## Sunday, October 17, 2021

### Learned the rocket equation. Been sick.

Yesterday I learned the Rocket Equation, instead of simply calculating burn Time and adjusting the mass for every second in s spreadsheet because the Rocket gets lighter as it burns through fuel.  Scott Manely had an old Video about it.

1. I hit a problem as I cannot reach 15,000m/s with just Raptors without making the Entire ship 90% Fuel.
2. I tried simply adding boosters and I hit the Tyranny of the Rockets Equation: "there is a limit to the amount of payload that the rocket can carry, as higher amounts of propellant increment the overall weight, and thus also increase the fuel consumption.[7] "
3. I started googling which lead me back to Delta-V budget, which references the Rocket Equation... which I didn't understand until I tried to design a rocket on paper that would reach 15,000m/s. This lead to discovering the Awesome Delta-V Map https://upload.wikimedia.org/wikipedia/commons/9/93/Solar_system_delta_v_map.svg  which lead me to review how much I really needed. I didn't need 15,000m/s - that's if I'm straight from the surface to leaving the planet - which we take for granted in Traveller - I just needed 9.6 or 10.6 km/s
1. Just Enough to get a Ride from a Space Tether... one of my favorite Scifi Concepts.
4. Travellers with a 1000 Mass Ton ship with Antiquated TL7 Boosters will need to pay the cost of  Booster Rental (which is about 500,000usd x 4 for 2M) to get about 5km/s and then blast the rest of the way with their high Impulse (Specific) aka Efficient Rockets to Low Orbit (Not saying earth because this is not only about earth).
1. The boosters will fall away and begin their Automated descent
as the Travellers climb they see other such services being conducted, scattered in the horizon 2-3 other ships being launched to Low orbit the way Planes in the sky are common occurrence.
5. As the Traveller reaches Low orbit exhausting much of the 1000 MT ship's fuel, they pay for the Services of a Tether to travel either to Geosyncronous Orbit or Lunar Transit for Refueling. the Ship will be paying for fuel twice because of the gravity well. They feel the skyhook catch the ships anchor and begin to hurl them forward accelerating. the Sound they hear is conducted through their suit into their vacc suits. the Ship master having booked some passengers and cargo on the moon a week earlier is hurled that direction.

6.  The Tether hurls the ship another 2Km/s (used to change orbit) and the ship begins another 1Kms burn to reach Lunar orbit and be caught by another Inertia Tether to slow down when they arrive. The Travellers take 4 days to arrive on the moon along the way shedding KMs as they encounter tethers that will slow them down where they will refuel and link up with their Habitat Ring, Radiators, and Fission Power.

So my tests came back and its not Covid. still the wife and I are quarantined to protect the kids. Hope to be able to focus more by next week, the 25th.