New launchers will make their debut, while NASA continues to fight spiralling costs

The maiden launches of the Boeing Delta IV and Lockheed Martin Atlas V, due in May, will be the highlights of the year, although many will be keeping a close eye on NASA's struggle to keep the International Space Station (ISS) on schedule and within budget. The Atlas V and Delta IV vehicles have been built under the US Air Force's Evolved Expendable Launch Vehicle programme, but will be flying commercial missions.

An International Launch Services-operated Atlas V 400-series booster will carry Eutelsat's Hot Bird 6 communications satellite into geostationary transfer orbit (GTO) from launch pad 41 at Cape Canaveral, Florida. The vehicle is based on the Atlas IIIA and IIIB rockets: the IIIA has flown only once, and the IIIB, which has two upper-stage engines rather than the IIIA's single, will make its inaugural flight this month, carrying the Echostar 7 television satellite. The new Atlas V may well rapidly supersede both rockets.

The Atlas V 400 is powered by a US-Russian RD-180 first-stage engine and an upgraded Centaur upper-stage engine. The main improvement on the Atlas III is a structurally-stable core stage. Earlier Atlas stages were pressure-stabilised. The first series Atlas V can lift 4.95t to GTO.

Meanwhile, the first in the Boeing Delta IV series, the Delta IV Medium, is being prepared for its maiden flight in May. The booster will lift Eutelsat's Atlantic Bird communications satellite into orbit from pad 37, formerly a Saturn I launch site, at Cape Canaveral. The Delta IV Medium will be able to lift 4.2t to GTO.

The first Ariane 5 of the year should be launched by the end of next month, and will carry the European Space Agency's environmental flagship, Envisat. It will be a chance for the operator, Arianespace, to prove itself again following the Ariane 5 launch failure in July, which stranded two communications satellites in low orbits.

The Space Shuttle is scheduled for up to seven missions this year, but NASA budget cuts may reduce this to five. This could mean only three missions to the ISS, which would delay its assembly and force crews to stay on the station longer. One of the ISS missions will include Jerry Ross, the first person to make seven spaceflights. Ross, a NASA mission specialist, first flew in 1985. NASA has promised to keep the ISS well within budget for at least two years to ward off any more criticism over poor financial management. Next month, the Space Shuttle will service the Hubble Space Telescope for the fourth time, and in May it will embark on an extended Spacelab science mission, which has already been delayed over a year.

Security precautions

Safety will remain the prime concern at NASA. A shuttle launch failure would have a dramatic effect on the ISS and human space transportation plans. The Space Shuttle has made 107 launches since 1981, including the Challenger disaster in 1986. The recent launch of Endeavour was accompanied by unprecedented precautions against terrorist attack, which are likely to remain in place.

In space science, two significant NASA Delta II launches are planned for July. The Comet Nucleus Tour (Contour) is a Discovery programme mission to fly past three comets, taking photographs, making spectral maps of the nuclei, and analysing the composition of the comets' tails. The spacecraft will fly past comet Enke in November next year, comet Schwassmann-Wachmann-3 in June 2006 and comet d'Arrest in August 2008.

NASA's Space Infrared Telescope Facility is the last of the Great Observatory series spacecraft, after Chandra, Compton and Hubble, and will continue work started by previous infra-red observatories. It is much smaller than originally planned and will be placed into an Earth-trailing solar orbit in June, giving it an excellent view of the sky and preventing it from overheating.

Source: Flight International