On-orbit adjustment concepts for the Generation-X Observatory

Daniel A. Schwartz, Roger Brissenden, Mark Freeman, Terrance Gaetz, Paul Gorenstein, Diab Jerius, Michael Juda, Paul Reid, Scott Wolk, Timo Saha, William Zhang, Stephen O'Dell, Susan Trolier-McKinstry, Derek Wilke

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations


Generation-X is required to be an X-ray observatory with 50 m2 effective collecting area and 0.1 arcsec half-power diameter (HPD) angular resolution at 1 keV. It is conceived that a launch vehicle such as that studied for the Ares V will carry a monolithic 16-m-diameter mirror to the earth-sun L2 point. Even with such a vehicle, the reflectors comprising the ≈ 250 nested shells must be extremely light-weight. Therefore their figure and alignment cannot be achieved on the ground, and likely could not be maintained through the launch environment. We will present a conceptual solution to those constraints: adjustable X-ray optics, as a case of "adaptive" optics where the stability once in orbit should require adjustments no more frequently than yearly. The figure would be adjusted via thin-film actuators deposited directly to the back (non-reflecting) side of each element. This bi-morph configuration would impart in-plane strains via the piezoelectric or electrostrictive effect. Requirements of the adjustment are to the order of a few nanometer precision. Each shell, and each module, must also be aligned, to tolerances of about 0.1 micrometer. We conceive that on-orbit data would be acquired by a built-in Hartmann system for the alignment adjustments and low-order figure, and by ring profile measurements of a very bright celestial X-ray source to correct figure errors up to the mid-frequency range of several hundredths cycles mm -1.

Original languageEnglish (US)
Title of host publicationAdaptive X-Ray Optics
StatePublished - 2010
EventAdaptive X-Ray Optics - San Diego, CA, United States
Duration: Aug 3 2010Aug 5 2010

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherAdaptive X-Ray Optics
Country/TerritoryUnited States
CitySan Diego, CA

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'On-orbit adjustment concepts for the Generation-X Observatory'. Together they form a unique fingerprint.

Cite this