Probably the most well known of Orbital’s products are the Pegasus and Taurus rockets and the Dawn interplanetary spacecraft.  The Pegasus was first conceived in 1987 as an air-launched rocket designed to boost satellites under 1,000 pounds into low earth orbit.  The first launch was in 1990.  The three stage rocket is flown to about 39,000 feet (11,900 m) and then released from the carrier aircraft at a speed of about Mach 0.82.  After a short freefall, its first stage rocket booster ignites. The third stage burnout occurs about 10 minutes into the flight at about 1367 miles (2200 km) from the launch point at orbital altitude. The rocket has a great success rate, having placed more than 75 satellites in orbit.  Because the rocket and carrier aircraft can launch from virtually any locations, it is popular with customers around the world.

The Taurus rocket is a four-stage, solid fuel, ground-launched rocket developed in 1989 based on the Pegasus.  It can accommodate larger, heavier payloads than the Pegasus rockets.  Payloads typically reach orbital altitude about 16 minutes after launch.  Taurus launches from Vandenberg Air Force Base for most missions.  Cape Canaveral Air Force Station, Wallops Flight Facility and the Reagan Test Site in Kwajalein, Marshall Islands may be used depending on the desired orbit inclination. Recently the Orbital Carbon Observatory, which was carried by a Taurus XL rocket, failed to achieve orbit after the payload fairing did not separate.  The launch is under review.  The subsequent launch of the Kepler telescope aboard the Delta II rocket, another of Orbital’s rockets, was moved one day later to accommodate engineers who are reviewing the hardware common to both rockets.

Dawn is a mission under NASA’s Discovery program to study the asteroids Vesta and Ceres, located in the main asteroid belt between Mars and Jupiter.  The spacecraft is powered by solar electric ion propulsion.  It was launched in September 2007 from the Kennedy Space Center.  It is expected to rendezvous with Vesta in 2011 and with Ceres about eight months later.

As NASA missions move toward a sustained human presence on the Moon and preparing astronauts for Mars missions, it is shifting the International Space Station (ISS) shuttle supply runs to the private sector.  The objective of the Commercial Resupply Services contract under the Commercial Orbital Transportation Services Project (COTS) is to facilitate private development of access to low Earth orbit.  "Our investment in the space transportation industry holds just as much promise for the future as government's investment in the railroads and airlines produced in the past," said Alan Lindenmoyer, manager of the Commercial Crew and Cargo Program Office at NASA's Johnson Space Center in Houston, TX. "Like any wise investor would, we chose a transportation provider whose innovative concept is based on solid engineering and a sound business plan."

Under the contract awarded to Orbital, the company will complete a demonstration flight in 2010.  A separate contract, awarded in December of 2008 commits Orbital to eight resupply missions between 2011 and 2015 to deliver cargo to the ISS. 

Orbital has stated that 70% of the components, subsystems and designs used in the cargo spacecraft have been used on previous missions, decreasing development costs and increasing the chances of successful missions.  The ISS visiting vehicle is a case in point.

The vehicle, named Cygnus, will consist of a common service module with interchangeable cargo modules.  Avionics from the Dawn interplanetary spacecraft will be included in Cygnus, as will the propulsion and power system from Orbital’s STAR GEO communication satellites.  Orbital is developing both pressurized (PCM) and unpressurized cargo modules (UCM), but only the unpressurized cargo module will be used in the demonstration flight.

The UCM are based on Orbital’s work on ExPRESS Logistics Carrier (ELC). The PCM are similar to the Multi-Purpose Logistics Module (MPLM) built by Thales Alenia.  The PCM are lighter and smaller and use a common berthing mechanism (CBM) as the interface to the ISS.

Cygnus will be transported by a new privately-developed medium class launch vehicle, called the Taurus II.  The Delta IV and Atlas, both part of the United States Air Force’s evolved expendable launch vehicles, are also capable of transporting the visiting vehicle. The rocket is projected to be able to deliver 4,750 to 7,250 kg of payload to low earth orbit and return 1,200 kg of cargo from the ISS to Earth.

Orbital will also provide mission planning and operation facilities and services.  Orbital will be utilizing four subcontractors for the development: Thales Alenia Space, the CS Draper Laboratory, Science Applications International Corporation and Odyssey Space Research.

By 2010, Orbital will need to develop and qualify the Taurus II; complete the visiting vehicle, integrate the visiting vehicle with the unpressurized cargo module.  Ground infrastructure and operations capabilities for the missions will also need to be established.  All this culminates with the demonstration flight in 2010 with a successful launch, rendezvous, capture by the Space Station Remote Manipulator System (SSRMS) and simulated berthing with the ISS.

There have been a few stumbles on the road.  Development costs and a poor global economy have decreased the company’s profit, although Orbital expects the profit to rebound once the development phase is complete.  The widely publicized, and as yet unexplained, failure of the Taurus XL rocket carrying the Orbital Carbon Observatory has cast a small cloud over the design and development. 

Perhaps the biggest hurdle won’t be an engineering issue at all.  Planetspace, a rival company, filed a protest in January 2009 with the Government Accountability Office (GAO).  Three companies, Planetspace, Orbital and SpaceX were rated by the Source Evaluation Board (SEB) for the resupply contract. 

The scores put SpaceX first, Planetspace second and Orbital a close third. However, when the final decision was made, Planetspace was left out of the contract.  The company was passed over despite its higher score and lower costs.  There are some indications that there were concerns with Planetspace’s plans to use an alternate launch vehicle until 2011 which would necessitate verification and integration of its orbital vehicle with two launch vehicles and its ability to control costs. Presumably Orbital was given the go-ahead based on its expertise in handling subcontractors, familiarity with the technologies involved and ability to control costs.  The GAO is expected to respond to the protest by mid-April 2009.