Get an overview of your conjunction events
The Conjunctions page provides an overview of all detected conjunction events in which one of your spacecrafts is involved.
It contains two parts:
- A conjunction timeline to visualize the expected TCA and criticality for all upcoming conjunction events of your individual spacecrafts.
- A conjunction table to provide further, more detailed information about the conjunction events, such as secondary spacecraft, miss distance, collision probability etc. The Assignment column indicates whether an organization has accepted to perform a collision avoidance maneuver should it be necessary. And the color bar indicates the criticality of the conjunction event. Note that the events are initially filtered to only show the events which are critical or should be observed.
By selecting a conjunction event in the table and clicking on More, you will be forwarded the dedicated coordination case page.
Moreover, you can switch between the Conjunction and the Action view. The Conjunction View provides an overview of all the expected conjunction events (as described before), while the Action View provides an overview of all Actions in all conjunction events. The switch to change the view is available in the upper left corner of the Dashboard.
Coordinating a conjunction event
For each conjunction event, a dedicated coordination case is generated, in which both organizations are invited to coordinate and mitigate the conjunction event. To further facilitate the coordination, different phases have been introduced in the coordination process, to guide the operators. Each phase is linked to suggested actions that should be performed within the given phase.
The coordination case page contains:
- A coordination timeline to visualize the time from conjunction detection to TCA with the different phases as well as the criticality evolution of the conjunction event.
- An updates tab to summarize all injected data and actions that happened so far in the conjunction event.
- An actions tab to illustrate all actions in a Kanban-like format, which are either assigned to your organization, to the other organization, or are already completed.
- An event summary tab to provide an overview of the most relevant conjunction information.
Criticality of a conjunction event
The conjunction events are categorized into three criticality classes: Critical, Observe, and Non-critical. The distinction is made by checking whether the collision probability or the miss distance of the conjunction event (either of them) are within a certain threshold. The collision probability and miss distance thresholds are defined based on industry best practices and are presented in the table below.
In the settings, you can change them to the thresholds your organization wants to use in operations.
| Class | Description | Collision probability | Miss distance |
|---|---|---|---|
| Non-critical | All data available at the current time indicates that it is not required to perform any mitigation measures. | < 1E-5 | > 0.27 km |
| Observe | All data available at the current time indicates that it is not required to perform any mitigation measures, but the analyses also show that the used metrics are close to the threshold of becoming critical. These cases should be observed and they therefore have a higher visibility in the system than non-critical cases. | 1E-5 ≤ x < 1E-4 | 0.135 km < x ≤ 0.27 km |
| Critical | The data available at the current time indicates that the event surpasses the defined thresholds for a critical conjunction which, when following the thresholds, would require a mitigation action to be taken. The threshold is suggested by the Space Safety Coalition. | ≥ 1E-4 | ≤ 0.135 km |
This classification can help operators to put their attention to the most relevant conjunction events. The criticality can change over time (increase or decrease) based on the availability of new data such as by receiving new CDMs with a new collision probability or miss distance estimation, or by uploading ephemeris.
Coordination phases
The following coordination phases are derived from industry best practices and can serve as a guideline for both organizations during the coordination. Each coordination phase has a deadline and is associated with unique actions.
| Phase | Description |
|---|---|
| Case assignment | One of the organizations accepts the assignment of performing a collision avoidance maneuver in case it becomes necessary. |
| Ephemeris upload | Providing up-to-date ephemeris from both organizations for an updated risk assessment. |
| Propose maneuver | The assigned organization uploads one or multiple tentative collision avoidance maneuvers, which can be used to assess the effect of the maneuver on the collision risk. |
| Confirm maneuver | The assigned organization selects one of the uploaded tentative maneuvers as the final collision avoidance maneuver that will be executed. |
| Execute maneuver | The assigned organization informs when the collision avoidance maneuver was executed successfully. |
The deadlines for each phase depend on the time available between detection of a conjunction event and its TCA.
Actions
Actions are elements to support the coordination process between operators. Actions typically have a clear description of the task, a deadline and an assignee. With this, both organizations clearly know who is responsible for what task and until when the execution of the task is expected. Actions are structured in a Kanban-like manner and are generated and assigned automatically by the system.
In correspondence with the coordination phases described above, the following actions are created in the course of a coordination case.
| Action | Description | Options and undoing the action |
|---|---|---|
| Confirm assignment | Either one or both operators are asked to take responsibility in the conjunction event. | You can accept or reject this responsibility. If you reject, the other operator is asked. If they also reject, you will be asked again. Changing the decision is also always possible via API. |
| Upload operational ephemerides | Providing up-to-date operational ephemerides for accurate risk assessment. This is recommended for both operators, roughly once a day. | You can upload as many ephemerides as you want. When you upload one, the action will be considered done and a new one for 24 hours later will be generated. If you don’t want to upload ephemerides, you can reject and won’t get any more actions of this kind. |
| Propose tentative collision avoidance maneuver plan | The operator who accepted the case assignment is asked to propose one or multiple tentative collision avoidance maneuvers. | You can upload up to 10 maneuvers; the action will remain open. If you decide you cannot or don’t want to maneuver, you can also reject the assignment; in that case the other operator will be asked to take over. |
| Select a maneuver plan | The operator who uploaded one or several maneuver plans is asked to select one of the proposed maneuvers as the collision avoidance maneuver that will be executed. This is a commitment; the maneuver plan is now treated as operational. | You get a “Confirm maneuver execution” action. This allows you to confirm execution of the maneuver once it was performed. |
| Confirm maneuver execution | The operator who selected a maneuver plan is asked to confirm once the maneuver was executed. | If something changes or goes wrong, you can let the other operator know of unplanned contingencies. In that case, you are asked to also upload up-to-date operational ephemerides through the “Upload operational ephemerides” action. |
| Validate maneuver execution | The operator who executed a maneuver plan is asked to inform the other operator whether the execution turned out successfully or not, so they know about the conjunction outcome. | Validation currently has to be done by the operator but might also be available automatically in the future. |
As an indication of urgency, actions are categorized into priority classes which are indicated by a color bar on top of the action. The priority is determined mainly based on the criticality of the conjunction event and the remaining time until TCA. The priorities and the associated colors are as follows:
- Urgent (red)
- Required (yellow)
- Recommended (blue)
- Optional (grey)
Workflow
Upon detection of a conjunction event via Space-Track, OKAPI:Astrolabe receives information about it in form of a CDM if authorized by the corresponding satellite operator. Based on the information in the CDM, the conjunction event will be categorized as critical or non-critical considering international guidelines.
Furthermore, OKAPI:Astrolabe generates a dedicated coordination case and invites both operators to the case. The coordination case collects and provides all relevant information to describe and assess the particular conjunction event for the operators. Within the coordination case, both operators can negotiate regarding who should perform a collision avoidance maneuver. Hereby, the main goal of the application is to avoid coordination cases which are critical but not assigned to any operator.