{"id":16416,"date":"2015-04-09T22:34:18","date_gmt":"2015-04-09T14:34:18","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/rain-research-satellite-ends-science-mission-heads-for-re-entry\/"},"modified":"2015-04-09T22:34:18","modified_gmt":"2015-04-09T14:34:18","slug":"rain-research-satellite-ends-science-mission-heads-for-re-entry","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/rain-research-satellite-ends-science-mission-heads-for-re-entry\/","title":{"rendered":"Rain research satellite ends science mission, heads for re-entry"},"content":{"rendered":"
\"Artist's
Artist\u2019s concept of the Tropical Rainfall Measuring Mission. Credit: NASA<\/figcaption><\/figure>\n

NASA has switched off research instruments aboard the long-lived Tropical Rainfall Measuring Mission, preparing the satellite for a destructive re-entry as soon as June and ending its 17-year run observing tropical cyclones from orbit.<\/p>\n

The TRMM satellite ran out of fuel last year and began an uncontrolled descent from an orbit 400 kilometers, or 250 miles, above Earth. Officials kept the craft\u2019s two instruments intermittently running until TRMM reached a predetermined altitude.<\/p>\n

The mission\u2019s primary sensor, a precipitation radar, was switched off for the final time April 1, according to Steve Cole, a NASA spokesperson.<\/p>\n

Officials planned to keep TRMM\u2019s other instrument, a microwave imager, operating a bit longer. The satellite\u2019s final scientific sensors were due to be deactivated Wednesday, said Michael Freilich, head of NASA\u2019s Earth science division.<\/p>\n

TRMM\u2019s orbit reached an average altitude of about 333 kilometers, or 206 miles, as of Wednesday.<\/p>\n

\u201cThis has been a long mission,\u201d Freilich said Monday in a presentation to the NASA Advisory Council\u2019s science committee. \u201cTRMM has been flying since November 1997.\u201d<\/p>\n

TRMM launched Nov. 27, 1997, aboard a Japanese H-2 rocket from the Tanegashima Space Center in Japan. Its mission was originally supposed to last three years.<\/p>\n

The project is jointly managed by NASA and the Japan Aerospace Exploration Agency. NASA was responsible for construction of the satellite and daily operations, and JAXA supplied the mission\u2019s radar instrument and the launcher.<\/p>\n

\"In
In one of TRMM\u2019s final radar passes, the spacecraft observed Typhoon Masak on March 30 in the Pacific Ocean. Credit: NASA\/JAXA\/TRMM<\/figcaption><\/figure>\n

\u201cTRMM has been the world\u2019s foremost satellite for the study of precipitation and climate processes in the tropics, and an invaluable resource for tropical cyclone research and operations,\u201d said Scott Braun, TRMM\u2019s project scientist at NASA\u2019s Goddard Space Flight Center in Maryland.<\/p>\n

The $650 million satellite\u2019s radar is the first of its kind ever flown in space, yielding unprecedented 3D views into tropical cyclones and storms in a belt near the equator. TRMM data helped forecasters at the National Hurricane Center predict tropical storm intensification.<\/p>\n

\u201cTRMM data provided the most accurate estimate ever of tropical rainfall and lightning and its variations,\u201d mission managers wrote in a notice to scientists on a NASA website. \u201cIt led to new insights into the structure and evolution of convective systems, including extreme events like tropical cyclones and flood producing storms. TRMM provided a benchmark climatology used to validate and improve global climate and weather forecast models and shed light on ways in which humans impact precipitation.\u201d<\/p>\n

NASA and JAXA launched a follow-on observatory last year named the Global Precipitation Measurement mission. The GPM satellite flies in a different orbit than TRMM, covering a wider swath of Earth from the tropics nearly to the poles to expand precipitation research to include winter weather.<\/p>\n

The new mission\u2019s upgraded instruments also detect lighter precipitation than TRMM, feeding data into long-range climate models and short-term weather forecasts.<\/p>\n

Freilich said TRMM is on pace to re-enter the atmosphere as soon as mid-June, up to a year sooner than officials predicted when TRMM ran out of propellant in July 2014. The satellite is succumbing to the minuscule amount of drag present in low Earth orbit, and TRMM\u2019s rate of descent will increase as it nears re-entry.<\/p>\n

\"TRMM
TRMM launched on Nov. 27, 1997, aboard a Japanese H-2 rocket. Credit: JAXA<\/figcaption><\/figure>\n

TRMM retained a small quantity of fuel to maneuver out of the way of space junk during the descent, a safety feature designed to avoid a collision that would litter orbital pathways with more debris and endanger other satellites.<\/p>\n

TRMM could fall anywhere between 35 degrees north and south latitude. Most of the craft will burn up, but experts expect some fragments will survive to Earth\u2019s surface.<\/p>\n

A decision made in 2005 by then-NASA Administrator Mike Griffin to extend TRMM\u2019s operations meant the mission would consume propellant originally set aside to lower the spacecraft\u2019s orbit for disposal over a remote stretch of the uninhabited South Pacific Ocean.<\/p>\n

Griffin\u2019s decision came after a report by a National Research Council panel recommended that NASA abandon plans to end the mission in time to ensure the satellite\u2019s re-entry could be steered away from populated areas.<\/p>\n

A risk review conducted by NASA in 2002 put the probability of a human injury or death caused by TRMM\u2019s uncontrolled re-entry at 1-in-5,000, about twice the casualty risk deemed acceptable for re-entering NASA satellites.<\/p>\n

The review said the additional risk of an uncontrolled re-entry could be \u201ctolerated in return for other (public safety) benefits.\u201d<\/p>\n

Griffin and scientists agreed, concluding that data collected by TRMM could aid in forecasting tropical cyclones, improving intensity predictions and potentially saving lives.<\/p>\n

The casualty risk from TRMM\u2019s re-entry is lower than other recent unguided satellite re-entries, such as the fall of NASA\u2019s Upper Atmospheric Research Satellite and a German X-ray astronomy satellite in 2011.<\/p>\n

The re-entry of the European Space Agency\u2019s GOCE gravity mapping satellite in 2013 posed a lower risk than TRMM.<\/p>\n

Without fuel, the TRMM satellite has a mass of 2,621 kilograms, or 5,778 pounds.<\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/i><\/b><\/p>\n","protected":false},"excerpt":{"rendered":"

Artist\u2019s concept of the Tropical Rainfall Measuring Mission. Credit: NASA NASA has switched off research instruments aboard the long-lived Tropical Rainfall Measuring Mission, preparing the satellite for a destructive re-entry as soon as June and ending its 17-year run observing tropical cyclones from orbit. The TRMM satellite ran out of fuel last year and began […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[1737,4024],"class_list":["post-16416","post","type-post","status-publish","format-standard","hentry","category-news","tag-re-entry","tag-trmm"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16416"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=16416"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16416\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=16416"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=16416"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=16416"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}