By continuing to use this site, you agree to the use of cookies. You can find out more by following this link Accept & Close ›
Space Blog

The challenges of spacecraft assembly, integration and test (AIT)

Every SSTL satellite undergoes meticulous inspection and thorough testing before it is launched into space, in order to withstand the tough conditions outside of the Earth's atmosphere.
SSTL's spacecraft are designed around a stack of module trays with each module performing a different function for the mission, such as power management, navigation, on-board computing, communication and propulsion.

SSTL Power System Module tray

Modules are assembled in the Flight Assembly cleanroom, one of a suite of cleanrooms housed in SSTL’s Kepler Building, and then tested for functionality and performance by design engineers in the huge first floor Laboratory, before being delivered into the Assembly Integration and Test Hall. Here the module trays are handed over to the AIT engineers and the process of stacking them in the structure, connecting them together, and attaching the solar panels, to form the flight-ready spacecraft begins. 
When Space Blog visited SSTL, a DMC3 spacecraft and the Kaz-MRES spacecraft were visible in the AIT Hall, undergoing assembly and testing.

Space Blog spoke to Steve Forster, Senior Assembly Integration and Test Engineer, to get a better understanding of the procedures that lead to a spacecraft being given SSTL’s ‘Space-ready seal of approval’. In this Blog we’ll cover the process up to what’s known as the ‘soft stack’ phase.
Steve explains that the Assembly, Integration and Test (AIT) campaign for every SSTL spacecraft starts with the flight harness - the craft’s complex series of wires, interconnections and connectors - and the Electrical Ground Support System Equipment (EGSE) that forms the ‘mission control’ for the testing process. To manufacture the harness to an exact fit, a wooden replica of the spacecraft, affectionately referred to at SSTL as ‘WoodSat’, is made. Then the thousands of wires and connectors that make up the spacecraft’s flight harness and which will ultimately link the spacecraft’s individual modules together are overlaid onto WoodSat. This process safely allows the wires to be cut to exact lengths and routed correctly around WoodSat in readiness for transferring the flight harness to the real spacecraft.

Overlaying the flight harness onto ‘WoodSat’
Once the module trays have been assembled and delivered into AIT, the ‘soft stack’ phase can begin where the spacecraft sub-systems are assembled into a ‘Flat Sat’ configuration and functional and performance tests are conducted to verify the interfaces between the modules. Tests include ambient pressure thermal cycling, conducted within SSTL’s 125 cubic metre walk-in thermal chamber, which can be used to check the workmanship, function and performance aspects of the spacecraft by subjecting it to temperatures ranging from -30 to +70 degrees centigrade in less than 90 minutes if required. During the final stages of the ‘soft stack’ phase the team then assemble the spacecraft using the flight structure, all the way up to mating the solar panels. 

Integrating modules into the stack
However, this is just a dress rehearsal and makes the spacecraft strong enough to handle but not fully ready for flight : the fasteners are only partially tightened and don’t have yet have adhesive applied – a process known as head staking.
Check back with Space Blog to find out what happens to the spacecraft during the final flight preparation stage. 





22 November 20130 Comments1 Comment

Back to Blog

Blog post currently doesn't have any comments.

About This Blog

SSTL's lowdown on cost effective space technology, small satellites, space science and interplanetary exploration.

Post Archive

December 2017(1)
October 2017(1)
May 2017(1)
January 2017(2)
October 2016(3)
September 2016(1)
July 2016(1)
June 2016(1)
April 2016(1)
March 2016(4)
February 2016(3)
December 2015(2)
November 2015(3)
October 2015(3)
July 2015(1)
May 2015(0)
May 2015(1)
April 2015(1)
March 2015(2)
February 2015(2)
January 2015(2)
December 2014(1)
November 2014(2)
October 2014(2)
September 2014(1)
July 2014(2)
June 2014(3)
May 2014(1)
April 2014(1)
March 2014(1)
February 2014(2)
January 2014(2)
November 2013(3)
October 2013(2)
September 2013(2)
July 2013(3)
June 2013(2)
May 2013(2)
April 2013(4)
March 2013(1)
February 2013(3)
January 2013(5)
December 2012(6)
November 2012(5)
October 2012(4)
September 2012(4)
August 2012(1)
July 2012(6)
June 2012(1)
May 2012(2)
April 2012(5)
March 2012(3)
February 2012(3)
January 2012(1)
December 2011(1)
November 2011(4)
October 2011(5)
September 2011(4)
August 2011(3)
July 2011(4)
June 2011(6)
May 2011(3)
April 2011(1)
March 2011(3)
February 2011(2)
January 2011(3)
December 2010(2)
November 2010(1)
October 2010(2)
September 2010(4)
August 2010(4)
July 2010(2)
June 2010(2)
May 2010(2)
April 2010(4)
March 2010(4)
February 2010(4)
January 2010(3)
December 2009(2)
November 2009(5)
October 2009(2)
September 2009(6)
August 2009(4)
July 2009(3)
June 2009(1)
May 2009(2)
March 2009(2)
February 2009(5)
January 2009(2)
December 2008(3)
November 2008(6)
October 2008(5)
September 2008(3)
August 2008(5)
June 2008(1)
May 2008(3)
April 2008(5)
March 2008(1)
February 2008(1)
January 2008(3)
December 2007(3)
November 2007(6)
October 2007(3)
September 2007(3)
August 2007(1)
July 2007(1)
June 2007(2)
May 2007(2)
April 2007(1)
January 2007(3)
December 2006(1)
September 2006(1)
May 2006(2)
January 2006(1)
December 2005(7)

Show/Hide All

If you like Space Blog, why not subscribe by RSS by clicking the subscribe button, or to recieve updates by email click the subscribe by email button.

*Comments Policy
SSTL reserves the right not to publish comments if they are deemed inappropriate.