Processing of nutritious, safe and acceptable foods from CELSS candidate crops.

A controlled ecological life-support system (CELSS) is required to sustain life for long-duration space missions. The challenge is preparing a wide variety of tasty, familiar, and nutritious foods from CELSS candidate crops under space environmental conditions. Conventional food processing technologies will have to be modified to adapt to the space environment. Extrusion is one of the processes being examined as a means of converting raw plant biomass into familiar foods. A nutrition-improved pasta has been developed using cowpea as a replacement for a portion of the durum semolina. A freeze-drying system that simulates the space conditions has also been developed. Other technologies that would fulfill the requirements of a CELSS will also be addressed.     

Long term changes in Venus sulfur dioxide

Pioneer Venus data from the first 5 years of operation show a decline by more than a factor of ten in SO₂ at the cloud tops. A consistent decline has also recurred in the amount of sub-micron haze above the clouds. The correlation between these two observables is 0.8 over this period. A plausible explanation is injection of SO₂ from episodic volcanism. The episodic behavior implies that steady state models of the Venus cloud chemistry and dynamics may be of limited use.     

Legal aspects of planetary protection for Mars missions.

The planning and execution of manned and robotic missions to Mars present a wide range of jurisprudential issues. Provisions to prevent the disruption of natural celestial environments, as well as damage to the environment of Earth by the return of extraterrestrial materials, are important components of the law applicable to mankind's activities in outer space, and have been supplemented by scientifically instituted planetary protection policies. However, divergent legal regimes may exist, as the space treaties in force are neither uniform in their provisions, nor identical as to the states which have signed, ratified, or adopted the international agreements. The legal requirements applicable to a specific mission will vary depending on the entities conducting the program and specific mission profile. This article analyzes the divergent international legal regimes together with the factors which will influence the determination of the standards of conduct which will govern manned and robotic missions to Mars.     

EXOSAT observations of NGC 1399 and NGC 1404: Two elliptical galaxies in the center of the Fornax cluster

Imaging X-ray observations of the Fornax cluster of galaxies centered on NGC 1399 and NGC 1404 are presented. NGC 1399 and NGC 1404, which are separated by about 10 arc minutes, are found to have an unusually high ratio of x-ray to optical flux. We consider the possibility that the x-radiation is produced by hot gas in the cores of the galaxies. Weak X-ray emission is also detected from a point almost exactly mid-way between NGC 1399 and NGC 1404. The combined emission from the galaxies is insufficient by over an order of magnitude to account for the the low-energy X-ray emission detected from this region by the HEAO-l satellite. It is suggested that the bulk of the HEAO-1 source is diffuse gas associated with the cluster as a whole, rather than individual galaxies.