The next flight of the American shuttle Atlantis for the last mission of maintenance of the orbital telescope Hubble in October will be more dangerous due to the greater quantity of orbital remainders that are found to that altitude, indicated Monday a responsible for the Nasa.
The risk that the trasbordador suffer in this mission a disastrous damage due to the impact of a micrometeorito or an orbital remainder is reckoned in 1 in 185 compared with the typical one 1 in 300 in the flights toward the International space station (ISS), needed John Shannon, director of the program of the trasbordador, in a press conference.
In the measure in which the director of this program cannot assume alone a risk over 1 in 200, the decision to carry out this mission should be taken for the highest responsible for the Nasa, like the director Michael Griffin, he added, explaining that he expects of all forms a green light.
The telescope Hubble orbit at some 563 kilometers from the Land, against some 354 km in the case of the ISS.
“Los micrometeoritos and the orbital remainders (MMOD) represent the major risk for all the flights of shuttles” and more to the altitude that is situated Hubble that to that of the ISS, underlined Shannon. It explained that the environment returned still more hostile in the last year after a Chinese test to destroy a satellite, the compulsory destruction on the part of the Air Force American of a satellite that was outside of control and the dismemberment of a Russian rocket.
But after the accident of the trasbordador Columbia when returned to the atmosphere in February of 2003 -caused by the impact of a piece of insulating foam that was removed of the tank of external fuel and perforated the thermal protection of its left wing- the Nasa set in motion efficient systems of inspection and repair in orbit, underlined Shannon. “Nuestra capacity to minimize these risks enlarged, what confidence offers us more”, emphasized.
The engineers have developed materials that can cover in the empty spatial one a crack in the thermal shields or a hole in the plates of carbon reinforced that protect the wings and the nose of the trasbordador, said Shannon. In those parts of the ship the temperature is the highest one (1,500 degrees Celsius) with the friction at high speed with the atmosphere during the return to the Land.
Predicting the worse thing, the Nasa will have a second one trasbordador, the Endevour, with two crew members, in the launching pad of the Spatial Center Kennedy, in Tip sugarcane Plantation (Florida, southeast), ready for to be launched to help the seven astronauts of the Atlantis of be necessary. As opposed to other missions toward the ISS, the Atlantis will be too far of the station to be adapted her in case of a serious damage.
“Sería necessary that the Atlantis suffer a rare and important damage caused by a micrometeorito or an orbital residue in a vital place to undertake a mission of rescue with a second ship”, needed nevertheless Shannon. This option been considered above all in case of serious damages caused by the impact of a piece of ice or of insulating foam during the launch, assured. Nevertheless, the risk has been hardly reduced by means of modifications and technological development since the catastrophe of the Columbia, said Shannon.
The Atlantis will carry out its quarter and last mission of maintenance of the telescope Hubble, first spatial telescope, launched in 1990 and that revolutionized the astronomy. Its successor, the spatial telescope James Webb, will be position in orbit in 2013 to more delay.