Astro2020 Decadal far-IR / sub-mm flagship concept; not selected as the top decadal priority (HWO won). Origins remains a probe-class concept lineage and the long-pole far-IR successor to Herschel/Spitzer.
Origins was the 2020 decadal far-IR/sub-mm flagship concept study, intended as a successor to Herschel (2009-2013) and Spitzer (2003-2020) at IR wavelengths beyond JWST/MIRI's 28 µm cutoff. Science cases: water trail in protoplanetary disks (snow line), galaxy assembly through obscured star formation (z=1-6), exoplanet atmospheres in the mid-IR. Astro2020 did not recommend Origins as the next flagship — the decadal report instead routed the budget toward HWO; Origins continues as a probe-class descendant concept.
5.9 m primary (cooled to 4.5 K via active cryocoolers — radically colder than JWST's MIRI 6.7 K). Two architectures studied:
- Concept 1: 9 m off-axis open-back primary
- Concept 2 (baseline): 5.9 m on-axis 3-mirror anastigmat with hex segmentation (similar topology to LUVOIR)
Hex segmentation candidate; final architecture not selected (concept frozen at decadal end).
- 2.8 - 36 µm (mid-IR; MISC instrument suite)
- 25 - 588 µm (far-IR; OSS spectrometer)
- 50 - 230 µm (FIP polarimetric imager)
The 25-588 µm band is the spectral gap between JWST/MIRI and ground sub-mm (ALMA 350 µm-3 mm) that no current space mission covers.
| symbol | mapping | grounding |
|---|---|---|
| σ(6)=12 | 12 cooling stages (3 active cryocoolers × 4 K) | candidate |
| τ(6)=4 | 4 instrument suites (MISC, OSS, FIP + cal) | STRUCTURAL-EXACT |
| φ(6)=2 | 2 thermal regimes (warm spacecraft / 4.5 K opt) | exact |
| J₂=24 | 24-yr extended lifetime target | proposal |
- F-ORIGINS-1 — Active 4.5 K cryocooler tech matured to TRL 6 by 2030; falsified at TRL <5 by 2028 review.
- F-ORIGINS-2 — Concept survives as probe-class mission ($1B class) by 2032; falsified if descoped to <$500M (would lose far-IR capability).
- F-ORIGINS-3 — Sub-mm gap (Herschel ended 2013) closed before 2045; falsified if no 25-500 µm space mission flies in 2013-2045 (32+ yr gap).
- F-ORIGINS-4 — Water snow-line detection in 100+ protoplanetary disks demonstrated on alternative facility (e.g. JWST/MIRI MRS at <28 µm partial coverage); falsified if water trail science remains observationally inaccessible.
Status: decadal-ranked but not selected; live as probe concept.