2010/03/04

JWST:James Webb Space Telescope sunshield passes critical design review

James Webb Space Telescope sunshield passes critical design review

03 Mar 2010

The James Webb Space Telescope sunshield has passed its critical design review, marking the successful completion of another mission milestone. The review certified that the sunshield design is complete and meets all the mission requirements; this clears the way for the start of manufacturing of the flight model sunshield.

The critical design review (CDR) took place 11-14 January at Northrop Grumman's facility in Redondo Beach, California. In addition to validating the sunshield design during the CDR, it was shown that the sunshield design meets the thermal, deployment and stray-light targets that had been set. The CDR also provided an opportunity to evaluate and approve the sunshield manufacturing and test plans. With the completion of these milestones the sunshield flight model can begin the manufacture and test phase.

Photo of the one-third scale sunshield membranes undergoing final inspection at the Nexolve facility in Hunstville, Alabama, U.S.A.  Credit: Nexolve

The large sunshield, measuring 22 m × 12 m, is a key element of the Webb spacecraft providing the stable, low-temperature environment (50K) that is required for the telescope and instruments. The sunshield is composed of five layers of Kapton, each only a few tens of microns thick. These layers are separated from each other and held in place by a complex system of latches, tensioners, spreader bars and telescoping boom assemblies.

In preparation for the critical design review, 18 separate sub-assembly design audits were conducted on this complex system with the goal of validating the sub-assemblies at the system level and evaluating the points where they interface.

In addition, prior to the CDR, a thermal test campaign (running from 23 November to 19 December 2009) was performed on a one-third scale model of the sunshield. The main goals of this campaign were: to test the sunshield's ability to block heat, and to verify computer models that will be used to extrapolate the results from the thermal performance of the scale model to that of the full-size sunshield. (Further details of these thermal tests can be found in the article "Turning up the heat: Finding out how well the Webb telescope's sunshield will perform" at NASA's JWST site; see related link in the right-hand menu).

The Webb telescope is a joint project of NASA, ESA and the Canadian Space Agency. Northrop Grumman is designing and developing the Webb spacecraft under contract to NASA Goddard Space Flight Center.


____________________________________
Last Update: 04 Mar 2010

Posted via web from Traction Lobe