Ellen Gray

Document Description

This excerpt from the November 2014 edition of The Earth Observer provides a summary of the activities at the PMM Science Team Meeting which took place from August 4 - 7, 2014. The PMM program supports scientific research, algorithm development, and ground-based validation activities for the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement (GPM) Core Observatory that launched on February 27, 2014.

TRMM Out Of Fuel, Continues to Provide Data
Pressure readings from the Tropical Rainfall Measuring Mission's (TRMM) fuel tank on July 8 indicated that the satellite was nearly at the end of its fuel supply. As a result, NASA has ceased maneuvers to keep the satellite at its operating altitude of 402 kilometers (~250 miles). With its speed decreasing, TRMM has begun to drift downward. A small amount of fuel remains to conduct debris avoidance maneuvers to ensure the satellite remains safe. Artist's visualization of the TRMM satellite in space over a tropical cyclone. Image Credit: NASA TRMM's slow descent will continue over the next 2 to...
IPHEx Campaign Demonstrates Two New Instruments
Three Radars are Better than One Putting three radars on a plane to measure rainfall may seem like overkill. But for the Integrated Precipitation and Hydrology Experiment field campaign in North Carolina recently, more definitely was better. During the field campaign, NASA's ER-2 research aircraft flew out of Robins Air Force Base in Georgia. HIWRAP is under the wing in the black compartment; the Cloud Radar System is under the other wing and is not visible; and the EXRAD radar is in the extended nose cone. Image Credit: NASA / Gerry Heymsfield The three instruments, developed by the High...
Remembering Dr. Arthur Y. Hou, 1947-2013
An old adage about environmental stewardship goes, “Think Globally, Act Locally.” When it came to rainfall, however, Arthur Hou, project scientist for the Global Precipitation Measurement mission from 2005 until his passing on November 20, 2013, took an approach of Think Globally, Act Globally. "We need virtually continuous observations everywhere to construct a complete picture of precipitation around the globe, and that requires a lot of resources. Fortunately, precipitation does not recognize national boundaries. It is in the best interest of every nation to pool resources together to make...

GPM Performs Maneuvers, Continues Calibration

The GPM spacecraft continues to perform normally. The GPM Microwave Imager and Dual-frequency Precipitation radar continue operations and calibration. The spacecraft performed two routine maneuvers. The first was a 180-degree yaw (left/right in the horizontal plane) turn. This is the second yaw turn that changes the orientation of the spacecraft; it is now flying forwards again. Yaw turns are performed approximately every 40 days for thermal control, as the angle between the spacecraft's orbit and the sun changes. This keeps the side of the spacecraft designed to remain cold from overheating
NASA Begins IPHEx Field Campaign
Rain, ice, hail, severe winds, thunderstorms, and heavy fog – the Appalachian Mountains in the southeast United States have it all. On May 1, NASA begins a campaign in western North Carolina to better understand the difficult-to-predict weather patterns of mountain regions. The field campaign serves as ground truth for measurements made by the Global Precipitation Measurement (GPM) mission's Core Observatory. GPM is an international satellite mission to observe rain and snow around the world. The advanced instruments on the GPM Core Observatory satellite, launched Feb. 27, provide the next...

High Gain Antenna Deployed

The GPM Core Observatory continues power positive, stable on the sun line and communicating with the GPM Mission Operations Center at NASA’s Goddard Space Flight Center in Greenbelt, Md. The spacecraft magnetic torquer bar polarity was adjusted to eliminate rotational momentum gain. Star trackers were turned on and the High Gain Antenna was successfully deployed. Within the next day or two, the spacecraft controllers at NASA Goddard will begin to use the antenna to communicate with the Tracking and Data Relay Satellite System for commands from the ground, data and health and safety information
 NASA & JAXA Launch Satellite to Measure Global Rain and Snow
The Global Precipitation Measurement (GPM) Core Observatory, a joint Earth-observing mission between NASA and the Japan Aerospace Exploration Agency (JAXA), thundered into space at 1:37 p.m. EST Thursday, Feb. 27 (3:37 a.m. JST Friday, Feb. 28) from Japan. A Japanese H-IIA rocket with the NASA-Japan Aerospace Exploration Agency (JAXA) Global Precipitation Measurement (GPM) Core Observatory onboard, is seen launching from the Tanegashima Space Center in Tanegashima, Japan. Image Credit: NASA/Bill Ingalls The four-ton spacecraft launched aboard a Japanese H-IIA rocket from Tanegashima Space...
Live from Japan: GPM Tweet Chat Recap
Global Precipitation Measurement is a big mission. You've got questions? We've got answers. Three days before launch of the Global Precipitation Measurement (GPM) Core Observatory from Tanegashima Space Center in Japan, NASA staff supporting the mission set up shop in the lobby of the Sun Pearl Hotel in nearby Minamitane for a live Twitter Q-and-A to answer questions about the mission and what it will do in orbit. GPM Project Manager Art Azarbarzin and supporting staff Ellen Gray and Rani Gran taking part in the GPM Twitter Q-and-A from the Sun Pearl Hotel on Feb. 25. They were also joined by...
GPM's Rehearsal Weekend at Tanegashima
This video introduces Minamitame Town, near the Japan Aerospace Exploration Agency's Tanegashima Space Center, from where the Global Precipitation Measurement mission's Core Observatory is scheduled to launch on the afternoon of Feb. 27, 2014 (EST). Image Credit: NASA's Goddard Space Flight Center/Michael Starobin Download this video in HD formats from the Scientific Visualization Studio On the first floor of the Spacecraft Test and Assembly building at the Japan Aerospace Exploration Agency's Tanegashima Space Center, Japan, a skeleton crew of blue-shirted NASA engineers for the Global...