Official name HALOSAT
Alternative name HaloSat
Cospar ID 1998-067NX
Norad ID 43549
Launch date 1998-11-20
Launch site TTMTR
Launch vehicle Antares-230
Country/Organization USA
Type application Astronomy, X-ray
Operator University of Iowa
RCS size MEDIUM
Decay date 2021-01-04
Shape Box + 1 Pan
Mass (kg) 6
Height (m) 0.3
Width (m) 0.2
Depth (m) 0.2
Span (m^2) 0.8
Contractors University of Iowa (prime); Blue Canyon Technologies (bus)
Equipment 3 XR-100SDD X-ray detectors
Configuration CubeSat (6U)
Power Solar cells, batteries

The HaloSat is an astronomical 6U CubeSat mission to study the Hot Galactic Halo.

This is an astrophysics science investigation mission to map the distribution of hot gas in the Milky Way and determine whether it fills an extended halo or the halo is compact with no contribution to the total mass of the galaxy. It will measure the oxygen line emission from the hot Galactic halo. A dedicated CubeSat enables an instrument design and observing strategy to maximize the halo signal while minimizing foregrounds from solar wind charge exchange interactions within the solar system.

The payload consists of threee XR-100SDD X-ray detectors. These X-ray detectors are silicon drift detectors (SDDs) commercially available from Amptek. Three redundant detector assemblies include an SDD, X-ray collimator, anti-coincidence shield, and all electronics. The baseline mission requirements can be achieved with two operating detectors; the minimum mission with one detector.

The satellite is built by Blue Canyon Technologies based on their XB1 bus and the L3 Cadet radio.

It was selected in 2017 by NASA's CubeSat Launch Initiative (CSLI) to be launched as part of the ELaNa program. It was launched on the ELaNa-23 mission on board of Cygnus CRS-9 to the ISS, where it was deployed on 13 July 2018 via the JEM airlock.

Satellite COSPAR Date LS Launch Vehicle Remarks
HALOSAT 1998-067NX 1998-11-20 TTMTR Antares-230 with Cygnus CRS-9, CubeRRT, Radix, RainCube, TEMPEST-D, Lemur-2 78, ..., 81, AeroCube 12A, AeroCube 12B, RadSat-g, EQUiSat, MemSat, EnduroSat One