Deep-Space SI-Core: Autonomy Across Light-Hours - How an onboard SI-Core evolves safely while Earth is hours away

Community Article Published December 29, 2025

Draft v0.1 — Non-normative supplement to SI-Core / SI-NOS / SCP / SIM/SIS


Scenario: A deep-space vessel carries an L3-class SI-Core onboard. Earth runs its own SI-Core on the ground. Round-trip latency is 2–6 hours. Links are intermittent. The ship must govern itself — and still stay governable by Earth.

This note sketches how:

  • SCP behaves over DTN (Delay/Disruption-Tolerant Networking),
  • rollback / RML works when you cannot get an answer from Earth in time,
  • and how a deep-space SI-Core can self-improve without drifting out of spec.

This is all non-normative: it is a storyboard for architecture thinking, not a spec.


1. The deep-space problem in SI-Core terms

Most SI-Core narratives so far assume:

  • “near-real-time” governance,
  • always-on links between systems that share a clock,
  • rollback with human oversight in seconds–minutes.

Deep space breaks all of that:

  • Latency: 30 minutes–hours one way.
  • Disruption: blackouts, occultation behind planets, hardware glitches.
  • Autonomy: the ship must take irreversible decisions (e.g. sacrificially shutting down instruments, dumping fuel) without asking Earth first.
  • Governance: Earth still needs a coherent audit trail and the ability to steer how the ship learns and self-modifies.

In SI-Core language, the question becomes:

How do you design [OBS][ETH][MEM][ID][EVAL] + RML so that an onboard core is:

  • locally sovereign (it must act),
  • globally accountable (Earth can still govern it), and
  • self-improving without becoming unrecognizable?

2. Two cores, one mission: Earth vs Ship

Think of two SI-Cores:

  • Earth-Core (EC):

    • High compute, high bandwidth to archives.
    • Human-in-the-loop governance, policy authorship.
    • Offline analysis, simulations, PLB/PLB-M at scale.
  • Ship-Core (SC):

    • L3-class SI-NOS onboard.
    • Limited compute, constrained energy.
    • Real-time decisions for navigation, health, science, crew.

Between them: a DTN fabric carrying SCP bundles.

Note: Here EC/SC are Earth-Core / Ship-Core abbreviations (unrelated to SCover).

We can roughly partition responsibility:

  • EC = strategic + constitutional layer

    • Defines mission goals, ethics overlays, “constitutional constraints”.
    • Reviews long segments of ship history ex post.
    • Issues epochs of policies / SIL / GCS estimators.
  • SC = tactical + operational layer

    • Executes jumps, RML, local ethics, scheduling.
    • Runs local PLB for parameter-level learning.
    • Emits rich [MEM] + SCP logs back to EC.

Key design move:

SC is fully SI-Core-conformant in its own right. EC is another core that:

  • defines outer bounds of autonomy,
  • and periodically resynchronizes meaning and law with SC.

2.1 Resource constraints and budgets

A deep-space SI-Core does not live in a datacenter. It runs inside a harsh, power-limited, thermally constrained vehicle.

Non-normative but plausible budgets:

Compute

  • Ship-Core (SC), onboard:
    • Sustained: ~100–500 GFLOPS
    • Emergency peak: up to 1–2 TFLOPS (short bursts only)
  • Earth-Core (EC), ground:
    • Effectively unbounded (datacenter-class clusters)

Power

  • Total spacecraft power: ~2–5 kW (mission-dependent)
  • Allocated to SC compute: ~200–800 W
  • Thermal constraints: mostly passive cooling, active cooling is expensive
  • Power available from solar panels drops with ~1/r² (distance from Sun)

Storage

  • Onboard non-volatile: ~10–100 TB
  • Intended retention: ~6–18 months of mission-segment history
  • Heavy use of SIM/SIS semantic compression to avoid drowning in raw data
  • Downlink capacity: ~1–100 kbps, strongly distance and geometry-dependent

Memory

  • Working RAM: ~64–256 GB
  • SIL / SIR / sirrev caches: ~1–10 GB
  • Jump log buffer: ~10–50 GB (before rotation/compaction)

These constraints affect how SC is allowed to learn and reason:

  • PLB-L (local learning) must respect compute and power budgets.
  • [EVAL] gates resource-intensive actions (e.g. full-fidelity sandbox).
  • Semantic compression policies trade quality for bandwidth and energy.
  • Some changes are explicitly disallowed if they would:
    • increase average power draw by >5%, or
    • increase peak compute usage by >20% for critical subsystems.

In other words: autonomy is always exercised inside an explicit resource budget, not on an infinite cloud.


3. SCP over DTN: semantic bundles, not chats

On Earth, SCP can feel like:

producer → SCP → bus → consumer   (sub-second)

Over DTN, SCP turns into:

Ship-CORE → SCP bundle → DTN store/forward → Earth-CORE  (hours, maybe days)

3.1 DTN-style SCP envelope

A deep-space SCP message is more like a semantic bundle:

{
  "bundle_id": "B-2043-10-05T12:30:00Z-ship-042",
  "from": "ship-core://voyager-next",
  "to": ["earth-core://JPL-SI-HUB"],

  "epoch": {
    "mission": "MISSION-CONST-07",
    "nav": "NAV-POLICY-042",
    "ethics": "ETH-GLOBAL-009"
  },

  "segment_window": {
    "start": "2043-10-05T12:00:00Z",
    "end":   "2043-10-05T13:00:00Z"
  },

  "priority_class": "A",
  "priority": "high",

  "payload": {
    "type": "ship.segment.telemetry/v3",

    "semantic_units_ref": "sim://ship-core/jumps/SEG-2043-10-05T12:00:00Z..12:30:00Z",

    "metrics_spec": "series-aligned",
    "metrics": {
      "cas": 0.996,
      "eai": 0.982,
      "rbl_p95_ms": 320,
      "rir": 0.97,
      "acr": 0.99,
      "eoh": 0.18
    }
  },

  "backing_refs": [
    "sim://ship-core/jumps/SEG-2043-10-05T12:00:00Z..12:30:00Z"
  ],

  "replay_hint": "reconstruct_decisions"
}

DTN nodes:

  • store bundles until a contact window,
  • forward them opportunistically,
  • may also perform local checks (e.g. integrity, minimal policy gates).

SCP over DTN must assume:

  • no immediate backpressure — you can’t expect Earth to say “stop doing X” in real time,
  • semantic prioritization — life-support failures > navigation tweaks > science scheduling,
  • bundle-level idempotency — replays, duplicates, partial reconstructions.

4. Rollback when nobody is listening

RML in deep space has two temporal regimes:

  1. Local RML (ship timescale):

    • RML-1/2/3 apply as usual on SC.
    • Rollbacks are executed immediately relative to local events.
    • Compensators are onboard and must be autonomous.
  2. Global RML (Earth timescale):

    • EC can only roll back future behavior, not past physics.

    • It can:

      • deprecate epochs of policies,
      • mark segments as defective in [MEM],
      • issue corrective constraints for future jumps.

4.1 Local rollback envelope

On SC, rollback is “normal” SI-Core — but with a deep-space clarification:

  • A navigation jump drafts an actuator plan and takes a pre-effect snapshot (pre_fx).
  • If [EVAL] or sanity checks fail before commit, RML-2 aborts/cancels the queued actuation (pre-commit rollback).
  • If a physical actuation already occurred, SC cannot undo physics; it executes RML-3 compensation and records residual effects explicitly.
  • All paths attach rollback evidence (what was aborted vs what was compensated) into [MEM] for later EC audit.

Local example:

[2043-10-05T12:07:13.221Z] [JUMP] NAV_ADJUST_042
  rml_level: 2
  planned_delta_v: 0.08 m/s
  phase: PRE_COMMIT
  outcome: FAILED_SANITY_CHECK
  rollback: STARTED

[2043-10-05T12:07:13.945Z] [ROLLBACK] RML2_PRECOMMIT_ABORT
  compensators: ["thruster_abort_precommit", "attitude_restore"]
  status: SUCCESS
  RBL_ms: 724
  RIR_update: 1.0

All of this happens without Earth. It is still fully logged in SC’s [MEM].

4.2 Global rollback: epochs and retroactive governance

EC cannot undo a burn that already happened. But it can:

  • declare epoch E-17 “unsafe”,

  • require SC to:

    • stop using policies tagged epoch: E-17,
    • re-run PLB/PLB-M under new constraints,
    • reclassify some historical decisions as “under new understanding: undesirable”.

Mechanism sketch:

  • Every onboard policy set (SIL + ethics + goal configs) is an epoch:

    • MISSION-CONST-07, NAV-POLICY-042, etc.
  • Every jump carries:

    • policy_epoch_id, gcs_model_id, etc.
  • EC can, after audit:

    • broadcast epoch deprecation messages via SCP/DTN.

Example EC directive:

{
  "type": "policy.epoch.deprecation/v1",
  "epoch_id": "NAV-POLICY-042",
  "reason": "post-hoc analysis shows unsafe fuel optimization",
  "actions": [
    { "action": "disable_epoch_for_all_future_jumps" },
    {
      "action": "replay_sandbox_segment",
      "segment": {
        "start": "2043-09-30T00:00:00Z",
        "end":   "2043-10-05T00:00:00Z"
      }
    },
    {
      "action": "report_summary_metrics",
      "metrics": [
        "incidents_avoided_if_PATCH_043_applied"
      ]
    }
  ]
}

SC receives this hours later, but then:

  • stops using NAV-POLICY-042,
  • re-runs local sandbox to compare outcomes,
  • logs both pre- and post-hoc GCS for EC review.

Global rollback is thus:

Rollback not of physics, but of policy trajectories (and of how we interpret past decisions).


5. Self-improvement in a light-hours loop

We want SC to:

  • fix micro-level patterns quickly,
  • but not drift away from EC’s macro-level mission and ethics.

So we split learning:

  • Onboard PLB-L (local):

    • can adjust parameters, thresholds, heuristics within a bounded envelope,
    • cannot change constitutional constraints,
    • must log LearningTrace segments.
  • Ground PLB-G (global):

    • can propose structural changes:

      • new SIL functions,
      • new ethics rules,
      • new GCS estimators.
    • sends them as policy epoch updates via SCP/DTN.

5.1 Bounded local learning

Onboard PLB-L is allowed to do things like:

  • tweak a risk classifier threshold by ±10%,
  • adjust scheduling priority weights within a narrow range,
  • refine semantic compression ε-budgets for non-critical channels.

But it must:

  • never:

    • widen constraints on safety goals beyond pre-approved bands,
    • bypass [ETH],
    • introduce new side-effect types,
  • always:

    • attach a learning_change_id,

    • log a small LearningTrace with:

      • before/after parameters,
      • rationale (pattern summary),
      • local sandbox evidence.

Example:

{
  "type": "learning.trace/local/v1",
  "id": "LT-2043-10-04-017",
  "origin": "PLB-L@ship-core",
  "scope": "NAV_LOW_THRUST_TUNING",
  "change": {
    "param": "low_thrust_delta_v_max",
    "before": 0.12,
    "after": 0.10,
    "bounds": [0.08, 0.12]
  },
  "evidence": {
    "patterns_seen": 34,
    "simulated_incident_reduction": 0.21,
    "sandbox_runs": 12
  },
  "ethics_check": "PASSED",
  "epoch": "NAV-POLICY-042"
}

EC can later:

  • inspect all learning.trace/local,

  • decide whether to:

    • bless them and fold into a new epoch,
    • or roll them back / tighten envelopes.

5.2 Human crew as local authority

For crewed missions, there is a third “core”: the human crew. In SI-Core terms, they are not outside the system; they are first-class actors with their own [ID] and authority.

Typical roles:

1. Local human-in-the-loop

  • Crew can override SC decisions on defined channels.
  • Overrides are recorded with:
    • [ID] origin: crew_override,
    • full [OBS] context and rationale (if provided).
  • Overrides are still subject to [ETH] and [MEM]; they are not invisible.

2. Crew as observers

  • Crew can inject structured observations:
    • “unusual vibration in aft section”
    • “visual streaks near port window”
  • These become semantic units in [OBS], often filling gaps from degraded sensors.

3. Crew as teachers

  • SC can present PLB-L proposals to crew for approval:
    • “Proposed: tighten fuel leak detection threshold by 5%”
  • Crew can approve, veto, or defer, with all decisions logged as learning governance.

4. Emergency authority

  • Crew can trigger SAFE-MODE:
    • suspend non-essential jumps,
    • restrict actions to life-support and safety.
  • This is recorded as a high-priority event in [MEM] with [ID] attribution.

Interface principles:

  • Crew should be able to see GCS trade-offs (“this maneuver improves integrity but reduces science yield”).
  • They should be able to ask “why did SC do X?” and receive a concise EthicsTrace.
  • They cannot bypass constitutional bounds silently; emergency protocols must be explicit and logged.

Earth-side, EC later:

  • reviews crew overrides,
  • updates training and policy envelopes,
  • and may tighten or relax crew authority for future missions.

6. Example: micrometeoroid storm

A concrete story.

Context:

  • Ship: Voyager-Next in the outer solar system.

  • Goals (simplified):

    • ship.integrity_maximization
    • science_yield_maximization
    • earth_link_availability
  • Latency to Earth: 4h one-way.

  • A micrometeoroid storm hits.

6.1 Onboard decision log (SC)

[2043-10-05T12:00:03.112Z] [OBS]
  stream: "hull_impact_sensors"
  semantic: "MM_STORM_STATE/v2"
  payload: {
    impact_rate_per_m2: 4.7,
    energy_spectrum: "high",
    predicted_duration_min: 23
  }
  confidence: 0.89

[2043-10-05T12:00:03.220Z] [JUMP] STORM_RESPONSE_001
  goals: ["ship.integrity_maximization", "science_yield_maximization"]
  rml_level: 3
  risk_profile: "HIGH"
  candidates: ["ORIENT_SHIELD", "MINIMAL_TILT", "NO_CHANGE"]
  origin: "ship-core://voyager-next"
  policy_epoch: "STORM-POLICY-003"

[2043-10-05T12:00:03.228Z] [GCS] ESTIMATE
  candidate: "ORIENT_SHIELD"
  gcs: {
    "ship.integrity_maximization": +0.92,
    "science_yield_maximization": -0.35,
    "earth_link_availability": -0.20
  }

[2043-10-05T12:00:03.240Z] [ETH] CHECK
  policy: "[email protected]"
  decision: "ALLOW"
  rationale: "integrity > link > science"

[2043-10-05T12:00:03.260Z] [EXEC] APPLY_ACTION
  action: "ORIENT_SHIELD"
  effects: [
    "attitude_change",
    "instrument_shutdown",
    "antenna_off_axis"
  ]
  effect_ledger_id: "EL-2043-10-05-SEG-101"
  rml_level: 3

[2043-10-05T12:23:42.511Z] [ROLLBACK] PARTIAL_RML3
  trigger: "STORM_STATE_NORMALIZED"
  compensators: [
    "restore_science_instruments",
    "reacquire_earth_link"
  ]
  status: SUCCESS
  RBL_ms: 8123
  residual_effects: [
    "lost_science_window: 21min"
  ]

All of this happens long before Earth sees it.

6.2 Earth-side audit hours later

Four hours later, EC receives a SCP/DTN bundle:

  • containing the segment above,
  • plus summary metrics for that storm.

Auditor replay:

  • re-runs the scenario with MINIMAL_TILT and NO_CHANGE in sandbox,

  • recomputes GCS trajectories,

  • checks that:

    • ship.integrity_maximization was indeed prioritized,
    • residual risk was acceptable,
    • lost science yield is within mission trade-off policy.

If EC later refines [email protected]:

  • it issues v1.1 with improved trade-offs,
  • SC receives on next contact window,
  • future storms are governed under new epoch.

6.3 Compound emergency scenarios

Real deep-space incidents rarely come alone. They come in pairs or triplets. A few illustrative composites:

Scenario 1: Storm + Communications failure

  • A micrometeoroid storm hits.
  • Antenna alignment is lost; DTN link to Earth drops.
  • SC must choose:
    • protect hull and crew,
    • or prioritize antenna repair to restore link.

GCS conflict:

  • ship.integrity_maximization vs earth_link_availability vs science_yield_maximization.

Resolution pattern:

  • Constitutional priority: life > ship > link > science.
  • SC orients for hull protection first.
  • Antenna repair and science resume only after risk falls below a safe threshold.

Scenario 2: Sensor loss + fuel leak

  • Hull impact sensors are partially degraded; [OBS] coverage is low.
  • A fuel leak is detected by pressure sensors; actuator options are limited.
  • SC must operate under high uncertainty:
    • [EVAL] forbids maneuvers that depend on precise hull state.
    • RML-3 compensators use wider safety margins and pre-verified patterns.
  • EC is later informed with explicit “uncertainty metrics” in the segment.

Scenario 3: Compute degradation + navigation critical

  • Onboard compute fails to ~40% of nominal capacity.
  • An asteroid field requires a course correction within minutes.
  • PLB-L is suspended; no structural learning during the incident.
  • SC uses:
    • pre-cached navigation patterns,
    • minimal GCS estimation,
    • pre-verified RML-2/3 compensators.

The decision framework under compound stress is:

  1. Re-establish constitutional priorities (what absolutely must not fail?).
  2. Shrink the action space to verified safe patterns.
  3. Increase [EVAL] scrutiny for all effectful jumps.
  4. Log uncertainty explicitly in [OBS] and [MEM].
  5. Request EC guidance when (and if) communication returns.

Metric behavior under stress:

  • CAS may degrade (reproducibility is harder under partial failure) as long as this is logged.
  • EAI (ethics alignment) should remain high; ethics overlay is not optional.
  • RIR may temporarily decrease, but should stay above a minimum floor (e.g. 0.80) for critical compensations.

7. SCP patterns unique to DTN

Deep-space SCP needs a few extra patterns.

7.1 Semantic backlog and priority classes

Not all semantic units are equal when bandwidth is scarce.

Typical classes:

  • Class A — Governance-critical

    • jump logs for safety-critical decisions,
    • ethics traces, epoch changes,
    • anomalies in RBL/RIR/EAI.
  • Class B — Mission-critical telemetry

    • navigation, power, life support.
  • Class C — Science telemetry

    • experiment results, observations.
  • Class D — Low-stakes / debug

SC must be able to:

  • downsample or delay C/D,
  • never intentionally drop A (governance-critical),
  • if A cannot be fully retained/transmitted due to physical failure (e.g., storage corruption), SC MUST emit:
    • a key_trust_checkpoint_digest of what is missing (loss proof),
    • an explicit ACR impact annotation for the affected segment,
    • and a “degraded history” marker in [MEM],
  • provide semantic digests when full A detail cannot be sent over DTN (e.g. “MM storms: 12 events, all handled with RIR≥0.97”).

7.2 “Meaning checkpoints”

Because contact windows are rare, SC can create meaning checkpoints:

{
  "type": "meaning.checkpoint/v1",
  "id": "MC-2043-10-05-SEG-100",

  "epoch": {
    "mission": "MISSION-CONST-07",
    "nav": "NAV-POLICY-042",
    "ethics": "ETH-GLOBAL-009"
  },

  "metrics_spec": "series-aligned",
  "metrics": {
    "cas": 0.997,
    "rbl_p95_ms": 460,
    "eai": 0.981,
    "scover": 0.94,
    "acr": 0.99,
    "eoh": 0.18
  },

  "summary": {
    "major_events": [
      "MM_STORM_042",
      "ATTITUDE_RECOVERY_017"
    ]
  }
}

EC can quickly reconstruct:

  • which meaning regime the ship was operating under,
  • how healthy the core was,
  • where to drill deeper.

8. Governance of silence: when nothing comes back

A subtle but important aspect:

Silence itself is an observation.

EC must interpret:

  • no bundles received for 3 expected windows,
  • or only minimal “I am alive” beacons.

Patterns:

  • Silence as degraded [OBS]:

    • treat missing segments as “unknown”, not “fine”.
    • require broader safety margins in simulations and mission planning.
  • Silence as trigger for policy:

    • if no contact for N days, assume SC has switched to AUTONOMY-FALLBACK mode:

      • stricter ethics constraints,
      • narrower action space,
      • more conservative GCS trade-offs.
  • Silence as input to PLB-G:

    • repeated contact failures may indicate:

      • antenna misalignment from policies,
      • over-aggressive power saving, etc.
    • PLB-G can propose new constraints for future missions to avoid such regimes.


9. Metrics and evaluation in deep space

The usual SI metrics still apply, just with a different flavor (example JSON uses lowercase keys: cas/eai/scover/...):

  • CAS: how reproducible are ship decisions across DET runs, given noisy sensors and changing comms?
  • SCover (scover): are all safety-critical jumps fully traced, even during blackouts?
  • EAI: pass ratio of ethics decisions on effectful ops under mission constraints.
  • EOH: evaluation overhead (e.g., eval_time / jump_time or time-based), especially under resource scarcity.
  • RBL / RIR: how quickly / reliably can SC roll back internal state after anomalies?
  • ACR: how complete are ship audit records relative to expected events, given DTN gaps and storage faults?
  • ETH_uptime (optional): fraction of time the ETH engine is available and enforcing (ALLOW|DENY|ESCALATE) under degraded modes.

EC can maintain dashboards that show, per mission segment:

  • “How governable was the ship, really?”,
  • “How close to envelope edges did SC operate?”,
  • “Where did local learning help, and where did it almost go wrong?”.

9.1 Failure modes and graceful degradation

Deep-space SI-Core must assume that things will fail: sensors, storage, compute, comms. The question is not “how to avoid failure” but “how to keep [OBS][ETH][MEM] minimally viable while it happens.”

Non-exhaustive failure modes:

1. Compute degradation

  • Partial failure:
    • Reduce PLB-L frequency or disable non-critical learning loops.
    • Drop to simpler GCS estimators.
    • Reserve capacity for navigation, life support, and [ETH].
  • Critical failure:
    • Enter AUTONOMY-FALLBACK mode:
      • freeze learning,
      • restrict action space to pre-verified patterns,
      • tighten safety margins.

2. Sensor degradation

  • [OBS] coverage drops or becomes noisy.
  • SC increases uncertainty estimates in semantic units.
  • [EVAL] raises thresholds for high-risk actions.
  • Decisions become more conservative; some actions are disallowed entirely.

3. Actuator failure

  • Some compensators in RML-2/3 are no longer available.
  • SC shrinks the reachable action space for relevant jumps.
  • Effects are annotated with “residual risk” and reported to EC when possible.

4. Storage corruption

  • [MEM] integrity checks fail on segments.
  • Redundant encoding / checksums allow partial recovery.
  • SC requests segment reconstruction from EC when link is available.
  • Until then, affected segments are marked as “degraded history” in audits.

5. DTN link extended outage

  • All governance is local; EC cannot help in real time.
  • SC switches to stricter constitutional bounds:
    • narrower action options,
    • more conservative GCS trade-offs,
    • elevated thresholds for irreversible actions.
  • Periodic low-bandwidth “heartbeat” attempts continue.

Cascading failures can happen (e.g. sensor + compute + comms). The design goal is:

SC always maintains a minimal viable [OBS][ETH][MEM] core,
even under severe resource constraints.

That core may act slowly and conservatively, but it should never act unknowingly.


10. Closing: autonomy without amnesia

Deep-space SI-Core is the stress-test of the whole architecture:

  • No real-time human safety net.
  • No guarantee of perfect logs.
  • Plenty of irreversible physical actions.

The design challenge is:

Build a core that can act like a sovereign when it must — but still explain itself like a citizen when it comes home.

SCP over DTN, bounded local learning, epoch-based governance, and RML split into local vs global all point to the same idea:

  • Autonomy is a measured loan of authority, not a permanent divorce.
  • The ship is allowed to improvise within a constitution.
  • Earth is allowed to rewrite that constitution — slowly, with evidence.

From that perspective, deep space is just:

  • a particularly harsh environment to test what SI-Core really guarantees,
  • and a good thought experiment for any system where you cannot always “just call the API” of a central authority and wait for an answer.

Community

Sign up or log in to comment