Old Instruments Gather New Data

RAIDS as viewed by an astronaut on the ISS. (Reprinted courtesy of NASA)

An Aerospace team took a set of instruments that had been sitting unused in a clean room for more than a decade, sent it up to the International Space Station (ISS), and used it to collect helpful data about a region of Earth’s atmosphere that up till this point has been largely unstudied.

“This was really a groundbreaking mission even though it was 15 years old,” said Dr. Rebecca Bishop, a research scientist in the Space Sciences Department at Aerospace.

Instruments on the ground only measure atmospheric properties up to about 110 km and instruments in space don’t measure below about 160 km. This leaves a tricky-to-measure area in the middle.

“This region within our community is affectionately known as the ‘ignorosphere,’” Bishop said.

The team of Bishop, Dr. James Hecht, Dr. Andrew Christensen, and Dr. Paul Straus used the Remote Atmosphere/Ionosphere Detection Sensor (RAIDS) Sensor Suite to combat that ignorance.


“The purpose of this project was to measure the temperature, density, and composition of a region of the atmosphere from about 80 km up to about 200 km,” Bishop said.

RAIDS, which is a joint mission with the Naval Research Laboratory (NRL), is a set of eight instruments (five of which were built at Aerospace) on a scanning platform (also designed and built by Aerospace).

The eight instruments are three photometers, a near-infrared spectrometer, a far and extreme ultraviolet spectrograph, and a near and medium ultraviolet spectrometer.

RAIDS was built from 1989 to 1991, but it had trouble getting a ride into space. It was scheduled to launch in 1994 and operate on a TIROS satellite, but was replaced with a higher priority payload.

This turned out to be a trend, and 11 potential domestic and foreign launch opportunities didn’t work out for RAIDS. However, after camping out in an NRL clean room for years, its time finally came.

An opportunity arose for it to ride to the ISS on a Japanese HTV cargo vessel. The Aerospace team pulled RAIDS out of storage, refurbished it, and it launched Sept. 11, 2009.

RAIDS surpassed its one-year minimum mission life by providing 13 months of excellent data, after which the scanning platform’s power system failed. RAIDS still provides data, but it is more limited.

The data that the team collected can help with atmospheric drag calculations and space weather models, and determine the environment’s impact on communications and radar systems.

“We believe this has been a very successful flight of something that otherwise was just going to become a museum piece,” Bishop said.


RAIDS shortly after installation on the ISS. (Reprinted courtesy of NASA)

RAIDS shortly after installation on the ISS. (Reprinted courtesy of NASA)

—Laura Johnson