AI & Technical question
How would you create a communication system from Earth to Mars?
- Atlassian
- AI & Technical
- Hard
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What this question tests
Tests technical systems thinking under extreme constraints, requiring the candidate to reason through real physical limitations like light-speed delay and bandwidth rather than a generic networking answer.
How to approach it
- State the core physical constraint upfront: Earth-Mars distance varies enormously, creating a one-way signal delay of several minutes to over twenty minutes at different points in their orbits, ruling out any real-time, request-response communication.
- Redefine the design goal given that constraint: build a store-and-forward, delay-tolerant network rather than a live connection, similar in principle to how deep space networks already operate.
- Address bandwidth and reliability: use relay satellites (around Mars and possibly at Lagrange points) to maximize line-of-sight communication windows, since Mars isn't always in direct view of Earth as both planets orbit.
- Propose a protocol approach: a delay/disruption-tolerant networking protocol that packages data for asynchronous transmission, retrying and rerouting through relays as line-of-sight windows open and close.
- Address prioritization: since bandwidth is scarce and delayed, critical data (life support telemetry, emergency alerts) must be prioritized over routine data (research telemetry, personal messages) in the queue.
- Define success as message delivery reliability and time-to-delivery within the physical constraints, not by any real-time latency target.
What a strong answer includes
- Grounds the design in the real, known physical constraint, several minutes to over twenty minutes of one-way light delay, rather than treating this as normal internet design.
- Correctly reframes the problem as delay-tolerant networking, not live connectivity, which is the actual technical challenge here.
- Proposes relay satellites to solve the line-of-sight problem, a real and necessary piece of any Earth-Mars communication system.
- Adds data prioritization for scarce, delayed bandwidth, showing systems-level thinking beyond just connectivity.
Common mistakes
- Proposing a design as if real-time, low-latency communication were achievable, ignoring the fundamental light-speed delay.
- Ignoring the line-of-sight problem caused by both planets' orbits and rotation.
- Not addressing how scarce bandwidth would be prioritized across data types.
Likely follow-up questions
- How would you handle a relay satellite failure?
- What data would you prioritize when bandwidth is constrained?
- How does this design change during a solar conjunction, when the sun blocks the signal path?
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More questions from Atlassian
Learn the skill behind it
Chapters of the AI PM course that teach what this question tests.
- Chapter 1: Foundations: the model and the decisions it forces on you
- Chapter 8: Evals: define good and make the number defensible
- Chapter 6: Agents and agentic architecture