Flight Project Support

ProjectDateAccomplishment and Impact
TESS2014

Accomplishments: Primary design tool for TESS supporting PDR.

Impact:  First adoption as primary mission support tool. D. Dichmann commented, “I can’t see how we could do TESS without GMAT.”

OSIRIS-REx Launch Window

2013

Accomplishments: Used GMAT to re-optimize the entire OSIRIS-REx launch window in 1 month of summer intern time.

ImpactImproved convergence properties, and computational time compared to previous software solution. GMAT's built-in scripting language and ease of invoking the GMAT executable via system calls permitted very powerful automations of highly complicated computational problems in OSIRIS-REx trajectory design and optimization. Project has chosen to use GMAT for this part of the OSIRIS-REx analysis suite.

OSIRIS-REx  TAG

2013

AccomplishmentsUsed GMAT to re-target OSIRIS Touch-And-Go sequence:  orbit asteroid, phase with asteroid rotation, land on the surface.

ImpactRapid verification of solutions from operational tool and extra validation of GMAT solutions.  GMAT solution is much simpler than implementation in the operational tool.

MAVEN

2013

AccomplishmentsUsed GMAT to investigate possibility  that launch vehicle upper stage could impact earth in the distant future. Mars-GRAM 2005 atmospheric model was put into GMAT and MAVEN used GMAT for IV&V of its mission orbit's station-keeping strategy.

Impact:   Saved analyst time. This type of analysis is easy in GMAT and hard in other tools. MAVEN used GMAT to verify and validate its mission orbit's station-keeping design strategy.

ACE

2009-2010

AccomplishmentsUsed GMAT to determine fuel required to change amplitude of the ACE Lissajous.

Impact:   A week of work using GMAT’s optimization methods found equivalent or cheaper solutions than senior design experts using current tools.

 MMS2012

AccomplishmentsUsed GMAT for end-to-end  formation modeling and optimization for all phases of MMS mission and for verifying analytical models for reference orbit evolution.    GMAT is now the baseline tool for ground system testing.   

Impact:   GMAT supported mission design for one of GSFC’s most complex missions from MMR through CDR.  GMAT is now the baseline tool for ground system testing.

 ARTEMIS2007-Present

Accomplishments:  Used GMAT to design optimal maneuvers for ARTEMIS in weak stability orbit regime.   ARTEMIS can only maneuver in the northern s/c hemisphere due to thruster locations.   This was a very difficult design/optimization problem to optimize fuel for weak stability trajectories with severe spacecraft limitations.

Impact: Enabled the mission.  D. Folta commented, “ We could not have flown ARTEMIS without GMAT”.

 LRO2010

Accomplishments: M. Mesarch used GMAT to determine optimal maneuvers to rotate the orbital line of apsides and change orbital dimensions.

Impact:  Saved 15% fuel over operational tool solutions and showed that the project’s planned maneuver locations were not fuel optimal.  Fuel savings extended the mission life by ~3 months.

 LCROSS2009

Accomplishments:  Used GMAT to optimize part of the LCROSS launch window analysis, and for post launch re-optimization.

Impact:  Rapid launch window optimization saved time over Copernicus configuration.   Demonstrated that launch injections errors were small enough that re-optimization was not necessary.

Proposal Development Support

Note: For competition sensitive reasons, current proposal support, which is significant, is not listed here.

ProjectDateAccomplishment and Impact

TESS

2012

Accomplishments: Used GMAT to design a reference mission for TESS.   Months of analysis in other tools did not find a feasible solution.  A week of part-time work in GMAT found optimal solutions that were 50% cheaper than those found other tools using traditional targeting methods.  Subsequently, a summer student used GMAT to optimize the entire TESS launch window taking only a month of analysis time.

ImpactQuickly found optimal trajectories that met all mission requirements across the launch window when traditional tool struggled.   Significant contribution to proposal effort that won the mission!

VRO-Dante 

2011

AccomplishmentsGenerated optimized Venus trajectories for half of the launch window.

ImpactRapid, easy optimization of integrated trajectories for launch window. 

Chopper

2011

AccomplishmentsUsed GMAT to generate integrated optimized rendezvous trajectories to comet across the launch window.

Impact:   GMAT optimization resulted in ~100 m/s fuel savings over previous tool.  Demonstrated flexibility in how GMAT can be configured to perform optimization.

 OSIRIS 2007

Accomplishments:  Used GMAT to verify optimal solutions generated by Lockheed Martin in early OSIRIS proposal stages.  Had to include custom constraints on oxidizer tank volume and maximize mass to orbit.

Impact:   Rapid, high fidelity verification (1 week of analyst time) of preliminary solution of Lockheed Martin patched conic mission design tools.

Research and Development Support

ProjectDateAccomplishment and Impact
EMTG-GMAT Integration

2014-Present

Accomplishments: Now able to export simple low-thrust trajectories designed in EMTG into GMAT reasonably robustly. Development took 3 months of 1.5 summer intern time. Modified EMTG to write out GMAT scripts and re-optimize patched conic solutions using fully integrated dynamics in GMAT.

Impact: Rapid mission development by using medium fidelity guesses from EMTG to seed high fidelity trajectory optimization in GMAT.


Force Model Interface2011

Accomplishments:  Won an IRAD to expose force model interface to MATLAB for use of high fidelity dynamics models by other tools.  Wrote prototype interface. 

 

Impact:  Don’t need to redevelop dynamics models when doing analysis in MATLAB or C.  (Still prototype though).
   
  • No labels