Comprehensive ISO Network (CISON)

• CISON is an integrated multi-tiered framework that enables scalable, predictive detection and characterization of interstellar objects.
• It combines dual-hemisphere wide-field surveys with rapid high-resolution follow-ups, reducing ISO recovery uncertainties and time delays.
• Leveraging differential Loeb Scale metrics and interceptor missions, CISON transforms reactive ISO observation into proactive planetary defense operations.

The Comprehensive ISO Network (CISON) is an integrated, multi-tiered observational framework designed to enable scalable, predictive discovery and characterization of interstellar objects (ISOs) in the solar system. Conceived as a solution to detection and follow-up limitations inherent in the current ad hoc ISO observational infrastructure, CISON provides a tightly coupled end-to-end system. Its architecture incorporates dual-hemisphere wide-field discovery, rapid high-resolution characterization—including lunar interferometric imaging—and selective escalation to interceptor missions. By implementing a differential formulation of the Loeb Scale for anomaly classification and risk assessment, CISON pivots ISO astronomy from a reactive to a predictive science and aligns it directly with planetary defense protocols (Trivedi et al., 29 Jan 2026).

1. System Architecture and Data Flow

CISON is structured as a three-layered, tightly integrated system with explicitly defined hardware and software interfaces:

• Dual-Hemisphere Wide-Field Discovery: Employs two wide-field telescopes (Rubin/LSST class, 8.4 m aperture each, northern and southern hemispheres) for continuous sky coverage.
• Rapid High-Resolution Characterization: Initiates sub-24 h follow-up using a lunar-based optical interferometer and a network of ground- or space-based spectrographs.
• Selective Escalation to Interceptor Missions: Triggers dedicated spacecraft interception for ISOs exceeding predetermined thresholds in anomaly or risk, as quantified by the Loeb Scale.

The data flow proceeds as follows:

1. Acquisition: Raw images from both hemispheres are processed through difference-imaging and transient detection pipelines, producing candidate ISO lists.
2. Preliminary Inference: An orbit and photometry inference module computes parameters such as absolute magnitude (H), hyperbolic excess velocity ($v_\infty$), geocentric distance ($\Delta$), and light curves.
3. Loeb Scale Decision Logic: Interim anomaly metrics $m_i(r)$ and instantaneous scores $S_{\rm inst}(r)$ are computed.
4. Branching: Objects reaching relevant triggers branch to either lunar-provided high-resolution imaging or spectroscopic follow-up. Both feed into Bayesian parameter estimation and Loeb Scale updating.
5. Interceptor Escalation: If refined effective score $S_{\rm eff}(r)$ or impact risk $H(r)$ exceed critical values, automated interfacing invokes an interceptor trajectory solver.

Automated, sub-24 h alerting and data transfer are embedded at each layer to minimize latency and maximize predictive capacity. Each module is a discrete hardware/software element, ensuring modularity and upgradeability (Trivedi et al., 29 Jan 2026).

2. Dual-Hemisphere Wide-Field Survey Design

CISON’s sky survey sub-network is modeled on twin Rubin/LSST-class observatories:

• Optical Parameters:
  • Apertures: 8.4 m (×2)
  • Field-of-view: 9.6 deg² per telescope (3.5° diameter)
  • Single-exposure depth: $m_{\rm lim}\approx24.5$ (30 s, r band)
  • Nightly sky coverage: $\sim$18,000 deg²/site; $\sim$36,000 deg² total
• Survey Cadence and Detection Rate:
  • Each field is revisited every 2–3 nights.
  • The instantaneous detection rate $\Gamma$ is proportional to $\mathcal{E}\,\epsilon(m_{\rm lim},\,v,\,\alpha)$, with efficiency $\mathcal{E}=A\,\Omega$ determined by collecting area $A$ and field-of-view $\Omega$.
• Performance Metrics:
  • ISO recovery: 4–6 yr$^{-1}$ (cf. $\sim$1 yr$^{-1}$ currently)
  • False-positive rate $<$0.1% after ML vetting
  • Missed ISO fraction $<$5%
  • Sky-tiling optimization is governed by pseudo-code maximizing ISO yield per unit area, penalizing high airmass and operational costs:

initialize grid G of unobserved fields for each time slot t in night-window: select field f* = argmax_{f in G}[Y(f)/(airmass(f)*cost(f))] observe f*; remove f* from G

• $Y(f)$ is the expected ISO yield per field from population models; $cost$ includes slew/readout overheads.

Dual-hemisphere deployment substantially removes seasonal blind spots and cadence gaps—a key failure mode for rapid ISOs (Trivedi et al., 29 Jan 2026).

3. High-Resolution Characterization: Lunar Interferometry and Spectroscopy

Triggered within 24 h of ISO discovery, CISON advances characterization using a two-pronged approach:

• Lunar Optical Interferometer:
  • Baseline $D\approx100$–200 m; wavelength range $\lambda=0.5$–2 µm
  • Angular resolution $\theta\sim\lambda/D \approx 5\times10^{-9}$–$2\times10^{-8}$ rad
  • At $\Delta=0.1$ AU, corresponding linear resolution is $\sim$100 m
  • Pointing/tracking latency $<$1 h
• Spectrographic/Imaging Follow-up:
  • Network of 2–10 m class telescopes, $R=2{,}000$–10,000 over 0.3–5 µm
  • $S/N \gtrsim 20$ for $m\sim20$ targets in $<$1 h; slew/response times $<$6 h
• Data Analysis:
  • Fringe-tracking and phase-closure reconstruct images via inverse Fourier transform: $$\mathbf{I}(\boldsymbol{\theta}) = \mathcal{F}^{-1}\{V(u,v)\}$$.
  • Fisher information matrix $\mathcal{I}_{ij}$ gains new orthogonal modes, collapsing degeneracies in size–albedo–shape estimations by factors of $10^2$–$10^3$.
  • Detailed rotation and surface features directly inform advanced non-gravitational acceleration models $\mathbf{a}_{\rm ng}\sim f\,\dot m\,u/M$.

Significance lies in the rapid reduction of parameter uncertainties, enabling both scientific study and timely risk assessment (Trivedi et al., 29 Jan 2026).

4. Interceptor Missions and Automated Escalation

For ISOs flagged as high-priority by the Loeb logic, CISON escalates to active interception:

• Trigger Criteria: Escalation is gated by $S_{\rm eff}(r)$—the effective Loeb scale score—or impact risk $H(r)$ crossing a critical threshold.
• Propulsion Requirements:
  • $$\Delta v \gtrsim v_{\rm rel}\,(1 - t_{\rm launch}/t_{\rm encounter})$$
  • Example vehicle: 500–1,000 kg dry mass, $\Delta v$ budget 10–12 km/s, $C_3<$50 km²/s²
  • Typical launch-to-rendezvous: 2–6 weeks
• Mission Timeline: Discovery → Orbit fit → Decision (Loeb) → Launch window → Cruise → Flyby/Rendezvous.
• Trajectory Design: Employs patched-conic approach with Lambert solvers.

This tier operationalizes ISO study as an active, rather than passive, discipline, and directly connects to planetary defense actions (Trivedi et al., 29 Jan 2026).

5. Differential Loeb Scale: Classification and Predictive Modelling

CISON’s architecture centers on a differential Loeb Scale logic that enables predictive, rather than strictly reactive, ISO prioritization:

• Metric Aggregation: Anomaly metrics $m_i(r)$ (trajectory, shape, spectral, non-grav accelerations, impact probabilities) feed into an instantaneous score:

$$S_{\rm inst}(r) = \sum_i w_i\,m_i(r) + \sum_{i<j}w_{ij}\,m_i(r)\,m_j(r)$$

with $w_i$, $w_{ij}$ mapping anomalies to a 5-level Loeb Scale.

• Time Evolution: The effective score $S_{\rm eff}(r)$ evolves via a relaxation equation:

$$\frac{dS_{\rm eff}}{dr} = \frac{S_{\rm inst}(r) - S_{\rm eff}(r)}{L}$$

where $L$ is a “relaxation length” (in AU), dictating convergence speed. CISON’s reduced uncertainties $\sigma_{m_i}$ permit smaller $L$, yielding faster decision capability.

• Predictive Distribution at Earth Encounter:

$$P\!\bigl(S_{\rm eff}(1\,\mathrm{AU})\mid D_{\rm det}\bigr) = \int d\boldsymbol{\theta}\;P(\boldsymbol{\theta}\mid D_{\rm det})\;\delta\!\bigl(S_{\rm eff}(1\,\mathrm{AU};\boldsymbol{\theta})-s\bigr)$$

This predictive approach underpins prioritized dynamic tasking for follow-up and defense operations.

6. Scalability, International Coordination, and Planetary Defense

CISON is structured for global, scalable operation and direct planetary defense integration:

• Resource Requirements:
  • Rubin North upgrade ($\sim$ $500$ M USD)
  • Lunar interferometer incremental ($\sim$ $200$ M, Artemis piggy-back)
  • Interceptor spacecraft ($\sim$ $150$ M each for 2–3 units)
  • Personnel: $\sim$50 FTEs (survey pipelines), $\sim$20 FTEs (characterization), $\sim$10 FTEs (mission & risk)
• International Collaboration:
  • Data sharing among LSST/NASA-PDCO (US), ESA NEOCC (EU), Japan, and Australia.
  • Joint ground-station network for lunar data.
• Planetary Defense Interfaces:
  • Refined orbit and probability results feed directly into Sentry (NASA) and CLOMON2 (ESA) risk tables.
  • Loeb-based alerts can invoke national/international mitigation groups, and interceptor integration aligns with existing defense protocols.

This coordination ensures CISON’s outputs are actionable within existing transnational safety frameworks (Trivedi et al., 29 Jan 2026).

7. System Performance Tables and Comparative Metrics

Component	Aperture/Baseline	FoV/λ-band	Limiting Mag/θ, S/N	Cadence
Wide-Field Surveys	8.4 m (×2)	9.6 deg² (r-band)	$m_{\rm lim}\approx24.5$	2–3 d
Lunar Interferometer	100–200 m	0.5–2 µm	100 m @ 0.1 AU	Target-of-opportunity
Spectrographs/Imagers	2–10 m class	0.3–5 µm	S/N$\gtrsim$20 @ $m$=20	Rapid follow-up
Interceptor Spacecraft	—	—	$\Delta v\approx$10 km/s	2–6 wk to rendezvous

Metric	Current Capability	CISON Improved
ISO Recovery Rate	$\sim$1 yr$^{-1}$	4–6 yr$^{-1}$
Size Uncertainty	$\gtrsim$100%	10–20%
Velocity Uncertainty	$\sim$few km/s ($v_\infty$)	$<$0.1 km/s
Loeb Convergence Time	weeks–months	days–weeks

These improvements quantify CISON’s transition from ad hoc, high-uncertainty ISO tracking to a rigorous, end-to-end operational network with real-time defense implications. The integrated design ensures maximal scientific return and direct relevance for planetary defense strategy (Trivedi et al., 29 Jan 2026).