The Altair Design and Minimum Functionality Approach

Paper number

IAC-08.D2.9.-D1.6.2

Author

Ms. Lauri Hansen, NASA Johnson Space Center, United States

Coauthor

Mr. John Connolly, NASA Johnson Space Center, United States

Year

2008

Abstract

NASA has announced that its new human lunar lander will be named “Altair”.  Along with the other transportation elements of the Constellation Program, Altair is being developed to fulfill NASA’s goal of re-establishing lunar exploration and creating a permanent lunar outpost.  The lander performs the functions of delivering up to four crew and payload to the surface of the moon and subsequently returning them to the Orion vehicle in lunar orbit.  It can also deliver large payloads in a dedicated cargo mode.  The first lunar mission is planned in the 2020 timeframe.

The Altair Project was established in April, 2007 under NASA’s Constellation Program, and has initially been structured as a small in-house design team.  The vision is to create a government team educated in lander design, and for this team to author excellent lander requirements prior to letting a prime contract for Altair development.   
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Recognizing that mass will be one of the major challenges in any Lunar Lander design, the project elected to pursue a “minimum functionality” approach for the initial design cycle.  The minimum functionality approach begins with the design of the minimum vehicle that will perform the mission, and no more.  Specifically, the initial minimum functionality approach does not consider contingencies, nor does it include redundancy (i.e., it is a “single string” implementation).  This design is NOT intended to be a final design, nor represent a spacecraft that has acceptable levels of risk.  However, beginning a design with a “minimum functionality” approach provides two data points that are critical at the early stages of design:

1) Maximum vehicle performance - If a minimum functional design cannot meet transportation architecture requirements, then a later, “fully functional” design will certainly not meet those same requirements.  This provides an early indication of a need to revise the transportation architecture. 
 
2) Safety/reliability baseline - A minimum functional design provides a starting point from which to make informed risk/cost trades, and provides a basis for buying down risk consciously.  


This approach is intended to emphasize risk mitigation in its many forms – reliability, testing, and dissimilar functionality, to cite some examples.  It recognizes redundancy as one of the options available to mitigate risks, but challenges redundancy as the correct or preferred solution for all risks.

This paper will update the international community on progress to date on the development of Altair, including the minimum functional approach taken to define the initial design.

Abstract document

IAC-08.D2.9.-D1.6.2.pdf

Manuscript document

IAC-08.D2.9.-D1.6.2.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.