Gentlefolk, <<... delta-v 9000 m/sec.... >>
The canonical figure is 10 km/s, despite a paper about ten years ago that fooled me and some others. Schemes to make any significant dent in that have born little fruit. If you accelerate faster to avoid gravity losses, your engines are heavier and you have more drag in the lower atmosphere. Wings let you use smaller engines, but cost mass and drag. High pressure pump fed engines are lighter and more efficient, but pumps eat mass budget. Trajectory optimization buys you a tenth of a km/s or something. I won't quarrel with a tenth of a km/s here or there and all that stuff is in the direction of goodness, but I suggest one take a deep breath, design for 10 km/s, and treat anything better than that as margin. --Best, Gerald _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
