Cosmic Hot Interstellar Plasma Spectrometer

CHIPS (Explorer 82) satellite
Names	Explorer 82 UNEX-2 CHIPS
Mission type	Extreme ultraviolet research
Operator	NASA / Space Sciences Laboratory
COSPAR ID	2003-002B
SATCAT no.	27643
Website	CHIPS
Mission duration	1 year (planned) 5 years, 3 months (achieved)
Spacecraft properties
Spacecraft	Explorer LXXXII
Spacecraft type	Cosmic Hot Interstellar Plasma Spectrometer
Bus	CHIPS
Manufacturer	SpaceDev
Launch mass	60 kg (130 lb)
Dimensions	5 × 2.8 × 3.2 m (16.4 × 9.2 × 10.5 ft)
Start of mission
Launch date	13 January 2003, 00:45:00 UTC
Rocket	Delta II 7320-10 (Delta 294)
Launch site	Vandenberg, SLC-2W
Contractor	Boeing Launch Services
Entered service	2003
End of mission
Deactivated	11 April 2008
Orbital parameters
Reference system	Geocentric orbit[1]
Regime	Low Earth orbit
Perigee altitude	578 km (359 mi)
Apogee altitude	594 km (369 mi)
Inclination	94.05°
Period	96.40 minutes
Explorer program ← RHESSI (Explorer 81) GALEX (Explorer 83) →

CHIPS (Cosmic Hot Interstellar Plasma Spectrometer, also Explorer 82 or UNEX-2) was a NASA Explorer program satellite. It was launched on 12 January 2003 from Vandenberg Air Force Base aboard a Delta II with the larger satellite ICESat, and had an intended mission duration of one year. CHIPS was the second of NASA's University Explorer (UNEX) mission class. It performed spectroscopy from 90 to 250 Angstrom (9 to 26-nm) extreme ultraviolet (EUV) light.^[2]

Mission

The primary objective of the science team, led by principal investigator Mark Hurwitz, was to study the million-degree gas in the local interstellar medium. CHIPS was designed to capture the first spectra of the faint, extreme ultraviolet glow that is expected to be emitted by the hot interstellar gas within about 300 light-years of the Sun, a region often referred to as the Local Bubble. Surprisingly, these measurements produced a null result, with only very faint EUV emissions detected, despite theoretical expectations of much stronger emissions. It was the first U.S. mission to use TCP/IP for end-to-end satellite operations control.

Spacecraft

The University of California, Berkeley's Space Sciences Laboratory (SSL) served as CHIP's primary ground station and manufactured the CHIPS spectrograph, designed to perform all-sky spectroscopy. Other ground network support was provided by ground stations at Wallops Flight Facility (WFF), Virginia and Adelaide, Australia. CHIPS's satellite bus was manufactured by SpaceDev.

Launch

CHIPS (Cosmic Hot Interstellar Plasma Spectrometer) is a NASA astrophysics spacecraft that was launched by a Delta II launch vehicle from Vandenberg Air Force Base at 00:45:00 UTC on 13 January 2003.^[1] The 60 kg (130 lb), triaxially-stabilized spacecraft has a spectrograph covering the 9-26 nm wavelength band at a resolution of 0.1 nm, scanning the entire sky in chunks of 5° x 27° segments during each orbit. The targets are the hot and diffuse nebula at about a million degrees temperature. The band covers several strong emission lines.^[3]

Solar observatory

In September 2005, the spacecraft was converted to a solar observatory.^[4] From 3 April 2006 to 5 April 2008, CHIPS performed 1458 observations of the Sun.^[5]

End of mission

Satellite operations were terminated in 11 April 2008 due to budget constraints.^[6]