As part of the on going effort within the Constellation Program to finalize the design of the Crew Exploration Vehicle’s (CEV’s) Orion capsule, a CEV Parachute Assembly System (CPAS) review was held over the summer to document changes to the parachute system that will reduce the capsule’s speed during descent and splashdown operations.
The CPAS presentation, available for download on L2, shows that Constellation teams have been extremely busy since their last “JTF” level review in the last quarter of 2008.
In fact, since the last JTF, engineers responsible for the development and placement on the flight vehicle of Orion’s parachute system have completed two Internal Design Reviews (one in December 2008 and one in May 2009), a PA-1 CPAS Test Configuration Review, a PA-1 Integration for mass properties and acoustic testing review, an Apex Forward Trade study, the CDT-2 Recovery Plan, and a CPAS Probabilistic Risk Assessment /Loss of Crew fault tree study.
During these reviews – particularly the PA-1 Integration for Mass Properties and Acoustic Testing – it was noted that PA-1 flight system integration occurred before initially intended.
“Accelerated integration of CPAS PA-1 Flight system due to DRFC water deluge to minimize PA-1 schedule impacts,” notes the CPAS presentation.
Additionally, the presentation discussed the Smart Release Test Article which will be used to test the new CPAS configuration.
For this test, a “Cardboard Honeycomb will be used to provide a large projected area and the correct limit cycle to test smart release.”
The test will also involve the recovery of the parachutes and CPAS system as a whole.
“Recovered chutes will be used to perform CPAS secondary test objectives and back stop design and reposition predictions will assist in CPAS recovery improvements,” notes the presentation.
This test will be the second in a series of drop tests designed to prove the concept behind the parachute system.
The first such drop test for the Orion capsule parachutes failed on July 31, 2008 when the “programmer chute” failed to place the Orion capsule mockup in the correct orientation.
A preliminary timeline for the test of the new CPAS configuration indicates a target test day later this year, although a date is yet to be confirmed.
As such, the new CPAS hardware (including parachutes, attach fittings, and related equipment) will weigh approximately 744 lbm, the Wake Shield Assembly structure will weigh 3,799 lbm with 200 lbm of instrumentation, and the Ballasts (including steel plates and existing hardware located within the “center tube” will weigh 3,274 lbm.
The Wake Shield Assembly is due to be completed in October according to the associated documentation, and is under the leadership of JSC (Johnson Space Center) Engineering.
Internal Design Review for Orion:
Moreover, the continued development of the test articles in parallel with the ongoing design changes to the flight version of the Orion capsule have lead to another Internal Design Review (IDR).
At this latest IDR the Orion capsule engineers and designers were given permission to proceed with their endeavors on the drogue, main, and pilot parachutes that will be part of the final Orion capsule design.
“Authority to proceed with long lead procurements for EDU canopies: Drogue, Mains, Pilots,” notes the IDR part of the CPAS presentation.
However, the teams were not given a go ahead to proceed with work on the auxiliary parachutes.
The reason for this decision is do mainly to uncertainties that still exist with the Orion capsule stemming from cutbacks and reduction in lift capabilities of the Ares I rocket.
“Vehicle Integration still in conceptual stage. FBC and Parachute compartment design still in work. Hold on Aux chutes until architecture settles.”
In fact, the presentation notes that the current design of the Orion capsule does not even contain the “volume” necessary for the main parachute system.
“Bulkhead moves, gusset redesign, and possible OML changes are being pursued to obtain volume needed for main parachute integration,” notes the CPAS presentation.
In fact, the volume and shape of Main Deployment Bag have been improved based upon data collected during the failed July 2008 drop test and numerous analytical/computer models of the nature of the ever-changing Orion capsule.
The bags are trapezoidal in design and have a new gusset system.
As such, an IDAT will be performed in the coming months to iron out the issues with the necessary elements of the parachute system and their integration into the flight version of Orion.
“IDAT study will step back and take a look from a vehicle prospective to see if we have the best integrated solution for all the critical events in the recovery phase,” notes the presentation.
L2 members: Documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.