Wednesday, November 22, 2023

Optimized Nuclear Thermal Rocket for 45 Days to Mars

Let us talk about something.  This is all about any damn fusion or fisson  Engine.

1  All the nasties can plausibly be vented into space.  This really cuts back on weight.
2  Fuel mass becomes way less
3  specific impulse will be far higher and controled with electromagnetics.  no heat erosion perhaps.
4  All of which allows continous thrust throughout the trip.

The pay off is that  the whole system can be lifted to earth orbit with our current infrastructure, however many tons and then be fired up after assembly applying a continous one g of thrust the whole way and doing a turnover to arrive at Mars low orbit with a matching velocity.

while we are at it, we can ship what is a rotational Mars Space Station to operate also at one g when we get there.  We should build one for ourselves first though.  Such a system would do assembly inside the hub and the ring will serve to sustain one g for living conditions.

The take home obviously is that this provides a practical solution for colonizing Matrs and the moon as well because we can actually rely on chemical rockets to land and take off from both the Moon and Mars..

Optimized Nuclear Thermal Rocket for 45 Days to Mars

Optimized Nuclear Thermal Rocket for 45 Days to Mars

November 17, 2023 by Brian Wang

Nuclear Thermal Propulsion (NTP) is the preferred propulsion technology for manned missions throughout the solar system. The state-of-the-art NTP cycle is based on solid core Nuclear Engine for Rocket Vehicle Application (NERVA) class technology that is envisioned to provide a specific impulse (Isp) of 900 seconds doubling chemical rocket performance (450 seconds). Even with this impressive increase, the NTP NERVA designs still have issues providing adequate initial to final mass fractions for high DeltaV missions. Nuclear Electric Propulsion (NEP) can provide extremely high Isp ( over 10,000 seconds) but with only low thrust and limits on mass to power ratios. The need for an electric power source also adds the issue of heat rejection in space where thermal energy conversion is at best 30-40% under ideal conditions.

This is a NASA Innovative Advanced concepts study. New Class of Bimodal NTP/NEP with a Wave Rotor Topping Cycle Enabling Fast Transit to Mars.

A novel Wave Rotor (WR) topping cycle is proposed that promises to deliver similar thrust as NERVA class NTP propulsion, but with Isp in the 1400-2000 second range. Coupled with an NEP cycle, the duty cycle Isp can further be increased (1800-4000 seconds) with minimal addition of dry mass.

The ISP can be over four times better than the NERVA class nuclear rocket and ten times better than chemical rockets.

This bimodal design enables the fast transit for manned missions (45 days to Mars) and revolutionizes the deep space exploration of our solar system. The current NASA chemical rocket missions need to take 180-270 days to get to Mars.

NERVA was about a $10 billion program (in today’s dollars) from 1955-1972.

The Rover/NERVA program was canceled before a prototype flight was achieved, but achieved a TRL 6 for the design requirements set in the 1960’s and 1970’s.

Many lessons learned from the entire Rover/NERVA program will help the current NTP program develop faster and at a lower cost back up to TRL 6.

There is again a nuclear thermal program at NASA.

The BWX technology company has been funded to make a nuclear thermal rocket. DARPA has finalized an agreement with Lockheed Martin for the company to begin work on the fabrication and design of the experimental NTR vehicle (X-NTRV) and its engine.

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