A Qualitative Analysis of Opportunities and Processes for Secondary and Hosted Payloads

Paper number

IAC-14,B4,5,12,x26225

Author

Mr. Andrew Ow, Stanford University, United States

Coauthor

Mr. Jonah Zimmerman, Stanford University, United States

Coauthor

Prof. G. Scott Hubbard, Stanford University, United States

Year

2014

Abstract

The smallest launch vehicles currently in use have payload capacities on the order of 500 kg. For smaller payloads, the only economical option is to fly as a secondary or hosted payload (SHP). In this configuration multiple payloads are launched atop a single rocket, either as separate free-flying spacecraft or as a single spacecraft, sharing the same bus for power and communications.
 
Secondary and hosted payloads are an ideal opportunity to utilize excess launch vehicle capacity, provide an economic benefit to the primary payload, and allow a small payload to reach orbit in a cost-effective manner. However, SHPs are relatively infrequent occurrences for reasons that are primarily programmatic and not technical in nature. In the United States, NASA has funded the development and launch of numerous small payloads on NASA and other government launches.
 
In order to determine the possible size or quantity of SHPs that could be placed on NASA launches, a previous work estimated the excess launch vehicle capacity as 1,650 kg per launch, averaged from 34 NASA launches over a 7 year period. This paper will begin by updating that work by including values for recent launches. In addition, a comparison of the frequency of SHP use amongst commercial and noncommercial customers was conducted based on 531 worldwide launches over a 7 year period. It was determined that 38% of commercial launches contained an SHP, compared to 24% of noncommercial launches. Official values of excess capacity for several NASA launches have been obtained, and these will be compared with our estimates in order to provide insight into their accuracy. Details will be given on the unofficial process that NASA uses for manifesting secondary payloads along with a discussion of problems that have been encountered.

Abstract document

IAC-14,B4,5,12,x26225.brief.pdf

Manuscript document

IAC-14,B4,5,12,x26225.pdf (🔒 authorized access only).

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