Questions tagged [hydrazine]

Hydrazine is an inorganic compound used as a monopropellant.

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NTR performance of hydrazine compared to ammonia?

Methane, ammonia and water are sometimes suggested as alternatives to hydrogen for a nuclear thermal rocket. While they have a lower specific impulse, they offer much better density, thrust, and ...
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Important new additives to hypergolic hydrazine-based fuels since 1972?

In "Ignition! An Informal History of Liquid Rocket Propellants", John D. Clark in one of the chapters gives an overview of the then current state of hydrazine and hydrazine derivatives. The ...
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What is wrong with hydrazine as a monopropellant?

While answering a question about if N2O was a practical monopropellant, I found that hydrazine was considerably more efficient. So, why do people want to replace it with N2O, if hydrazine is more ...
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What makes CAPSTONE-1's eight hydrazine thrusters so "super small, high-performance"? How do they work without any tank pressurization?

The NASA Ames Feature Innovative Propulsion System Gets Ready to Help Study Moon Orbit for Artemis says: CAPSTONE’s journey to the Moon will take about three months, starting with its launch to low-...
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Did the EU successfully ban hydrazine? What about French Guiana?

Hobbes' answer to Is the EU really banning “toxic propellants” in 2020? How is that going to work? includes Yes, the EU is aiming to end the use of hydrazine by ~2020. This has been in motion since ...
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Dragon Superdracos: how much MMH/NTO propellant?

How much Monomethylhydrazine + Dinitrogen tetroxide (MMH/NTO) hypergolic propellant does the Dragon crew module carry and how much burn time does that afford them during launch escape if one is ...
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Could New Horizons' thrusters' ISP be as low as 157 sec?

A discussion below How much of a deep space spacecraft's structural mass is useless dead weight after launch? Any plans to shed it in the future? has lead to https://nssdc.gsfc.nasa.gov/nmc/...
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Does the volume of hydrazine propellant stored at 22 bar change?

I'm working on an extracurricular project and I'm trying to determine what volume of propellant tank I need to 12.14 kg of hydrazine propellant stored at 22 bar. I researched and found this pressure ...
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Would symmetrical dimethylhydrazine work as a hypergolic fuel?

Hydrazine and its various derivatives have been used as hypergolic fuels. hydrazine monomethylhydrazine (MMH) unsymmetrical dimethyl hydrazine (UDMH) Aerozine 50 is a mixture of 50% hydrazine and ...
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Why does New Horizons have ~2 kg of unusable "trapped" hydrazine?

The 2018 arXiv preprint The New Horizons Kuiper Belt Extended Mission by the New Horizons team says in section 6, pp. 21-22: Nevertheless, throughout the 2020s, there is significant potential for ...
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Are the APUs on the SLS SRBs planned to be hydrazine powered?

I recently read that the Space Launch System core stage, which uses renamed / slightly reworked Space Shuttle Main Engines and therefore requires a hydraulic system to service said engines, will use ...
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Is it bad if hydrazine freezes on a spacecraft? Is it always kept as liquid, or can it be safely allowed to freeze and then thawed when needed?

After having read this answer I wondered what happens if hydrazine freezes. It looks like it is "normal" and not like water, in the sense that it contracts when freezing, unlike water which expands ...
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What was the result of the propellant predictions in the last chapter of "Ignition!"?

In John D. Clarke's Ignition! (1972), the author spends the last chapter making predictions about the future of liquid rocket propellants. I thought these were very interesting, but I realize the book ...
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Why does Juno use "mixed oxides of nitrogen" oxidizer for propulsion? Which ones?

In the recent Spaceflight 101 article Rocket Burn postponed for NASA’s Juno, to remain in elongated Jupiter Orbit until December it says: Juno uses a bi-propellant main propulsion system with ...
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Why Was DARPA's Orbital Express Refueling Program Discontinued?

From 2006-2008 DARPA ran a program called Orbital Express(wikipedia link) which was "a safe and cost-effective approach to autonomously service satellites in orbit." The program had several goals: ...
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Why did SpaceX choose to use Hydrazine over newer "green" propellants for Dragon 2?

Firstly, I understand the need to use hypergolics over cryogenics as part of Dragon 2's abort and landing sequence - they provide "instant on" thrust and are throttlable with very wide ...
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