Low Profile Multi-Payload Vibration Isolation System
Payloads such as satellites or spacecraft, which are mounted on launch vehicles, are subject to severe vibrations during flight. These vibrations are induced by multiple sources that occur between liftoff and the instant of final separation from the launch vehicle. A direct result of severe vibrations is that sensitive payload components may experience damage and failure. To address this, ATA designed a unique payload adapter with special emphasis on its vibration isolation characteristics.
In conjunction with the Air Force Research Laboratory (AFRL), ATA developed a generic payload adapter using materials, mechanical design, and manufacturing methods to minimize the cost while meeting specific design requirements. These include isolation above a specified frequency, capability for multiple payload manifests, and integrated damping. The payload adapter was initially designed for an ICBM-derived launch vehicle using decommissioned Peacekeeper (PK) missiles; however, ease of expandability to different launch systems was incorporated as a key design requirement. Furthermore, the adapter offers the ability to launch multiple payloads to meet “ride-sharing” requirements.
The design consists of an annular plate that has top and bottom face sheets separated by radial ribs and close-out rings. These components are manufactured from graphite epoxy composites to ensure a high stiffness to weight ratio. The design is tuned to keep the frequency of the axial mode of vibration of the payload on the flexibility of the adapter to a low value. This is the main strategy adopted for isolating the payload from damaging vibrations in the intermediate to higher frequency range (45Hz-200Hz). A design challenge for this type of adapter is to keep the pitch frequency of the payload above a critical value in order to avoid dynamic interactions with the launch vehicle control system. This high frequency requirement conflicts with the low axial mode frequency requirement and this problem is overcome by innovative tuning of the directional stiffnesses of the composite parts.
Features and Benefits
- Complete spacecraft isolation
- Low profile package eliminates need for adapter cone and effectively stretches payload bay
- Low axial stiffness isolates payload(s) from damaging frequencies (e.g. 45-200Hz for solid rockets)
- High pitch stiffness avoids dynamic interactions with launch vehicle control system and minimizes sway
- Frequency-tuned to avoid resonant burn issues associated with solid rocket motors
- Can accommodate single payload or multiple payloads
- One design applicable to range of payloads avoiding need for customization on launch-by-launch basis
- Lightweight composite construction
- Qualification tested to a factor of safety of 1.4
- Patented design (US Patent No. 7,222,823)
For more information about ATA’s payload adapter, please contact us.
Related Technical Papers
Thomas, G.R., C.M. Fadick, and B.J. Fram. “Launch Vehicle Payload Adapter Design with Vibration Isolation Features.” 12th Annual SPIE International Symposium on Smart Structures and Materials, San Diego, California, Mar 2005.