Questions tagged [design]

Questions about how space vehicles and related hardware are designed. See also [structural-design] and [engine-design].

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Have there been any square 4U (2x2) cubesats?

How much did each MarCO 6U cubesat weigh? suggests that the density of a MarCO 6U cubesat might be as low as 0.75 g/cm^3 whereas I think they are usually about twice that. That led me to speculate ...
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How much did each MarCO 6U cubesat weigh?

Yes the answer is zero now because they are weightless, but I used past tense. In any event, let's try to find a good, reliable source for each spacecraft's mass and whether that number is dry or ...
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Essential sensors for cubesat ADCS

We are building a 3U satellite to orbit Earth and measure space debris. Between gyroscope, GPS, IMU, magnetometer, Sun sensors and star tracker, which would be essential sensors for the ADCS? Or ...
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Why do Ingenuity's legs differ?

In the pictures below, I notice that not all of the legs of Ingenuity are the same (look at the end of them, directly touching the surface). It looks like a single one is different than the other 3. ...
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How to design heatshield bluntness?

How is the bluntness or curvature of a heat shield of a reentry spacecraft designed? If the answer depends on size and mass, consider a deep space sample return "mini capsule" 50 cm in ...
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Are there any uncrewed spacecraft that maintain(ed) an atmosphere?

In How do phonesats stay cool? I wonder if phonesats might have had "cabin pressure" to keep the phones from overheating since they are not designed for space. But now I'm just wondering if ...
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Why are stages not connected by the engine nozzle? Why are interstages used?

First, a clarification: I understand the aerodynamic reasons that interstages are used, and I understand that the shockwaves that would be generated without an interstage would wreck the rocket. My ...
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Why put chromium on the back side of this JPL-designed solar sail?

This 2013 JPL presentation Solar System Escape Architecture for Revolutionary Science March 2013 Conference NIAC Phase 1: 2012-2013 by PI: Jeff Nosanov Co-Is: Dr. Daniel Grebow, Dr. Brian Trease, John ...
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Could the kinetic energy in the Sun's solar wind power an ion propulsion system for an interplanetary spacecraft?

I am wondering if the kinetic energy of the Sun's solar wind could energize heavy ions to the point in which they would produce enough momentum to propel an interplanetary spacecraft. To help ...
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What criteria influence launcher aspect ratio?

One factor when designing a launcher is the total $\Delta V$ required. For a given $\Delta V$, engineers can define the propellant quantity. From this quantity they can define the volume of the ...
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How will SpaceX's VisorSat work? How could a sunshade articulate to shade parts of Starlink satellite as it orbits the Earth?

CNET's Elon Musk wants SpaceX to launch the next generation of space telescopes says: The billionaire entrepreneur said that "VisorSat" satellites equipped with a sunshade to block ...
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Balancing Perseverance Mars Rover; couldn't they just “move stuff around a little” rather than add 6+ kg of dead weight?

The NASA News item NASA's Perseverance Mars Rover Gets Balanced says: Just as an auto mechanic places small weights on a car tire's rim to bring it into balance, the Perseverance team analyzed the ...
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How is Cryogenic fuel kept… Cryogenic in rockets [duplicate]

How is cryogenic fuel & oxidizer kept at cryogenic temperatures in rockets? I am mostly interested in the first stage of launch vehicles rather than something like a Centaur that keeps hydrolox ...
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rocket engine design

Do we need to preheat both the fuel e.g. LH2, and the oxidizer e.g. LOX, by running conduits around the nozzle? I presume both being cryogenic, preheating would be a must otherwise, engines will have ...
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(Possibly fictional) Can you locate this mysterious Project Orion design with NERVA engines as RCS?

Some years ago, I happened to see a drawing of a hypothetical Project Orion (the Nuclear Pulse Propulsion one) type spaceship, that had the notable (and highly questionable, IMO) feature of having a ...
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Why were the openings of the LiOH canisters in Apollo different shapes in the first place?

Many of you probably know the famous "square peg in a round hole" situation on Apollo 13. All three astronauts were in the LM and there was a build up of CO2 from the astronauts exhaling. They had to ...
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Why does the Perseverance rover have such complicated shaped spokes in its wheels?

Phys.org's NASA's Perseverance Mars rover gets its wheels and air brakes has some interesting photos includes some nice photos and below I've included a cropped section of a photo of one of ...
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Bipropellant RCS systems: Do they go together with docking? Or with manned spaceflight?

In a recent discussion, I asked about using a certain bipropellant system for RCS thrusters (I was actually thinking about it as fuel for an MMU jetpack or the "scooter" commonly imagined in science ...
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Are black and white stripes any better than uniform gray for thermal control?

Q: What color is a spaceship? Several answers and comments on Why were Europe's first few satellites so stylish? Why the pronounced alternating white and black stripes? contain phrases like "...
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What is the load path for thrust in a rocket engine? [duplicate]

This may be a duplicate of this question but I wasn't sure if I could hijack that one to clarify or regenerate interest there. What is the distribution of axial force in a combustion chamber? My ...
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What are common rocket fuselage designs?

I am wondering about the basic design considerations when building a rocket body. is it made as a separate hollow cylinder with standalone tanks inserted inside? is it made so that the tank walls are ...
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What is the limit to which we can scale up uniformly in all directions Space Shuttle SRB before it becomes unable to take off?

Let's say we like the Space Shuttle design so much, we want to use it as a reference for our new rocket. But we want to build rocket which will be capable of launching larger payload into Earth's ...
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Are few kilogram RTG's possible with similar mass-specific power to current designs?

This answer to Mass ratio of solar-electric versus radioisotope thermo-electric power for propulsion; beyond how many AU do RTGs win? estimates a crossover at about 4.3 AU, so a trip to the outer ...
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Why do Soviet and Soviet-derived rockets hot-stage instead of using ullage motors?

I am only aware of one US rocket that used hot-staging for maintaining proper ullage during stage seperation--the Titan family. Otherwise, US rockets tend to use reaction control systems or small ...
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Why is the diameter of the boosters of some launch vehicles smaller than the diameter of their payload fairing?

Whilst watching yesterday's Starliner launch I've noticed how skinny that Centaur (3.1m) looks compared to the CST-100 (4.5m). Looking up the Atlas V I was amazed to find out that it has even larger (...
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Have there been any spacecraft designs with a bilaterally asymmetric cockpit?

One of the things that makes the Star Wars films so visually distinctive is the asymmetric spaceships, for example the Millennium Falcon below whose cockpit is located in the top right corner as ...
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How does the SpaceX Dragon nosecone separate?

SpaceX's Dragon uses a nosecone to protect the docking port during ascent. The nosecone seems very large. 1/3 of the capsule's height large. And yet, it separates while the second stage engine is ...
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Mass ratio of solar-electric versus radioisotope thermo-electric power for propulsion; beyond how many AU do RTGs win?

Solar-electric propulsion has been used several times now in deep space missions. This question explores the scalability in comparison to Radioisotope thermoelectric generation or other nuclear-based ...
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Falcon 9 Type Rocket with Raptors

I've seen the question "Why don't SpaceX just use Raptors in the F9 now since their better" asked here and there, and I understand why it isn't possible to do that- they're not a drop-in replacement ...
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Why was the nose cone on the Space Shuttle's external tank pointy?

Inspired by comments under this answer to this question Just how pointy does a rocket's nosecone need to be? (see also Why are the nose cones of current spacecraft less pointy?) Why was the ...
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Is the mass of paint relevant in rocket design?

(Prompted by this answer): Do the designers of large rockets* (have to) take the mass of the exterior paint into account? If so, do we have examples of actual design changes/decisions based on this (...
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Does any US rocket, historical or current, besides those using LH2 as fuel apply thermal insulation for propellant?

Besides those using LH2 in a booster and/or sustainer stage, that is. EDIT: I should have made it clear that this applies to launch vehicles, not spacecrafts flying deep space mission. EDIT: OK, I ...
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Why is the relative axial position of oxidizer vs fuel tank inverted in the upper stages of most rockets?

In the first stages of most rockets, e.g. Atlas V, Delta IV and Falcon 9, the oxidizer tank is stacked on top of the fuel tank, with the usual explanation that such an arrangement gives the rocket a ...
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Are large spin gravity spaceships practical considering strength of materials

Are spaceships using spin-gravity to simulate normal earth gravity on their inner surface practical considering materials available today (i.e., steel, carbon fibre, etc.)? Imagine the spaceship as ...
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Are these sliding ullage bulkheads in the OTRAG rocket? How do they seal?

This answer to Were there any non-state organizations to organize space flight and colonizations in the second half of the 20th century? mentions OTRAG and links to Astronautix's OTRAG page. The ...
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What is “additional line load” [N/mm] for the Ariane 5 launch vehicle?

In the textbook Spacecraft Systems Engineering 4th ed. page 14, table 2.1 ("Acceleration values for the Ariane 5 launch vehicle") provides data on the loading of the Ariane 5 spacecraft. One of the ...
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Why aren't RCS openings an issue for spacecraft heat shields?

A spacecraft which needs to both maneuver and enter the atmosphere needs both a reaction control system and a thermal protection system (aka heat shield). As the heat shield needs to be on the outer ...
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How does Orbex save structural weight by using coaxial tanks?

British aerospace company Orbex is developing a small orbital rocket called Prime, which uses propane and liquid oxygen in two coaxial tanks. One key aspect of propane is that it remains liquid at ...
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Saturn I's four outer engines' gas generator exhaust, why not vent to the side like the four inner engines?

At about 04:58 in Scott Manley's new video NASA Might Be Giving Away A Saturn I Rocket - Here's Why I Love This Vintage Booster he says: So the four engines in the ...
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Did von Braun have “a thing” for fins? Why did Saturn I block 2 get fins because it's a “von Braun” rocket?

At about 05:55 in Scott Manley's new video NASA Might Be Giving Away A Saturn I Rocket - Here's Why I Love This Vintage Booster he says: So the Saturn; the first ...
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Are there liquid fueled rocket boosters having coaxial fuel/oxidizer tanks?

Reading this question, instead of stacking two tanks, are there boosters where tanks are coaxial, (like a thermos bottle) having a trussed or tridimensional structure between inner and outer tank? ...
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Why aren't rockets built with truss structures inside their fuel & oxidizer tanks to increase structural strength?

I've been wondering how a rocket fuselage can support all the weight of the upper stages when it is only made of a cylinder of very thin sheet metal. (Especially considering acceleration, vibration ...
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Why do all recent proposed lunar landers have payloads on top?

Every recently-proposed vacuum lander I've seen has its payload as far off the ground as possible. This necessitates cranes, ladders, and elevators to get things down. (Starship may be a partial ...
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How do these cubesats' whip antennas work?

This answer has identified the three 1U cubesats shown in the question, and links to Engineers Rule's Maya-1: The Philippines’ First CubeSat along with the video Animation of MAYA-1, The Philippines' ...
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What criteria dictate solar panel design?

On space craft equipped with solar panels, those panels comes with various form factors and number. 2 straight rows (e.g. progress, rosetta,...) more straight rows (e.g. ATV, Juno,...) only one ...
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Minimal heating a realistic reentry vehicle could achieve?

In this question, I asked whether it would be possible to make a reentry vehicle that could slow down from orbit and glide to the ground entirely passively. The answers and comments point out several ...
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Are there any designs of geostationary satellites available online?

Are there any designs of perhaps old geostationary satellites available online? After searching around I was mostly able to find either crude diagrams or designs for little cubesats, but nothing for ...
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Why have androgynous docking systems seemingly fallen out of favour?

There are two basic types of spacecraft docking systems: Non-androgynous docking systems (examples: every U.S./Russian docking system currently in use for docking spacecraft) have two separate, ...
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Why aren’t rocket stages modular and interchangeable?

Being an avid player of Kerbal Space Program, it is intensely frustrating to return to the real world and have to remind myself that rocket stages can’t generally be swapped out between rockets (...
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What was the volume of the Space Shuttle orbiter, not just the crew cabin or cargo bay but the total volume of the entire craft?

For context, after an in-depth Google search, I asked the question "What was the volume of the Space Shuttle orbiter, not just the crew cabin or cargo bay but the total volume of the entire craft?" on ...

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