A new means of space propulsion... closed loop pulse propulsion... here's the idea

[mikelewis]

2. The Math

can we estimate all the variables, place the spaceman in a suit with the double barrel, weigh him, fire off the two rounds, calculate his speed after the firing, figure out the resistance level and how much to remove from the momentum of the slugs... best assumptions here and then add that momentum to the current momentum of the astronaut please... best guesses here are fine
ChatGPT
To make a rough estimation of the scenario you're describing, we need to consider several factors and make a number of assumptions. Let's break it down step by step:

Mass of the Astronaut and Gear:

Assume the astronaut's mass (including the spacesuit) is around 100 kg (a round figure for simplicity, though spacesuits can be quite heavy).
The mass of a double-barreled shotgun can vary, but let's assume it's around 4 kg.
Shotgun Recoil:

The recoil of a shotgun depends on the specific ammunition used. Let's assume a standard 12-gauge shotgun shell, which typically has a muzzle velocity of about 400 m/s and a mass of about 28 grams (0.028 kg) per slug.
When both barrels are fired, the total mass of the projectiles is 0.056 kg.
Calculating Recoil Velocity:

According to the conservation of momentum,
�
gun
?
�
gun
+
�
slugs
?
�
slugs
=
0
m
gun
​
?v
gun
​
+m
slugs
​
?v
slugs
​
=0, where
�
gun
m
gun
​
is the mass of the astronaut and gear,
�
gun
v
gun
​
is the recoil velocity,
�
slugs
m
slugs
​
is the mass of the slugs, and
�
slugs
v
slugs
​
is the velocity of the slugs.
Effect of Bullets Redirected Back at the Astronaut:

If the bullets are redirected back at the astronaut and hit him, their momentum would be added to his. However, since the bullets would lose energy due to sound and heat, not all their momentum would be transferred. For simplicity, let's assume 90% of the momentum is transferred back.
The bullets and astronaut are moving in the same direction after firing, so the momentum adds up, not cancel out.
Let's perform the calculations with these assumptions.

Finished analyzing
python
Copy code
# Given data and assumptions
mass_astronaut_gear = 100 # in kg (astronaut + spacesuit)
mass_shotgun = 4 # in kg
mass_slugs = 0.056 # Total mass of two slugs in kg (0.028 kg each)
velocity_slugs = 400 # Muzzle velocity in m/s

# Total mass of astronaut and gear
total_mass = mass_astronaut_gear + mass_shotgun

# Conservation of momentum to find recoil velocity
# m_gun * v_gun + m_slugs * v_slugs = 0 => v_gun = -(m_slugs * v_slugs) / m_gun
recoil_velocity = -(mass_slugs * velocity_slugs) / total_mass

# Assuming 90% of the slugs' momentum is transferred back to the astronaut
momentum_transfer_percentage = 0.9
effective_momentum_slugs = momentum_transfer_percentage * mass_slugs * velocity_slugs

# The effective recoil velocity after momentum transfer (adding because in the same direction)
effective_recoil_velocity = recoil_velocity + (effective_momentum_slugs / total_mass)

recoil_velocity, effective_recoil_velocity

Result
(-0.2153846153846154, -0.021538461538461562)
Based on the assumptions and calculations:

The initial recoil velocity of the astronaut and gear after firing the double-barreled shotgun is approximately
?
0.215
?0.215 m/s (negative sign indicating direction opposite to the bullet's motion).
After the bullets are redirected back and 90% of their momentum is transferred to the astronaut, the effective recoil velocity is approximately
?
0.022
?0.022 m/s.
This means that initially, the astronaut is propelled backwards at about 0.215 m/s. After the bullets hit him and transfer their momentum, his speed is reduced to around 0.022 m/s in the same direction. The significant reduction in speed is due to the partial transfer of momentum from the slugs to the astronaut. ​​