Taking IMAX into space – and back
Femap and NX Nastran helped accommodate the late addition of a 555-pound IMAX camera to a NASA shuttle payload
A tune-up for the Hubble telescope
On August 7, 2008, the space shuttle Atlantis will lift off for a fifth and final servicing of the Hubble space telescope. During this mission, astronauts will add capabilities to Hubble in the form of two new instruments, the Cosmic Origins Spectrograph and the Wide Field Camera 3. They’ll also attempt to repair some of the existing equipment and deliver new gyros and batteries to extend the telescope’s life through 2013. The Canadian company, IMAX Corp., which has footage from previous Hubble servicing missions, will be filming this voyage as part of the production of a new film about the Hubble telescope, scheduled for release in early 2010.
The 555-pound IMAX camera will make the trip safely into outer space and back thanks to a support structure designed by Pagnotta Engineering, Inc. using the Femap™ and NX™ Nastran® finite element analysis (FEA) solution from Siemens PLM Software. Pagnotta Engineering provides mechanical design and analysis services such as this to customers in aerospace, aircraft, aircraft flight simulation,medical and consumer products. Its current customer roster includes Lockheed-Martin, Orbital Sciences Corp., Rockwell Collins Corp., Northrop Grumman, Eagle-Picher Technologies, NASA Langley Research Center and SGT, Inc.
Small space, short timeframe
The IMAX camera work was done for Orbital Sciences Corp., a NASA contractor.“Our job is to get the camera up there in one piece and back, which involves protecting it from the extreme forces of lift-off and re-entry,” says Mike Pagnotta, the company’s president. He and his colleagues had a short timeframe in which to do this work because the decision to add the camera to the shuttle’s payload was made at a relatively late date.
“All of the space in the carriers that hold this type of equipment had already been allocated, plus, the IMAX camera required a specific orientation to allow it to have the best field of view for filming the work being performed on Hubble,” Pagnotta explains.Orbital managed to find some space in the upper part of one carrier, and then assigned Pagnotta Engineering the task of meeting the demanding requirements for protecting the camera within that limited amount of space.“Part of our challenge was that there was limited space, and the structure we designed had to be significantly stiffer than the carrier it was on,” Pagnotta continues.“The other part of the challenge was that Orbital wanted this done as quickly as possible.”
Fast trade studies
Pagnotta Engineering used Femap and NX Nastran for the project, in part because of the software’s reputation. “NX Nastran not only has the name recognition of Nastran but it is now used by most of the large customers we work with, so our customers have the confidence that we only use the best tools.” says Pagnotta.
The other reason for the use of this software is that Pagnotta knew from experience that it would allow the kind of fast conceptual design and trade studies needed for this type of work.“With Femap we can build geometry very quickly, which is what we had to do in this case.We’d create a model of the structure in Femap, run a modal analysis in NX Nastran and if the model didn’t work we could quickly tweak the design and try again.”
Two engineers worked on this project. They used Femap and NX Nastran to evaluate numerous iterations of several major structural configurations before they homed in on one design that seemed to meet all the requirements. In addition to modal analysis, the work included stress analysis (with NX Nastran) and fracture analysis (with a code developed by NASA), as well as all the required reports.
This work began in April and by August the drawings were signed.“I would challenge anyone to do it quicker,” Pagnotta says. Orbital was so pleased with the speed of the turn-around that they asked Pagnotta Engineering to remain involved with the project and help develop the test plan for the structure.“The fact that they asked us to stay on beyond the completion of the design isn’t normal,” Pagnotta says.“They were very happy that we were able to quickly satisfy the mechanical requirements, which were considerable.”
This ability to tackle complicated jobs quickly and give customers quality results has allowed Pagnotta Engineering to thrive and grow.“Because we can turn jobs around quickly we get repeat work,” he says. “And we can do this because we have the right software tools.”