Chandra X-ray Observatory

Chandra X-ray Observatory (Chandra or CXO, earlier called the Advanced X-ray Astrophysics Facility or AXAF) is an X-ray observing satellite launched 1999 and still operating in 2026. USA budgeting efforts propose to eliminate funding of its operation in 2027 even if it is still operational. Instruments (the SIM, i.e., Science Instrument Module):

• ACIS "Advanced CCD Imaging Spectrometer".
• HRC "High Resolution Camera" with two detectors:
• HRC-I "imaging".
• HRC-S "spectroscopy", with Transmission gratings (high resolution spectroscopy):
• HETGS (or HETG) "High Energy Transmission Grating Spectrometer" (0.4-10 keV).
• LETGS (or LETG) "Low Energy Transmission Grating Spectrometer" (0.09-3 keV).

Chandra projects to carry out lengthy X-ray observation of objects have been labeled X-ray Visionary Projects (XVPs).