HEA Missions

1  Chandra Observatory

Deployed on July 23, 1999, from the Space Shuttle Columbia, the Chandra X-ray Observatory is one of NASA's four "Great Observatories" and its flagship mission for X-ray astronomy. Today, the science and flight operations of the Chandra X-ray Observatory are directed for NASA from SAO in Cambridge from the Chandra X-ray Center (CXC). The Operations Control Center (OCC), under the direction of NASA's Marshall Space Flight Center, is also part of the CXC.

2 hinode

Solar-B, now renamed Hinode (the Japanese word for "sunrise") was launched on September 23, 2006, from Kyushu, Japan. Onboard the satellite was the X-Ray Telescope (XRT), a high-resolution grazing incidence telescope, designed and developed by a Japan-U.S. collaboration, which included SAO, NASA Marshall Space Flight Center, Japan Aerospace Exploration Agency (JAXA), and the National Astronomical Observatory of Japan (NAOJ).

3.5  IRIS logo

The primary goal of the Interface Region Imaging Spectrograph (IRIS) explorer is to understand how the solar atmosphere is energized. The IRIS investigation combines advanced numerical modeling with a high resolution UV imaging spectrograph. SAO was responsible for designing, fabricating, testing and delivering the UV telescope feed for the spectrograph and slit jaw imager, and SAO scientists assist with IRIS science operations


The Solar Dynamics Observatory, SDO, is the first mission to be launched for NASA's Living With a Star (LWS) Program, a program designed to understand the causes of solar variability and its impacts on Earth. SAO is a major partner in the mission, having built the four UV/EUV telescopes of the Atmospheric Imaging Assembly (AIA) and delivered them to the PI institution, Lockheed Martin.

HEA New Missions

Energetic X-ray Imaging Survey Telescope

The Energetic X-ray Imaging Survey Telescope (EXIST) is a proposed hard X-ray deep survey mission that would image the entire sky during each 95-minute orbit. EXIST's primary objective is to study the birth and evolution of black holes on all size scales with a temporal range from microseconds to years.


With image quality comparable to that of HST and collecting area 1000 times that of Chandra, the proposed X-ray observatory Gen-X will observe the first generation of black holes, stars, and galaxies and trace their evolution to the present epoch.

Smart-X logo

The Square Meter Arcsecond Resolution Telescope for X-rays is a proposed successor to Chandra with comparable resolution (~0.5"), lower mass, and 30 times the effective area. HEA is helping develop the technology for its optics and detectors.

HEA Heritage Missions


The Einstein Observatory was the first orbiting X-ray observatory to use an imaging telescope for making pictures of extrasolar X-ray sources.


The X-ray astronomy team at American Science and Engineering, which later became the nucleus of the CfA's HEA group, discovered the first extrasolar X-ray source in 1962 using a sounding rocket. During the 1960s and 1970s, suborbital sounding rockets were the pioneering instruments used to study the X-ray sky until they were superseded by longer-lived orbiting observatories.


The Roentgen Satellite, ROSAT, a Germany/US/UK collaboration, was launched on June 1, 1990 and operated for almost 9 years. The HEA division provided the high resolution imager, operated one of the ROSAT Science Data Centers, and produced a software suite for data reduction, PROS, operational within IRAF.

TRACE logo

TRACE is a NASA Small Explorer (SMEX) mission to image the solar corona and transition region at high angular and temporal resolution in UV and Extreme UV wavelengths. TRACE was launched on a Pegasus launch vehicle from Vandenberg Air Force Base in April 1998, and has made a large contribution to our understanding of the dynamics of the solar corona. TRACE is a joint project of SAO and Lockheed-Martin for NASA.


Uhuru was the first successful orbital X-ray astronomy mission. Small Astronomical Satellite A became Explorer 42 after launch from the San Marco platform off the Kenyan coast on 1970 Dec 12, and was also given the Swahili name Uhuru in commemoration of the launch site. Uhuru carried out a 2-10 keV sky survey, generating successively improved X-ray source catalogs culminating in the 4U (4th Uhuru) catalog.