Artist's concept of Enterprise module docked to Russian portion of International Space Station. Photo: SPACEHAB

Russian Aviation and Space Agency, Rosaviacosmos, has endorsed the development of the first commercially operated module of the international space station in hopes of charging rent to its partners.

The Enterprise module proposed by U.S.-based Spacehab Inc. and developed by RKK Energia will take place of the Docking and Stowage Module, known by its Russian abbreviation as SSM, on the Russian segment of the ISS, according to the agreement reached in Moscow on February 16.

Alexander Derechin, head of RKK Energia's international marketing division, confirmed that his company signed the agreement on the Enterprise with Rosaviacosmos and Spacehab.

Last week, Rosaviacosmos officially requested NASA to evaluate the plan to replace the Docking and Stowage Module with the Enterprise.

Within the agreement with Spacehab Inc. and RKK Energia, Rosaviacosmos would provide the Proton rocket to launch the Enterprise. The use of the Proton will allow RKK Energia to expand the design of the Enterprise, to give it the capability of the habitation and experiment module. Spacehab and RKK Energia originally proposed the Enterprise as a commercial "multimedia studio" in space.

Earlier plans also called for the Enterprise to be launched by the Zenit rocket capable of delivery up to 13 tons into the low earth orbit. The Proton rocket with the estimated cost of around $100 million can lift as much as 21 tons into the similar orbit. According to Alexander Botvinko, Rosaviacosmos Deputy Director, the current design of the Enterprise, envisions a 12-ton class vehicle, based on the Soyuz spacecraft.

Enterprise rent
Russian space officials said that Rosaviacosmos planned to rent the Enterprise module to its partners at NASA, European Space Agency, and Japanese space agency NASDA. The new module will be offered "in a package" with the Soyuz TMA spacecraft, which could serve as "lifeboat" for the additional crewmembers working onboard the Enterprise. In such combination, the long-term crew of the ISS could be increased up to six people from the present three.

Currently, NASA plans to build its own habitation module (known as U.S. Hab) as well as so-called Crew Return Vehicle, CRV. Combined they would provide the capabilities for seven people onboard the ISS. However neither craft is expected to be ready anytime soon, if ever.

The latest ISS assembly schedule published by NASA calls for the Hab to be launched in September 2005, while the CRV is not expected to be operational until December of the same year. But President George W. Bush has targeted the module and CRV for cancellation in an effort to reduce the station's soaring costs.

Japanese and European modules for the ISS are not expected to fly before May and October 2004, respectively.

In the meantime, the Spacehab Inc. and RKK Energia announced previously that the Enterprise module could be launched as early as 2003, or at least two years earlier than NASA would achieve a larger crew capability using its own hardware.

A second Soyuz escape pod
To use the Soyuz spacecraft as a lifeboat for a six-member station crew, two of the three-seat capsules will have to be "parked" at the ISS simultaneously. One Soyuz has already docked to the ISS as a part of the Russian contribution in the ISS program and Rosaviacosmos was in negotiations with NASA about a commercial purchase of the second Soyuz for the U.S. segment.

Specifically for this role, RKK Energia, developed so-called Soyuz TMA version of the standard Soyuz TM spacecraft. The TMA version, where "A" stands for "anthropometric," features a redesigned interior which allows taller crewmembers to board the craft. Without such limitations Soyuz TMA could serve as a "lifeboat," however its serial production was stalled by the lack of funds. NASA, which originally requested the development of the Soyuz TMA, refused to pay RKK Energia for the project, citing inability of the Russian government to finance the production of the vehicle.

FGB-2 module role
Rosaviacosmos decision to support Spacehab/RKK Energia project also means a setback for a rival alliance including Boeing and Moscow-based Khrunichev enterprise. Last July, two companies announced their own plans to launch so-called commercial space module, CSM, to the ISS.

Boeing and Khrunichev eyed the same docking port on the station for CSM, to which Spacehab and RKK Energia hoped to attach the Enterprise. Since CSM would be based on the available hardware, theoretically it could be launched earlier than the Enterprise module.

Khrunichev planned to convert FGB-2 control module into the CSM. The FGB-2 served as a back up for the Zarya control module, the first element of the ISS built by Khrunichev under contract with Boeing. By the time Boeing and Khrunichev announced their plans, the FGB-2 was about 70 percent complete.