Once upon a time, the United States was the world leader when it came to doing business in space: We launched most of the world’s commercial satellites. But after the disastrous Challenger explosion of 1986, then-President Reagan banned the shuttle from carrying commercial payloads (a ban that remains in effect), and the European Space Agency quickly began to grab more and more of the commercial market.

In an attempt to woo back customers, the two leading U.S. rocket companies are now unveiling their next-generation expendable launch vehicles. Lockheed Martin’s Atlas 5 and Boeing’s Delta 4 rockets are built with modular parts so engineers can string different components together, depending on the size and shape of the payload. That reduces the cost of the operation. And because the rockets are assembled before arriving at the launch site, there’s less of a wait at the site so satellites can be sent off more quickly.

The U.S. military is keen on keeping both rocket programs aloft–so much so that the Pentagon gave each company $500 million and later signed contracts for launch services with both. These investments are meant to ensure that top secret payloads stay out of foreign hands.–irene brown


The Atlas 5 (left, 1) and Delta 4 rockets are built with modular parts enabling them to be tailored to the specific needs of the customer. Starting from the top, one or two satellites are placed in an appropriately sized payload casing (there are six size options). An upper stage booster is then attached to the payloads to propel them to their final place in orbit. Core boosters, carrying liquid propellants, provide the power for liftoff, assisted if necessary by small, solid-fuel strap-on rockets.


The RD-180 is a newer version of an engine originally built for Russia’s ill-fated Buran shuttle and Ukrainian Zenit boosters. It burns liquid oxygen and kerosene, producing 860,200 pounds of thrust. It is a joint project of the United States and Russia.


Boeing’s RS-68 engine is the first large rocket motor to be built in the United States since the 1970s, when Boeing’s Rocketdyne division built engines for the space shuttle. Burning liquid hydrogen
and liquid oxygen, the RS-68 provides 650,000 pounds of thrust, releasing only steam as a byproduct. After 16,000 seconds of ground-based test firings, the engine will debut on the Delta 4 inaugural flight this summer.


In the commercial arena, the chief competition for the new American rockets comes from the European Space Agency’s Arianespace, which controls about half the market. Coming on strong are programs being developed in India and China, which hope to offer prices so low neither American nor European companies will be able to compete. Japan’s struggling government-sponsored H-2 program is not yet regarded as significant competition. The Russian and Ukrainian boosters are sold in partnership with American aerospace companies.

(Bottom left)
A. Ariane 5: ESA (European Space Agency)

B. Proton: Russia

C. Zenit: Ukraine

D. GSLV: India

E. Long March: China

F. H-2: Japan