ICESAT/CHIPSAT Launch Scrubbed
Today’s launch of the ICESAT and CHIPSAT spacecraft aboard a single Delta 2 from Vandenburg Air Force Base was srubbed when problems arose in a Helium tank in the booster’s first stage. The next launch attempt will be tomorrow, Sunday 12 January 2003.
Mission background (Source: Vandenburg Air Force Base)
The Laser Altimetry Mission, recently known as ICESAT for Ice, Cloud and land Elevation Satellite, will accurately measure the elevations of the Earth’s ice sheets, clouds, and land and answer fundamental questions about the growth or shrinkage of the Earth’s polar ice sheets and future global sea level rise or fall. ICESAT also will measure the heights of clouds for studies of Earth”s temperature balance and will measure land topography for a variety of scientific and potential commercial applications. In addition to providing the spacecraft, Ball Aerospace will integrate and test the primary instrument on the ICESAT satellite,the Geoscience Laser Altimeter System. The laser altimeter is being developed at NASA’s Goddard Space Flight Center, Greenbelt, MD, and will provide precise elevation of the land, ice, and clouds that are overflown.
The laser is completely eye-safe to individuals on the ground. It works by transmitting short pulses of infrared light and visible-green light to measure ice sheet elevation and land topography (infrared light) and measurements of clouds and aerosols (green light). The distance from the spacecraft to clouds and to Earth’s surface will be determined from measurements of the time taken for the laser pulses to travel to these targets and return. Similar instrumentation has been flown on aircraft over the Greenland ice sheet for proof-of-concept experiments.
The Greenland and Antarctic ice sheets cover 10 percent of the Earth’s land area, and contain 77 percent of the Earth’s fresh water and 99 percent of its glacier ice. Measurements of the ice sheets are essential for assessing whether future changes in ice volume will add to the sea level rise, which is already occurring, or whether the ice sheets might grow and absorb a significant part of the predicted sea level rise.
ICESAT is one in a series of spacecraft for NASA”s Earth Science program which will study the Earth’s system and the effects of natural and human-induced changes on the global environment.
CHIPSAT Cosmic Hot Interstellar Plasma Spectrometer (replaces previous secondary payload CATSAT). CHIPSAT is the first mission of NASAs low-cost University-Class Explorer (UNEX) series. It will be launched for its one-year mission as secondary “piggyback” payload on a Boeing Delta 2 rocket. The approximately 70 kg micro-spacecraft will carry one science instrument, the Cosmic Hot Interstellar Plasma Spectrometer, or CHIPS.
CHIPS will capture the first spectra of the faint, extreme ultraviolet glow that is expected to be emitted by hot interstellar gas within about 300 light-years of the sun. CHIPS data will help determine the temperature,ionization state, and other physical conditions in nearby hot interstellar gas.
