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"
189
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3answers
187 views
energy needed to accelerate in space
I was thinking about possibility of cargo transport between, say, earth and mars when a “pusher” accelerates propulsion-less cargo vessel, which is catched and decelerated at the other end of ...
1
vote
2answers
81 views
Using inflatable balloons to collect hydrogen from space as a simple solution for radiation shielding
I've seen this video where around the 4:59 mark it states hydrogen is the "best element" to protect humans from cosmic rays:
Even if it's not completely true,...
12
votes
4answers
2k views
Cyanobacteria as Life Support?
I'm aware that cyanobacteria are responsible for the Great Oxidation Event and are very effective at turning CO2 into oxygen so it stands to reason that with the proper nutrients for the bacteria, you ...
4
votes
2answers
114 views
Has anyone suggested using an electrically powered sling or centrifuge mass thrower as a form of electrically powered spacecraft propulsion?
Has anyone suggested using an electrically powered sling as a form of electric propulsion for a space craft? It might be a centrifuge type arrangement with a way to release part of or all of the ...
14
votes
8answers
5k views
Would a duct tape spacesuit be practical?
Spoilers ahead for season 2 of For All Mankind.
Essentially duct tape wrapped around the body, over clothing which looks like standard NASA jumpsuits for pressurized environments onboard spacecraft. ...
1
vote
1answer
79 views
Lunar starship descent motors' tank design
Just recently nasa has announced the lunar starship as the winner of the Artemis lunar lander contract which i have to say I'm very excited about. In the latest render however, the nose cone of the ...
12
votes
1answer
3k views
Why is an inflatable balloon inside a fuel tank not used to prevent fuel from “sloshing around”?
After seeing all the Starship failures, having something with a membrane keep things in place seems like an obvious solution. Has it been considered or tested - or do we simply lack a material that is ...
0
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0answers
97 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 ...
0
votes
1answer
159 views
Flying saucer shape rocket vs cylindrical shape rocket
Here's my hypothesis-
Cylinder shaped large rocket is not suitable for vertical landing due to its high center of mass and bulky weight. However an equally weighing saucer shape rocket has more ...
4
votes
0answers
231 views
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 ...
2
votes
1answer
68 views
Potential Fusion Drive system calculation issue
I will start off by saying that this is an entirely hypothetical drive system with plenty of handwaving and optimistic physics. My question I think is fairly simple and may just be something that ...
1
vote
3answers
264 views
Why SpaceX want to land the rocket on the ground?
click for full size
Won't it be easier and save a lot of money to just catch it or land it in a basket?
So rocket coming down can open arm longer than the diameter of the high basket where it goes ...
1
vote
4answers
255 views
Starship: Maximum damage if hijacked and weaponised?
Any sufficiently advanced space technology is indistinguishable from a weapon of mass destruction if misused.
In the event that SpaceX lost control of a Starship to EvilHackers, what's the most damage ...
1
vote
1answer
102 views
would using both skyhooks and rockoons together be useful?
If my goal with a particular rockoon platform is not for it to reach space on its own but rather reach the lower end of some kind of some kind of skyhook, would the baloon part of the rockoon be more ...
3
votes
1answer
57 views
attitude thrusters sharing a common combustion chamber
Most smaller satellites and other larger but simpler space craft with a less demanding mass fraction tend to use cold gas thruster, importantly with a common or as few as possible pressure vessels, ...
4
votes
2answers
147 views
Using lasers to reach the Karman line
I've just seen this Anton Petrov video: New Type of Laser Levitation Could Help Us Explore the Mesosphere. It's about this new form of levitation that uses lasers to heat up the air underneath a craft,...
3
votes
1answer
162 views
Why are Starship's tanks curved the way they are?
Since Starship has to feed its engines in two kind of situations :
-during ascent, acceleration is colinear to Starship's longitudinal axis.
-at the end of the belly dive, acceleration is normal to ...
7
votes
5answers
977 views
Earth Launch System with Water Propellant
Water based thrusters have been proposed (and possibly tested by now) for use in satellites and other in-space vehicles - see this NASA article. The idea is to perform electrolysis on the water to ...
1
vote
2answers
125 views
launch rocket like bullet from steam/air rifle?
I've included an image depicting how exhaust energy from a rocket launch can be recouped by turning it into a large scale pressure cooker by the use of some kind of platform=sabot (thanks @...
2
votes
2answers
200 views
Can we engrave on the Moon by focusing laser from the Earth?
I would like to know if it is possible to make an engraving or burning moon's surface by focusing high energy laser beam from earth?
5
votes
2answers
1k views
Can you Hoverslam without going vertical?
Problem of the day, that pesky Starship Hoverslam.
Imagining a crazy (childish) contest to see who could flip at the lowest altitude and brake to 0 rate of descent and land, it was (hilariously) ...
3
votes
3answers
180 views
Have any rocket fuel systems actually been explosive, and could have detonated proper?
Never mind that this is the 18th question to have the rocket-explosion tag.
To the question "Would the Dragon escape pod have survived this event?" asked about the AMOS-6 mission, Elon Musk ...
5
votes
3answers
134 views
Can we generate electricity from Martian sandstorms? If so can it be used for powering colonies?
Rapidly varying electric fields inside dust storms have been observed and studied for years.
The winds in the strongest Martian storms reach 60 miles per hour.
2
votes
1answer
162 views
What if we launched rockets from space using the slingshot method and centripetal force? Would that be possible?
Would we have to build a orbiting launch station that uses centripetal force to launch the rockets? Or a station that freely floats through space not in a planets orbit? Would something like this ...
2
votes
0answers
99 views
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 ...
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votes
1answer
145 views
New Shepard payload capacity to orbit?
If the current Blue Origin New Shepard were modified as little as possible to work as the first stage of a two-stage rocket, what would be its maximal LEO payload?
To put it in other words: out of all ...
2
votes
3answers
305 views
Bucket loop between Earth and Moon?
Please don't bite my head off. If this is so stupid that it deserves to be squashed, I'm quite happy to delete the question. I mainly would like to know whether anyone's ever suggested this (I ...
1
vote
0answers
75 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 ...
1
vote
1answer
144 views
Can Starship use dedicated smaller auxiliary landing fuel tanks?
Would it be better for Starship to have a separate set of small fuel tanks dedicated to landing the ship, maybe controlled separately or plumbed differently.
2
votes
1answer
129 views
Liquid Nitrogen Diluted Rocket
Imagine a rocket that uses a mixture of liquid nitrogen and oxygen as the oxidiser.
It is designed like an oxidiser-rich staged-combustion engine, however there is so much nitrogen in the mixture that ...
4
votes
1answer
122 views
Could artificial magnets orbiting the sun be used to accelerate spacecraft, like a magnetic “gravity” assist?
Say there's a powerful magnet in an orbit between those of Earth and Mars. Could a spacecraft traveling between those planets save propellant by performing a slingshot maneuver using its magnetic ...
5
votes
0answers
19 views
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 ...
3
votes
0answers
50 views
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 ...
4
votes
1answer
211 views
Could a tank of water under the launch pad be used instead of a flame trench?
A flame trench is a massive expensive thing that needs constant repair. After each launch, concrete and steel suffer cracks, chips, melting etc., and require expensive, time consuming repair.
Would it ...
3
votes
2answers
679 views
One mothership and many droneships concept for interplanetary travel
In sci-fi movies, like Independence Day, we find one big mothership flanked by many small droneships.
Take-off and landing giant spaceship is technically difficult and dangerous. The landing surface ...
1
vote
2answers
100 views
Orbital Chinese firework-cluster
I remember when I was younger I had heard this story about the Chinese using primitive fireworks, and even strapping them to a bamboo glider in an attempt to reach the moon. This story probably isn't ...
9
votes
6answers
2k views
Using water as a high density storable hydro-lox propellant
Hydro/lox is an excellent fuel choice and has been used in many engine/rockets with high ISP requirements, however, the two biggest drawbacks of the propellant are its density and boil-off. Could this ...
2
votes
0answers
35 views
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, ...
-2
votes
2answers
118 views
Can we just throw a satellite in to mars orbit with a very high spin?
I am thinking about this scenario of throwing a satellite to Mars orbit with a high spin, Can we just throw that? one hypothesis can be that high-frequency spinning generates apparent gravity so it ...
3
votes
2answers
115 views
Viability of beamed regolith propulsion?
This question is inspired by two existing spacecraft propulsion concepts.
Beam-powered propulsion involves a spacecraft being propelled by a beam of some kind, and one potential type of beam would ...
3
votes
0answers
140 views
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?
1
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4answers
186 views
Are crewed spacecraft missions that appear stationary from the ground possible?
I've looked at https://en.wikipedia.org/wiki/Spacecraft and the following question arose.
For crewed spacecraft missions, can a spacecraft remain stationary in the sky i.e. not moving once launched ...
2
votes
0answers
64 views
Conceptual reusable orbital launch engine prototype for nanosatellites [closed]
I have realised that the process in which we go to space is highly inefficient and we should create a hypersonic spaceplane which take offs and goes to low earth orbit to release nanosatelite and ...
0
votes
1answer
143 views
Can a spacecraft be propelled by two electromagnets of different size? [duplicate]
I watched a video of a toy car moving with 2 magnets, one bigger than the other. The answer I received was that the video was real, the toy car indeed moves.
So, I was wondering, if an object with 2 ...
6
votes
0answers
176 views
Would this Starship design alternative be viable?
Considering Starship atmospheric entry, belly dive and "bellyflop",
latest iteration displays four aerodynamic surfaces, two aft fins and two carard fins.
Soon will this configuration be put ...
5
votes
3answers
2k views
Terraforming Mars using a combination of aerogel and GM microbes?
Silica aerogel is a technology that's been proposed for colonisation of Mars. Basically, it's a very good insulator that's also transparent to visible light, and could be used to warm up parts of Mars ...
2
votes
1answer
83 views
Can I “tack” towards a laser beam from which I am powering my 100% efficient & massless ion engine?
As far as I know, for light and particles taking special relativity into account:
\begin{align}
E^2 &= (T + m_0c^2)^2\\
&= p^2 c^2 + m_0^2 c^4 &\text{ (particles)}\\[1.5em]
E &= p ...
0
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0answers
96 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 ...
3
votes
2answers
221 views
Lunar landing in cotton candy?
When spacecraft land on Earth, they use the atmosphere to slow down.
On the Moon there's no atmosphere, so spacecraft must instead use rockets to slow down from orbital velocity.
Would it be possible ...
asked Oct 24 '20 at 14:43
SE - stop firing the good guys
29.2k2 gold badges99 silver badges172 bronze badges
2
votes
1answer
94 views
What are the practical limits of a rocket that receives propellant from the surface?
The Orion spacecraft was supposed to be propelled by igniting nuclear bombs behind it. Its proponents successfully demonstrated the concept using conventional explosives, on a small scale, for a few ...
