15.8.1 — Planetary Defence — maturity: soon

NEO Discovery Surveys

Systematically detecting, cataloguing and characterising near-Earth objects using space-based infrared and visible survey telescopes before they become impact threats.

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A nation that cannot see the threat cannot act on it. Ground-based NEO surveys are throttled by daylight, weather and atmospheric seeing — meaning objects approaching from the sun-ward direction, precisely the most dangerous low-warning trajectories, are routinely missed until days or hours before closest approach. A sovereign space-based survey constellation removes every one of those constraints: operating in the thermal infrared from orbit, it detects dark asteroids ground telescopes miss entirely, derives physical size directly from thermal flux rather than assumed albedo, and closes the sun-blind zone that has historically given humanity almost no warning on the most hazardous approach geometries.

The satellite stack for this mission is a modest constellation of cryogenically cooled mid-wave infrared (MWIR) telescopes in a Venus-like inner solar system orbit or a high-inclination heliocentric orbit, supplemented by visible-band survey units in an L1 halo or a sun-synchronous LEO for near-term cadence. Each pass builds an astrometric arc; repeated observations over weeks tighten orbital solutions to the precision needed for hazard classification. On-board moving-object detection pipelines reduce the data downlink burden by transmitting candidate tracklets rather than full frames, allowing a small ground segment to sustain continuous sky coverage without heroic bandwidth.

The operational outcome is a nationally owned catalogue of potential impactors with independent orbital solutions — not a data subscription licensed from a foreign operator that can be throttled, withheld or simply cancelled. When a newly discovered object demands a deflection decision, the nation with its own high-confidence orbital arc is the one whose voice carries weight in international coordination forums. Every month of survey data compounds like an insurance policy: the catalogue grows, the residual risk shrinks, and the warning time — the single variable that determines whether any deflection mission can succeed — extends proportionally.

What matters

NASA's DART and ESA's Hera missions confirm deflection works, but success depends entirely on warning time measured in years, not weeks — that window only exists if discovery surveys are already running.
The 2013 Chelyabinsk impactor, ~20m diameter, was completely undetected before entry; objects in that size class require space-based infrared survey to be found reliably ahead of impact.
Orbital solutions derived from a single nation's independent astrometric arc give that nation standing to trigger or veto a deflection campaign in international coordination bodies such as the UN COPUOS Action Team 14.
US export controls on cryogenic detector arrays (ITAR/EAR) mean any nation relying on American suppliers can have its survey capability embargoed at the moment a geopolitical crisis coincides with an impact emergency.

Sovereignty score: 9/10 — A nation without its own discovery survey is entirely dependent on foreign catalogues for the warning time that determines whether any planetary defence action is even possible.

Geopolitical leverage: orbital solutions are political currency in UN COPUOS and IAWN; nations that supply independent astrometric data shape deflection decisions, those that do not are relegated to implementing decisions made by others.
Supply-chain vulnerability: cryogenic MWIR detector arrays and precision telescope optics are ITAR/EAR-controlled; a sovereign programme must qualify European, Japanese or domestically developed detector technology before a crisis forces the issue.
Escalation control: a deflection impactor on a near-Earth trajectory is kinetically indistinguishable from an ASAT or ballistic threat during the approach phase — a nation with its own tracking data can immediately rule out hostile origin rather than waiting for a foreign power's assurance.
Data continuity: commercial or foreign-operated survey services carry subscription, sanctions and geopolitical discontinuity risk at exactly the moment — a newly discovered hazardous object — when uninterrupted data flow is most critical.

Reference architecture

Payload: Mid-wave infrared (3–5 µm) survey telescope, 50 cm aperture, HgCdTe focal plane array cooled to 40 K by passive radiator plus single-stage Stirling cooler, 2° × 2° instantaneous field of view; secondary visible-band CCD channel (500–900 nm) for albedo cross-check and astrometric precision
Bus class: ESPA-class microsat, 250 kg wet, 600 W total power budget, 400 W available to payload and thermal management; body-mounted GaAs solar panels augmented by one deployable panel
Orbit: Primary: Venus-trailing heliocentric orbit at 0.72 AU, period ~225 days, maximising sky coverage in the sun-ward blind zone; secondary demonstrator unit in an L1 halo orbit (1.5 million km from Earth) for near-term operational cadence and ground-station link budget validation; constellation of 3 primary vehicles for full ecliptic coverage
Ground segment: Deep-space ground station partnership (34 m dish, X-band uplink/downlink, 200 kbps average science data rate); sovereign 15 m backup dish for housekeeping and command; orbital determination computed at a national space operations centre using open-source Find_Orb and OrbFit pipelines running on sovereign hardware
Software & data
Latency
Cost band
Lead time

References

NASA Planetary Defense Coordination Office — NEO Surveys — NASA's PDCO coordinates ground- and space-based NEO surveys and maintains the public catalogue of known near-Earth objects, noting that roughly 40% of the estimated NEO population in the 140m+ hazardous size range remains undiscovered.
ESA Space Safety Programme — Planetary Defence — ESA's planetary defence programme describes the Flyeye telescope network and future space-based survey assets, emphasising that Europe is developing independent discovery capability to reduce reliance on a single national programme.
UN COPUOS Action Team 14 — International Asteroid Warning Network — The UN Office for Outer Space Affairs documents that impact response decisions will be made through IAWN and SMPAG, and that member states with independent observation data have formal standing to shape those decisions.
B612 Foundation — Sentinel Mission Heritage and Lessons Learned — B612's Sentinel programme demonstrated that a Venus-trailing infrared space telescope could discover 90% of NEOs larger than 140m within ten years of operation, a rate unachievable from ground-based observatories alone.
IAU Minor Planet Center — NEO Confirmation Page — The MPC's confirmation pipeline illustrates how rapidly astrometric arcs must be extended after first detection — independent national survey assets that can provide follow-up observations remove dependency on a single consortium's telescope time.