Elon Musk on Twitter: T/W will be ~1.5, so it will accelerate unusually fast. High T/W is important for reusable vehicles to make more efficient use of propellant, the primary cost. For expendable rockets, throwing away stages is the primary cost, so optimization is low T/W. twitter.com/elonmusk/stat…
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πŸ“°︎ r/spacex
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πŸ‘€︎ u/RootDeliver
πŸ“…︎ Jan 30
🚨︎ report
Why Hyper Propellant overclock is the best v.redd.it/mnohhrd18hc61
πŸ‘︎ 1k
πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/DongerBot5000
πŸ“…︎ Jan 20
🚨︎ report
NASA successfully demonstrates non-toxic β€œgreen” propellant, creating opportunities for its use in a wide range of future spacecraft. spacenews.com/green-prope…
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πŸ“°︎ r/space
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πŸ‘€︎ u/upyoars
πŸ“…︎ Jan 23
🚨︎ report
Been working on some rocket propellant and thought you might enjoy a little test piece v.redd.it/0k5yxhjt38d61
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πŸ‘€︎ u/keatonfisher
πŸ“…︎ Jan 24
🚨︎ report
Saturn's moon Rhea has a mysterious material on its surface β€” Hydrazine, an inorganic compound, a colorless liquid with the same pungent smell as ammonia. Here on Earth, it is used in pharmaceuticals, agrochemicals, and as a propellant for spacecraft. inverse.com/science/satur…
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πŸ“°︎ r/space
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πŸ“…︎ Jan 26
🚨︎ report
Proposal for a new configuration of Starship: the Propellant Depot Ship

The launch window for Mars missions is only open every 26 months. In this relatively short time frame have to be inserted all the ships into the parking orbit and being refueled as well.

However, there is a fundamental flaw in the in-orbit refueling sequence we know: the ship goes up first and the propellant follows it and as a consequence, the first cargo ship has to wait almost 26 months for its trans-Mars injection burn.

It's a significant problem because in 2 years a lot of R&D happens in all the colonization-related technologies. Just think about the progress that happened since the end of 2018 in the fields of batteries, solar cells, boring machines, robots, drones, 3D-printers... Ideally, these pieces of equipment are being developed and optimized as long as possible and go to the parking orbit lastly.

To do that orbital propellant depots have to be used. Using tanker ships would be obvious but using specialized depot ships would be an even better choice. These propellant depot ships would remain in orbit for decades and serve all the following deep space missions.

Their main differences compared to the tanker ships would be:

  1. lack of all EDL-related equipment: no ceramic tiles & thermal protection, header tanks, body flap-related equipment (motors, batteries etc.), sea-level Raptors,
  2. + 3 vacuum-optimized Raptors
  3. solar panels (on one side of the "body flaps"*) radiators (on the other side of the "body flaps"*) and heat pumps for keeping the propellant at superchilled temperatures for years
  4. reflective coating on every other surface for the best possible thermal insulation
  5. elongated body for maximized propellant capacity
  6. in the aft cargo bay: robotic fueling arm for safe and convenient in-orbit refueling

* these parts of the ship wouldn't act as body flaps, hence the quotations marks

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πŸ“°︎ r/spacex
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πŸ‘€︎ u/Col_Kurtz_
πŸ“…︎ Dec 31 2020
🚨︎ report
A New Satellite is going to try to maintain low Earth orbit without any propellant universetoday.com/149660/…
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πŸ“°︎ r/space
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πŸ‘€︎ u/Sumit316
πŸ“…︎ Jan 18
🚨︎ report
Propellant Loading
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πŸ‘€︎ u/Armand9x
πŸ“…︎ Jan 28
🚨︎ report
Elon (about SN8 15km flight): Stable, controlled descent with body flaps would be great. Transferring propellant feed from main to header tanks & relight would be a major win. twitter.com/elonmusk/stat…
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πŸ“°︎ r/spacex
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πŸ‘€︎ u/ReKt1971
πŸ“…︎ Oct 31 2020
🚨︎ report
Starship Landing Propellant Requirements

TL;DR:

Starship needs 100 m/s of landing delta-v to land on Earth and about 480 to land on Mars. This corresponds to 6 tons of propellant on Earth and 30 tons of propellant on Mars (for a 100 ton payload and a 120 ton ship). The propellant tank sizes that arise from this propellant requirement matches the actual header tank sizes we have seen within 10%.

Full post:

This post is an in-depth response to a question posed in this post, a response I provided in the comments, albeit in a much more summarized manner. The question was this: how will starship slow down and land on Mars?

This is a question that gets talked about a lot, and that we have been given a clear answer to, but not something that everybody understands. To answer the question, we begin by looking at starship's approach to Mars.

After launch from Earth, starship will be on an interplanetary trajectory that will put it on a fly-by trajectory past the red planet. Course adjustments during flight will allow it to approach the planet and enter the atmosphere at a prescribed altitude, velocity, and angle. For common transfers to Mars, entry velocities may be on the order of five to six kilometers per second. While the atmosphere of Mars is extremely thin, at these speeds it presents a significant barrier and will do a lot of work to decelerate starship. Starship could do a direct entry into the atmosphere, braking all the way down below orbital velocity in one pass, or it could do many passes, reducing its velocity and lowering its apoapsis (highest point on its orbit) with each pass, much like the MRO did. Musk has stated that direct entry to Mars can be done but multi-pass aerobraking on Earth may be a necessity (higher entry speeds and thicker atmosphere).

No matter the entry method Starship chooses, its trajectory through the atmosphere will be designed so that it first bleeds off its orbital energy going horizontally in the upper atmosphere, before falling into a vertical belly flop until it reaches terminal velocity (velocity where the force of gravity cancels the drag force). From an altitude-versus-range perspective the entry should be somewhat similar to an Apollo reentry:

[Apollo reentry altitude versus range](https://preview.redd.it/iyt6btzg2e761.png?width=474&format=png&auto=we

... keep reading on reddit ➑

πŸ‘︎ 124
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πŸ‘€︎ u/agruffgriff
πŸ“…︎ Dec 25 2020
🚨︎ report
NASA awards SpaceX $53.2 million for a "large-scale flight demonstration to transfer 10 metric tons of cryogenic propellant between tanks on a Starship vehicle" nasa.gov/directorates/spa…
πŸ‘︎ 4k
πŸ“°︎ r/spacex
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πŸ‘€︎ u/675longtail
πŸ“…︎ Oct 14 2020
🚨︎ report
Elon: T/W will be ~1.5, so it will accelerate unusually fast. High T/W is important for reusable vehicles to make more efficient use of propellant, the primary cost. For expendable rockets, throwing away stages is the primary cost, so optimization is low T/W. twitter.com/elonmusk/stat…
πŸ‘︎ 22
πŸ“°︎ r/SpaceXStarship
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πŸ‘€︎ u/FutureMartian97
πŸ“…︎ Jan 30
🚨︎ report
Yokosuka MXY-7 Ohka (Cherry Blossom) at the Steven F. Udvar-Hazy Center. Unlike most Ohkas, which were powered by 3x Type 4 Mark 1 Model 20 solid-propellant rocket motors, the Type 22 was powered by an Ishikawajima Tsu-11 motorjet (essentially a piston-powered jet engine). reddit.com/gallery/krrzni
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πŸ“°︎ r/WWIIplanes
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πŸ‘€︎ u/MrPlaneGuy
πŸ“…︎ Jan 06
🚨︎ report
Going to Mars and back TWICE with a 100% reusable rocket (no cheats, no clipping, no orbital propellant depot) reddit.com/gallery/ktaohi
πŸ‘︎ 66
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πŸ‘€︎ u/farbeyondhorizons
πŸ“…︎ Jan 08
🚨︎ report
In the near-term future, which will be more important as a rocket propellant, hydrolox or methalox?

Hydrolox (liquid hydrogen/oxygen) has been used as a high-efficiency rocket propellant since the 1960s, and is great for sending spacecraft on high-energy trajectories beyond low Earth orbit. Hydrogen and oxygen are available all over the solar system, mostly in the form of water ice. However, it has the drawbacks of being hard to store, needing very low temperatures, and active boil-off mitigation.

This is why SpaceX is using methalox (liquid methane/oxygen) for their Starship launch vehicle, even though it is less efficient in terms of specific impulse/exhaust velocity. It can be more easily stored for long periods of time, and by using the same propellant on both stages, manufacturing and operational costs can be reduced (hydrolox tends to have low density and engines using it have lower thrust, so it is not optimal for first stages). The vehicle is designed for SpaceX's main goal of Mars colonization, and methalox can be produced from the Martian atmosphere and ice through the Sabatier reaction.

However, if your eventual goal is making space habitats from asteroids and moons instead, which is more practical for rocket-based launch vehicles in the near term?

SNels0n made the case for methane here, even though they weren't a "planetary chauvinist": >IMO, methane is a better rocket fuel choice than hydrogen for big space projects. We can store methane. Hydrogen tends to leak out of pretty much everything. Granted 4,400 m/s is bigger than 3,700 m/s but once we reach the "storage depot" stage, specific impulse is no longer the biggest concern.

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πŸ“°︎ r/IsaacArthur
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πŸ‘€︎ u/mikusingularity
πŸ“…︎ Jan 19
🚨︎ report
Russian tankers loading a propellant charge into their T-72A
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πŸ“°︎ r/TankPorn
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πŸ“…︎ Jan 20
🚨︎ report
Heads or tails? The short disappeared, what does this mean? How will it impact the stock compared to if the short was still on it? Is this pure gain no fight? Or does it leave us with a lack of propellant? reddit.com/gallery/l9g596
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πŸ“°︎ r/HCMCSTOCK
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πŸ‘€︎ u/ArtemisEchos
πŸ“…︎ Jan 31
🚨︎ report
"NASA stood down from a second attempt to complete a critical propellant loading and countdown demonstration test of its first Space Launch System (SLS) Core Stage... Issues with activating ground-controlled heaters stopped the second attempt before propellant loading could begin." nasaspaceflight.com/2020/…
πŸ‘︎ 71
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πŸ‘€︎ u/magic_missile
πŸ“…︎ Dec 18 2020
🚨︎ report
Hyper Propellant

Finally got a hyper propellant oc and wanted to know what mods should I put on the pgl to maximize damage output?

πŸ‘︎ 8
πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/Colacom
πŸ“…︎ Jan 30
🚨︎ report
NASA successfully demonstrates non-toxic β€œgreen” propellant, creating opportunities for its use in a wide range of future spacecraft. spacenews.com/green-prope…
πŸ‘︎ 81
πŸ“°︎ r/Futurology
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πŸ‘€︎ u/upyoars
πŸ“…︎ Jan 23
🚨︎ report
How many astronauts will be on the first manned flight to Mars? What will they be bringing, and how much would a propellant plant weigh?
πŸ‘︎ 16
πŸ“°︎ r/SpaceXLounge
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πŸ‘€︎ u/OhFuckThatWasDumb
πŸ“…︎ Dec 31 2020
🚨︎ report
Hyper propellant or fat boy

I’ve noticed a lot of people like both, and there’s a constant debate on which is better, so I was wondering how many people like both, or like to use the Breach Cutter

View Poll

πŸ‘︎ 5
πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/rats_r_underated
πŸ“…︎ Jan 24
🚨︎ report
Top coated what's finished so far, also found a way to mount the the optional propellant tanks which I think look pretty cool. Onto the funnels next! reddit.com/gallery/kxie03
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πŸ“°︎ r/Gunpla
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πŸ‘€︎ u/JamieCFPV
πŸ“…︎ Jan 15
🚨︎ report
And now for a sublunarian semi-demi-parabolic hyperloop launch system that even recovers the propellant from the first stage as it spits money back to Earth, hastily sketched on a cocktail napkin. reddit.com/gallery/kqzvzi
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πŸ“°︎ r/SpaceXLounge
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πŸ‘€︎ u/treysplayroom
πŸ“…︎ Jan 05
🚨︎ report
How can I pressurize propellant tanks?

I've wanted to build liquid rocket engines for a very long time and now is when I will do it. Can anyone help me with how to do it, or recommend a subreddit that might help? Ethanol and Liquid Oxygen if that helps. Thanks!

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πŸ“°︎ r/rocketry
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πŸ‘€︎ u/danzelchen_
πŸ“…︎ Jan 10
🚨︎ report
Hyper Propellant is my new favorite

I used to not know how I felt about Hyper Propellant until today. I had a Gunner on a salvage mission lower my health to about 50% with his mini gun and it kinda pissed me off. Then, when my shield charged, he lowered me down to 10% with his pistol. I just looked at him, shot him once with Hyper Propellant, and that was the end of that. Gg. Rock and Stone.

πŸ‘︎ 27
πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/DongerBot5000
πŸ“…︎ Jan 09
🚨︎ report
SLS Team Completes Propellant Loading of Core Stage During Green Run Test – Artemis blogs.nasa.gov/artemis/20…
πŸ‘︎ 60
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πŸ‘€︎ u/ForeverPig
πŸ“…︎ Dec 21 2020
🚨︎ report
YOU GUYS GOTTA TRY THIS! Use the "Hyper Propellant" Overclock and the mods shown below, it’ll turn this grenade launcher into an RPG! It’ll one shot Wardens, Menaces and Oppressors if you hit the weak spots!
πŸ‘︎ 180
πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/Shamrock_Chug
πŸ“…︎ Nov 17 2020
🚨︎ report
ELI5 difference btw explosive and propellant?

Can someone explain in simple 5-yo terms what the difference between and explosive and a propellant is?

I get our powders are propellants as they ... propel ... our bullets. But damn if they don’t make an explosion while doing that. Or not?

I read the technical explanation of explosive but was left confused.

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πŸ“°︎ r/reloading
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πŸ‘€︎ u/CelluloseNitrate
πŸ“…︎ Jan 23
🚨︎ report
ARCA on ISRO using eco friendly propellants

https://youtu.be/o_vuqd-ilRg is this vid arca announced isro started its eco friendly propellant Dev. What they missed that ISRO never said they would use water and is using proven tech. Like hydrogen peroxide (valid fuel and works not like ARCA using water heated by batts which is never done and heating by batts is a bad idea.British black arrow also used hydrogen peroxide) for eco friendly prop.and if u think about it SpaceX are also eco friendly using methalox and sebatier process to be carbon neutral ,that’s something ISRO also could do someday .ULA delta 4 heavy is all hydrogen rocket making it the most eco friendly rocket yet.just wanted to post this.(and no offence ,based on ISRO’s track record they will take a LONG time to do eco friendly propellant so ARCA should not jump to conclusions with this.

πŸ‘︎ 6
πŸ“°︎ r/ISRO
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πŸ‘€︎ u/Heavy_Fortune7199
πŸ“…︎ Jan 30
🚨︎ report
Aesthetically-pleasing Rocket Propellant solution
πŸ‘︎ 53
πŸ“°︎ r/opus_magnum
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πŸ‘€︎ u/PseudoGravity
πŸ“…︎ Jan 08
🚨︎ report
Hyper propellant overclock bugged?? v.redd.it/x1n60omxqeb61
πŸ‘︎ 12
πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/betamao
πŸ“…︎ Jan 15
🚨︎ report
Elon (about SN8 15km flight): Stable, controlled descent with body flaps would be great. Transferring propellant feed from main to header tanks & relight would be a major win. twitter.com/elonmusk/stat…
πŸ‘︎ 259
πŸ“°︎ r/SpaceXLounge
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πŸ‘€︎ u/ReKt1971
πŸ“…︎ Oct 31 2020
🚨︎ report
Tool to separate a bullet from the cartridge and remove the propellant
πŸ‘︎ 39k
πŸ“°︎ r/specializedtools
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πŸ‘€︎ u/dartmaster666
πŸ“…︎ Jun 20 2020
🚨︎ report
How Rocket Propellant Tanks Affect Rocket Guidance? Anti-slosh Baffles youtu.be/39CB511Y1dQ
πŸ‘︎ 74
πŸ“°︎ r/aerospace
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πŸ‘€︎ u/WESPACEWALK
πŸ“…︎ Jan 03
🚨︎ report
Shuttle Discovery external tank and propellant line connection points. These two hatches had to shut and lock securely in space after ET separation. A lot was riding on those locking mechanisms. reddit.com/gallery/k32eev
πŸ‘︎ 96
πŸ“°︎ r/spaceflight
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πŸ‘€︎ u/tbone985
πŸ“…︎ Nov 29 2020
🚨︎ report
A recently published paper on solid propellants that's big on the news lately

A recently published paper on nano-additives for performance enhancement in the solid propellants.
 
Layered magnesium diboride and its derivatives as potential catalytic and energetic additives for tuning the exothermicity of ammonium perchlorate
[ https://www.sciencedirect.com/science/article/abs/pii/S0040603120301830 ]


######Highlights
β€’ Adding 1 wt.% ball-milled MgB2 increases the energy of ammonium perchlorate by 78 %.
β€’ Adding 1 wt.% ball-milled MgB2 reduces the decomposition temperature by ∼73 Β°C.

######Background
The thermal decomposition characteristics of Ammonium perchlorate (AP) significantly affect the combustion performance of the propellant, which in turn determines the degree to which energy can be extracted. To improve the thermal decomposition of AP, fuel additives and burn rate modifiers are incorporated in the fuel.

Generally, metals with a high heat of combustion are used as fuel additives. Some energetic metal fuel additives include Li, Be, B, Si, Al, Mg, Ti, and Zr. Li and Be are not widely used because they are highly toxic and expensive. Aluminum is the most commonly used metal fuel additive because of its wide availability, ease of handling, the high heat of combustion (31.4 MJ/kg), and also more economical.
 
On the other hand, several burn rate modifiers are added to AP to improve the burning rate of the propellant. The burn rate modifiers or combustion modifiers are classified as catalysts (increase the burning rate) and inhibitors (decrease the burning rate) based on their activity on the combustion performance of the propellant.
 
Boron is another universal fuel additive in propellants; it exhibits the highest theoretical heat of combustion in terms of both volumetric (135.8MJ/L), and gravimetric (58.5MJ/kg) terms. Yet, scientists are not able to effectively utilize the potential of boron because of the challenges associated with its combustion. The challenge is that upon combustion, boron forms a viscous boron oxide layer on the surface that limits further oxidation of boron.
 
######Research We then demonstrated that pristine MgB2 (P-MgB2 ) is a potential catalytic and energetic additive for enhancing the thermal decomposition characteristics of AP. To further enhance the activity of P-MgB2, we prepared mechanically activated-MgB2 (MA-MgB2 or micro derivatives) by developing an optimized ball milling recipe.

... keep reading on reddit ➑

πŸ‘︎ 53
πŸ“°︎ r/ISRO
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πŸ‘€︎ u/ravi_ram
πŸ“…︎ Dec 08 2020
🚨︎ report
Dreadnought(s) done quick (Hyper Propellant & Critical Weakness ftw)
πŸ‘︎ 6
πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/Chief_Wiggum_269
πŸ“…︎ Jan 30
🚨︎ report
HAL delivers largest ever cryogenic propellant tank for GSLV MK3 twitter.com/HALHQBLR/stat…
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πŸ“°︎ r/ISRO
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πŸ‘€︎ u/lava_pan
πŸ“…︎ Nov 30 2020
🚨︎ report
Do any rocket engines inject gaseous propellants?

Seems like a stupid question considering you wouldn't want phase changes in the regerative cooling jacket and store the propellants as a liquid in the propellant tanks. I was mostly interested in whether you could inject two gases and have their streams impinge and if that was an efficient way of combustion. Although I imagine the raptor engine ox-rich and methane-rich propellants are gases when they inject and any fuel in a closed cycle for that matter.

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πŸ“°︎ r/rocketry
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πŸ‘€︎ u/TheSilverEmperor
πŸ“…︎ Jan 17
🚨︎ report
Deepcore 40mm PGL w Hyper Propellant OC, aka Mobile Railgun
πŸ‘︎ 115
πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/WetworkOrange
πŸ“…︎ Nov 10 2020
🚨︎ report
Green propellant successfully demonstrated on NASA mission spacenews.com/green-prope…
πŸ‘︎ 4
πŸ“°︎ r/SpacePolicy
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πŸ‘€︎ u/spacepolicy
πŸ“…︎ Jan 22
🚨︎ report
Ah yes, the most powerful and i n n o v a t i v e of all rocket propellants: condensed dihydrogen monoxide
πŸ‘︎ 96
πŸ“°︎ r/SpaceXMasterrace
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πŸ‘€︎ u/Tanamr
πŸ“…︎ Nov 18 2020
🚨︎ report
Updated full propellant plumbing schematic for SN8 twitter.com/fael097/statu…
πŸ‘︎ 39
πŸ“°︎ r/SpaceXLounge
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πŸ‘€︎ u/fael097
πŸ“…︎ Nov 12 2020
🚨︎ report
Is it possible to use potassium chlorate with combination of sugar as a solid propellant?
πŸ‘︎ 5
πŸ“°︎ r/rocketry
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πŸ‘€︎ u/BowRat
πŸ“…︎ Jan 08
🚨︎ report
Hyper Propellant Vs Fat Boy

Which is better?

View Poll

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πŸ“°︎ r/DeepRockGalactic
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πŸ‘€︎ u/Tf2-is-godlike
πŸ“…︎ Jan 26
🚨︎ report

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