Cygnus Departs ISS Signalling Successful End of COTS Program

International Space Station (ISS) crew members released Orbital Sciences Corporation’s Cygnus cargo spacecraft this morning.  Cygnus is now maneuvering away from the ISS and will reenter tomorrow.  The spacecraft, filled with 3,000 pounds of trash, will burn up in the atmosphere.  That will bring to an end not only this demonstration mission, but NASA’s Commercial Orbital Transportation Services (COTS) program as Orbital joins SpaceX in providing operational cargo resupply services.

The COTS program, also called “commercial cargo,” began in 2006.  It is a public-private partnership where NASA and two companies, Orbital and SpaceX, shared the costs of developing space transportation systems to take cargo to the ISS.   The two systems, Orbital’s Antares rocket and Cygnus spacecraft and SpaceX’s Falcon 9 rocket and Dragon spacecraft, are now operational and transitioning into the Commercial Resupply Services (CRS) program. 

NASA contracted with Orbital for eight CRS missions and with SpaceX for 12 CRS missions through 2016.  Orbital’s first CRS mission is scheduled for December 8, just over six weeks from now.   SpaceX already has launched two and the next is scheduled for February 2014.  The fixed price CRS contracts are for $1.9 billion with Orbital, and $1.6 billion with SpaceX.

These two U.S. systems join Russia’s Progress, Japan’s HTV and Europe’s ATV cargo transportation systems as means to take cargo to the ISS, which typically has six people aboard at any time.   Crews rotating on 4-6 month shifts have permanently occupied the ISS since November 2000.  The space shuttle was originally intended to be the main transportation system to take crews and cargo back and forth to ISS throughout its lifetime, but the U.S. decision to terminate the shuttle program after construction was completed meant that other systems were needed for the space station’s operational period, which will last through at least 2020. (NASA is trying to build support for extending that to 2028, which would be 30 years after the first ISS modules were launched.)

Cygnus, HTV, ATV and Progress are designed only for transporting cargo up to ISS; none of them return to Earth.  Only SpaceX’s Dragon makes a round trip.  Crews are ferried to and from ISS on Russian Soyuz spacecraft.   NASA is in the midst of another public-private partnership, the “commercial crew” program, where three companies are competing to build systems to transport crews so that NASA does not need to pay Russia for such services and also to provide redundancy.   SpaceX’s Dragon spacecraft is one of the contenders in that program.  It can be outfitted to carry people as well as cargo.  Orbital is not competing in the commercial crew program, however.   The other two commercial crew competitors are Boeing and Sierra Nevada.

The COTS program achieved its technical goal; NASA now has two companies competing to provide cargo resupply services for the ISS on a commercial basis.  Whether the business case will prove out probably will not be known for many years.