Large aperture telescopes benefit all astrophysics as well as planetary and Earth science. They provide unprecedented spatial resolution, spectral coverage, and signal to noise, advancing all of these science areas. Envisioning the need for future large segmented telescopes to one day exceed the fairing size of existing or even planned launch vehicles, NASA will need to begin considering the in-space assembly (iSA) of these future assets. In addition, robotically assembling space telescopes in space rather than deploying them from single launch vehicles offers the possibility, in some circumstances, of reduced cost and risk for even smaller telescopes. This possibility, however, has not been proven. Therefore, following discussions within NASA’s Science Mission Directorate (SMD) and Astrophysics Division (APD), the SMD Chief Technologist and APD Division Director have commissioned a study to assess the cost and risk benefits, if any, of the iSA of space telescopes.

In particular, the study must answer the question: “When is it advantageous to assemble space telescopes in space rather than to build them on the Earth and deploy them autonomously from individual launch vehicles?” The Study Charter (on the right) describes the plan for the study deliverables, process, and membership. The goal for completion of the study is May 2019 culminating in a submitted whitepaper to the National Academies’ 2020 Astronomy & Astrophysics Decadal Survey.


Universe Today video describing in-Space Assembly:

iSAT 20m concept

iSAT ConOps Graphical Storyboard: 20m Segmented UV/V/NIR telescope

iSAT: Benefits and Challenges Table


Video: Building in Space! On-orbit Servicing, Assembly, and Manufacturing (OSAM)

Video: Animation of a 20-meter in-Space Assembled Telescope


Viewgraphs: Concept for an iSAT Technology Demonstrator

Enabling Space Telescope Technologies: OPTIIX Technology Feed-Forward, presented to AAS by David Redding et al., January 10, 2013