Which observatory/satellite was launched into space first, Hakucho or Chandra X-ray Observatory?
Chandra X-ray Observatory The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space observatory launched on STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources 100 times fainter than any previous X-ray telescope, enabled by the high angular resolution of its mirrors. Since the Earth's atmosphere absorbs the vast majority of X-rays, they are not detectable from Earth-based telescopes; therefore space-based telescopes are required to make these observations. Chandra is an Earth satellite in a 64-hour orbit, and its mission is ongoing as of 2017 .
Rohini (satellite) Rohini is the name given to a series of satellites launched by the Indian Space Research Organisation (ISRO). The Rohini series consisted of four satellites, all of which were launched by the Satellite Launch Vehicle (SLV) and three of which made it successfully to orbit. The series were mostly experimental satellites.