band
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Spacecraft Mass Budget

Subsystem mass rollup with reserve margins. Enter per-subsystem dry mass, see total CBE + MEV with 20/10/5% reserves.

CBEMEVmargindry mass
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Delta-V / Rocket Equation

Tsiolkovsky rocket equation solver. Input Isp, wet/dry mass → Δv. Or target Δv → required propellant mass.

IspTsiolkovskypropellantHohmann
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GSD Calculator

Ground Sample Distance for imaging payloads. Altitude, focal length, and pixel pitch → GSD at nadir and off-nadir.

GSDimagingfocal lengthpitch
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Orbit Propagator (Kepler)

Simple Keplerian orbit propagator. Altitude, inclination, eccentricity → period, ground velocity, eclipse fraction.

orbitKeplerperiodLEO
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Hohmann Transfer Calculator

Two-burn transfer between circular orbits. Both burns, total Δv, transfer time, and departure phase angle.

Hohmanntransfer orbitLEO to GEOphase angle
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Sun-Synchronous Orbit

Required retrograde inclination from altitude via J₂ nodal precession, plus period, revs/day and RAAN for a chosen LTDN.

SSOinclinationJ2LTDN
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Solar Array Sizing

Array area from daylight/eclipse load, eclipse fraction, cell efficiency and EOL degradation. SMAD power-budget method.

EPSpower budgetBOLEOL
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Antenna Gain & Beamwidth

Parabolic dish gain in dBi, half-power and first-null beamwidth, and quadratic pointing loss. UHF through Ka band.

dBiHPBWpointing lossX-band
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Defense — program control

Cost, readiness and sustainment numbers for DoD 5000.02 milestone reviews.

13 live nowOrbit, RF, power, cost, readiness, sustainment
118+ moreBehind the Aerospace and Defense packs
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Aerospace adds the high-fidelity propagator, constellation optimizer, Lambert solver, cislunar design studio and the SMAD 8-phase workflow with SRR/PDR/CDR gate packages. Defense adds CMMC tracking, threat modeling, DoDAF views and CDRL/SDRL management against DoD 5000.02 milestones.