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This capability is available only to enabled Operations audiences. Studies are preliminary screening results. They cannot be operationally approved or exported as OCM commands, even when a nominal target is met.

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Create a study

  1. Open Maneuvers → Planner → New Plan. In Overview, choose LEO disposal in Maneuver Type.
  2. Name the plan, select a spacecraft and one chemical or electric propulsion device, then choose Next. In Disposal study, select an existing precise state or orbit solution. The selected device carries forward from Overview.
  3. Enter your maximum modeled propellant spend and campaign start/end in UTC. The calculation uses mass from the selected state, plus catalogue dry mass, drag properties and the chosen device’s thrust, Isp and maximum burn duration.
  4. Declare the coast from the source epoch to your campaign start. If known intervening maneuvers exist, select a later state through the existing state-data workflow. Review any existing orbit-freshness notices.
  5. Declare your jurisdiction/authorization context, ESA baseline adoption, constellation population, operational duration and relevant lifecycle dates. Leave unknown optional values blank.
  6. Select Lowering + natural decay or Nominal controlled return. Controlled studies additionally require your nominal surface-region center and radius.
  7. Review recommendations, adjust study targets if needed, then choose Calculate preliminary study. You can cancel a queued or running calculation.
A TLE/GP conversion is not a precise starting orbit. Missing essential catalogue data must be completed in the existing spacecraft workflows; launch mass is not substituted for current state mass.

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Recommendations and your targets

The initial five-year target runs from your declared end of mission, including the powered campaign. It is a Valar good-practice preference, not a universal European law. Attributed sources can have different or stricter deadlines and different clocks. For example, French mission-duration and megaconstellation conditions differ, and an adopted ESA baseline uses strictly-less-than-five-year wording with its own lifecycle clock and probabilistic assessment method. You may change the lifetime, maximum post-burn apogee and study mode. Source requirements remain visible and unchanged. Choosing a less stringent target does not demonstrate a waiver. Country selection alone does not determine every licence or contractual obligation; coverage and unknown applicability remain explicit.

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Review a retained study

Select the study in the shared Planner plan list, alongside other plans. Disposal rows are labelled Preliminary and show their calculation outcome. The study opens in the Planner details pane; its URL can be reopened directly. Spacecraft filtering applies to disposal rows, and the time filter uses their creation date. Use Load older disposal plans to retrieve earlier retained studies. The currently opened study remains visible across the time filter. Review:
  • Trajectory: nominal altitude/perigee/apogee history, active campaign time, passive or ballistic time, total time from end of mission, consumption and remaining modeled inventory. A qualifying natural-decay result may need no burn.
  • Maneuvers & coasts: actual timestamped intervals, device, thrust/Isp, consumed mass and propulsion delta-v. Coasts and fractional epochs are retained.
  • Assessments: numerical consistency, selected modeled targets and unresolved requirements. Incomplete search or no candidate does not prove physical infeasibility.
  • Requirements: source versions, clocks, applicability/evidence limits and your selected targets.
  • Frozen inputs: the chosen source, state mass, original/transformed frames, device and physical settings. Later orbit/catalogue edits do not change the study.
To investigate different dates, requirements or settings, use New Plan again. Each calculation is retained separately; the earlier study is preserved. No operational approval or OCM export is available for disposal studies.

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What the numbers mean

The result is the best numerically consistent candidate found in a bounded search, not a guaranteed global minimum. Natural lifetime uses a fixed atmospheric reference scenario and stops at a 120 km perigee proxy; it is not a forecast or a legally equivalent definition of reentry. A 100-year estimate can be censored. Nominal controlled studies must satisfy the selected device’s actual terminal capability and return promptly to a computed surface point inside your selected region. An electric device may be unable to do this; the study will not silently switch devices or turn a slow spiral into a controlled result. Density factors 0.5, 1 and 2 are displayed as scenarios. Factor 1 governs the nominal trade; the others are advisory sensitivities, not calibrated probability bounds. Numerical refinement checks stability, not real-world accuracy.
A nominal intact-body surface intersection is not an actual surviving-debris footprint or a conservative casualty-risk bound. Casualty probability, fragmentation, hardware reliability and statistical footprint confidence remain indeterminate without the necessary evidence. Fleet collision risk, passivation and toxicity are also not certified by this study.