KSC Next Gen Site - Highly Reusable Space Transportation

KSC Next Gen Site ___Questions? Comments?

Highly Reusable Space Transportation Study

A rocket works by combining fuel with oxidizer, but all the oxidizer, unlike cars or airplanes, all the oxygen, is carried aboard the rocket. Not so for cars or airplanes. The physics of a rocket mandates that most of the rocket at lift off is thus propellant. Most of the rocket is not rocket structure holding the propellant nor other parts of the rocket. By weight, it's mostly propellant. Some numbers - a typical passenger jet plane may be 30% propellant, in this case jet fuel, and 70% aircraft, by weight. For a rocket the propellant may be in the range of 85% propellant and 15% rocket, by weight. This 15% does not make for an easy design, one that will be robust and can preoccupy itself with affordability, ease of operation, reliability or safety. Mostly at 15% of something to hold 85% of something else, the preoccupation is just to get of the ground, and if need be return, such as with the Space Shuttle. Expendable launch vehicles do not significantly depart from this basic reality. Separating / dropping stages during ascent is simply a means of discarding structure that is no longer required for the rest of the ride, but which was still just as fragile and weight limited.

Now imagine some of the oxidizer was taken from the air as the spaceship traveled through the atmosphere. The topic of Rocket-Based Combined Cycle spaceships was explored extensively in the HRST work as to it's effects on affordability of operations, reliability and safety. Potentially, in theory, such extreme machines using SCRAM cycles, if the barrier of thermal management and materials, both external and internal, could be overcome, could get to where an aircraft-like spaceship, taking off horizontally, would be as much as 35% "ship" and *the rest propellant, vs. 15% today with stages and the throwing away of stages. The possibilities are explored here in the broader context of the effect such technology could have on creating routine, affordable access to space.

*...see the wiki for more on what the term "mass fraction" means...

*...also see the NASP wiki...

1998

Final Reports > AN OPERATIONAL ASSESSMENT OF CONCEPTS AND TECHNOLOGIES FOR HIGHLY REUSABLE SPACE TRANSPORTATION (HRST), Executive Summary (Adobe .pdf version - 130Kb) and Full Report (Adobe .pdf version ~ 1MB), by the Highly Reusable Space Transportation Study, Integration Task Force, Operations, November 1998.

1997

Defining the Parameters for Affordable Space Transportation, Zapata, E. and Dankhoff, W.F., Aerospace America magazine, November 1997

The HRST "Guide" August 29, 1997

Highly Reusable Space Transportation Architectural Assessment Form, April 30, 1997

A Quality Function Deployment Method Applied to Highly Reusable Space Transportation, Zapata, E., Space Technology & Applications International Forum (STAIF), Albuquerque, New Mexico, January 30, 1997

1996

Report on Rocket Engine Life Analysis (Adobe .pdf version, ~15MB). The report describes methods to extend rocket engine life, increasing safety in flight as well as reducing operational costs, such as by reducing failures. Additionally, the data supports a means to avoid having to remove engines from flight to flight for future reusable systems (as done currently on Shuttle).

Advanced Reusable Propulsion Technologies Announcement / Airbreathers, July 1996

HRST Selectees Announcement, May 1996

1995

Highly Reusable Space Transportation, An Advanced Concepts Study, July 1995

_____________________

Also see:

_____________________

Website Contact: Edgar Zapata, NASA Kennedy Space Center