Case
Study #6
The Case of the Stymied StarLight
|
The Goals |
| The
purpose of the StarLight mission at NASA's Jet Propulsion Lab (JPL) is to demonstrate
technologies for the Terrestrial Planet Finder (TPF), a space telescope that will,
for the first time, be able to detect Earth-like planets orbiting nearby stars
and to examine them for signatures of life. The new telescope, planned for launch
in 2015, will exploit the theory that habitable planets - those capable of supporting
life -- will have atmospheres containing water vapor and carbon dioxide, and that
those containing life will have atmospheres containing the important biomarkers
of oxygen, ozone, and methane. Earth's atmosphere, for example, contains these
molecules whereas the atmospheres of lifeless Venus, and (as far as we know) lifeless
Mars consists almost entirely of carbon dioxide. The atmosphere of a planet reflects
the light of the parent star. The atmospheric composition, and thus the possibility
of life, can be inferred by analyzing the spectrum of that light - if only engineers
could find a way to detect this very faint signal. |
The Technical Details |
| Planet
detection faces two major challenges. The first is to see the faint light reflected
by a planet from a distance of dozens of light years (hundreds of trillions of
miles). The second and more difficult challenge is to separate the reflected light
of a planet from the much brighter light of its parent star. To discern such detail
requires unprecedented angular resolution. The larger the diameter of a telescope,
the better its angular resolution. A telescope constructed like the Hubble Space
Telescope would have to be at least the size of a football field - far beyond
our current ability to build, much less launch into space. |
| One way to
surmount this obstacle is with interferometry. Using this approach, light simultaneously
collected by two or more telescopes stationed at least 100 meters apart is reflected
to a central location where the beams are combined (interfered) in such a way
that the light from the star is cancelled out. Interferometry in space requires
precision formation flying of spacecraft to 10 centimeters, and subsequent active
control of the interferometer optics to an accuracy of a few nanometers (billionths
of a meter, or thousands of times smaller than the diameter of a human hair). |
| The StarLight
mission, planned for launch in 2006, is intended to demonstrate precision formation
flying and long-distance interferometry in space. As originally envisioned, it
consisted of three spacecraft: two spacecraft which collect light, and one spacecraft
that combines the light from the two other spacecraft. |
| In
1998 the team projected that it would barely be able to keep the cost of the mission
within their $180M budget. |
The Crisis |
| In
the summer of 1998 the project was notified that a significant portion of the
non-NASA funding - nearly a third of the total budget - would not be available.
The team unsuccessfully attempted to replace the missing $50M by enlisting other
customers. The team then considered cost-saving alternatives such as reducing
the inter-spacecraft distances to 20 meters (possibly using a boom, and giving
up the formation flying demonstration) or using lasers instead of starlight for
the interferometry demonstration. When none of these ways of descoping (settling
for something less than the original goal) proved attractive to NASA, it appeared
to the team that the objectives of the mission could not be met within the $130M
budget, and that in about eight weeks, at the next briefing to NASA Headquarters,
the mission would have to be cancelled. |
The FAI Solution |
| Gary
Blackwood, one of the project team managers, had recently participated in a Frontier
Associates' Leader Workshop conducted at JPL. The purpose of this workshop is
to "provide a technology for producing breakthrough results with others."
One of the techniques presented in the workshop is for handling situations in
which things don't go as planned and breakthrough solutions are needed. |
| Instead
of looking forward from the present and asking, "How are we going to
overcome this obstacle?" a team using the FAI technique looks backward from
the future and asks, "How did we accomplish our goal?" Looking
back from the future promotes creativity, often referred to as "thinking
out of the box." Instead of a solution involving reduction of their
goal, the team creates a breakthrough that generates a result better than
their original goal. |
| In
a few of the steps in the FAI approach, the team: |
| • | builds
a powerful commitment |
| • |
gets clear about the real goals
that forward that commitment |
| • | brainstorms
on how they fulfilled those goals |
| The
StarLight team created a powerful commitment that they entitled "Forward
the Search for Life in the Universe." |
| They
saw that their real goals to forward that commitment were: |
| • | a
breakthrough in formation flying to an accuracy of 10 centimeters |
| • | a
breakthrough that demonstrated the feasibility of interferometry in space requiring
optical control to a few nanometers |
| They
recognized the original mission scenario of three spacecraft flying in a linear
formation was only one way of reaching these goals. Standing in the future and
looking back, the team brainstormed about other ways they might have achieved
their goals. |
| In
brainstorming, no solution has to be feasible. Instead of just three alternatives
(find $50M, descope, or cancel), by looking back from the future the team was
free to come up with many pages of possible solutions. Then they analyzed for
feasibility. |
The Results |
| In
reviewing the possibility of a 2-spacecraft solution, the team saw that they could
put the combining instrument on one of the two telescopes rather than on a third
spacecraft, and add a fixed delay line (an "optical detour") to compensate
for the distance the light had to travel from the other telescope. By borrowing
from 10th grade math, they saw that if the joint combiner-collector spacecraft
were located at the focus of a parabola, and if the other collector spacecraft
flew back and forth along the parabola, all NASA's original mission goals
could be accomplished with only two spacecraft. In fact, the new solution was
in many ways better than the original design. It would deliver the same results
but was less expensive and likely to be more reliable. In acknowledgment of their
ingenious solution, the team received an award from JPL. |
| By
making this breakthrough, the team developed a new view toward obstacles, and
they've since produced many other major breakthroughs. As with the first, these
breakthroughs resulted from "thinking outside the box" rather than from
exhaustive testing and experimentation. In addition, the StarLight team now saw
itself as capable of producing breakthroughs as needed to successfully overcome
any obstacle to the commitment they had built. |
Summary |
| When
faced with a difficult obstacle, a team usually focuses on solving the problem
in front of them, which almost inevitably leads to descoping. The result typically
costs more, takes more time, or produces less than originally planned. In using
FAI's method for resolving difficult problems, including building a powerful commitment,
being clear about the real success criteria, and asking "How did we accomplish
the success criteria?" a team can reliably produce a breakthrough, a result
better than originally planned. |
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Article
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© 2002 Frontier Associates, Inc.
Permission is granted
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information are included. |
