Questions tagged [design-alternative]

Questions about alternative designs the asker has thought of, such as "why was X built this way and not this way"

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Has there ever been a deliberate "Find A Satellite" challenge? Actually, could there be?

Companies often offer rewards for finding security issues in their products or their own IT systems, and hackathons have a long history. I'm just wondering if there has ever been a deliberate ...
uhoh's user avatar
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How do you "make" a soliton? (recent peer-reviewed theoretical work in FTL travel)

I've just read an Article on the new approach on Warp Drives Dr. Erik Lentz describes. Instead of creating a bubble with negative energy density, he describes a Soliton in spacetime, which he ...
Mat NX's user avatar
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Using electrodynamic tethers for countering precession?

One of the potential uses of electrodynamic tethers for satellites is generating thrust without needing to expend reaction mass. Could this potentially be used to counteract precession, allowing ...
Pitto's user avatar
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"Hybrid" statite design for a Dyson bubble?

One proposed design for a Dyson sphere is the Dyson bubble, which consists of statites (satellites that use light pressure to counteract gravity). In this design, the statites remain stationary ...
Pitto's user avatar
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4 votes
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Why did NASA never launch crewed Orion missions on a Delta IV Heavy to the ISS?

Following the successful EFT-1 mission, why didn't NASA start launching crews to the ISS on the Orion spacecraft? This question deals about why crews weren't sent to the Moon, but I wonder why wasn't ...
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Exterior "running lights" on ISS?

In Scott Kelley's memoir "Endurance," he describes how challenging it is to navigate the exterior of ISS when in Earth's shadow, and he mentions that his Russian colleagues would just stay ...
jelder's user avatar
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Giving rocket propellants an opposite charge for perfect mixing?

One of the challenges in achieving theoretical efficiency is the mixing of both an oxidiser and fuel. This means separating both propellants from each other whilst pairing them with their counterpart. ...
R. Hall's user avatar
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Why is the Fuji capsule design philosophy not seen in other proposals?

Fuji is my favorite unflown dead spacecraft proposal (narrowly beating out Dynasoar). I am well aware of why Fuji has its weird/unique design, but what I'm curious about is why it's unique. In my ...
Anton Hengst's user avatar
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Cooling an aerospike spike via "fuel diversion"?

My question is, could an aerospike be cooled via diverting a very small quantity of your fuel (fuel used since it has a higher heat capacity than oxidizer and won't, you know, turn your engine into an ...
YuccaWorks's user avatar
3 votes
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61 views

Could not an adapted RASSOR appear to be crucial for the Perseverance rover to find possible biosignatures on Mars?

Is it not very likely that most of the material that could contain possible biosignatures, like clays and carbonate containing minerals, will be below a layer of dust or regolith on Mars ? That the ...
Cornelis's user avatar
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3 votes
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Can the bleed-off fuel in an open expander cycle be substituted for another liquid?

In all expander cycles, fuel is used as the working fluid to generate the pressure difference necessary to drive the pumps. This makes sense in a closed expander cycle as it'll eventually be used in ...
R. Hall's user avatar
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If the ISS went to the moon, what would fail first

If the ISS was propelled into an orbit (any orbit) around the moon, what would fail first?
tomh's user avatar
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Could pressurized steam be an effective propellant for satellites?

If you had a small pressure vessel and a matte black external boiler that could utilize the heat of the sun, would pressurized steam be feasible for maneuvering a small satellite?
owegner75's user avatar
3 votes
1 answer
153 views

Alternative small mass payload transportation from the moon to L5 besides rail gun and mass driver?

This question asks about a low cost transportation from the lunar surface to a space settlement at L5. Moon mining is can be a revolutionary breakthrough in sustaining a space economy, but large scale ...
8A 26 KSHITIJ .S .DEEPAK's user avatar
2 votes
0 answers
73 views

"Semi" hybrid rocket? Throttleable solid fuel rocket?

Are there any published examples of "hybrid" rockets that used a propellant grain of mixed solid fuel and oxidizer where the injected component was only needed to sustain the burn without ...
BCS's user avatar
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How do different stages attach to each other?

I started learning about rockets recently, and while searching for information, I found some ways that different stages separate, but I wandered if it was possible that they could reattach to a ...
Bromito's user avatar
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Can ten (or more) rockets be used together to launch one massive object?

With computer flight controls where they are today, what would stop us from building a relatively large space station on earth, but then using 10 or 20 or even 100 falcon heavy or Starship or SLS ...
oeste's user avatar
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Can Lorentz forces partially cancel centrifugal forces?

If we had a tidally stabilised skyhook (https://en.wikipedia.org/wiki/Space_tether#/media/File:Skyhooks.gif) with electric charge and with a vector of force aiming towards the center of the Earth, ...
John's user avatar
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213 views

Mining Venus' surface using lasers?

One of the issues with colonizing Venus is the harsh conditions at the surface. People have proposed using floating habitats in the upper atmosphere, where conditions are milder, and gathering ...
Pitto's user avatar
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2 votes
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Would this 'hybrid expander cycle' engine be practical?

This is another attempt at making closed expander cycle a bit more efficient (the first attempt was here). The design combines some elements of both the open and the closed expander cycles (hence the "...
irakliy's user avatar
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1 vote
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How heavy is an orbital pogo stick?

Moving people from a A to B in space often requires a significant change in velocity, requiring propellant eating into the mass budget. But most of this propellant is "wasted" in moving a ...
SE - stop firing the good guys's user avatar
1 vote
0 answers
250 views

Technological challenges to sending a high altitude balloon to space and orbit from 50 km?

Below At what altitude would I have to go in a lighter than air balloon to be above all wind and just have the earth rotate underneath me? there is a comment: If you want to be above all winds, you ...
uhoh's user avatar
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1 vote
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120 views

How many Starship launches would it take to build this simple centrifugal space station concept?

Every centrifugal space station design I have seen uses either a large curved material or an inflatable structure. There have been no large scale curved material construction in space and only one ...
user1886419's user avatar
1 vote
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205 views

Orbit to Orbit Transport Stage

Would it be faster or cheaper to have a lander, SSTO, and/or SpaceX Mars rocket to rendezvous connect with a more efficient engine or "transport stage" or another lander, SSTO? When the spacecraft ...
Muze's user avatar
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1 vote
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191 views

Very Low Gravity Bicycle

There are a couple of existing questions about riding bicycles off of Earth. Designing a bicycle for Mars? Can you ride a bicycle on Deimos? Bicycles are lightweight and proved a reliable method ...
James Jenkins's user avatar
1 vote
1 answer
181 views

Would mass drivers be able to transport base material on the moon more efficiently than drones?

I am a hobbyist working on a climate change adaptation idea that is a variation of orbital sun shades. It would project soil/material from the moon to provide targeted shading for whatever part of ...
T.A. McKay's user avatar
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101 views

SSME/RS-25:; Why arent high pressure and low pressure pumps coaxial?

The Space Shuttle Main Engine low pressure pumps to prevent cavitation at the main pumps. This pumps were driven by separate turbines fed by high pressure fluid from the main pumps. Why? It just adds ...
Abdullah's user avatar
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Inserting optical elements into a ring laser gyroscope to sense all three axes

Ring laser gyroscopes (RLGs) leverage the physics of ring laser interferometers and the Sagnac effect to sense rotation in a single plane. My understanding of RLGs is that they are independent systems ...
Jonathan L.'s user avatar
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137 views

Is it possible to build a starship out of clay?

I know it may sound silly but my consideration is to reduce costs due to the amount of metal used in standard space ships. Wood/bamboo for framing and clay around it, that is it for the hull. I'm NOT ...
André Dias's user avatar
0 votes
0 answers
227 views

How should mass specific impulse calculated for relativistic exhaust?

This answer says: Optimising for Isp only is problematic, as it's simply: $$I_{sp} = \frac{v_e}{g}$$ Which is the same as optimising for exhaust velocity. With no constraints on thrust, particle ...
uhoh's user avatar
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How is it possible to reduce the weight of a high-energy laser?

To provide some context.. I have designed an interstellar spacecraft called Solar One. It employs a combination of 3 propulsion methods: nuclear fusion, beam-powered propulsion , and photon propulsion....
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