GPM Event Timeline

The timeline below highlights important dates for GPM including recent events and those planned for the future up until the planned launch of our Core Spacecraft. Events include mission reviews, spacecraft/flight reviews, ground command and control segment reviews, planning workshops, and the launch.

(If you would like a larger, printable version of the timeline, click here (PDF). For details on the events that have taken place in the past few months, just click on that milestone in the timeline to view the corresponding article.)

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GPM System Requirements Review Is a Success!

On June 4 and 5, 2002, GPM conducted a System Requirements Review (SRR) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC). This SRR was the first of several critical reviews to be held at the mission and system level. During the SRR, the entire architecture of GPM was reviewed, including the Core and Constellation Spacecraft, the instruments, the Mission Operations System, the Precipitation Processing System, and the Ground Validation System.

The goals of the SRR were to provide a baseline status of GPM, assess the progress thus far, and ensure that the project is advancing according to plan. At the SRR, GPM formally accepted the GPM Level 1 Requirements (which NASA Headquarters drafted to define the scope of the project), and presented the GPM Level 2 Requirements, along with a plan showing how to achieve them.

At the SRR, the review board assessed the entire GPM architecture, including the Core and Constellation Spacecraft (depicted here), the instruments, the Mission Operations System, the Precipitation Processing System, and the Ground Validation System.

Two review teams presided over the SRR—the Independent Review Team (IRT) and the System Review Team (SRT). The IRT consists of representatives from organizations external to GSFC, while SRT members hail from inside the Goddard environment. Review team members were carefully selected to ensure that experts from a comprehensive array of relevant disciplines were available to review the requirements. These same review teams will conduct the additional mission and system level reviews that are scheduled later in the GPM life cycle.

During the SRR, the review boards generated Requests For Action (RFAs), and raised some important issues that must be considered as GPM proceeds toward the design phase. None of the issues were “showstoppers.” In fact, some of the concerns were answered in subsequent presentations as the SRR continued. GPM management does not foresee any problems in addressing the remaining issues, and will submit a plan for resolving them to the review teams in the near future.

Overall, the SRR proceeded favorably, and GPM will now enter into the Preliminary Design (PD) phase. During this stage, engineers will produce Level 3 System Requirements (which are derived from the Level 2 Requirements) for each element of GPM. The PD phase will culminate in the Preliminary Design Review (PDR), currently scheduled for the fall of 2003.

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GPM Workshop Held in Tokyo

The second Global Precipitation Measurement (GPM) International Planning Workshop was held at the Shinagawa Pacific Hotel in Tokyo from May 20 to 22, 2002. The United States’ National Aeronautics and Space Administration (NASA), the National Space Development Agency of Japan (NASDA), and Japan’s Communications Research Laboratory (CRL) organized the conference. Nearly 200 scientists from more than 20 countries/regions participated in the Workshop, representing research institutions, operational forecasting agencies, and space agencies. Representatives attending the Workshop were from:

Two keynote speeches were presented the first day of the Workshop, as well as presentations on expectations and possible contributions by individual organizations. The second day began with reports on the development status of hardware, followed by detailed discussions on GPM science. Issues on data, algorithms, and collaboration partnerships were discussed on the third day. All representatives expressed their interest in GPM and stipulated their data requirements.

During the Workshop, numerous organizations declared their support for GPM. A letter from Professor Achache [ESA, Committee for Earth Observation Satellites (CEOS) chairman] was introduced at the meeting. The letter stated that ESA, as the Chair of CEOS, intends to participate in GPM because of the major contribution the mission will make to the World Summit (elimination of poverty; prevention of desertification; improved water resource management, agriculture, disaster prevention, etc.)

Representatives from organizations all over the world are working together to implement GPM, with the goal of obtaining a more accurate measure of global precipitation.

The Director of the World Climate Research Programme (WCRP), Dr. Carson, gave his endorsement to the mission at the Workshop. In particular, he mentioned that studies relating to the water cycle are urgently required within the Integrated Global Observing Strategy (IGOS), because rain data over the ocean are sparse. The summary of the International Panel for Climate Changes (IPCC) third assessment report (TAR), which was aimed at policy makers, points out this fact. Dr. Carson noted that GPM will play an important role in the study of climate change.

Dr. Ginati of ESA reported that EGPM has been selected as one of three missions (out of 25 that applied) to proceed to Phase-A, as a potential opportunity mission in the Earth Observation Plan. In addition, the Megha-Tropiques satellite, a joint venture of France and India, is due to be launched in 2006, and both nations expressed their willingness to cooperate with GPM.

NASA has already organized GPM science working groups to focus on the nine GPM science themes (see http://gpm.gsfc.nasa.gov/science.html). Reports from the individual teams are currently under review.

Researchers involved in atmospheric sciences and climatology stressed the importance of GPM’s observation of precipitation, and the new measurements using the dual-frequency radar. The researchers also discussed how such data would impact studies of global circulation and monsoons. In addition, the hydrologists outlined the different applications of GPM data pertinent to short- to mid-term water-related issues such as flood forecasting and drought.

In conclusion, the Workshop participants recommended that, in recognition of the potential benefit to mankind, the concerned agencies and organizations support GPM, the development of the required satellite constellation system, and the creation of suitable research and applications initiatives. They respectfully submit that the concerned agencies and organizations help establish this program with all due expedience, and enable other interested nations to cooperate and collaborate.

By Toshio Iguchi (CRL) and Riko Oki (NASDA)

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