MSL’s Widgets: Adding Robustness to Martian Sample
Acquisition, Handling, and Processing
Chris Roumeliotis Chris.Roumeliotis@jpl.nasa.gov
1
, Brett Kennedy bkennedy@jpl.nasa.gov
1
, Justin
Lin justin.y.lin@jpl.nasa.gov
1
, Patrick DeGrosse patrick.degrosse.jr@jpl.nasa.gov
1
, Ian Cady ian.w.cady@jpl.nasa.gov
1
,
Nicholas Onufer Nicholas.P.Onufer@jpl.nasa.gov
1
, Deborah Sigel Deborah.A.Sigel@jpl.nasa.gov
1
, Louise
Jandura louise.jandura@jpl.nasa.gov
1
, Robert Anderson robert.c.anderson@jpl.nasa.gov
1
, Ira
Katz Ira.Katz@jpl.nasa.gov
1
, Eric Slimko Eric.M.Slimko@jpl.nasa.gov
1
, Daniel
Limonadi daniel.limonadi@jpl.nasa.gov
1
1
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099
Abstract - Mars Science Laboratory’s (MSL) Sample
Acquisition Sample Processing and Handling (SA-SPaH)
system is one of the most ambitious terrain interaction and
manipulation systems ever built and successfully used
outside of planet earth. Mars has a ruthless environment
that has surprised many who have tried to explore there.
The robustness widget program was implemented by the
MSL project to help ensure the SA-SPaH system would be
robust enough to the surprises of this ruthless Martian
environment. The robustness widget program was an
effort of extreme schedule pressure and responsibility, but
was accomplished with resounding success. This paper
will focus on a behind the scenes look at MSL’s robustness
widgets: the particle fun zone, the wind guards, and the
portioner pokers.
Keywords: Mars Science Laboratory (MSL); Particle Fun
Zone (PFZ); Vertical and Horizontal Portioner Poker;
Wind Guards; Wind Tunnel Testing, Robustness Widgets.
1 Introduction
The Martian environment has never proven to be fully
predictable and has held many surprises for spacecraft,
destroying or even severely crippling many. In this respect,
the Mars Science Laboratory (MSL) project embarked on a
path to tackle the harsh Martian environment. An analysis
was performed which identified areas of the Sample
Acquisition Sample Processing and Handling (SA-SPaH)
system where the unknown characteristics of the Martian
environment posed significant risk to the robustness of the
overall system. While the basic elements of the robustness
widgets had been discussed as early as August 2007 (see
Figure 1), the decision to take the steps to flight for these
was not made until late December 2010. In order to be
incorporated into MSL, the widgets had to be designed,
fabricated, and tested by late May 2011. In those scant five
months, the team had to go from cartoon sketches on
napkins and previously defined keep-in zones to fully flight
qualified elements. This process included developing
sufficient understanding of how the widgets would be used
by the rover such that we were not endangering other
functions. In the case of the Observation Tray, which later
became incorporated into the widget named the Particle Fun
Zone (PFZ), this process was largely one of ensuring access
by the sample-bearing tools. At the other end of the
spectrum, the Wind Guards required an extensive test
program inside a wind tunnel that simulated the conditions
of Mars.
Figure 1. Early concepts of the Observation Tray, which is
mounted on the PFZ, included a simple flat plate (left) as
well as a faceted “bug-eye” (right) that presented a
horizontal surface even when the rover was tilted.
In the end, we were in a position that required that the
widgets be installed onto the rover before testing was
complete to buy back time. This came with the
understanding that they may need to be removed prior to
launch on November 26
th
, 2011, if the ensuing testing
revealed that their presence posed any unforeseen risk to
the system.
2 Robustness Widget Overview
The robustness widgets were conceived to essentially
tackle the unpredictable nature of the Martian environment.
Below is a picture that highlights the location of each
robustness widget’s respective location on the MSL rover.
© 2013 California Institute of Technology.
Government sponsorship acknowledged.