009 - Notifications
Purpose
This document describes the design for notifications in the Monitor Space Hazards service. It aims to be the central design artefact to coalesce thinking on notifications.
Context and scope
One of the key benefits of Monitor Space Hazards is that it provides a system of engagement between Satellite operators, Orbital Analysts, Emergency Response Teams, Regulators, other UK government agencies, and the UK Space Agency on conjunction and re-entry events. A key means of doing this is via notifications (mainly email, but also possibly SMS) and during the original Alpha for the service it was decided to offload this to the central GOV.UK Notify service. The rationale behind this is that GOV.UK Notify has already done the heavy lifting in implementing a GDS compliant email and SMS service with several clients that make integration simple.
Goals and Non-Goals
Goals:
- Ensure satellite operators, orbital analysts, emergency response team members, regulators, other UK government agencies, and UKSA employees receive notifications about upcoming conjunction and re-entry events when they cross specified thresholds
- Ensure orbital analysts receive notifications when ephemeris data is uploaded by satellite operators
- Ensure satellite operators receive notifications that new analysis for a conjunction event is available based on their uploaded ephemeris data
- Ensure that satellite operators receive notifications when no new events meet their thresholds daily (if they select this in their settings)
- Ensure that organisation admins receive notifications when a new member is added/removed or when a user’s permissions are changed
- Ensure members receive notifications when they are added/removed
- Ensure all users could be notified if Space-Track or Monitor Space Hazards goes down for a certain length of time [time TBD based on user research]
- Ensure UKSA admins receive notifications when a new organisation is added
- Ensure notifications sent comply with the GOV.UK Notify guidance
- Provide user authentication through Auth0
- Enable users to turn off notifications entirely if desired
Non-goals:
- Implementing a notifications service from the ground-up.
The actual design
The architecture for sending an email or SMS via GOV.UK Notify is near identical:
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- The service sends an email, or text message, notification to GOV.UK Notify
- GOV.UK Notify sends the email, or text message, to the provider
- The provider delivers the email, or text message, to the recipient
- The recipient receives the email, or text message, and sends a delivery receipt to the provider
- The provider sends the delivery receipt to GOV.UK Notify
- GOV.UK Notify receives the delivery receipt and sends an API response to the service
- The service receives the API response
It is envisaged that GOV.UK Notify will be called primarily from the Python back-end, but on an exception basis (where it makes sense) from the Node front-end also. The only scenario for considering sending notifications from the front-end right now is for magic links. All other notification events should be triggered from the back-end.
User defined thresholds for notifications for events
Users will be able to adjust notification settings by amending the threshold for notifications in their account settings page. Default thresholds will be used before users first sign-in; however, they will be asked to review/edit these the first time they log in.
For satellite operators accessing the conjunction service, the default settings will be based on typical values but users will be able to edit all of the thresholds used to determine the sending of notifications: Probability of collision, Total miss distance, Radial miss distance, and Time to event. They will be informed that “It is your responsibility to set the thresholds so that you can operate your satellite successfully.”
For government users accessing the conjunction and re-entry services, they will be able to adjust the notifications they receive by joining different distribution lists on their account settings page. The criteria for sending notifications to different distribution lists will remain largely unchanged from UKSA’s Standard Operating Procedures prior to the digitisation of these services.
For re-entry alerts, government users will also be able to select geographical areas of interest, meaning they will only receive alerts about re-entry events if their selected areas of interest might be impacted.
How will users be notified?
The notifications will be sent to the registered email accounts of the users and as text messages to their phone numbers (if they choose to receive these).
The email notifications will be sent using GOV.UK Notify. The service includes unlimited free emails and the ability to track how many messages are sent and find out which ones are not being delivered. There is also a performance SLA for 95% of emails and text messages to be sent within 10 seconds. It is supported by the Government Digital Service 24 hours a day, 7 days a week. This gives us confidence that email notifications will not go down suddenly for an extended period of time, which could increase the risk of a collision or a re-entry event going unnoticed.
Types of notifications
An important mechanism that GOV.UK Notify uses is templates and the Monitor Space Hazards service team have produced a template for each event that triggers a notification. The current list of events to trigger a notification is:
- Notifications relating to events:
- New events that cross user thresholds
- Updated events that cross user thresholds
- New UKSA analysis for an event
- Updated event that no longer crosses user thresholds (post MVP)
- No events have met thresholds (in the last 24 hours) (post MVP)
- Notifications relating to user management
- New member added/suspended/removed from your organisation
- Organisation admin has changed
- New UK satellite has been added to Monitor Space Hazards
- User authentication via Auth0
- Ephemeris data is created or updated for a particular satellite of interest
- SpaceTrack has been unreachable for a configurable period of time
Emails to operators warning of upcoming conjunction events passing user thresholds will include a list of all event URLs and their TCA in an email. These emails will bundle together all events that have met the notification criteria since the last notification was sent. Event notifications will be sent every 12 hours and at start and end of day e.g. 8am / 8pm. This pattern will be tested with users at private beta.
User journey for setting notification thresholds and choices
The journey for users to set their notification thresholds and choices differs between the first time they log in and subsequent times.
First time logging in to Monitor Space Hazards:
- Sign in via Auth0
- Page where users choose whether to receive email or text notifications for various communications
- Page where users view/update their default notification thresholds
Subsequent uses of Monitor Space Hazards (to adjust default notification settings):
- Log in via Auth0
- Homepage
- Account settings
- Adjust notification type settings
- Adjust event notification threshold settings
What will the notifications say?
Templates can be found in GOV.UK Notify.
GOV.UK Notify’s guidance says: “You cannot convert text into a link. Research shows that people like to check a URL looks genuine before clicking the link in an email. This is hard to do if the URL is hidden behind clickable link text.”
Alternatives considered
Given the eligibility of the Monitor Space Hazards service to use GOV.UK Notify, and its default position for eligible services, no alternatives were considered. If the choice of GOV.UK Notify proves to be a problem, then the exit-costs of leaving are considered low given the low investment in initial integration (via the clients available) and ongoing billing (all emails are free and SMS up to 150,000 messages annually).
Limits
If you repeatedly send text messages to the same number the phone networks will block them.
There’s an hourly limit of:
- 20 messages with the same content
- 100 messages with any content