Power Budgeting

Model power generation, storage, and consumption for orbital compute systems across the full orbital cycle.

Status: Early Access — Request API key

Overview

Power in orbit is fundamentally different from Earth:

Solar only — Primary power source is photovoltaic
Eclipse periods — No generation during Earth shadow
Battery cycling — Must store enough for eclipse
Degradation — Solar cells degrade over mission life

Quick Start

from rotastellar import RotaStellarClient

client = RotaStellarClient(api_key="rs_...")

power = client.planning.power(
    orbit="LEO-550",
    compute_load_w=500,
    duty_cycle=0.8,
    mission_life_years=5
)

print(f"Solar array: {power.solar_array_m2} m2")
print(f"Battery: {power.battery_kwh} kWh")
print(f"Available during eclipse: {power.eclipse_power_w}W")
print(f"EOL margin: {power.eol_margin_percent}%")

import { RotaStellarClient } from '@rotastellar/sdk';

const client = new RotaStellarClient({ apiKey: 'rs_...' });

const power = await client.planning.power({
  orbit: 'LEO-550',
  computeLoadW: 500,
  dutyCycle: 0.8,
  missionLifeYears: 5
});

console.log(`Solar array: ${power.solarArrayM2} m2`);
console.log(`Battery: ${power.batteryKwh} kWh`);

curl https://api.rotastellar.com/v1/planning/power \
  -H "Authorization: Bearer rs_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "orbit": "LEO-550",
    "compute_load_w": 500,
    "duty_cycle": 0.8,
    "mission_life_years": 5
  }'

Parameters

string

required

Orbit specification (e.g., LEO-550, GEO)

number

required

Peak compute power consumption in watts

number

default:"1.0"

Fraction of time compute is active (0-1)

number

default:"5"

Mission duration for degradation calculations

number

default:"50"

Non-compute power (thermal, comms, ADCS)

number

default:"0.3"

Maximum battery depth of discharge (0-1)

Response

{
  "solar_array": {
    "area_m2": 3.2,
    "power_bol_w": 960,
    "power_eol_w": 768,
    "degradation_percent_per_year": 2.5
  },
  "battery": {
    "capacity_kwh": 0.85,
    "cycles_per_day": 15.5,
    "eol_capacity_percent": 80
  },
  "power_profile": {
    "sunlit_available_w": 680,
    "eclipse_available_w": 420,
    "average_available_w": 580
  },
  "margins": {
    "bol_margin_percent": 25,
    "eol_margin_percent": 12
  },
  "recommendations": [
    "Consider 10% larger array for operational margin",
    "Battery supports 5-year mission with 80% EOL capacity"
  ],
  "orbit_profile": [
    {"phase": "sunlit", "duration_min": 57, "power_w": 680},
    {"phase": "eclipse", "duration_min": 35, "power_w": 420}
  ]
}

Power Budget Breakdown

Typical LEO Power Budget

Subsystem	Power (W)	Notes
Compute (peak)	500	GPU/TPU workloads
Compute (idle)	50	Standby mode
Thermal	30-100	Heaters during eclipse
Communications	20-50	Varies with data rate
ADCS	10-20	Attitude control
Housekeeping	20-30	Avionics, sensors

Power Modes

# Model different operating modes
power = client.planning.power(
    orbit="LEO-550",
    modes=[
        {"name": "full_compute", "power_w": 500, "duration_percent": 60},
        {"name": "reduced", "power_w": 200, "duration_percent": 30},
        {"name": "idle", "power_w": 50, "duration_percent": 10}
    ],
    mission_life_years=5
)

Eclipse Operations

During eclipse, power is limited to battery capacity:

power = client.planning.power(
    orbit="LEO-550",
    compute_load_w=500,
    eclipse_strategy="reduced"  # or "full", "suspend"
)

# Check eclipse power availability
if power.eclipse_available_w < 500:
    print(f"Must reduce to {power.eclipse_available_w}W during eclipse")

Eclipse Strategies

Strategy	Description	Use Case
`full`	Maintain full power	Large battery, short eclipse
`reduced`	Reduce compute during eclipse	Balanced approach
`suspend`	Suspend compute, housekeeping only	Minimal battery

Degradation Over Mission Life

Solar arrays and batteries degrade over time:

# Compare BOL vs EOL power
power = client.planning.power(
    orbit="LEO-550",
    compute_load_w=500,
    mission_life_years=7
)

print(f"Year 1 available: {power.solar_array.power_bol_w}W")
print(f"Year 7 available: {power.solar_array.power_eol_w}W")
print(f"Degradation: {power.solar_array.degradation_percent_per_year}%/year")

Design Recommendations

Solar array sizing

Size for end-of-life (EOL) power needs plus 10-20% margin. Account for degradation: ~2.5%/year in LEO due to radiation.

Battery sizing

Size for eclipse duration + margin. Limit depth of discharge to 30-40% for long cycle life.

Operational flexibility

Design for multiple power modes. Ability to reduce compute load extends operational flexibility.

Getting Started

Planning Tools

Orbital Intelligence

CAE

Operator Agent

Mission Control

Orbital Runtime

Orbital Sim

Distributed Compute

SDKs

Resources

Power Budgeting

Power Budgeting

Overview

Quick Start

Parameters

Response

Power Budget Breakdown

Typical LEO Power Budget

Power Modes

Eclipse Operations

Eclipse Strategies

Degradation Over Mission Life

Design Recommendations

Next Steps

Thermal Simulation

Feasibility Analysis

​Power Budgeting

​Overview

​Quick Start

​Parameters

​Response

​Power Budget Breakdown

​Typical LEO Power Budget

​Power Modes

​Eclipse Operations

​Eclipse Strategies

​Degradation Over Mission Life

​Design Recommendations

​Next Steps

Thermal Simulation

Feasibility Analysis

Power Budgeting

Overview

Quick Start

Parameters

Response

Power Budget Breakdown

Typical LEO Power Budget

Power Modes

Eclipse Operations

Eclipse Strategies

Degradation Over Mission Life

Design Recommendations

Next Steps