The Advanced Composition Explorer
The Advanced Composition Explorer (ACE) was recently selected as one of two new Explorer‐class missions to be developed for launch during the mid‐1990's ACE will observe particles of solar, interplanetary, interstellar, and galactic origins, spanning the energy range from that of the solar wind (∼1 keV/nucleon) to galactic cosmic ray energies (several hundred MeV/nucleon). Definitive studies will be made of the abundance of nearly all isotopes from H to Zn (1≤Z≤30), with exploratory isotope studies extending to Zr(Z=40). To accomplish this, the ACE payload includes six high‐resolution spectrometers, each designed to provide the optimum charge, mass, or charge‐state resolution in its particular energy range, and each having a geometry factor optimized for the expected flux levels, so as to provide a collecting power a factor of 10 to 1000 times greater than previous or planned experiments. The payload also includes several instruments of standard design that will monitor solar wind and magnetic field conditions and energetic H, He, and electron fluxes. We summarize here the scientific objectives, instrumentation, spacecraft, and mission approach that were defined for ACE during the Phase‐A study period.
Additional Information© 1990 American Institute of Physics. Published online 20 March 1990. The ACE Phase-A study could not have been completed without the contributions of many individuals, including exceptional efforts from many scientists, engineers, and staff at the various Investigator Institutions. D. Mehoke of JHU/APL was the systems engineer for the spacecraft study team. He and the other members of the spacecraft study team at JHU/APL deserve thanks for their response to the tasks given them. We are grateful to R. Farquhar of GSFC and D. Dunham of Computer Sciences Corp. for providing trajectory calculations for ACE. The ACE Technical Officers at GFSC were E. Mercanti and T. Karras and their aid in providing liaison with the GSFC Project Office was appreciated. We are thankful for the support of S. Nylund of JHU/APL who was largely responsible for formulating the ACE Data Plan. We also appreciate the assistance of G. Floyd of GSFC for helping to formulate the ground data capture and mission operations and control systems. Our efforts in defining the telecom parameters for ACE benefited from discussions with W. L. Martin of JPL. Finally, the ACE Phase-A report achieved its final form due to the considerable effort and expertise of L. Sartain, C. Silva, and K. Gary, all of Caltech. The ACE Phase-A Study was supported by NASA Contract NAS5-30340.
Published - 1989-26.pdf