Questions tagged [design]

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

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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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1answer
93 views

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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1answer
124 views

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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1answer
198 views

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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121 views

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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2answers
100 views

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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118 views

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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1answer
93 views

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 ...
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658 views

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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9k views

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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286 views

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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1answer
146 views

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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3answers
204 views

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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1answer
174 views

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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Special Case Constellation Analysis Approach: Walker Constellation with Circular (e = 0) orbit in LEO

I am familiar with the general approach to propagate orbits using orbital parameters, and how to account for basic J2 perturbations. I am looking to perform some analysis on large walker ...
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Was the Titan SRM thrust vs time curve engineered to allow for acceleration switches to initiate staging sequence events?

This answer describes the timing between the Titan III Stage 0 (SRM's) and Stage 1 events. The Titan first stage ignited just prior to SRM separation: Titan Stage I ignition occurs at ...
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2answers
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How feasible is the Delta-Glider?

In Dr. Martin Schweiger's freeware spaceflight simulator Orbiter 2016, a very popular(but fictional) spacecraft is the Delta-Glider. It is capable of take-off from a runway, has hover engines for ...
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152 views

How many motors on the new Mars 2020 rover? (and other questions)

With so many different motors on the new Mars 2020 rover, I'd like to ask if each motor programmed to operate independently or can the different motors operate in sync with each other? Also, as a ...
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257 views

Why is multi-spool pump very rare on rockets?

The only one I know of is the LP LOX pump on RD-0120. A multi-spool design is already a default for jet engines, which are basically turbine-driven air pumps. A multi-spool pump can save at least the ...
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1answer
473 views

Why did the cones of the Mercury and Gemini capsules have a neck?

As highlighted by the green double-arrow lines in the pictures below, the Mercury and Gemini capsules had a (roughly) cylindrical "neck" at the end of the capsule cone. If they had instead followed ...
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1answer
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Tradeoffs to consider for OBDH system design for a Multi-Spectral Imager payload? (Enceladus Mission)

I am having a problem with designing the On Board Data Handling (OBDH) system for our MSI (Multi-Spectral Imager) payload. Our payload will be detached from Orbiter and it will take photos (for ...
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How common are “parallel stages” in a launch vehicle?

I'm being told in this answer and in this comment that the fourth stage of the Farside rocketoon lies in the center of the four "cores" of the third stage. See this answer for several pictures of ...
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526 views

Just how pointy does a rocket's nosecone need to be?

There are some beautiful images of the Qu8k rocket launch on this web page and I show a few below. There's a video (below) and the PDF Qu8k Final By Derek Deville, November 27, 2011 The stainless ...
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How does the inter-propellant seal works in kerosene/LOX and UDMH/NTO rockets?

I get that the inter-propellant seal on the SSME LOX HP pump is simply a series of cascading regular seals trying to eliminate bleed-through by venting and letting boil at each stage, so that when ...
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1answer
83 views

Are new precision gyroscopes used in spaceflight pretty much all optical?

Gyroscopes are used in spaceflight as parts of inertial systems to monitor spacecraft attitude. They are not absolute, they will drift slowly over time and so need occasional calibration via other ...
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How much more hardware is needed in a cross-fed CBC rocket than a non-cross-fed one?

Is it just a matter of adding a multi-in fuel manifold?
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Are LiPo batteries more suitable for 1st stage electric power than Li-ion batteries?

I've just ran across two mentions in Scott Manley's videos of LiPo batteries (Lithium-polymer) in first stage launch applications. These involve power levels of megawatts. Why The Electron Rocket May ...
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1answer
178 views

What set of units does the Orion capsule cockpit instrumention use?

Shuttle was English, ISS is metric. What's Orion? For example: What units are inertial velocity displayed in?
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208 views

Why didn’t the space shuttle external tank have pressure-relief vents?

During a space shuttle abort, it would have been vitally important not to allow the vehicle to droop below 265 kilofeet during powered flight, as excessive aerodynamic heating below 265 kft would have ...
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486 views

Why are planetary probe RTGs tilted at a jaunty angle?

This image from here: Does the Dragonfly project (quadcopters on Titan) envision attached RTG's or would they be static and revisited for charging? and this image show that the RTGs on these two ...
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2answers
2k views

Why latest Landsat satellites have solar panel on only one side?

It is normal for satellites to have solar panels on both sides of the body. But Landsat satellites, from Landsat 4, seems to have the solar panel on only one side. Are there any specific advantages ...
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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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1answer
178 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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What is the most aerodynamic Satellite?

From what I understand at least in the lower orbits you want the least amount of drag possible. My brain is telling me that a long pole or submarine shape satellite orientated to the direction of ...
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3answers
274 views

What are some notable computer systems used in space probes?

I was reading about Cassini and learned that it used a CPU architecture I'd never heard of before, called MIL-STD-1750A. This got me thinking. What are the most common (or otherwise notable) CPU ...
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1answer
159 views

Are 2 satellites joined better than 2 apart?

Could new satellites be designed to intercept other older functioning artificial satellites or space junk already in orbit to add weight to the new satellite in order to last longer in orbit?
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Conditions and sensors that can be used for parachute deployment?

I'm looking for an explanation on ideal conditions/considered factors when a parachute is deployed (particularly in large competition rockets). Also what sensors should be used to measure these ...
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1answer
326 views

Why does PSLV use four stages to get to LEO, and why do they alternate solid, liquid, solid, liquid?

Is there a simple way to explain why ISRO's PSLV launch vehicle uses four stages to get to LEO, and why they alternate as follows: ...
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1answer
132 views

How to waterproof a rover?

What changes would be needed to a late model rover to enable it to function under water? What would prevent a rover from functioning under water as is? related: https://astronomy.stackexchange.com/...
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195 views

What is the maximum pressure a rocket body can experience?

Given that the alloys (typically made of aluminum or titanium) are optimized for being as light and as durable as possible, what is the maximum pressure a rocket like the Falcon 9 would be designed to ...