Spartan Infrared Camera

Spartan Infrared Camera. It was a cryogenically cooled infrared imaging instrument designed to fly aboard the Space Shuttle as part of the Shuttle Pointed Autonomous Research Tool for Astronomy (SPARTAN) program. Developed by NASA's Goddard Space Flight Center, its primary mission was to conduct high-resolution observations of celestial objects in the mid-infrared spectrum, a region heavily obscured by Earth's atmosphere. The autonomous, reusable platform was deployed and retrieved by the Space Shuttle during multiple missions in the 1990s, contributing valuable data to the field of infrared astronomy.

Overview

The instrument was a key component of NASA's strategy to develop cost-effective, reusable platforms for space science. The SPARTAN program, managed by the Goddard Space Flight Center, provided a free-flying satellite that could be launched, operated, and retrieved by the Space Shuttle. This particular camera was specifically engineered to exploit the clarity of space for infrared observations, complementing larger observatories like the Infrared Astronomical Satellite (IRAS) and preceding the capabilities of the Spitzer Space Telescope. Its development involved collaboration with scientists from institutions like the University of Arizona and leveraged technologies from projects such as the Infrared Telescope Facility.

Design and specifications

The camera's core was a boron-doped silicon photoconductor array, specifically a 128 x 128 pixel Si:Ga detector, which was sensitive to light in the 2 to 120 micrometre range. To achieve the necessary sensitivity for detecting faint infrared sources, the entire optical system was cooled to temperatures near absolute zero using a superfluid helium dewar, a technology also used on missions like the Infrared Space Observatory. The instrument's telescope was a Cassegrain reflector with a 15-centimeter aperture, and it utilized a set of discrete bandpass filters, including ones centered on 4, 8, 12, 21, and 70 micrometres, to make observations at specific infrared wavelengths.

Scientific objectives and mission history

Its primary scientific goals included mapping interstellar dust emission, studying star formation regions, and investigating the nuclei of active galaxies. The camera flew on three dedicated Space Shuttle missions: first on STS-56 aboard Space Shuttle *Discovery* in April 1993, then on STS-64 aboard *Discovery* again in September 1994, and finally on STS-77 aboard Space Shuttle *Endeavour* in May 1996. During the STS-64 mission, it successfully observed targets such as the Orion Nebula and the Galactic Center, providing crucial data on interstellar material. These flights were part of a broader series of SPARTAN missions that also carried other instruments, like the SPARTAN 201 coronagraph.

Instrumentation and operation

Once deployed from the Space Shuttle's payload bay, the satellite operated autonomously for a period of about two days. The camera's observations were pre-programmed, with the instrument using its own attitude control system to point and stabilize itself with arcminute precision. The cryogenic system's limited lifetime dictated the observation schedule, with the superfluid helium supply typically lasting 40 to 50 hours. Data was stored onboard in solid-state recorders for later retrieval after the Space Shuttle's crew used the Remote Manipulator System (Canadarm) to capture the satellite and return it to Earth.

Data and legacy

The data collected provided important insights into the distribution of polycyclic aromatic hydrocarbons and warm dust in regions like the Orion Molecular Cloud Complex. Its observations contributed to the foundational knowledge used in planning subsequent major infrared space telescopes, including the Spitzer Space Telescope and the James Webb Space Telescope. The success of the reusable SPARTAN platform demonstrated the value of shuttle-based autonomous missions and informed the design of later small satellite projects. The camera itself is now part of the historical collection of NASA artifacts.

Category:Infrared telescopes Category:NASA space probes Category:Space Shuttle payloads