Determination of Nuclear-rocket Power Levels for Unmanned Mars Vehicles Starting from Orbit about EarthNuclear-powered Earth-orbital-launch probes can place greater payloads in orbit about Mars than chemical vehicles if reactor power exceeds 50 mw. Suitable reactor powers for this missionARE ABOUT 150, 400, AND 1000 MW FOR 33,000-, 81,000-, AND 200,000-LB VEHICLES, RESPECTIVELY. Whereas a 33,000-lb vehicle requires greater than a 200-day coast, a 145-day coast is feasible for an 81,000-lb vehicle. A hydrogen temperature of 4000 F in the nozzle appears to be a good compromise. Use of a solid-propellant rocket to achieve an orbit about Mars from coast yields no payload advantage. Using optimum firing dates, a 33,000-lb vehicle could orbit an acceptable payload about Mars, and an 81,000-lb vehicle could land freight on Mars. (Author). |
Contents
INTRODUCTION | 2 |
Comparisons with Chemical Rockets | 8 |
Firing a month before or after optimum date | 14 |
1 other sections not shown
Common terms and phrases
1000 megawatts 33,000-lb vehicle requires apoares altitude assumed atmospheric drag Cavicchi and James chemical vehicles curves D-474 acceptable payload D-474 Initial NASA DETERMINATION OF NUCLEAR-ROCKET enthalpy exceeds 50 mw figure 7(a freight on Mars gravitational constant hazardous hits hydrogen stagnation temperature hydrogen temperature hyperbolic velocities ical vehicles James W leaving the orbit LEVELS FOR UNMANNED load plus powerplant Mars from coast meteoroid protection miles mission mum firing dates naut nozzle appears nuclear reactor Nuclear-powered Earth-orbital-launch probes NUCLEAR-ROCKET POWER LEVELS obtainable from NASA orbit about Earth orbit about Mars payload advantage payloads in orbit place greater payloads powerplant weight propellant reactor power exceeds Richard H soft landing solid-propellant rocket specific impulse TECHNICAL NOTE D-474 temperature of 4000 TN D-474 acceptable TN D-474 Initial UNMANNED MARS VEHICLES vehicle could land vehicle could orbit vehicle requires greater vehicles if reactor Washington NASA TN weight leaving orbit Wt+i+s/WH2 yields no payload