85
votes
Accepted
Why do space operations use "nominal" to mean "working correctly"?
As explained in the answer that Organic Marble dug up, aerospatial "nominal" is really a shorthand for something like within the allowed tolerances around the nominal (i.e. specified) value. We can ...
- 170k
80
votes
Are there any “Third Order” acronyms used in space exploration?
Yes.
NUTI => NASCOM User Traffic Interface
NASCOM => NASA Communications
NASA => National Aeronautics and Space Administration
Found by parsing this list of over 14,000 NASA acronyms
It also ...
71
votes
Accepted
Name for geostationary orbit around another planet
I'll go with Emily Lakdawalla who in her blog post about stationkeeping in Mars orbit wrote (emphasis mine),
What is a geostationary orbit like at Mars? I have to pause here for a brief discussion ...
- 75.5k
60
votes
Accepted
What is the difference between Cape Canaveral and Kennedy Space Center?
Supplementary answer:
Some of the confusion arises because there is also a geographic feature named Cape Canaveral. It's pretty much the green area shown in the other answer, east of the Banana River....
- 187k
55
votes
Accepted
Was "Apollo" an acronym for "America’s Program for Orbiting Lunar and Landing Operations"?
From a pre-launch press release for Apollo 11:
Among the many missions conceived at that time was a manned journey to the Moon and back. Dr. Silverstein himself named it "Apollo" after one ...
- 122k
50
votes
What is "mission design"? What do mission designers do (if such a designation exists)?
Yes, there are people whose sole job is "mission design." They design the trajectory that a spacecraft should follow to fulfill its mission and all of the maneuvers needed for that to happen....
- 6,300
49
votes
What is an "octet" in the context of NASA's LunaNET Interoperability Standard? ("internet on the Moon")
An octet is an 8-bit byte. Historically, "byte" wasn't always 8 bits (and still isn't, with some architectures having different byte sizes today); "octet" is unambiguous and widely ...
- 170k
48
votes
Accepted
Why is Jupiter called a "Gas Giant"?
Jupiter being a gas giant is not about its appearance, as another answer stated. It's only about the mass distribution of a planet.
Jupiter's mass is 320 Earth masses, while we know from the Juno ...
- 2,985
48
votes
Do scientist who study martian geology typically use the term areology?
Good question. I work on the Curiosity team, and I hear "geology" all the time, but never "areology." Too bad, really, since it's a great word, and I love the R/G/B Mars series.
- 1,405
47
votes
Are there any “Third Order” acronyms used in space exploration?
I gave an example of one a while back in this answer:
Alternate version by Magic Octopus Urn
Alternate version by Eric Duminil
- 187k
46
votes
Accepted
What is the story behind specific impulse being expressed in seconds?
It's even simpler than a German-American disagreement. It's use of ambiguous units.
The term "specific X" means the amount of X you can get from a unit mass of something. For instance, in batteries, ...
- 18.3k
38
votes
Who coined the phrase 'Rapid Unscheduled Disassembly'?
Here's a reference from 1967 in "The MAC Flyer", Volume 14, Issue 5. This appears to be a periodical of the US Military Airlift Command. I have not been able to locate full text (but would certainly ...
- 481
37
votes
Accepted
What is an "octet" in the context of NASA's LunaNET Interoperability Standard? ("internet on the Moon")
Is "octet" just a fancy word for "byte"
No, they mean very different things.
A "byte" is the smallest unit of addressable memory of a specific CPU architecture. That ...
- 19.9k
35
votes
Can "engine" and "motor" be used interchangeably in spaceflight? Are there any cases where they can't be?
"Motor" by convention refers to a solid rocket, "engine" by convention to a liquid rocket. There can be exceptions.
...the word "motor" is as common to solid rockets as ...
- 187k
34
votes
Accepted
What is and what isn't ullage in rocket science?
But I still don't completely understand what is or isn't ullage in rocket science context.
Ullage technically is the space in a tank of liquid which is gas-filled instead of liquid-filled.
For a ...
- 170k
33
votes
What is the difference between Cape Canaveral and Kennedy Space Center?
Cape Canaveral is composed of two items, the Kennedy Space Center, run by NASA, and the Cape Canaveral Air Force Base, run by the Air Force. Because they are two very different organizations, the ...
- 122k
32
votes
Accepted
What is "anti-geysering" and why would you turn it off 70 seconds before launch?
Partial answer to
What is "anti-geysering"...
tl;dr Anti-geysering systems are intended to stop geysering, which is a phenomenon that can occur in long vertical pipes of cryogenic fluid ...
- 187k
29
votes
Accepted
What is the name of the area on Earth which can be observed from a satellite?
What is the name of this line or this area?
line
A term for the line that's perfectly usable for this purpose is "horizon".
The horizon, the line line separating the land from the sky, ...
28
votes
Name for geostationary orbit around another planet
Geostationary orbits are synchronous orbits, which are also circular and equatorial.
You could describe orbits around other planets in the same way, as circular, equatorial & synchronous orbits.
...
- 6,957
26
votes
Can "engine" and "motor" be used interchangeably in spaceflight? Are there any cases where they can't be?
According to Wikipedia, they are effectively interchangable:
Motor and engine are interchangeable in standard English. In some engineering jargons, the two words have different meanings, in which ...
- 170k
24
votes
Accepted
Are any "strap-on" boosters held in place by actual straps?
The Soyuz line all the way back to the R-7 has straps or cables connecting the boosters to the core. The straps, plus a "socket" on the core catching the front tip of the booster, are apparently how ...
- 170k
23
votes
Why "strap-on" boosters, and how do other people say it?
These boosters are called “strap-on” because there is little structure besides the separation mechanism holding them on, and the rocket is still a viable launch vehicle without them. In a few designs, ...
- 2,947
23
votes
Accepted
Do scientist who study martian geology typically use the term areology?
A search on arXiv for "areology" produces no results. A search on ADS produces two results (one of which has the subtitle "The Geological Environment of Mars"). So the term is ...
- 5,108
23
votes
What is the name of the area on Earth which can be observed from a satellite?
What is the name of this line or this area?
Typically, the part of the earth's surface that a satellite can view at any moment is known as its footprint, a term frequently used for remote sensing ...
- 347
23
votes
Term for deformation due to gravity
The generic term is tidal deformation. At a distance of ~385000 km, the Moon subtly distorts the shape of the Earth. Those distortions are readily visible in the Earth's oceanic tides, and not quite ...
- 75.5k
20
votes
What is the difference between a space plane and a space shuttle?
A plane, or airplane, aeroplane, is:
An airplane or aeroplane (informally plane) is a fixed-wing aircraft
that is propelled forward by thrust from a jet engine, propeller, or
rocket engine.
All ...
- 1,746
19
votes
Accepted
What does "in the bucket" mean?
The space shuttle throttled down its main engines from the normal setting of approximately 104% to around 67% as it was passing through the region of max dynamic pressure ("max q"), to make sure that ...
- 187k
19
votes
Are there any “Third Order” acronyms used in space exploration?
While not exactly space exploration there is at least one fourth order acronym for NASA earth observation systems (mostly earth sensing satellites).
EPR - EED2 Program Roadmap
EED - EOSDIS ...
- 207
19
votes
What does "reaction" in "reaction control system" and "reaction wheel" refer to?
I think there is little doubt that "reaction" refers to the "equal and opposite reaction" of Newton's third law.
First consider "reaction control system". In principle, ...
- 11.4k
Only top scored, non community-wiki answers of a minimum length are eligible