S-550

Description

The S-550 capsule was intended to carry up to six people (normally 2 or 3) and significant internal and external cargo on resupply missions to the International Space Station (ISS). Unlike the other COTS competitors, the S-550 capsule was explicitly a human-operated vehicle - while it had automated flight functions, it was intended to be flown with crews for any space station mission, with the crew in control for all rendezvous and dockings with ISS.{{cite report

Design

The overall vehicle was design was for a 10 ft-diameter ballistic capsule, weighing 7500 kg including payloads. The capsule was projected to weigh 3059 kg "wet" (with 2 crew and consumables, but not cargo), the service module 1755 kg "wet" including rocket propellants, and 2300 kg of internal cargo or passengers within the capsule. Additional mass in external unpressurized cargo could be obtained with increased launch vehicle capacity beyond 7,500 kg or by trading off internal cargo for external cargo.

Capsule shape

The S-550 capsule is a sphere-cone type lifting ballistic space capsule, similar to the shape of the film capsule reentry modules in the Corona spy satellite, but much larger. The general shape was also used by COTS competitor T/Space's CXV capsule. The capsule design shape had a spherical nose section diameter of 0.8 of the base diameter and 10 degree conical half-angle (see Atmospheric reentry).

Capsule layout

The capsule consisted of two structures - an outer aeroshell, which supported the ablative heatshield (thermal protection system), and an inner pressurized cylinder containing the crew, systems, and cargo space.

Most of the spacecraft systems were at the front of the cylinder, up against the front bulkhead. The crew were seated in one row near the rear bulkhead and access hatch, with 2 "crew" seats on the sides with flight controls on the rear bulkhead and one passenger in the middle. Cargo was carried in the middle of the capsule, at the capsule's center of gravity, to simplify loading effects on reentry angles and lift.

Descent and landing

The S-550 capsule was intended to descend under a parachute system and touch down on land, using an inert aluminum foam crush structure in the nose of the capsule to attenuate the roughly 7 meter per second touchdown velocity. The landing did not require any active controls or systems to operate safely. Emergency landings in the water were handled by capsule flotation systems.

Service module

The service module was intended to provide rocket thrusters to control spacecraft attitude and provide orbital maneuvering capability to rendezvous with the International Space Station and then reenter the Earth's atmosphere. It included some structure, propellant tanks, and rocket motor systems.

References

References

1. "COTS Vendors". NASA Johnson Space Center.
2. [http://www.venturerspace.com/announcement.html Venturer Aerospace pursues NASA Commercial Orbital Transportation Services contract] {{webarchive. link. (2006-05-26 , March 15, 2006)
3. [https://selenianboondocks.blogspot.com/2006/03/venturer-space-cots-proposal-s-550.html Venturer Space COTS Proposal: The S-550] Jon Goff, 16 March 2006
4. [http://www.thespacereview.com/article/609/1 Small steps forward for NewSpace], Jeff Foust, The Space Review, Monday, April 24, 2006
5. [http://www.venturerspace.com/SA05.ppt Getting There the Easy Way - Venturer Aerospace: Manned Spaceflight to Earth Orbit and Beyond] presentation at Space Access 2005 conference, April 28, 2005
6. [http://www.venturerspace.com/ Venturer Aerospace not selected for COTS, pursuing followup business], May 10, 2006