December 21, 2007 Commercial space services provider SPACEHAB has announced the success of a mid air retrieval demonstration test performed as part of its Advanced Research and Conventional Technology Utilization Spacecraft (ARCTUS) Program. ARCTUS represents a low-cost, low-risk Commercial Orbital Transportation Service (COTS) solution for cargo delivery to the International Space Station (ISS). The ARCTUS Program will support NASA’s requirement to fill the International Space Station (ISS) cargo supply gap between the space shuttle’s planned retirement in 2010 and the replacement Orion program scheduled to be operational in 2015.
Using flight-proven components to reduce development costs and program risk the ARCTUS design eliminates most of the program's non-recurring engineering labor costs and, with minimal modification of existing components, accommodates ISS cargo requirements. Also, since ARCTUS is derived from Centaur components, it is naturally compatible with the Atlas V family (400 and 500 series) of launch vehicles and ARCTUS utilizes world standard interfaces ensuring compatibility with most other large rockets such as Delta IV and Falcon 9.
ARCTUS is comprised of three modules:
- An Unpressurized Cargo Module (UCM) located on the forward end of the vehicle, which provides the means to carry the external cargo. The UCM can accommodate 3 metric tons or greater (subject to launch vehicle capability) of cargo (including Orbital Replacement Units for the ISS).
- A Pressurized Cargo Module (PCM) which can hold over 2 metric tons of internal cargo in its 18 cubic meter volume with extended options available providing upwards of 31 cubic meters, carrying more than 4 metric tons of pressurized cargo.
- The Service Module (SM) which is located on the aft end of vehicle and provides the interface with the launch vehicle, the ISS interface (Common Berthing Mechanism, CBM), and the spacecraft Propulsion System.
ARCTUS flight operations start at launch from the Atlas pad, LC-41, at Cape Canaveral Air Force Station. ARCTUS will separate from the Atlas-Centaur upper stage and execute a series of maneuvers to phase with the ISS. At a point of 3km from the ISS, ARCTUS will start the ARPO phase to rendezvous and be captured by the ISS SSRMS. Upon successful berthing, ARCTUS will be configured and cargo transfer operations will begin the docked operations phase. After cargo transfer is complete, the ISS SSRMS will unberth and release ARCTUS. The spacecraft will then separate from the ISS and begin the reentry and recovery phase.
Prior to reentry of the PCM, separation mechanisms are used to allow for separation of the UCM and SM. After successful jettison of the UCM and SM, the PCM performs burns to reenter the Earth’s atmosphere with a trajectory targeting landing off the east coast of Florida. The combination of a rigid, ablative nose cap and inflatable heat shield protect the vehicle during reentry heating. Upon successful reentry, a conventional drogue and parafoil system will slow the vehicle for recovery. A Mid Air Retrieval (MAR) operation will be used to minimize landing loads for the cargo.
It is this mid air retrieval (MAR) operation that the test, performed by Vertigo Incorporated and United Launch Alliance (ULA), demonstrated the feasibility of. A mass simulator was carried by helicopter to an altitude of 5,000 feet and then released under a parafoil. The helicopter was then able to capture a drag line being trailed behind the chute, lift the combined mass, collapse the parafoil, and gently place the simulated spacecraft on the ground. The benign environment provided with MAR is critical for recovery of sensitive microgravity experiments while also enabling rapid recovery and delivery to the end customer. By contrast, the Russian Soyuz spacecraft makes a relatively hard landing on solid ground.
“The mid air capture will ensure that all of the cost and care invested to send valuable samples to space will result in the maximum yield when safely returned to Earth,” he said. “We are very pleased with our working relationship with ULA and look forward to achieving many successful milestones together to reach the ultimate goal of flying ARCTUS to low Earth orbit in 2010,” said SPACEHAB, Inc. Chief Executive Officer Thomas B. Pickens, III.
Video from the mid air retrieval can be accessed at the official ARCTUS program website.