Questions tagged [design]
Questions about how space vehicles and related hardware are designed. See also [structural-design] and [engine-design].
221
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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 ...
5
votes
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 ...
3
votes
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 ...
5
votes
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 ...
23
votes
2answers
5k views
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 (...
2
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1answer
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 ...
3
votes
0answers
106 views
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 ...
2
votes
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 ...
3
votes
1answer
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 ...
6
votes
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 ...
25
votes
2answers
2k views
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 ...
4
votes
2answers
154 views
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 ...
1
vote
2answers
145 views
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 ...
7
votes
3answers
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 ...
10
votes
4answers
1k views
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?
...
25
votes
6answers
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 ...
7
votes
3answers
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 ...
18
votes
3answers
2k views
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' ...
5
votes
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 ...
1
vote
0answers
62 views
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 ...
2
votes
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 ...
8
votes
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, ...
6
votes
1answer
198 views
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 (...
2
votes
0answers
80 views
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 ...
2
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0answers
31 views
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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1answer
84 views
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 ...
12
votes
2answers
2k views
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 ...
6
votes
1answer
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 ...
8
votes
1answer
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 ...
12
votes
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 ...
3
votes
1answer
53 views
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 ...
0
votes
1answer
73 views
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 ...
3
votes
4answers
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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0answers
51 views
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 ...
2
votes
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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vote
0answers
44 views
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?
3
votes
0answers
114 views
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 ...
4
votes
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?
1
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1answer
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 ...
9
votes
1answer
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 ...
11
votes
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 ...
18
votes
6answers
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 ...
3
votes
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 ...
8
votes
1answer
1k views
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 ...
6
votes
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?
2
votes
0answers
51 views
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 ...
6
votes
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/...
1
vote
1answer
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 ...
