Space Architecture

Thursday, November 27, 2008

Use Multi-Payload Adapters to reduce launch costs

For more than a year, I have been fixated on one question: why does it cost so much to get into space?

A previous blog entry discussed trends in launch costs. Namely, that “Steven Buckley noted that while the capabilities of the vehicles have grown—the Minotaur 4, derived from the Peacekeeper ICBM, has nearly four times the payload capability of a Pegasus XL—the vehicles have all had 'flyaway' costs of about $20 million a launch” [from “Reducing launch costs: a lower limit?” by Jeff Foust].

Steven Buckley also co-wrote a paper with Tim D. Luddeke and Horst D.E. Knorreck in 2003 titled “Low-Cost, Flexible Spacelift for Research and Development Satellite Using Peacekeeper ICBM Derived Space Launch Vehicle”. In the abstract, they say,

Over 40 years ago, the federal government decided it was prudent to store decommissioned ICBMs for possible future use. National Space Transportation Policy allows for the use of these assets as space launch vehicles on a case-by-case basis and under specified terms. The Air Force's Rocket System Launch Program (RSLP) is chartered to store and manage the reutilization of surplus Intercontinental Ballistic Missions (ICBMs)...

RSLP and the Air Force Research Laboratory, Space Vehicles Directorate are currently developing a Peacekeeper Space Launch Vehicle (PKSLV) Multi Payload Adapter (MPA), designed to allow several payloads to be launched in a variety of configurations to maximize our ability to meet unique customer requirements. More importantly, this multi-payload configuration also allows customers to cost share space access thus reducing their overall program cost.

Using the MPA, the PKSLV can lift eight 300lbm [sic] satellites into a two-year polar orbit for approximately $20M or $2.5M per satellite. This equates to a pound to orbit cost of $8,300/lb.

The principle at work here is the same as in any other transport vehicle: the more people or stuff you fit into the vehicle, the lower the cost of moving those people or stuff per unit of mass, distance, or energy. Economy of scale.