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Questions tagged [engineering]

Questions regarding the design or process of design of a spacecraft.

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46
votes
8answers
12k views

What would be the (most difficult) challenge to make a “10,000 year satellite”?

Update: Bezos' recent Tweeted update on the 10,000 year clock. Also see The Verge's Construction begins on Jeff Bezos’ $42 million 10,000-year clock The discussions associated with the question Can ...
31
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1answer
6k views

How do manned spacecraft achieve an airtight connection while docking?

By another question I was reminded how hard it is to build airtight equipment such as vacuum chambers from multiple pieces. Docking or berthing space ships / space station modules is a rather similar ...
30
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1answer
3k views

Why do the Shuttle's external tanks appear to be rusted?

Wikipedia article states as STS-1 at liftoff. The External Tank was painted white for the first two Space Shuttle launches. From STS-3 on, it was left unpainted. I wonder why the ...
25
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4answers
9k views

Why is SpaceX building the Big Falcon Ship before the Big Falcon Rocket?

I believe that SpaceX is planning on building the BFS (Big Falcon Spacecraft) before the BFR (Big Falcon Rocket), which serves as the first stage for the second-stage BFS. Does anyone know why they ...
24
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1answer
2k views

How realistic would the Sea Dragon engine be to produce given today's technology?

Just learned of the Sea Dragon proposal from back in 1962. From the Wikipedia entry The first stage was to be powered by a single enormous 80,000,000 pounds-force (360 MN) thrust engine burning RP-...
21
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3answers
5k views

Why isn't there research to build a standard lunar, or Martian mobility platform?

While many terrestrial mobility platforms have been very successful, why are we spending millions to every rover device making it unique? Sure enough, different worlds offer different conditions, but ...
19
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2answers
8k views

What is the ideal shape for a rocket?

Obviously there are many factors that go into the design of a rocket. However, to me, many rockets seem very tall and skinny. What I mean is that an ideal rocket would have as little mass used for ...
19
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2answers
2k views

How does the Saturn V Dynamic Test Stand work?

This photo instantly provokes a ton of questions in me: It shows the Dynamic Test Stand at Marshall SFC with the Enterprise, which was a Space Shuttle test vehicle, suspended for vibration testing. ...
19
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1answer
6k views

How did they solve Saturn V pogo oscillation problems?

From what I understand, pogo oscillation was already a known problem for Saturn V rocket's first stage (and likely other stages, not sure) long before, say, Apollo 11, especially on its central out of ...
18
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1answer
3k views

Why design new rocket engines instead of using the existing types?

Already in the 1960s rocket engines seem to have achieved near maximum chemical efficiency. What are the reasons for new designs being in demand? How much better could a new engine design be than the ...
18
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3answers
3k views

How are fuel tanks filled with cryogenic hydrogen?

Cryogenic hydrogen can react with the atmospheric Oxygen to produce an explosion: as well as being cold enough to liquefy (and possibly solidify) atmospheric oxygen, which can be an explosion ...
18
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2answers
3k views

Why do pressure fed engines have combustion instabilities?

Reading about the Sea Dragon idea, I came upon this argument against it, which sounds compelling, but relies on more detailed knowledge than I have: Those are to be pressure-fed to avoid "...
15
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4answers
2k views

What is the intent of attaching legs to the rocket?

SpaceX Adds Landing Legs to Falcon 9 Rocket for Next Launch Still thinking why they added legs to the rocket's first stage? What are the advantages of attaching the legs to the rocket? Does that ...
15
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3answers
1k views

Why do KSC crawler-transporters use caterpillar treads instead of rail tracks?

The two Kennedy Space Center crawler-transporters, used to transport Saturn V, Shuttle and SLS rockets to the launchpad, move on caterpillar treads: Here's a SpaceFlight Insider video clip about ...
15
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1answer
3k views

Why are Curiosity's wheels aluminum rather than titanium?

I was just reading this article on how Curiosity's aluminum wheels are getting pretty dinged up. Usually titanium alloy is considered an upgrade from aluminum alloys in most applications, from ...
14
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4answers
3k views

How feasible is it to harvest isotopes of Helium or Hydrogen from the gas giants?

The gas giants in our solar system have abundant quantities of Helium and Hydrogen. Is it possible to harvest these resources there? Does NASA have any plans to build some permanent base in space for ...
13
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4answers
7k views

How big would a manned ascent stage for Mars need to be?

For a manned mission to Mars that isn't a one-way trip, we'll need an ascent stage that can reach orbit from Mars' surface. How big would this need to be to transport e.g. 3 astronauts to orbit? We've ...
12
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1answer
2k views

Why was the Hubble Space Telescope purged with nitrogen gas?

Wikipedia states that The telescope had to be kept in a clean room, powered up and purged with nitrogen, until a launch could be rescheduled. Spacecraft are always kept in a clean room ...
11
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1answer
628 views

Purpose of hemisphere under shuttle nose cone (Enterprise)

I noticed a small hemisphere protruding from the dorsal side of the Enterprise space shuttle's nose cone, forward of the front landing gear. I have no clue what its purpose is but am far from an ...
11
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2answers
442 views

What happens next if the root cause of one rocket failure won't be identified?

Supposing that in a rocket failure engineers don't find what the root cause was, what will happen next? In general if the root cause will never be fully understood is there a law, rule, or standard ...
11
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1answer
650 views

Why does the YF-75D nozzle have such a strong spiral pattern?

Why does the YF-75D nozzle material have such a strong spiral pattern? Is it a result/biproduct of a manufacturing process only, or does it have some specific function? edit: The last, cropped ...
10
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1answer
495 views

What improvements does SpaceX Falcon 9 Block 5 have over prior version?

Does SpaceX disclose what improvements their Falcon 9 Block 5 will have over the Block 4 model? If so, what improved features will it have? I have heard general comments about it in the news, but I ...
10
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1answer
2k views

How does a space probe differ from a satellite in terms of materials used and size?

Both of those space vehicles are meant to carry out different tasks. How are materials selected for both of them such that it benefits their task? And is size a debatable factor while building these ...
10
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2answers
2k views

Transitioning into space software engineering

I have been a Web Developer in London since I graduated in 2012. My skills reside mainly in the Microsoft stack (MSSQL, .NET, C#, MVC and all the front-end stuff). I have always been very interested ...
10
votes
2answers
394 views

Which are the benefits and challenges for a new SLS rocket version with four SRB? [closed]

Which are the benefits and the challenges for a new Space Launch System (SLS) version with four Solid Rocket Boosters (SRB)? Benefits i mean what would gain in payload capabilities, how much more ...
10
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3answers
692 views

Strategies for combating ESD and ground plane potential shifts on spacecraft charging?

What are some common design guidelines/practices to combat the electrical effects of spacecraft charging(e.g. ESD, ground plane shift). Is it to focus on more resilient parts, and reduce resistance/...
10
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1answer
6k views

What material properties would be necessary to shield a lander from the environment of the Venusian surface?

On March 1, 1982, the Venera 13 lander survived for 127 minutes in an environment with a temperature of 457 °C (855 °F) and a pressure of 89 Earth atmospheres (9.0 MPa). This says nothing of the ...
10
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1answer
980 views

Function of the RL10 Oxygen Turbopump's Splined Shaft End

The oxygen turbopump in the RL10 upper stage engine has been openly discussed by NASA for some decades now, in publications like SP-8107. On page 8 of this document is a drawing of this turbopump. The ...
9
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2answers
337 views

What mitigation procedures are in place in space systems to prevent whisker growth?

It has been found (from missions like the Long Duration Exposure Facility, LDEF) that some metals, especially tin and cadmium in solders, used in space-electronics assemblies, form crystal whiskers ...
9
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1answer
1k views

Why is a purging process necessary for static firing test of liquid rocket engines?

In Chapter 7 of Modern Engineering for Design of Liquid propellant Rocket Engines by Huzel and Huang, mentions the following engine cut off procedure. The cutoff sequence usually consists of ...
9
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3answers
2k views

Troubleshooting a DIY Ion Thruster

Been following a Make-Magazine article on how to make your own ion thruster: https://makezine.com/projects/ionic-thruster/ Went through the tutorial step by step, not seeming to get any thrust out of ...
9
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1answer
711 views

Has any work been done on alternatives to rolling element bearings in rocket turbopumps?

Specifically: Using some high pressure gas (before or after combustion) as a fluid bearing. A superconducting maglev bearing, possibly using fuel as coolant. Any related work is also welcome.
9
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4answers
280 views

What engineering processes (satellite/space vehicle related) require an atmosphere

So we all know that there are lots of engineering processes that are made 100 times better by negligible gravity, and that certain engineering process need to be performed in a vacuum (electron beam ...
9
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1answer
1k views

What are/were the rails leading into the flame trench of pad 39A used for?

In this Google Street View you can see what appear to be rails leading down into the flame trench under launch pad 39A. What was/is the purpose of those rails?
9
votes
1answer
179 views

Do modern CFD codes reduce the number of test firings in an engine program?

Given the complexity of liquid propellant rocket engine development, I wonder if (and how much) modern Computational Fluid Dynamics (CFD) codes help to reduce overall development costs. Do they ...
8
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4answers
29k views

Becoming an astronaut with engineering background

Which engineering branch will be most suitable for becoming an astronaut, and what other options do I have if I want to become an astronaut with an engineering background?
8
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1answer
514 views

Sea level static test of an upper stage possible?

As we know that for the upper stages of the rocket, we need high propulsion efficiency thereby high specific impulse. For that we employ a nozzle with higher expansion ratios. Now, if we conduct the ...
8
votes
2answers
381 views

What are the practical engineering difficulties in building and launching large inflatable modules?

Currently there seem to be two efforts under way: Bigelow Aerospace RKK Energiya The latter source (an article in the Popular Mechanics by Anatoly Zak) intimates that structural creep is a major ...
8
votes
1answer
352 views

Why were individual shuttle tiles changed from white to black or black to white?

The Paper Space Scale Models website has a PDF which details changes to the STS Orbiter Markings on a per-mission basis. Most of the changes are in the tiles. It can be seen that often a single black ...
8
votes
1answer
871 views

Why are the nose cones of current spacecraft less pointy?

You would think that with the quest for aerodynamic efficiency in current spacecraft that the nose-cones at the pointy end of the launch-vehicle would have a sharp taper, more so for craft that aren't ...
8
votes
1answer
1k views

Is there a diagram of different nozzle diameters to scale?

I am looking for a diagram that shows the different diameters of various nozzle openings, including Rocketdyne's F1 (150 inches) SpaceX's Merlin (66 inches), the Air Force's Delta IV Heavy, and NPO ...
8
votes
1answer
249 views

Has any spacecraft to date suffered catastrophic gasket degeneration in space?

A gasket is a precisely formed body of some (yielding) material placed at a mating surface usually to prevent leakage. It may also be constructed of an alloy as was done in early IC engines. ...
7
votes
2answers
883 views

Why aren't orbital vehicles made of plastic?

Why aren't orbital vehicles made of plastic? Some type of plastic have good characteristic such as airloys which have low thermal conductivity, good pressure resistance and very low density. Why don't ...
7
votes
4answers
2k views

What is the difference between Space Dynamics & Astrodynamics in the engineering perspective?

Within the context of Aeronautics, there are seemingly different meanings corresponding to Space Dynamics and Astrodynamics. What is the difference between them in an engineering perspective, such as ...
7
votes
2answers
725 views

How are spacecraft engineered to prevent overheating?

Been reading about early space exploration again, especially Sputnik 2 (1957) and Venera 1 (1961). Both of these suffered from overheating. It strikes me that a metal object will easily "absorb" the ...
7
votes
3answers
509 views

How well can hybrid motors be throttled?

Pretty self explanatory: down to what percentage can hybrid rocket engines be throttled to? And what fuel / oxidiser combinations allow for the greatest throttling? I'm planning on using hybrids for ...
7
votes
1answer
102 views

What parameters of an rocket engine determines whether it is fit for any more static hot fire test?

Typically engines built are repeatedly hot fired to analyses their performance. In between tests, what are the review that the engine undergoes? How is an engine gauged suitable for a hot fire ...
7
votes
2answers
90 views

Monoatomic species at orbital altitudes

Besides monoatomic oxygen, what other monoatomic or chemically reactive atmospheric or environmental constituents, if any, are present at orbital altitudes that aren't present at lower altitudes, and ...
6
votes
1answer
897 views

How do the booms on ISS (and other spacecraft) extend and retract?

In an answer to my previous question, OrganicMarble posted a video: The booms like through the center of ISS solar panels are quite common in space use - supporting ...
6
votes
3answers
592 views

Was computer aided design used on the Space Shuttle Program?

With the Space Shuttle system being as complex as it was I was wondering the following; did the initial engineering teams in the 70's use any form of CAD/CAE or did they simply utilize the same ...