51.   Hess said the space agency plans to build five of the safers as soon as possible.

52.   However, he would not say at a news conference to what lengths the American space agency is willing to go to prevent a premature visit by Tito.

53.   However, it permitted the space agency to design a spacecraft that uses less fuel, making it smaller and cheaper to launch by hundreds of millions of dollars.

54.   However, the space agency has not ruled out the possibility of an earlier landing, if weather conditions are more favorable on Saturday.

55.   However, the space agency was thwarted by technical, financial and political obstacles.

56.   However, the two space agencies believe the unusual experiment is well worth the cost.

57.   However, the U.S. space agency is closely monitoring Russian spacecraft production and developing options to make up for lapses in the Progress missions where it can.

58.   However, the space agency will not make a final decision on the excursion to retrieve an external experiment package until after the first of the year.

59.   If the space agency and Boeing do not reach a schedule agreement, the Air Force will establish the schedule.

60.   If the gains are sufficient, the U.S. space agency hopes it will support the resurrection of science experiments suspended by the collision.