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SLSTD — System-Level Segmented Telescope Design

Created: 2026-04-07 (session 67)

Summary

SLSTD was the pre-Decadal HWO telescope system design program (2018-2023). Four completed projects, all focused on building the system engineering foundation for large segmented space telescopes capable of exo-Earth direct imaging. Contractors: Lockheed Martin and Ball Aerospace (2 projects each). Highest TRL achieved: 4 (Lockheed Martin [116135], 2019-2023). Succeeded by CT4LT (2024-2026) using the same contractor base.

4 projects, all Completed. TRL range: 2-4. 0 Transitioned_To.

Correction (session 68): Session 66 documented [116135] as "TRL 6" based on proposal language ("we propose to achieve system TRL 6 by 2025"). Live API (session 68) shows trlCurrent=4 with no trlEnd=6 field. The TRL 6 was the proposal target, not the achieved result. Highest confirmed SLSTD TRL is 4.

Portfolio Overview

Field Value
Total projects 4
Completed 4 (100%)
Program ID 92304
Mission Directorate SMD/APD
TRL range (end) 2 to 6
Key contractors Lockheed Martin (2), Ball Aerospace (2)
Key NASA contacts John M. Grunsfeld, Anthony M. Bluth

Data snapshot: 2026-04-04.

Projects

116102 — ULTRA: Ultrastable Large Telescope Research & Analysis

  • Lead: Ball Aerospace, Boulder CO
  • PI: John S. Knight
  • Period: 2018-05-01 to 2019-04-30 (1 year)
  • TX: TX08.2.2 Structures and Antennas
  • TRL: ?→2
  • Views: 1178
  • Co-Is: Kevin Patton, Remi Soummer (STScI), James T. Mooney, Laurent A. Pueyo (STScI)
  • Focus: System engineering study for a segmented 10-m observatory with high-contrast coronagraph applicable for HabEx/LUVOIR. Outputs: architecture trade analysis, technology gap identification, development paths. Based on modeling tools validated on Ball's deployable segmented telescope demonstrator (the "world's only optical deployable segmented telescope" at that time).
  • NASA contact: James T. Mooney, Anthony M. Bluth

116101 — System-Level Segmented Telescope Design

  • Lead: Lockheed Martin, Palo Alto CA
  • PI: Larry D. Dewell
  • Period: 2018-04-02 to 2019-04-01 (1 year)
  • TX: TX08.2.2 Structures and Antennas
  • TRL: not reported
  • Views: 1054
  • Co-Is: William D. Marquardt, Jeffrey Klingzahn, Jay Daniel, Raymond Bell
  • Focus: Three mission architectures (OST, HabEx, LUVOIR) requiring "extreme levels of dynamic stability and precision pointing and wavefront error performance over long observation durations." First-phase architecture study.

116134 — Ultra-Stable Telescope Research and Analysis – Technology Maturation

  • Lead: Ball Aerospace, Boulder CO
  • PI: Laura E. Coyle (also PI of CT4LT [183305])
  • Period: 2019-09-15 to 2021-09-14 (2 years)
  • TX: TX08.2.1 Mirror Systems
  • TRL: 2 (trlEnd=2)
  • Views: 1126
  • Co-Is: Anthony M. Bluth (NASA), Matthew East, Remi Soummer (STScI), Todd Lawton
  • Focus: HabEx/LUVOIR direct imaging of exo-Earth candidates with high-contrast coronagraphs. Large-area segmented primary mirrors with unprecedented dynamic stability requirements. This is Ball's second-phase SLSTD work, after the 1-year ULTRA study.
  • Significance: Laura E. Coyle is the direct continuity link to CT4LT [183305] at BAE Systems (Ball successor). Remi Soummer (STScI) bridges to the coronagraph algorithm community.

116135 — Technology Maturation for Astrophysics Space Telescopes

  • Lead: No lead org listed in TechPort (data gap)
  • PI: Alison A. Nordt (Lockheed Martin)
  • Period: 2019-09-01 to 2023-03-01 (3.5 years — longest SLSTD project)
  • TX: TX12.4 Manufacturing — ML mismatch to TX08.2.1 Mirror Systems
  • TRL: 4 (live API; see correction note in summary)
  • Views: 1204 (highest in SLSTD; highest across SLSTD cohort)
  • Co-Is: Robert Egerman, Lynn N. Allen, William D. Marquardt, John M. Grunsfeld
  • Focus: Coronagraph technology imposes "unprecedented requirements on telescope dynamic stability, optical system alignment sensing and control, and vibration isolation." Segmented primary mirror requiring "new manufacturing technologies."
  • Significance:
  • TRL 4 (confirmed session 68 via live API) — proposed TRL 6 not achieved within project period. TRL 4 = component/subsystem validated in laboratory environment.
  • John M. Grunsfeld as Co-I — former NASA astronaut, Hubble Space Telescope servicing astronaut (STS-109, STS-125), and SMD Associate Administrator 2012-2016. His involvement signals top-level NASA astrophysics institutional investment. Email: john.m.grunsfeld@nasa.gov.
  • 3.5-year duration (vs 1-2 years for other SLSTD projects) reflects more substantive hardware maturation.
  • Same project title as CT4LT [183304] (Lockheed Martin, Alain Carrier) — the explicit successor relationship is named in the project title.

The Coronagraph Observatory Architecture Stack

SLSTD documented the pre-Decadal technology gap analysis for: 1. Primary mirror segmentation: how to fabricate, test, and control a segmented ~8-16m mirror with sub-nanometer figure control 2. Dynamic stability: thermal and vibrational disturbance rejection at picometer levels (required for 10^10 contrast coronagraphy) 3. Wavefront sensing and control: alignment sensing for the segmented mirror + coronagraph WFC loops 4. Vibration isolation: decoupling the coronagraph instrument from spacecraft disturbances (reaction wheels, solar pressure)

These remain the Tier-1 technology gaps for HWO as documented in NASA APD annual technology reports. The SLSTD work produced the requirements and the first-generation models; CT4LT is implementing solutions.

Key Personnel Network

  • Laura E. Coyle (Ball→BAE): PI on [116134] and [183305] — the continuity thread for "ultra-stable" optical system R&D
  • Remi Soummer (STScI): Co-I on [116102] and [116134] — brings coronagraph science algorithm perspective to hardware development
  • Laurent A. Pueyo (STScI): Co-I on [116102] — coronagraph algorithm expert (dark hole digging, direct imaging retrieval)
  • John M. Grunsfeld (NASA): Co-I on [116135] — institutional champion
  • Anthony M. Bluth (NASA): Contact on [116134] and [116102] — NASA government lead for Ball contracts
  • William D. Marquardt (LM): Co-I on [116101] and [116135] — LM structural engineer across both phases
  • programs/ct4lt.md — Direct successor (2024-2026); same contractor base
  • programs/exep.md — Roman Coronagraph Instrument (EXEP, TRL 9) is the technology demonstration downstream
  • programs/gcd.md — AFTA-WFIRST [17551] (GCD, TRL 6, 2013-2017) is the GCD-side predecessor; SLSTD followed the same timeline in parallel for the observatory-level (not just coronagraph instrument) work
  • programs/sat.md — SAT feeds instrument subsystems; SLSTD/CT4LT handle telescope-level integration
  • topics/astrophysics-technology-pipeline.md — Full pipeline synthesis

Open Threads

  1. [116135] TRL 4 scope: What specifically reached TRL 4 in LM's technology maturation work? Mirror segment fabrication? Stability isolation system? The description targets three areas: non-contact vibration isolation, picometer laser metrology, and large-scale segment manufacturing. Without documents, which of these hit TRL 4 is unclear. No library items found (confirmed session 68).
  2. Ball deployable telescope demonstrator: [116102] mentions Ball had "the world's only optical deployable segmented telescope." Where is this hardware? Was it flight demonstrated? Likely relates to Ball's work on JWST-era segment handling testbeds.
  3. STScI's role: Both Soummer and Pueyo (STScI) appear in Ball projects but not LM projects. Why? STScI manages Hubble and will manage Roman science operations — their involvement may reflect early HWO science operations planning embedded in the technology work.