Engineering specifications for large aperture UVO space telescopes derived from science requirements

Abstract

The Advance Mirror Technology Development (AMTD) project is a three year effort initiated in FY12 to mature by at least a half TRL step six critical technologies required to enable 4 to 8 meter UVOIR space telescope primary mirror assemblies for both general astrophysics and ultra-high contrast observations of exoplanets. AMTD uses a sciencedriven systems engineering approach. We mature technologies required to enable the highest priority science AND result in a high-performance low-cost low-risk system. To provide the science community with options, we are pursuing multiple technology paths. We have assembled an outstanding team from academia, industry, and government with extensive expertise in astrophysics and exoplanet characterization, and in the design/manufacture of monolithic and segmented space telescopes. A key accomplishment is deriving engineering specifications for advanced normalincidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicles and their mass and volume constraints.

Dark Hole Maintenance and A Posteriori Intensity Estimation in the Presence of Speckle Drift in a High-contrast Space Coronagraph

“…Finally, if the performance of the above algorithm deteriorates for large k, one may perform a recalibration every k r steps, as follows (Eqs. (32) and (33)): u 0 (k r ) ← u 0 (k r ) + ∆u (k r )…”

“…In reality, the PSF will change due to thermal and dynamic drift of the telescope as well as DM drift, translating directly into errors in estimates of planet intensity and limits on the achievable Signal-to-Noise Ratio (SNR) ( [18]). As a result, the potential of high-order disturbances such as mechanical and thermal stresses over periods of tens of days can impose tight stability requirements on the optical elements of the observatory and instrument ( [27,32]). One alternative that relaxes stability requirements is the recently proposed Linear Dark Field Control (LDFC).…”

Pair-based Analytical model for Segmented Telescopes Imaging from Space for sensitivity analysis

“…Current methods for error budget are simulations of end-toend propagation through the optical system, with variations of factors that are known to impact the contrast: segment phasing errors, segment surface quality, local or global vibrations, resonant modes on the segments, quasi-static aberrations due to thermal drift, and so on. 27,28 Because of the large number of factors that affect contrast, a multitude of cases need to be tested. Because of the computational burden involved, these studies can be dauntingly slow.…”

Advanced mirror technology development (AMTD) project: 2.5 year status

“…1 One of our key accomplishments is that we have derived engineering specifications for advanced normal-incidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicle and its inherent mass and volume constraints. 2 To assist in architecture trade studies, the Engineering team develops Structural, Thermal and Optical Performance (STOP) models of candidate mirror assembly systems including substrates, structures, and mechanisms. These models are validated by test of full-and subscale components in relevant thermo-vacuum environments.…”