Like other instruments on the Lunar Reconnaissance Orbiter (LRO)*, the Lunar Orbiter Laser Altimeter (LOLA)* has evolved from technology developed for previous NASA spacecraft. Thanks to several upgrades, LOLA is producing data that honors and advances the tradition of its predecessors.

LOLA is one of seven instruments on LRO that are helping to characterize the lunar surface and provide important data, paving the way to return humans to the moon. LOLA’s primary objective is to measure the lunar surface elevation and produce a geodetic topographic map of the moon for lunar science studies and future explorations. This will aid future missions by providing topographical data for safe landings and enhance exploration-driven mobility on the moon.

Conceived and built by a team of engineers and scientists at NASA’s Goddard Space Flight Center, LOLA is a descendant of the Mars Orbiter Laser Altimeter (MOLA)* that was flown on the Mars Global Surveyor spacecraft and the Mercury Laser Altimeter (MLA)* that is currently deployed on MESSENGER (NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission)*. LOLA performs similar tasks to that of its predecessors, but it does so with a three to five times greater level of accuracy than MOLA and timing resolution that is significantly better than MLA.

The primary upgrade to LOLA is the use of a diffractive optical element (DOE) to split a single laser pulse into five beams, producing five independent measurements across a swath and creating a more detailed map of the local topography within a region.

“With each laser pulse, we get a more detailed understanding of the local slope and terrain, which gives us a better landing site scale topography with a single measurement,” said Luis Ramos-Izquierdo, LOLA optics lead. “The upgrade from a single laser in previous laser altimeters to five on LOLA is an exciting advancement that has already generated some amazing images of the south polar region of the moon.”

LOLA also is the first laser altimeter on a NASA spacecraft to carry a one-way laser ranging (LR) system that utilizes a small telescope on a high-beam antenna to optically detect and timestamp laser pulses from Earth, determining LRO’s precise orbit position.

“Knowing the precise location of the spacecraft helps to improve the resolution of the topographic measurement made by LOLA,” said John Cavanaugh, LOLA system’s engineer. “The orbit of the craft is constantly changing by meters, and determining the exact location of the satellite is essential. If you make that measurement without knowing the location of the spacecraft, you don’t have an absolute reference for the topography.”

These upgrades not only are helping LOLA obtain data that will assist future lunar missions, but they are also providing stunning images that will enhance the public’s understanding of the moon. Members of the LOLA project team have been working to pass along the advancements from LOLA to future NASA missions—including the Geoscience Laser Altimeter System (GLAS)* on the Ice, Cloud, and land Elevation Satellite-II (ICESat-II)*—and they have been working closely with Goddard’s Innovative Partnerships Program (IPP) Office on potential commercialization of the LOLA technology.

“The lessons learned from this mission are important for the development of the next generation of instruments,” said Ramos-Izquierdo. “Future missions will be able to benefit from LOLA, just like LOLA benefited from MOLA and MLA.”

Photo credit: Chris Gunn

Craig Tooley code: 451 years at NASA: 26 field of research: Spacecraft Systems birthplace: Dallas, TX education: BS, Mechanical Engineering, University of Evansville MS, Mechanical Engineering, University of Maryland

Could you tell us a little bit about the projects you worked on before LRO?

I came to Goddard in 1983 after receiving a bachelor of science in mechanical engineering from the University of Evansville in Indiana and have been here ever since, earning a master’s degree in mechanical engineering at the University of Maryland along the way. I spent the first half of my career working on space shuttle-related projects, including serving as the mission manager and mechanical lead for five successful Spartan solar-science missions.

After working in the shuttle world, I moved on to be the deputy project manager for the Triana mission*, an Earth-observing satellite to be placed at a sun-earth libration point that is fully developed and that NASA, together with NOAA , now plans to launch in 2012. I then joined the Hubble servicing group, where I worked as part of the EVA servicing team that developed procedures and trained astronauts for the successful Hubble Servicing Mission 3B in 2002. Immediately before being asked to start up LRO in 2004, I led the Hubble Space Telescope Instrument Development Office, overseeing the development of instruments to be installed during the fourth and final Hubble servicing mission.

How would you describe your day-to-day responsibilities as LRO project manager?

It has been an honor and a real pleasure to be the project manager for this mission. I have the joy of getting to be proud of over 300 people who dedicated their lives to LRO’s success over the past 4 1/2 years.

The development of the LRO spacecraft was an in-house mission, so my role as the project manager prior to launch was a little different than for a mission with a prime contractor, where the spacecraft is procured. Goddard essentially served as the prime contractor, so in addition to keeping an eye on programmatic aspects of the mission such as budget and schedule, I spent much of my time directly working with the engineering and development team that designed, fabricated, and developed the spacecraft, which in many ways has been the most satisfying part of the mission.

Now that the spacecraft is flying, I serve as a mission director with responsibility for managing operations, making sure that all of the wheels are turning properly and everything is going as planned. The operations team does most of the post-launch work, although the systems engineers and the engineering team are engaged during the initial commissioning phase. Within the next few months, my role likely will be transitioned to the Space Science Mission Operations (SSMO) group here at GSFC.

How did the scope of the LRO mission evolve?

When LRO originally was envisioned in 2004, it was designed to be one in a series of unmanned missions to the moon. We were part of a stable of projects under a larger program here at GSFC. LRO evolved when NASA’s Exploration Systems Mission Directorate (ESMD)* decided that we didn’t need to fly any additional unmanned missions to the moon, and it went from being embedded in an integrated program to being a stand-alone project here at Goddard.

Photo courtesy of Chris Gunn Craig Tooley

How is LRO paving the way for NASA to go back to the moon and beyond?

The primary objective of LRO is to conduct investigations to prepare for future lunar exploration. LRO will scout for safe and compelling lunar landing sites, locate potential resources with special attention to the possibility of water ice, and characterize the effects of prolonged exposure to the lunar radiation environment. LRO’s instrument payload consists of seven scientific instruments from partner institutions around the nation and the globe, including one instrument contributed by the Institute for Space Research in Moscow. These instruments will provide lunar imagery, topography, temperatures, and more.

Returning to the moon with LRO will also enable the pursuit of scientific activities that address fundamental questions about the history of Earth, the solar system, and the universe—and about our place in them.

LRO was launched on an Atlas V 401 rocket in June and will be in a commissioning orbit until September 15, while we test and calibrate equipment. It then will move to its final orbit, a circular polar orbit approximately 50 km (31 miles) above the surface of the moon. LRO will spend a year in the NASA Exploration mission, collecting detailed information about the moon and its environment. Once the Exploration phase is completed, NASA Science will take the keys to LRO and fly it for at least 2 years as a scientific, discovery-driven project.

How were you able to get LRO from concept to launch in less than 4 1/2 years?

The schedule for LRO was even more aggressive than the calendar would indicate. Unlike most missions, no preliminary studies or pre-Phase A work were done for LRO; we basically started with an objective and a blank slate. So, it was a very daunting schedule from the beginning.

The most important factor in our success thus far is that we have an extraordinary team of people working on this project. We started with a core, almost turnkey team who were very familiar with each other and had experience working on projects with tight deadlines. When we assembled the initial LRO team, we were fortunate to get the individuals who we wanted to join our team as many of them sought to join the mission on their own initiative. As we brought in new people, they have assimilated into and resonated with the core team very well.

Collectively and individually, we quickly developed open and honest dialogue, which was essential because often people had been asked to do things much faster than makes them comfortable. We’d push to make quick decisions as opposed to pondering for a long time, but we also keep the lines of communication open and make adjustments, even reverse decisions, when necessary.

Other key factors are that the design of the mission as well as the hardware we used were engineered from the beginning to achieve our mission of exploring the moon and bringing back a multi-faceted atlas of information to enable the next steps for sending humans to the moon. The purpose of the mission was not to develop state-of-the-art technology—we just didn’t have time for that—though we did make some exciting technology advancements. As much as possible, we adapted existing technology to meet our needs. For example, the lunar instruments on LRO are all variations of instruments that are operating around other planets in the solar system. In areas where we moved the technology forward, we often drew from technology that was already in production at Goddard. In creating the spacecraft, for instance, we tapped into state-of-the-art technology that was already being developed at Goddard, including technology that was in production for the Solar Dynamics Observatory (SDO)*.

Can you give some other examples in which LRO is responsible for the creation or evolution of state-of-the-art technology?

The state of the art for precision-pointed high- gain multi-band communication antenna systems at GSFC now resides in LRO, thanks to the work that our engineers have done to develop the LRO High-Gain Antenna System (HGAS)*. HGAS began under the SDO and LRO adapted the design for the harsh lunar environment. The overall LRO communication system includes a newly designed Ka-band Travelling Wave Tube Amplifier (TWTA) which was in research development at NASA’s Glenn Research Center but was quickly moved forward to production for LRO. Now, the HGAS is being incorporated into the Global Precipitation Monitor (GPM)* mission, and many of our engineers are moving over to GPM, continuing the Goddard tradition of sharing technology so that the next mission does not have to reinvent the wheel.

Also, the LRO flight software has been phenomenally successful. This has been one of the many highlights of the mission development. This is interesting because Project Managers often struggle with software development. When I talk with people outside of Goddard about the LRO software, they are sure that I am not telling them about the trouble, bugs, and unexpected costs we encountered while developing and implementing it. But our experience has been just the opposite. It has really been a joy to see how well the software has worked. Some of the software is new and but much of it is an evolution of what has been used here before, including the GSFC Core Flight Executive (cFE)* which is at the heart of the LRO flight software. The use of the cFE on LRO represents the first step in a much larger effort to provide an automated, platform-independent system that offers reusable software to all types of missions.

[Read more about LRO technologies below.]

How has the IPP Office and technology transfer in general been important for LRO?

Goddard’s dedication to technology development, reuse, and sharing with next-generation missions—which is fostered and encouraged by the IPP Office—is one of the reasons that Goddard got the LRO mission. NASA knew that we could complete this mission quickly and successfully, in part because of Goddard’s track record for developing and promoting new technologies. I would point to HGAS and the Flight Software as specific examples. This mission has been a total team effort, and its success thus far is a significant accomplishment that should make everyone at Goddard proud.

Photo courtesy of Erwan Mazarico LOLA's range imaging system can optically detect laser pulses from Earth, determining LRO's precise orbit position

NASA photo by Bill Ingalls The Lunar Reconnaissance Orbiter and Lunar Crater Observation and Sensing Satellite bound for the moon, June 18, 2009

The Space Link Extension – Return Channel Frames (SLE-RCF) software library (GSC-15458-1) is being used by the LRO mission. It helps to monitor the health and safety of spacecraft by enabling space agency ground support and mission control centers to develop standardized and interoperable mission control applications for space telemetry data. The software library eliminates the need for missions to implement custom data communication designs to communicate with any ground station. The two main tasks accomplished via the SLE-RCF software library are processing user requests and receiving data from ground stations and ground support assets. The software library contains three layers:

• SLE (Space Link Extension)
  for the abstract workings of the protocol
• DEL (Decoding and Encoding Layer)
  to decode and encode the abstract messages used by the SLE layer
• TML (Transport Mapping Layer)
  to transfer the encoded messages via some underlying transport layer protocol, such as as the transmission control protocol (TCP)

The library accepts configuration or SLE-RCF directives from the user and responds accordingly. Incoming data, both telemetry frames and status messages, are processed and the appropriate callback routines are triggered by the library.

• Offers simple implementation containing less than 30 routines (whereas existing SLE-RCF libraries contain more than 1,000 routines), helping to increase reliability and easing maintenance and enhancement
• Reduces costs by significantly reducing the number of people and time needed to develop new software; for example, for LRO, what formerly would have taken five people working one year to add and modify existing software, took only one person working 3 months to develop new software
• Enables ground stations and mission user facilities across different space agencies to interoperate without the need for ad hoc and custom data communications designs

• Worldwide mission control centers

NASA photo by Pat Izzo A view of the control room at NASA's Goddard Space Flight Center in Greenbelt, Maryland, where engineers managed the LRO's arrival at the moon

NASA screen captures from the FlexPlan program

FlexPlan Mission Planning System

Technical Details

FlexPlan (GSC-15558-1) provides space agencies with a generic mission planning and scheduling software product that optimally organizes, schedules, and plans mission activities on the ground and onboard spacecraft—enabling ground operators to monitor the status of memory content onboard the spacecraft and the progress of planned activities throughout the mission. FlexPlan’s components are divided into two categories:

• Core components
  modules responsible for the generation of conflict-free schedules
• Supporting components
  modules supporting the additional requirements of LRO and for status awareness of planned activities
  

Users can define flight rules and mission rules as well as events, resources (including availability profiles), tasks, and operations of the mission. Using this information, master schedules are created to define specific scenarios in the mission and break the mission up into as many scenarios as the user specifies. Additional tools detect and resolve conflicts raised by the schedule generator.

FlexPlan’s modular architecture allows its components to interact via a database, enabling various components to run at different times or concurrently by multiple operators. The FlexPlan architecture allows it to be easily extended with additional modules to support specific mission requirements or needs. It has a “pluggable” architecture that uses a publicly available XML interface to adapt easily to different types of missions without the need to configure the external interface to a specific input format.

In addition, FlexPlan uses an ID system to track every output on the schedule to the input from which it was generated. This enables the system to update the status of all activities in a Web-based client. The operations team can change all the elements defined in the mission planning process during the operational lifetime of the mission.

Benefits

• Lowers operation and maintenance costs by using Soft Algorithms, providing great flexibility that supports changes in the mission quickly and easily
• Offers a flight-proven, highly configurable design that can be efficiently configured for different missions (sometimes taking less than 1 month to incorporate new mission rules)
  

Applications

• Other NASA missions including Landsat Data Continuity Mission (LDCM) and Landsat-8
• Other government agencies including the European Space Agency (ESA) and the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT)
• Any mission involving spacecraft

NASA photo by Debbie McCallum LRO's High-Gain Antenna System stretches out toward the camera in this photo, taken in a clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland

NASA photo by NASA/Goddard Space Flight Center The LRO spacecraft sits horizontally, showing its entire instrument suite

LRO High-Gain Antenna System

Technical Details

Originally developed under NASA’s Solar Dynamics Observatory (SDO) program, enhancements in LRO’s High-Gain Antenna System (HGAS) incorporate a high data-rate Ka-band communication link as well as an S-band link for tracking, telemetry, and command of the spacecraft (GSC-15518-1).

The HGAS features an axially symmetric dual reflector in a Cassegrain configuration, and a secondary reflector supported by struts over a primary reflector. This secondary reflector features an embedded Frequency Selective Surface (FSS) technology, which enables dual use of a single antenna. A Kaband feed horn is mounted at the base of the primary reflector, and energy fed to the horn radiates to the secondary reflector, illuminating the primary reflector. The antenna’s main radiation beam is formed predominantly by the energy distribution on the primary reflector. The S-band feed is housed inside the secondary reflector, at the focal point of the primary reflector. The secondary reflector is transparent to the S-band feed’s radiation and reflects the Ka-band radiation from the corrugated horn feed, located at its outer focal point. Radiation from the S-band feed passes seamlessly through the secondary reflector and is reflected by the primary reflector, forming the S-band beam.

Benefits

• Allows circular polarization at wide angles and maintains polarization purity and performance because of its novel, compact S-band feed design
• Incorporates a laser-ranging telescope that measures the distance between the Earth and the spacecraft to within 10 cm
• Employs FSS technology to enable the dual use of one antenna (Ka- and S-band), eliminating the need for two separate antennas, lowering costs, and avoiding an impractical mechanical and RF system design
  

Applications

• Spacecraft that uses both Ka- and S-band communication links
• Satellite communication businesses
• Commercial antennas over a variety of bandwidths

NASA screen capture from the Integrated Trending and Plotting System

Integrated Trending and Plotting System

Technical Details

The Integrated Trending and Plotting System (ITPS) (GSC-15532-1) is a comprehensive tool for storage, extraction, and analysis of spacecraft housekeeping telemetry data. It reports information to engineers, ground controllers, and scientists regarding status and health of spacecraft and instruments. First developed for Landsat 7, ITPS was enhanced for LRO to provide a more flexible network interface supporting publish, subscribe, and messaging. This capability allows for plug-and-play and loosely coupled interfaces between the trending system and the rest of the mission operations tools. Thus, this software allows LRO to evolve as new technologies are developed or new versions are created, without affecting other components or systems in the mission management environment. ITPS can be used to monitor the spacecraft and components during pre-launch, ground-based integration and testing, and during launch and early orbit—enabling diagnostic, trending, or early issue identification.

Benefits

• Uses inexpensive personal computer, commercial off the shelf (COTS), and government off the shelf (GOTS) products to reduce mission operations and engineering costs
• Allows access to the complete full-resolution mission telemetry data archive, reducing the time to perform telemetry analysis from up to seven days to a few hours
• Increases efficiency by routine task automation and online data access
• Enables long-term trending and analyses by access to data over the life of the mission
• Improves accuracy by enabling mission management to predict or troubleshoot spacecraft issues before or after they occur, by providing timely and accurate access to all spacecraft parameters
• Decreases risk by enabling mission management to upgrade, test, or replace components without impacting other components or the existing system
• Features a modular design, enabling its use in various missions

Applications

• Other NASA missions including SDO and Fermi Gamma-ray Space Telescope (formerly GLAST)
• Stock market analyses
• Automobile and housing industry trends and market analyses
• Any industries that need to plot data trends

Tech Briefs Awards

Software Release Awards

Space Act Awards