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"
328 questions
3votes
1answer
321views
Using rocket engines as vacuum pumps for high altitude hot fire testing
The test of the rocket's second-stage engine can be carried out using a small nozzle model. Or you can run such test in a dedicated vacuum facility, which can better reflect the performance of the ...
2votes
0answers
54views
Would a hybrid engine with fuel-side full-flow staged combustion and a gas generator for the oxidizer pump be feasible in a hydrolox engine?
Fuel-rich staged combustion offers excellent performance for hydrolox engines, but it introduces a serious engineering challenge: the seal between the fuel-rich preburner turbine and the LOX turbopump....
- 121
5votes
3answers
222views
${}^{3}$He based fusion propulsion, linear magnetic confinement with MeV protons out one end; new or old idea, and what are major challenges/concerns?
CNN's April 3, 2025 Nuclear-powered rocket concept could cut journey time to Mars in half describes a commercial effort to build a form of nuclear space propulsion based on fusion of very light ...
- 153k
-4votes
2answers
118views
Idea for space propulsion [closed]
Do you think this Idea is possible? Thank you It is simillar to EmDrive. https://en.m.wikipedia.org/wiki/EmDrive
-4votes
2answers
207views
Would this simple fuel depot work?
The second stage (Starship) with an extra load of fuel gets to LEO, opens a double-layer rubber bag (with sun-reflection), and pumps fuel into it. Then disconnects and lends back at the launch tower? ...
1vote
1answer
130views
How does one make propellant from recycled space junk?
While Burn 1st stage structural material as fuel? asks about a spacecraft consuming itself, inspired by the Monty Python poem "Horace", yhis question is inspired by recent news about a ...
- 153k
11votes
6answers
4kviews
In retrospect, should they have provided more RTG fuel and a more powerful radio for Voyager?
Adding extra RTG fuel disks would increase the weight of the entire vessel only slightly, but give it a much, much longer lifetime. It would also allow for the instruments to still be running, and for ...
12votes
2answers
4kviews
Why do you even need a heatshield - why not just cool the re-entry surfaces from inside?
Is it conceivable to instead of having a heatshield, to just have some sort of material or mechanism on the inside, that can convert the heat into something else? A back of napkin calculation shows ...
- 759
4votes
4answers
377views
Is it possible to construct a way to breathe in space without a helmet?
Why you can't just go to space in a dive suit with some additional cooling. In fact what if you had the equivalent of a snorkel for breathing and a ski-mask type visor, well insulated to avoid ...
- 759
1vote
1answer
143views
Could inflatable habitats be used on an artificial gravity station?
If you take an inflatable module such as the Sierra Space's LIFE, could you arrange them all around the ring of an artificial gravity station? My main question here is regarding the structural ...
- 167
2votes
0answers
88views
A Mars Sample Return Misson Profile
The first and second modules are both launched to Earth's Orbit. Their iodine ion engines get them on their way to Mars. The first module is in a free return trajectory. The second module is in a ...
user57372
3votes
1answer
135views
Could we convert lunar regolith into a trinitite landing pad with an atomic weapon?
My thinking here is that a modern thermonuclear weapon would not weigh very much and that by detonating one an appropriate distance above the lunar surface, the regolith could be melted into a hard ...
- 9,353
1vote
0answers
200views
Which rocket engines used this exotic cycle?
A "Hypergolic, Full Flow, and Closed Catalyst" cycle Left side: All hydrazine goes through the centrifugal fuel pump All hydrazine goes through thermal decomposition Out of it comes hot ...
user57372
7votes
2answers
2kviews
Diagonal ice tunneling rover to reach a safe pressure in Mars?
Is the ice on Mars deep enough to bore down into it to sustain around 10 PSI (69 kPa) air pressure? The device I have in mind is a rover with a reactor that melts through the ice slowly to create a ...
4votes
3answers
2kviews
Reducing required length of a mass driver using loop?
If you had a loop of electromagnets with an encapsulated payload inside vacuum tubes, how fast could you accelerate the capsule to before it reached some maximum velocity? What effect would scale have ...
