The TUS (Tracking Ultra-violet Set up) space fluorescence detector has to be launched in 2010 as a separated platform in Foton (Bion) mission prepared by the Samara enterprise. This detector was designed for another satellite and the updated variant of the TUS detector for a new platform is presented. The data on UV glow of the atmosphere obtained in operation of one pixel of the TUS detector on board the Moscow State University “Universitetsky-Tatiana” satellite was taken into account in design of the updated TUS detector. The data on UV transient flashes registered in “Universitetsky-Tatiana” mission are of special interest. Electronics of the TUS detector able to select and register different types of UV events in the atmosphere is presented.

The TUS project (EECR study from space by observation of the atmosphere fluorescence) came to the construction stage. The UV sensor of the TUS detector is operating on board the "Universitetsky-Tatiana" satellite. Results of UV measurements are presented.

The Tracking Ultraviolet Set Up (TUS) instrument has been designed to observe from space the fluorescence light in the atmosphere when Extensive Air Shower (EAS) or other phenomena such as meteors or dust grains traverse it. The TUS design concepts will allow us to construct the next generation of fluorescence detectors with increasing light collection power and higher resolution. The KLYPVE instrument with collection power 5 times larger of the TUS will be the next space detector. Light collection is obtained with the help of segmented “low frequency Fresnel type” mirrors. Photo receiver retina in the focal consists of modules of PM tubes. For stable performance in conditions of variable light noise and variable temperature the tube type with a multi-alcali cathode was chosen. Voltage supplies for PMT in one module were designed for keeping the performance of photo receiver retina uniform when the tube gain change. From every tube the signal amplitude is recorded in time bins of 400ns. The digital data are kept and analyzed in the module FPGA connected to the central FPGA controlling all data. The RAM memory is large, capable to record events with different duration of the light signal (up to several seconds). The preliminary event data are analyzed in the triggering system of the central FPGA. The trigger criteria have several options for events of different origin (different pixel signal duration). The trigger integration time is controlled from the space mission center. The performances of the detector were simulated and zenith angle dependent trigger efficiencies were calculated. The TUS detector will be efficient in recording “horizontal” EAS (zenith angles more than 60°), developed to their maximum above the cloud cover. The EAS Cherenkov light, back scattered from the cloud cover, will be recorded and will improve data on the EAS direction and position of maximum. For better accuracy in physical parameters of the events and for the experimental check of this accuracy the performance of two TUS detectors at the space platform was recommended. The accommodation of 2 TUS detectors at space platform of the “RESURS O” type was tried and approved. The TUS prototypes are being tested in the Mexican mountains. The photo receiver of two PM tubes with the TUS electronics on-board of the MSU Tatiana satellite is measuring the atmosphere light background.

We report on the current status of the TUS space mission project: its goals and the progress achieved so far. The Fresnel mirrors design, performed checks and their production are discussed. Also we discuss our future plans including auxiliary analysis of the fluorescence light yield measured this year by LAPP (Annecy), JINR (Dubna) and LIP (Lisbon) MACFLY Collaboration.

The TUS/KLYPVE space experiments have been proposed to study the energy spectrum, composition and arrival direction of the Ultra High Energy Cosmic Rays (UHECR) by detection from the space satellites of the atmosphere fluorescence and Cherenkov light produced by UHECR initiated Extensive Atmosphere Showers (EAS). The TUS set up is a prototype of the KLYPVE. The aim of the TUS experiment is to detect a dozen of UHECR events in the energy region of the GZK cutoff, to measure the light background, to test the atmosphere control methods, to study a stability of the optic materials, of PMTs, and of DAQ in the space environment.

The space TUS detector of UV fluorescence light radiated by EAS of Ultra High Energy Cosmic Rays (UHECR) is under preparation for the launch in 2009-2010. The TUS instrument will have ~2 sq. m. mirror concentrator area and 256 PMT pixels in the photo receiver at the mirror focal surface. The TUS mission is now planned for operation at the Small Space Apparatus separated from the main Foton-4 satellite launched by SCB “Progress”. The “Universitetsky-Tatiana” satellite data on the night atmosphere UV glow helps to organize the trigger system effectively separating EAS events from the background atmospheric events. The TUS detector will be used not only for UHECR study bur also for observation of other atmospheric phenomena of UV radiation.