Lazuli Space Observatory

• Lazuli Space Observatory is a 3-meter aperture, space-based facility that delivers rapid-response imaging and spectroscopy over visible to near-infrared wavelengths.
• It integrates an unobscured, off-axis, free-form TMA telescope with a suite of three instruments (WCC, IFS, ESC) to achieve diffraction-limited performance and high sensitivity.
• Operating from a 3:1 lunar-resonant, highly elliptical orbit, it enables routine target-of-opportunity observations within four hours and provides immediate, open-access data.

The Lazuli Space Observatory is a 3-meter aperture space-based astronomical facility designed to deliver rapid-response imaging and spectroscopy across the visible to near-infrared wavelengths (400–1700 nm). Integrating an unobscured, off-axis, free-form three-mirror anastigmat (TMA) telescope with three distinct, simultaneously-fed scientific instruments, Lazuli targets high-precision, time-domain astrophysics, stellar and planetary characterization, and cosmological studies. The observatory's architecture is optimized for rapid slewing and scheduling flexibility, enabling routine target-of-opportunity (ToO) observations within four hours—a temporal responsiveness not previously achieved for a space facility of comparable scale. Lazuli operates from a 3:1 lunar-resonant, highly elliptical orbit, supporting continuous sky coverage and stable observing conditions. Its open-science model ensures all observational data are immediately available to the community with no proprietary period (Roy et al., 5 Jan 2026).

1. Optical and Mechanical Design

At the core of Lazuli is an unobscured, off-axis, free-form TMA telescope. This configuration comprises a 3 m diameter silicon carbide (SiC) primary mirror (M1) with surface figures controlled to tens of nanometers RMS, free-formed secondary (M2) and tertiary (M3) mirrors polished to similar tolerances, and a beam fold to a fast steering mirror (FSM) for closed-loop jitter correction. The TMA design tilts and decenters all powered mirrors, eliminating central obscuration and delivering a wide, flat focal surface. End-to-end Fresnel simulations predict system wavefront errors (WFE) below 50 nm RMS across the science field after on-orbit alignment and stabilization.

The expected Strehl ratio at 633 nm is

$$S \simeq \exp\left[ - \left( \frac{2\pi \sigma_{\text{WFE}}}{\lambda} \right)^2 \right]$$

so for $\lambda = 633$ nm and $\sigma_{\text{WFE}} = 50$ nm, $S \approx 0.8$, ensuring diffraction-limited performance. The angular resolution at this wavelength is $\lambda/D \simeq 0.043"$, over a $0.5^\circ \times 0.25^\circ$ focal area (Roy et al., 5 Jan 2026).

The entire scientific payload is integrated on a 4,000 kg spacecraft bus, accommodating a 2.6 m launch fairing, and is designed for thermal stability ($\Delta T < 0.1$ K hr$^{-1}$ slews), continuous power, and high-reliability operation.

2. Instrument Suite

Lazuli's focal plane hosts three side-by-side scientific channels, each tailored to specific observational goals:

Wide-field Context Camera (WCC)

The WCC images a $35' \times 12'$ region using a mosaic of filters spanning 350–1000 nm. The focal plane utilizes 15 Sony IMX 455 CMOS sensors (17 mas pix$^{-1}$, read noise $\simeq 2$ e$^{-}$, dark current $1.5 \times 10^{-3}$ e$^{-}$ s$^{-1}$ pix$^{-1}$) and eight BAE qCMOS sensors (21 mas pix$^{-1}$, $<$0.3 e$^{-}$ noise) for high-cadence, low-noise operations. The WCC can run region-of-interest modes up to 200 Hz, sampling phenomena on timescales down to 5 ms. Photometric precision is $\lesssim$50 ppm for $r \simeq 12$ mag stars (1 hr), with $5\sigma$ point-source sensitivity of $r \simeq 25$ mag per hour.

Integral Field Spectrograph (IFS)

The IFS delivers continuous 400–1700 nm spectra at $R \simeq 100-500$ via a diamond-turned aluminum image slicer producing 58 slices per subfield, which are rearranged into pseudo-slits and dispersed with a prism. Two selectable fields of view (2.3"×4.6" at 40 mas sampling; 4.6"×8.8" at 80 mas) convene on a 4k×4k H4RG HgCdTe array (1700 nm cutoff). IFS throughput exceeds 40% (400–1000 nm) and 50% (NIR), with $\lesssim$25 e$^{-}$ read noise (goal 20 e$^{-}$), and dark current $<$0.01 e$^{-}$ s$^{-1}$ pix$^{-1}$. A 3D calibration module injects lamp-plus-Fabry–Perot signals for system-level calibration. Laboratory measurements show stability at few $\times 10^{-4}$ over hours.

ExtraSolar Coronagraph (ESC)

The ESC supports two channels (400–540 nm; 560–750 nm), each passing through a FSM, two MEMS deformable mirrors (1k, 2k actuators), and a charge-6 vector-vortex mask. The system achieves raw contrast of $10^{-8}$ at separations $\geq3\lambda/D$ and post-processed contrasts near $10^{-9}$ employing KLIP, spectral/ angular differential imaging. Inner working angle is 0.15" (goal 0.12"), outer working angle $\geq0.4"$, and end-to-end throughput a few percent at 630 nm. Detection limits for point-source planets reach flux ratios $f_p/f_\star \sim 10^{-8}$ (raw) and $10^{-9}$ (post-proc., 1 hr).

A summary table of instrument key performance parameters is provided below.

Instrument	Bandpass (nm)	Notable Performance
WCC	350–1000	$<50$ ppm/hr photometry, $r \simeq 25$ mag (1hr, $5\sigma$)
IFS	400–1700	$R\sim100$–500, $\gtrsim$50% throughput, $\lesssim$25 e$^-$ noise
ESC	400–750 (split)	Raw $10^{-8}$, Post-proc. $10^{-9}$, IWA 0.15", OWA $\geq0.4"$

3. Orbit, Operations, and Pointing Control

Lazuli is inserted into a 3:1 lunar-resonant, highly elliptical orbit (perigee ≃70,000 km, apogee ≃285,000 km, period ~9 days, inclination 29°), a configuration previously utilized by IBEX. This orbit places the observatory outside Earth's radiation belts, limits total annual eclipse time (≈2.4 hr yr$^{-1}$), and achieves thermal stability essential for optical performance. The design yields continuous access to $\gtrsim$70% of the sky per orbit, with fields observable for at least 130 days/year.

Data return is supported by a commercial X-band network (≈70 GB day$^{-1}$). High-speed slews ($\sim1^\circ$ min$^{-1}$), dynamic queue scheduling, and nearly real-time command uplink enable initiation of ToO observations within four hours of trigger receipt. The pointing system integrates reaction wheels, passive vibration isolation, low-frequency structural filters, and an FSM in a $>$200 Hz closed loop, utilizing qCMOS guide sensors to achieve jitter $\lesssim3$ mas RMS, safeguarding coronagraphic performance (Roy et al., 5 Jan 2026).

4. Science Programs and Capabilities

Lazuli's science portfolio is structured around three core areas:

1. Time-Domain and Multi-Messenger Astrophysics: Rapid ($<$4 hr) response capabilities enable imaging and spectroscopy of gravitational-wave kilonovae, fast blue optical transients (FBOTs), shock breakouts, and AGN flares. For example, a 1 hr IFS exposure yields S/N$>$5 at 600 Mpc for kilonovae analogs to GW170817 ($M_\text{peak}\approx-15$ mag) and permits multi-band tracking of evolving spectral energy distributions to probe r-process yields and merger geometry. The WCC enables high-cadence, millisecond photometry of compact object phenomena.
2. Stars and Planets: High-contrast imaging with the ESC enables direct detection of giant planets and exozodiacal dust (e.g., $\epsilon$ Eridani, $\tau$ Ceti, $\alpha$ Cen). The WCC's narrow-band H$\alpha$ filter and millimag photometric precision allow mapping of accretion hotspots. The IFS provides simultaneous 400–1700 nm spectra suitable for retrieving atmospheric constituents (H$_2$O, Na, K, TiO/VO, hazes) with R ≈ 100–500 and S/N$\gtrsim$20 per resel in minutes for warm Neptunes and Jupiters. WCC photometry at the 50 ppm/hr level refines TESS/PLATO exoplanet ephemerides, measures orbital decay, detects exomoons via transit timing variations, and enables survey of Earth-sized planets around bright stars.
3. Cosmology: The IFS facilitates standardized, low-systematics spectrophotometric distances to Type Ia supernovae ($0<z\leq1.5$) using SALT3 and twins analysis, yielding 0.08 mag distance precision for $z=1$ events ($m_J\approx22$ mag, S/N$\approx$20). Uniform coverage of the rest-frame 400–680 nm window across redshift mitigates cross-instrument calibration errors, constraining cosmological parameters ($w_0$–$w_a$) and $H_0$. Lazuli also targets Cepheid variables as independent $H_0$ anchors and monitors lensed SNe for time-delay cosmography.

5. Data Policy, Software, and Community Access

Lazuli is structured as an open, community-driven facility. Three Science Working Groups define requirements, and observing time is allocated via an independent, peer-reviewed Time Allocation Committee. There is no proprietary period; all science data—raw, calibrated, and high-level products—are released immediately.

To facilitate scientific use, Lazuli provides open-source pipelines, exposure time calculators, and end-to-end simulators. The data archive includes APIs and modular analysis tools, creating a computational framework for time-domain transient classification, exoplanet retrieval, and cosmological inference. This approach embodies a next-generation observatory philosophy centered on rapid scheduling, agile deployment, and broad accessibility (Roy et al., 5 Jan 2026).

6. Development Philosophy and Relevance

Lazuli adopts a development model emphasizing "schedule as a feature" and structured risk tolerance for cost constraint. The observatory marries high-heritage hardware with agile engineering practices and a focused instrument set. Its operational and data-distribution policies are intentionally open, aiming to accelerate scientific discovery and inform future large-scale flagship missions. By maintaining immediate data release and shared computational resources, it aligns with contemporary trends toward transparency and reproducibility in observational astrophysics (Roy et al., 5 Jan 2026).