SPINR Mission Overview
The Experiment:
SPINR studies astronomical phenomena using spectrographs developed for the ongoing TERRIERS satellite project at the Center for Space Physics at Boston University. These instruments are four Single Element Imaging Spectrographs (SEIS) (Cotton, et al,1994) which are simple, efficent systems capable of recording the spectrum of a wide field while imaging the same area. In order to map the two dimensional field the system is spun about its viewing axis and a reconstruction algorithm we have developed (Cook etal, 1995, Stephan etal, 1995, and Betremieux etal, 1993) is used to separate the two dimensional image of the field. This technique yields a full three dimensional data set including right ascension, declination, and wavelength which can be used to study both the spectrum of multiple objects in the field as well as light from the diffuse background. The instrument yields a spectral resolution of approximatly 5-10 Angstroms over a bandpass of 800A to 1400A, with a spatial resolution of 5-15 arcminutes over a 10 by 10 degree field of view.

The experiment studied the Upper Scorpius Cloud, particularly the relationship between dust grain size and composition by mapping the ultraviolet (UV) flux across the region. The collection of stars scattered throughout the field can be used for absorption studies. It is likely that this dual approach of measuring both the scattering and the absorptions properties of the interstallar medium will prove more productive than either method would independently.

The Science:
SPINR sampled a collection of stars in the constellation of Scorpio. The data included...............

The Instruments:

The main scientific instruments on this payload are four TESS (Tomographics EUV SpectrographS) spectrographs, an Extreme Ultraviolet use of the SEIS design. They were developed and tested here at Boston University ( Cotton, et al,1994). The SEIS design is revolutionary because it uses a toroidal (cross section of a hollow torus) grating. The spectrum is taken in the horizontal direction, while the field of view is imaged in the vertical direction. This ability to gather both spatial and spectral information in a one-bounce system makes it ideal for UV studies.

Structural System
The structural systems of the rocket include an optics section which holds the four TESS spectrographs and star tracker as well as an electronics section separated by a vacuum bulkhead. Each spectrograph mounts to a plate that then mounts to one side of the block. The star tracker is mounted to a flange that attaches to each side of the block. The block is then mounted to a bulkhead with the spectrograph's look direction pointed away from the bulkhead. (See Diagram).

Electronics Section
The electronics mount to the other side of the instrument bulkhead on the sides and top of a U-shaped structure. A video camera is mounted to this structure and looks out a window in the bulkhead looking in the same direction as the spectrographs.

In the picture you see the electronics section looking down onto the instrument bulkhead; also visible are the High Voltage Power Sources (HVPS) which are used to turn the detectors. (See Diagram).

High School Accelerometers
Included in the electronics section was a 3-axis accelerometer built by highschool students.


Guidance, navigation, and control (telemetry), recovery and finally the experiment section need to go through structural testing to insure their safety and reliability during the launch and reentry phases of the mission. The rocket goes through:
  • Moment of Inertia Test
  • Bend Testing
  • Spin-Balance Test
  • Shake Tests