ACE Satellite

There are at least two ACE satellites in space that produce information that is of value to the amateur radio operator. The United States maintains the The Advanced Composition Explorer (ACE) Satellite and the Canadian Government maintains the Atmospheric Chemistry Experiment (ACE) Satellite.

The Canadian's Atmospheric Chemistry Experiment Satellite is also known as SCISAT-1. This satellite carries instrumentation used to measure the chemistry of Earth's atmosphere. The primary use of SCISAT-1 is measuring ozone depletion in the Arctic stratosphere.

SCISAT-1 lead scientist, Dr. Peter Bernath, is located at the University of Waterloo. Data collected from the Canadian ACE Satellite is disseminated through the Department of Chemistry at the University of Waterloo to other universities and interested industry and organizations.

SCISAT-1 is an international project. Funding for the satellite is primarily through the Canadian Space Agency. Ray Nassar and Elizabeth Bernath /Canadian Space Agency / Univ. of Waterloo

Usually when an ACE Satellite is referenced in space weather literature it is this satellite being mentioned.

ACE was launched in August of 1997. ACE is a National Aeronautics and Space Administration (NASA) Explorer mission. The principal investigator is located at JPL/Caltech. Mission web pages change. Currently the Home page for ACE is being managed from Caltech.

It is the purpose of the ACE Science Center (ASC) to facilitate the distribution of data from the Advanced Composition Explorer (ACE) spacecraft. ASC's responsibility includes archiving data and preparation of data to be archived at the National Space Science Data Center (NSSDC). ASC has the additional responsibility of making sure that ACE data is publicly available.

ACE data is provided as Level 1 or Browse data for monitoring large particle and magnetic field data at various time intervals. This data, while accurate, is not furnished for research use. Level 2 data is available for scientific use and publication. Level 3 data is data that is contributed to the ACE mission by outside sources.

The ACE Science Center serves as the interface between project scientists and the Flight Operations Team. "The ACE Science Center's centralized services are intended to guarantee appropriate use of data formatting standards, improve communications, and reduce redundant effort in data processing".

Numerous agencies and universities publish data that is exactly complementary with ACE data. NOAA is among these agencies. NOAA is one of the primary interfaces between ACE data acquisition and the amateur radio community. ACE Real Time Solar Wind (RTSW) data has been made available to the public by NOAA through cooperation with the ACE project since 1998.

The ACE Satellite serves as Earth's sentry for Solar generated particles and magnetic waves. It is the primary source for the measurement of solar wind speed.

The ACE Satellite is positioned at a Lagrangian L1 point . This places ACE about 1.5 million km from Earth and 148.5 million km from the Sun. The space craft is approximately 1/100 of the distance from the Earth to the Sun. The satellite travels in an elliptical orbit in gravitational equilibrium between the Sun and Earth. This orbit gives it an excellent view of the Sun and a range of deep space beyond.

This web page contains an article on one of the principle instruments of the space physics and space weather industries. As such, the article should be an informative, up-beat description of the instrument and the important role that it serves. The scope of the article has been narrowed by information recently received by the Webmaster and others in correspondence from NOAA. The nature of the Agency's notification to us is the termination of ACE Satellite services. The termination of services goes beyond the fact that dissemination of ACE Satellite measurements by NOAA is being phased out. NOAA is not a culprit in the mater. It is the ACE Satellite itself that is being phased out.

Finding a point in this article to publish information on the termination of the ACE Satellite Mission has been difficult. We have elected to make this article one that describes the ACE Satellite and the mission that it full-fills today. Thus, news concerning termination of the ACE Mission comes at the Article's end.

Image: ACE Satellite 1.6 meters across and 1 meter high, not including the four solar arrays and the magnetometer booms attached to two of the solar panels. The fuel supply for the Satellite is hydrazine. Five hundred (500w) watts of

power are generated by the solar panels. The satellite's spin axis approximates a line running from the Sun toward Earth. Spin rate of the satellite is 5 rpm. Instruments are located on the top of the Satellite pointed toward the Sun. Click image to enlarge. SRL/Caltech

ACE is an early warning devise giving scientist on Earth approximately one hour advance warning of geomagnetic storms. It monitors solar flares and other large and small solar events. It also provides near-real-time solar wind information.

"The primary purpose of ACE is to determine and compare the isotopic and elemental Actual photograph of solar wind (light colored flares) taken with the Sun at full eclips. Photo courtesy NASA

Actual photograph of solar wind (light colored flares) taken with the Sun at full eclips. Photo courtesy NASA

composition of several distinct samples of matter, including the solar corona, the interplanetary medium, the local interstellar medium, and Galactic matter." NASA

Matter sampled by the 9 instruments aboard ACE include "the solar corona, the interplanetary medium, the local interstellar medium, and Galactic matter. " SRL/Caltech

ABOVE: The above graphic is an actual image displaying solar wind. Most of the time, graphics showing solar wind are artists' conceptions of the phenomena. Here, we have an actual photograph of solar wind (light colored flares). The dark central object is Earth's Moon. The Sun is in full eclipse. NASA

All values displayed in the following graphic are derived directly from the scientific instrumentation aboard the ACE Satellite. Measurements are transmitted to NASA's stations on Earth through NASA's Deep Space Network.

The data path in the below graphic involves direct transmission from NASA to NOAA's Space Weather Prediction Center (SWPC). Data is then transmitted from the Space Weather Prediction Center directly to this Website (www.zseltvay.com and www.kc4cop.bizland.com - are presently consolidated in our only public website). The data in the Graphic is updated every 5-minutes. The only other delay results from the combination of actual data processing and transmission through the World Wide Web.

Because the data refreshing rate described above may be too slow for some of our readers, this Website also sports direct (alternate) data links to NASA, NOAA, and other terrestrial and orbiting observatories.

This is a graphical data feed from the Space Weather Prediction Center (NOAA). The data displayed is real-time. Other ACE real-time data feeds on this Website include data received directly from NASA with data updates every minute and every five minutes.

While a more detailed list of the instrumentation will follow, we will outline here what the instruments are actually measuring and what the public has instant access to:

How Long will the Sun Bather Remain Aloft? Not forever. NASA claims that the ACE Satellite has enough fuel aboard to keep it stationed at its L1 point until 2019. Now, NOAA has added its predictions concerning the final operation of ACE Satellite services.

This web page contains an article on one of the principle instruments of the Space Weather Industry. As such, the article should be an informative, up-beat description of the instrument and the important role that it serves. The scope of the article has been narrowed by information recently received by the Webmaster and others in correspondence from NOAA. The nature of the Agency's notification to us is the termination of ACE Satellite services. The termination of services goes beyond the fact that dissemination of ACE Satellite measurements by NOAA is being phased out. NOAA is not a culprit in the mater. It is the ACE Satellite itself that is being phased out.

Pending Termination of ACE Satellite Services

Webmaster Receives Direct Notification Nrom NOAA Concerning theTermination of ACE Satellite Services

This entry concerning the termination of ACE Satellite services was added to the Website in September, 2006. NOAA notified the webmaster and other users of real-time solar wind data that the ACE Satellite mission is closing down its operation. There are no plans for providing maintenance to the space craft or to the scientific instruments aboard her. NOAA advised us that there are no plans to replace the ACE Satellite or to launch space craft that would provide the same data that we currently receive from ACE.

The notification we received from NOAA included a description of the current ACE Satellite Mission and its intended operation up until final Mission Termination. In our notification, the ACE Satellite's condition was divided into a description of the anticipated instrument failure and space craft failure.

We have published information from the correspondence we received from NOAA on an accompanying webpage.

NOTE: The ACE Satellite is owned by NASA. The Satellite is currently being operated by NASA (JPL/Caltech).

How does the Web Site staff gain quick access to archived data from the ACE Satellite ?

In the spirit of amateur radio, we are providing our secret link for obtaining archived ACE data with only a few key strokes. Archived data via computer inquiry. Archived Data from NASA's Advanced Composition Explorer (ACE) Satellite