swap_horiz RXTE Alternatives

1

Cassini-Huygens

The Cassini-Huygens mission, operated by NASA and ESA, was a space-based observatory dedicated to studying Saturn and it...

Decommissioned Nasa Planetary Space Based

9.8 Brilliant

2

Kepler Space Telescope

The Kepler Space Telescope was a NASA observatory launched in 2009. It monitored over 150,000 stars for dips in brightne...

Decommissioned Optical Nasa Space Based

9.6 Brilliant

3

Parker Solar Probe

The Parker Solar Probe is a NASA observatory spacecraft investigating the Sun’s outer atmosphere, the corona. Launched i...

Solar Nasa Space Based Heliophysics

9.6 Brilliant

4

Planck

The Planck mission was a European Space Agency-operated observatory designed to study the Cosmic Microwave Background (C...

Decommissioned Microwave Space Based Cmb

9.4 Excellent

5

Hipparcos

Hipparcos was a European Space Agency observatory launched in 1989. It performed groundbreaking measurements of stellar...

Parallax Decommissioned Space Based Astrometry

9.4 Excellent

6

SOHO

SOHO is a space-based observatory operated jointly by NASA and the European Space Agency. It monitors the Sun’s activity...

Solar Nasa Space Based Esa

9.3 Excellent

7

Spitzer Space Telescope

The Spitzer Space Telescope was a NASA space-based observatory operating from 2003 to 2020. It utilized infrared light t...

Survey Decommissioned Nasa Infrared

9.2 Excellent

8

Fermi Gamma-ray Space Telescope

The Fermi Gamma-ray Space Telescope is a NASA observatory orbiting Earth. It detects high-energy gamma rays, providing i...

Survey High Energy Nasa Space Based

9.1 Excellent

9

Herschel Space Observatory

The Herschel Space Observatory is a decommissioned space-based observatory operated by the European Space Agency (ESA)....

Decommissioned Infrared Space Based Esa

9.1 Excellent

10

Solar Dynamics Observatory

The Solar Dynamics Observatory (SDO) is a space-based observatory operated by NASA. It provides continuous ultraviolet i...

Solar Nasa Space Based Heliophysics

9.1 Excellent

11

Neil Gehrels Swift Observatory

The Neil Gehrels Swift Observatory is a NASA spacecraft dedicated to studying high-energy astrophysical events. Launched...

Nasa Space Based Gamma Ray X Ray

9.0 Excellent

12

Compton Gamma Ray Observatory

The Compton Gamma Ray Observatory was a NASA space-based observatory that operated from 1991 until its decommissioning i...

Decommissioned High Energy Nasa Space Based

8.9 Great

13

ROSAT

ROSAT, short for Röntgensatellit, was a German-led space observatory launched in 1990 for X-ray and extreme-ultraviolet...

Germany Decommissioned All Sky Space Based

8.6 Great

14

Uhuru

Uhuru was a NASA-operated space observatory launched in 1970 as the first satellite dedicated specifically to X-ray astr...

Historical Nasa Space Based X Ray

8.6 Great

15

Einstein Observatory

The Einstein Observatory, originally designated HEAO-2, was a pioneering NASA X-ray telescope launched into Earth orbit...

Historical Nasa Space Based X Ray

8.5 Great

16

XRISM

XRISM (X-Ray Imaging and Spectroscopy Mission) is a space observatory jointly developed by JAXA and NASA, launched in Se...

Nasa Space Based Spectroscopy X Ray

8.5 Great

17

IXPE

The Imaging X-ray Polarimetry Explorer (IXPE) is a NASA space observatory launched on December 9, 2021, designed to meas...

Nasa Space Based X Ray Esa

8.2 Great

18

Suzaku

Suzaku was a Japanese space telescope developed for X-ray astronomy by the Japan Aerospace Exploration Agency in collabo...

Decommissioned Space Based Spectroscopy X Ray

8.1 Great

19

EXOSAT

EXOSAT was a European Space Agency space observatory launched in 1983 to study X-ray sources beyond Earth. Operating unt...

Decommissioned Historical Space Based X Ray

7.6 Good

20

Astro-H / Hitomi

ASTRO-H, later named Hitomi, was a Japanese X-ray astronomy satellite developed by JAXA with international partners, inc...

High Resolution Decommissioned Space Based X Ray

4.5 Poor