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Explorers Missions Chart Link to RXTE Mission Description Link to ACE Mission Description Link to FUSE Mission Description Link to IMAGE Mission Description Link to WMAP Mission Description Link to SWIFT Mission Description Link to THEMIS Mission Description Link to WISE Mission Description Link to SAMPEX Mission Description Link to FAST Mission Description Link to SWAS Mission Description Link to TRACE Mission Description Link to RHESSI Mission Description Link to AIM Mission Description Link to IBEX Mission Description Link to NuSTAR Mission Description Link to IRIS Mission Description Link to ICON Mission Description Link to TESS Mission Description Link to SNOE Mission Description Link to HETE-II Mission Description Link to CHIPS Mission Description Link to Integral Mission Description Link to CINDI Mission Description Link to TWINS Mission Description Link to SUZAKU Mission Description Link to ASTRO-H Mission Description Link to GOLD Mission Description Link to NICER Mission Description

Explorers Missions

Over the years, NASA has launched a series of “Explorer” spacecraft carrying a wide variety of scientific investigations. It is not only the longest running series of spacecraft, but has produced highly-durable (i.e., well-engineered) spacecraft as well.

Medium-Class Explorers (MIDEX)

Investigations characterized by definition, development, launch service, and mission operations and data analysis costs not to exceed $180 million total cost to NASA.

Operational MissionsACE | Swift | THEMIS | WISE
Past MissionsFUSE | IMAGE | RXTE (XTE) | WMAP (MAP)

Explorer (EX)

Investigations characterized by definition, development, launch service, and mission operations and data analysis costs not to exceed $200 million each (fiscal year 2011 dollars), excluding the launch vehicle.

Missions in DevelopmentICON | TESS

Small Explorers (SMEX)

Investigations characterized by definition, development, launch service, and mission operations and data analysis costs not to exceed $120 million total cost to NASA.

Operational MissionsAIM | IBEX | IRIS | NuSTAR | RHESSI (HESSI)
Past MissionsFAST | GALEX | SAMPEX | SWAS | TRACE

University-Class Explorers (UNEX)

Investigations characterized by definition, development, launch service, and mission operations and data analysis costs not to exceed $15.0M (real year dollars) total cost to NASA. UNEX missions will be launched by a variety of low cost methods

Past MissionsCHIPS | SNOE

Missions of Opportunity (MO)

Investigations characterized by being part of a non-NASA space mission of any size and having a total NASA cost of under $55 million. These missions are conducted on a no-exchange-of-funds basis with the organization sponsoring the mission. NASA intends to solicit proposals for Missions of Opportunity with each Announcement of Opportunity (AO) issued for EX, UNEX, SMEX, and MIDEX investigations.

Missions in DevelopmentAstro-H | GOLD | NICER
Operational MissionsCINDI | Suzaku (Astro-E2) | TWINS
Past MissionsHETE-2

Internationals

Operational MissionsINTEGRAL