Concept for a large scalable space telescope: in-space assembly

Abstract

We present a conceptual design for a scalable (10-50 meter segmented filled-aperture) space observatory operating at UV-optical-near infrared wavelengths. This telescope is designed for assembly in space by robots, astronauts or a combination of the two, as envisioned in NASA's Vision for Space Exploration. Our operations concept for this space telescope provides for assembly and check-out in an Earth Moon L2 (EML2) orbit, and transport to a Sun-Earth L2 (SEL2) orbit for science operations and routine servicing, with return to EML2 for major servicing. We have developed and analyzed initial designs for the optical, structural, thermal and attitude control systems for a 30-m aperture space telescope. We further describe how the separate components are packaged for launch by heavy lift vehicle(s) and the approach for the robot assembly of the telescope from these components.

An Efficient and Versatile Means for Assembling and Manufacturing Systems in Space

“…greater than 10-meter diameter primary mirror) optical systems in space has been a dream of space scientists for many decades. Many concepts for such telescopes have been developed over the years, with one of the more recent examples being a 30-meter space observatory operating at the ultra violet-optical-near infrared (Hubble-like) wavelengths, 1 as shown in Fig. 2.…”

“…Other examples include large platforms that can serve as infrastructure to support on-orbit servicing and assembly operations or communications transponder parks. Of particular and persistent interest to the Space Science Community is the desire for Large Space Telescopes in the 10-50 meter aperture range 1 that would revolutionize space astronomy. The technology needed to enable developing and fielding these large telescopes resides in the section of OCT's portfolio; "Near Earth Object Detection and New Tools of Discovery" (build very large telescopes and interferometers).…”

Control of a Hypersegmented Space Telescope

“…Mass is minimized both by 1) reducing segment size so that segment thickness can be reduced, without requiring additional degrees of freedom of actuation internal to the segment for shape control; and 2) minimizing the mechanical interconnections between segments. In-space assembly, either robotic or with astronauts, is plausible if the interconnection tasks are straightforward [10,14,15] and if control can be used to correct errors resulting from not having a precision deployable structure [6].…”

“…There are of course additional design and manufacturability issues regarding the segments, actuation, and sensing. Highly segmented concepts have also been introduced for ground-based telescopes [9], and other space telescope concepts with 1000 or more small segments have been proposed [10]. Membrane-based approaches have also been suggested for large lightweight space telescopes (see, e.g., the review by Santer and Seffen [11]); however, these may also require somewhat similar controls technology to provide adequate optical surface quality.…”

New paradigm for rapid production of large precision optics: frozen membrane mirror technology

“…For the FMMT approach, this translates into a set of different figure commands and solving the edge mounting geometry problem. With recent discussion of in-space deployment, assembly, 4 and manufacturing 5 of large telescopes, the FMMT process is a viable candidate for enabling the production of large telescopes in space. This is in part because the precision membrane material is deployable and transportable in a rolled form.…”