Aeronautics and astronautics – Spacecraft – Spacecraft formation – orbit – or interplanetary path
Reexamination Certificate
1999-12-01
2001-10-02
Jordan, Charles T. (Department: 3643)
Aeronautics and astronautics
Spacecraft
Spacecraft formation, orbit, or interplanetary path
Reexamination Certificate
active
06296206
ABSTRACT:
TECHNICAL FIELD
This invention relates to spacecraft dispensers, and more particularly to a satellite dispenser having a cantilever, bi-level platform configuration which allows the satellites to be deployed to be supported at a lower surface of each, while significantly reducing the overall weight of the dispenser without reducing its payload capability.
BACKGROUND OF THE INVENTION
Background Art
Space vehicle dispensers are used to deploy a plurality of satellites (typically between 4-12 satellites) into low earth orbit (LEO) during a launch vehicle (LV) mission. The dispenser provides the structural link between the satellites and the launch vehicle. Typically, there are also mounted on the dispenser various electromechanical systems, including space vehicle deployment mechanisms, ordnance, and avionics lines. In some applications, it is preferred to mount the satellites at their lower surfaces on a stable, horizontal platform, rather than along a vertical surface to a central post.
With the significant expense associated with placing a plurality of satellites into low earth orbit, it is of the utmost importance that the dispenser be constructed so as to be as lightweight as possible without sacrificing structural strength, and while being able to support a plurality of independently deployable satellites thereon. One prior dispenser approach is the “Dual Manifest using external structure.” In this approach, the payload fairing is split into two payload modules: an upper module and a lower module. For example, the payload fairing may be divided into a 30 foot (9.15 meter) tall lower module and a 45 foot (13.725 meter) tall upper module. Each module has its own dispenser which includes a horizontal platform for supporting a plurality of satellites thereon. During launch vehicle ascent, the upper payload fairing is jettisoned; however, the lower payload module goes into orbit. The penalty for carrying the extra payload module weight (i.e., the weight associated with the fairing of the lower payload module) to low earth orbit is less payload which can be carried into orbit. Also, the lower payload module fairing debris stays in orbit for approximately 9-12 months, which can raise the risk of damage to one or more of the deployed satellites.
Another approach is the “Dual Manifest using an internal support structure (ISS)”. With this approach a full length fairing is used to encase the dispenser. Inside the full length fairing on an inner surface thereof is a slightly smaller diameter ISS with a dispenser at the bottom and on top. The ISS length is typically less than half the full fairing length, but its typical diameter (10-15 feet or 3.05-4.58 m) still represents a significant weight relative to the total payload being carried into orbit. During launch vehicle ascent, the full fairing is jettisoned. The performance gained by jettisoning the full fairing more than offsets the added weight of the ISS, thus resulting in better launch vehicle performance than the Dual Manifest using external structure approach. The drawbacks associated with using an ISS are added structural complexity and cost, as well as additional integration and operability complexities.
It is therefore a principal object of the present invention to provide a satellite dispenser for packaging a large quantity of up to about 12 or more LEO satellites in a dual platform manner while eliminating the need for an internal or external support structure associated with the dispenser, to thereby significantly reduce the overall weight of the dispenser, to thus maximize the payload capability of the dispenser.
It is still another object of the present invention to provide a satellite dispenser that allows the jettisoning of maximum fairing weight during launch vehicle ascent.
It is yet another object of the present invention to provide a satellite dispenser capable of supporting a large number of independently deployable satellites in a manner without requiring modification to presently used separation mechanisms for deploying such satellites.
It is still another object of the present invention to provide a satellite dispenser which can be constructed without additional cost over present day satellite dispenser systems and with existing manufacturing processes.
SUMMARY OF THE INVENTION
The present invention relates to a cantilever, bi-level platform satellite dispenser apparatus and method which obviates the need for internal or external support structure to be used with the dispenser. The dispenser generally comprises a lower platform assembly having a center post projecting therefrom and an upper platform assembly secured to a portion of the center post. Preferably, the upper platform assembly is secured to an upper terminal end of the center post. A first subplurality of satellites, typically between 2-6 satellites, can be supported on the lower platform assembly and without assistance from the center post. An additional subplurality of between about 2-6 satellites can also be supported on the upper platform assembly, also without assistance of the center post. Each subplurality of satellites is supported on its respective platform in a “cantilever” fashion offset from the longitudinal axis of the center post. This arrangement, together with the manufacturing techniques used to manufacture the components of the dispenser, provides for minimum structural weight of the dispenser while inherently providing a design that allows jettisoning of the entire fairing of the launch vehicle during launch vehicle ascent.
The lower platform assembly generally comprises a lower platform member disposed on an edge of a lower outer cone. The terminal end of the center post opposite to the end supporting the upper platform assembly is secured to the lower platform member, which is in turn supported by at least one of the lower inner cone or lower outer cone. Outermost edges of each of the lower inner and outer cones are secured to a base ring, which is used to support the entire dispenser apparatus on a surface of a portion of the launch vehicle.
The upper platform assembly is somewhat similar to the lower platform assembly in construction and includes an upper ring, a support cone and an upper platform member. The upper platform member is secured to the upper support cone adjacent a terminal edge of the upper support cone, while an opposite terminal edge of the upper support cone is secured to the upper ring. The upper ring is in turn secured to a terminal end of the center post opposite to the end that is secured to the lower platform assembly. In this manner the upper platform assembly is spaced apart elevationally from the lower platform assembly without requiring a portion of the center post to extend outwardly of the upper platform member. Furthermore, no separate support structure, either internal or external to the fairing, is employed. This weight savings in turn allows heavier payloads to be carried by the launch vehicle. This, in turn, contributes to more cost efficient operation of the launch vehicle.
In the preferred embodiments each of the upper and lower platform members also includes a plurality of openings intended to allow access to conventional separation assemblies. The separation assemblies are used to secure a plurality of satellites on each platform member so that the satellites can be readily deployed at the appropriate time during ascent of the launch vehicle.
The preferred embodiments thus provide a lightweight spacecraft dispenser apparatus which allows the jettisoning of maximum fairing weight during launch vehicle ascent. The preferred embodiments of the dispenser apparatus of the present invention may further be assembled using widely available construction materials and conventional construction techniques.
REFERENCES:
patent: 2925965 (1960-02-01), Pierce
patent: 2938686 (1960-05-01), Van Winkel et al.
patent: 2958260 (1960-11-01), Anderson
patent: 2976806 (1961-03-01), Risk et al.
patent: 3107616 (1963-10-01), Boaz et al.
patent: 3380687 (1968-04-01), Wrench et al.
patent: 3420470 (1969-01-01), Meye
Chamness Darrell S.
Vincent Thomas Raymond
Harness & Dickey & Pierce P.L.C.
Jakel Kevin
Jordan Charles T.
The Boeing Company
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