Wednesday, October 9, 2013

Godspeed, LADEE! AGI software-based Flight Dynamics System to be tested on mission to Moon

I have been reading some of the links I passed earlier and hope you have had a chance to do the same.  I was interested in what was being done with AGI's ASTROGATOR. for the Flight Dynamics System. 

I remember the work that was being done to plan for a possible Lunar Prospector mission.  Folks from Goddard Space Flight Center came to NASA Ames one day with their copy of Swingby to see if it could be used to help speed up orbit designs.

My jobs in support of the Pioneer Mission went away with those missions ending.  I went to work for Lam Research for a year and a half, and then I got a call from Rick Campo who was now working for Lockheed/Martin on the Lunar Prospector mission. Would I like to see if there might be a way to display live instrument data for a Lunar Prospector web site? 

I had to chose if I wanted to leave a full time teaching job at Lam Research to take a half time job with Orbital Sciences Corporation to work on software for the web site. YES!  (later that would become full time - then half time - then no time, with visitor passes, but that is another Pioneer Anomaly story)

Launch dates slipped, as happens with new space missions, and new possible lunch profiles needed to be worked out. Swingby had turned into a commercial product.  This was acquired by AGI and used for the Lunar Prospector mission.

This software is again used here for LADEE as mentioned in Jim Woodburn's AGI blog. If you haven't read the blog already, take a look. He has more links as well.  

By the way, you can get a free version of STK and then buy the more expensive modules only if you need them. I have version 9 (which I haven't learned how to use) and now version 10 is out. :-)

Godspeed, LADEE! AGI software-based Flight Dynamics System to be tested on mission to Moon
NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft is in the nose-cone of the Minotaur V rocket, awaiting launch from Wallops Flight Facility in Virginia tonight at 11:27 p.m. EDT. This mission marks many firsts—it’s the first spacecraft built in-house at NASA’s Ames Research Center in Moffett Field, Calif., without a prime contractor, the first launch of the U.S. Air Force’s five-stage Minotaur V vehicle, managed and operated by Orbital Sciences Corp., the first lunar mission flown by Orbital and the first lunar mission launched out of Wallops. According to the NASA website, this approximately 160-day “robotic mission will orbit the Moon to gather detailed information about the structure and composition of the thin lunar atmosphere and determine whether dust is being lofted into the lunar sky. Once launched, the spacecraft will enter into a series of phasing orbits that will allow it to approach the Moon from its leading edge, travel behind it and reemerge to execute a 3-minute Lunar Orbit Insertion maneuver that will place it in an elliptical retrograde equatorial orbit for 24 hours. A series of maneuvers will then be performed to reduce the orbit to nearly circular with a 156-mile altitude. After this, a 100-day Science Phase will commence, followed by a decommissioning period when the altitude will be lowered and the spacecraft will impact the lunar surface.”

The LADEE Flight Dynamics System (FDS) was built by our good friends at Applied Defense Solutions (ADS) and Space Exploration Engineering (SEE), in close coordination with Ames  where mission operations will be performed after launch. I was privileged to be part of the peer review team for the LADEE flight dynamics design and was very impressed by the exceptional quality of the people on the team. ADS has used AGI products to operate well more than 20 military, NASA and commercial spacecraft, including IBEX, LCROSS and theRadiation Belt Storm Probes, and the LADEE FDS is no different. The system is based on our STK, STK Astrogator and Orbit Determination Tool Kit software. Because the software has been proven in so many operational NASA missions and is in use at most centers, the LADEE team was confident in using it for their FDS. It also made collaboration that much easier.

Also significant was the reuse of AGI products. Since the software has been employed for many other operational missions, including those in deep space, using it helped reduce technical risk and testing time.


About Jim Woodburn

Dr. Jim Woodburn is AGI's chief orbital scientist. He is responsible for the maintenance, enhancement and verification of all STK functions that rely on orbital or attitude dynamics.


Here is a 13 page Microsoft Word document about history of STK.


Software Architecture and Use of Satellite Tool Kit's ... - IEEC 

This paper describes the history of the software program and reasons behind the numerical ...
 In 1996 AGI bought Navigator from CSC, and obtained the rights to ... 
A summary of the libration point and deep-space missions that employed ..... 
BeforeSwingby was built, the Goddard Mission Analysis System (GMAS) was used  ...

Software Architecture and Use of Satellite Tool Kit’s Astrogator Module for Libration Point Orbit Missions
John Carrico, Emmet Fletcher

Analytical Graphics, Inc.


The Satellite Tool Kit (STK) Astrogator software module is the third and most recent version of a program originally developed by NASA Goddard Space Flight Center (GSFC).  This software lineage - Swingby, Navigator, Astrogator – started in 1989 and has since been used to design and operate many missions, including the non-low Earth orbit missions Clementine, Wind, SOHO, ACE, Lunar Prospector, the AsiaSat 3 rescue, and MAP.  This paper describes the history of the software program and reasons behind the numerical methods employed. The authors also discuss the software design methodology and goals that led to this mature software product.  Limitations encountered during analysis and operations use are described, as well as subsequent architecture changes made to alleviate them, reduce risk, and support automation.


Astrogator is the maneuver planning and trajectory design module of Satellite Tool Kit (STK), a completely commercial off-the-shelf (COTS) software program developed by Analytical Graphics, Incorporated (AGI)[i].  Astrogator is fully integrated within STK and, among other things, can be used to generate the orbit ephemeris and attitude history of spacecraft.  These data are then available for subsequent analysis and processing by other modules in STK, such as calculating station acquisitions, lighting times, communication links, coverage effectiveness, and Sensor obscurations.


The software linage of Swingby, Navigator, and STK/Astrogator has been used for the analysis and operations of the majority of Libration point trajectories, as well as several Cislunar, Lunar, asteroid, and interplanetary missions, since it’s first use for the Clementine (DSPSE) mission.  The feedback from use in early missions has caused significant enhancements for the most recent incarnation, STK/Astrogator.  The driving requirement to have a single software tool support pre-launch mission analysis, operations, and contingencies has been a major factor in selection of algorithms and methods, and several innovative solutions have been implemented to accomplish this task.

The close working relationship between software industry and government experts has been instrumental in the development of a commercial software product with a mature feature set able to support Libration point and other multi-body missions.

Finally the integration of the trajectory software package Astrogator with the other mission analysis capabilities of STK has proven to be valuable for many analysis and operational tasks:  The ‘normal’ post-trajectory-design numerical tasks have been streamlined and automated, ensuring consistency, reducing risks, and allowing studies that would otherwise be time and cost prohibitive.  Additionally, the interactive and advanced computer graphics capabilities have become an invaluable aid to understanding the complex trajectories that exist in the multi-body problem.

[i] Analytical Graphics, Inc. web site at

And another look at "The Astrogator's Guild"

The Astrogator's Guild

Mike, John and other astrogators guide you through the gravity fields of space

LADEE Trajectory Update: 10-08-13

LADEE is now in its last rev in the 24 hour capture orbit, and preparing for LOI-2, which will lower the spacecraft into a 4 hr orbit.  LOI-2 is scheduled for 10:38 UTC (3:38 AM PDT) Wed. morning, Oct. 9. Here’s the view from LADEE to the Moon:

Some Orbital links



As you may have noticed from the material, there are interested and talented personnel working behind the scenes on space missions. Hope you have some young ones coming up through the educational system that are being inspired to be creative. Got to help the granddaughter in first grade use spheres, cones, and tubes to make her idea of a Unicorn robot.

Thanks for looking up with me.  
- LRK -