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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13 votes
2 answers
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Can a rocket refuel on Mars from water?

Can a rocket run only on hydrogen and oxygen? Could a rocket, rover, and electrolysis machine be sent to either of Mars' poles to excavate ice to make hydrogen and oxygen to refuel an unmanned rocket? ...
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-2 votes
1 answer
257 views

Could a rocket launch off water horizontally in stages us using water and air for lift to save fuel? [duplicate]

A term I have heard is the "water was like class". Meaning that the water had 0 waves. Could a rocket be modified to take off a horizontal surface starting slowly increasing throttle on each stage? ...
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28 votes
8 answers
7k views

Would a grinding machine be a simple and workable propulsion system for an interplanetary spacecraft?

I am wondering if any space agency has ever considered using a grinding machine as a propulsion system for an interplanetary spacecraft. This system would not be used to lift the spacecraft off of a ...
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3 votes
1 answer
275 views

Could escape velocity be achieved in the atmosphere?

When rockets launch for orbit they travel up and the air thins respectively to the speed increasing. How fast can a rocket for travel at sea level before it would fail or the elevation would have to ...
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2 votes
2 answers
315 views

Break Away Valves for Launch [duplicate]

I forgot to hang up the fuel pump and broke it off and costed around 80 dollars to replace. While there I wandered could this be adapted to a rocket in some way? How much fuel capacity would be saved ...
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4 votes
1 answer
527 views

Could a "nuclear turbo-jet" be built?

Being familiar with jet engines myself, I wonder whether a similar device could be built to provide high $I_{\text{sp}}$ and high thrust in vacuum and space. Using the tried-and-true turbojet formula ...
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3 votes
0 answers
253 views

Could a steam Engine outperform other electric producing devices in space? [closed]

What would be the Specific Impulse of a steam-based propulsion system like this model in space? Are there any types of engine that works this way? Could 2 tanks be designed to rotate slowly in space ...
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0 votes
1 answer
240 views

Sharp nose or Blunt nose vehicle for higher reentry speeds?

Hypersonic Technology Vehicle 2 (HTV-2) is a crewless, experimental hypersonic glide vehicle rocket glider developed as part of the DARPA Falcon Project capable of flying at 13,000 mph (Mach 17.53, 21,...
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10 votes
1 answer
681 views

Does a high staging number have diminishing returns? Is there a way to address that mathematically?

I was reading this question: Help me understand what Farside, a ten "stage" rockoon looked like? How was it configured? Comments link to Highest stage counts in actual launchers? but here ...
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1 vote
0 answers
204 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 ...
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-1 votes
1 answer
146 views

What is the vapor pressure limit of liquid metals in space?

Would liquid metal be stable in space unlike most other liquids like water? Are there any metals that has a high vapor pressure limit? Side question: Can liquid metal be given an electromagnetic ...
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3 votes
3 answers
414 views

"Hybrid" ion engines?

If it's possible, could you use "hybrid" ion engines, maybe VASIMR, running on a mix of hydrogen, argon, and oxygen to exceed the velocities produced by any other ion engine? Could buckyballs also be ...
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0 votes
2 answers
108 views

When does reusable lower rocket stages become benificial?

Can lower stages of current rockets be replaced to reusable and more efficient boosters with parachutes? Would reusable rocket stages save money?
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1 vote
1 answer
140 views

Rainbow Space Probe?

Can a probe be sent out to shine a white laser through the atmosphere of a planet to measure a rainbow spectrum to determine composition, temperature, density etc.? Water drops refracts about at a ...
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0 votes
0 answers
54 views

Why don't astronauts/ships/stations carry portable 'magnetospheres'? [duplicate]

As I understand it, cosmic radiation is one of the biggest dangers/problems to space exploration. Some cursory research seems to suggest that it wouldn't take very strong magnetic fields to deflect ...
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1 vote
0 answers
166 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 ...
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2 votes
1 answer
171 views

Why did Deep Space 1 use solar concentrators?

@Hobbes' answer mentions that Deep Space 1 used special refractive solar concentrators attached to photovoltaic cells. According to SCARLET: The innovative array uses 720 lenses to focus sunlight ...
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0 votes
1 answer
58 views

Reaction Drive Launch Catapult

I want to suggest a variation on the launch catapult. The rocket assembly is accelerated vertically through momentum transfer, by a reaction driver on the ground. In concept the driver would be a ...
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6 votes
3 answers
275 views

Creating your own artificial gravity by running. (Part 1 - the basic idea)

The main motivation for artificial gravity is the astronauts' health Usually artificial gravity is supposed to work by rotating the spacecraft. See diagram A. Wouldn't it be much simpler to simply ...
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5 votes
3 answers
686 views

Two 1000 kg gold spheres orbit their CM in near-contact, great way to measure G or limited by spaceflight issues?

The hypothetical, non-existent crowdfunding site go-launch-me is so confident, they are offering a two-for-one special. For a limited time, if your project is funded they will foot the bill for a 2nd ...
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18 votes
6 answers
9k views

Why can't they just drop a solar winch down from a shuttle and have planes fly up and clip things on?

Why can't they just drop a solar winch down from a shuttle and have planes fly up and clip things on? I know of the idea to have a space lift but the cable necessary is too expensive. Why can't we ...
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-1 votes
2 answers
219 views

Is rail gun conversion possible? [closed]

can a rail gun be converted into a "High Velocity Pulse Engine",to be used as a "Jump Drive" to achieve light speed capabilities.
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1 vote
0 answers
56 views

Is it possible to "shape" area impacted by radiation shielding during interstellar travels? [closed]

If I have uderstood radiation/other shielding described in other questions correctly...it will be among other things provided by magnetic field(s) generated by superconductors. Is it possible to ...
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3 votes
1 answer
234 views

Could protons in the Sun's solar wind be used to create a photonic laser thruster for a spacecraft?

I have a conceptual idea for a photonic laser thruster for a spacecraft and I am wondering if this particular idea has already been thought of and whether or not it is capable of generating enough ...
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5 votes
3 answers
557 views

If specific impulse is directly related to exhaust velocity, would a ion post-accelerator improve the Isp of a propulsion system?

I understand that ion- and hall thrusters resemble a particle accelerator, and that led me to wonder if a post-accelerator (particle accelerator) used to boost the velocity of the ions would improve ...
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2 votes
1 answer
242 views

Why rockets are not tossed up before launch [duplicate]

Ok, I understand the nature of my question but anyway why the rockets are not tossed up before launch. It could introduce a huge handicap for a rocket in terms of reduced distance it has to travel, ...
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13 votes
3 answers
4k views

Rocket flywheel instead of battery/generator (crazy idea)?

The Electron rocket is launched using a battery instead of generator... I saw some video about research into using flywheels for energy grid buffer storage, I think that they could reach higher ...
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  • 413
2 votes
1 answer
412 views

Is a ballistic blimp entry possible on this way?

Could the entry of Mars with balloons work by inflating to equalize with the atmospheric air pressure, while establishing buoyancy before meeting the ground? Would a balloon pop if dropped from space?...
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1 vote
1 answer
410 views

Liquid shield for spacecraft? [closed]

Could an alloy of hot or cold liquid metal be made magnetic by adding electricity to the molten ball to give it magnetic properties to wirelessly attach it to a space craft to use as a shield shown in ...
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1 vote
2 answers
473 views

How does the speed and volume of particles differ in producing thrust in space?

Does a slower detonation velocity push a ship more the same way explosives with a slower detonation velocity moves dirt better? At the same rate does slower particles produce more thrust from a ...
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1 vote
1 answer
244 views

Diamagnetic Polar Orbit

This has nothing to do with electricity, Electrodynamic propulsion, or light sails. I am asking can a flat surface made of diamagnetic material like light sail displace Earth or the Sun's magnetic ...
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21 votes
4 answers
4k views

What would be necessary in order for us to achieve a single stage to orbit, reusable rocket?

I have read articles and seen videos explaining why an SSTO (Single Stage To Orbit) rocket* is not possible. But I was wondering... What would be required to achieve this? Answers can be literally ...
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10 votes
1 answer
532 views

Why is the Otto II monopropellant fuel not used in spaceflight applications?

Is anyone familiar with the chemical/thermodynamic properties of Otto II fuel (a monopropellant used in torpedoes)? It is composed of nitrated propylene gycol with a couple additives that make it non-...
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18 votes
3 answers
3k views

Could a spacecraft be made out of wood?

Could a spacecraft use organic materials, like wood or bone or shell or other tissues, as an interface to the vacuum and radiation of space? Would wood outgas and crack up in space? I wonder if life ...
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5 votes
7 answers
1k views

Vacuum launch, essentially free after system built

Outside Earths atmosphere is the vacuum of space and its immense power. If a cylindrical tube of sufficient strength and size were built tall enough to reach the edge of atmosphere would it not be ...
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4 votes
1 answer
267 views

Could momentum transfer be practical (e.g., for orbital insertion at Pluto)?

Constraining exploration of outer bodies to flybys (such as New Horizons) seems unfortunate in terms of the amount of science that can be done per mission. Using a slower planetary approach has ...
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2 votes
2 answers
262 views

Space elevator/tower through magnetic repulsion? What are the technical problems?

As more material weight leads to higher stress for a space elevator I have been asking myself if a kind of tower thats based on magnetic repulsion would not be an alternative. While I know that ...
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5 votes
3 answers
581 views

Could Earth's electric grid be used to power rocket launches via cable?

If our regular huge power plants on the ground could be used to power part of a rocket launch, launch mass would be smaller since fuel would not have to be carried on board. I wonder what are the main ...
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  • 26.2k
9 votes
3 answers
765 views

What are the deal-breakers with a preheated Hydrogen gas tank orbital rocket?

Consider this thought process: In selecting the propellant for a reaction engine, lower atomic mass is better because equipment is largely temperature limited, and lighter gas will get higher ...
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