82

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 speculate about how that shorthand evolved. Example: Assume the thrust of an engine according to its design and specification -- its nominal thrust -- is 45 kN, ...


81

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 contains a vast number of second order acronyms, but the example above is the only third order acronym I could find through initial analysis.


69

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 of semantics. The authors of this paper discuss "areostationary" for Mars orbits as opposed to "geostationary" for Earth, and Wikipedia uses the same convention,...


58

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. On this geographic feature Cape Canaveral is built Cape Canaveral Air Force Station. Today's Kennedy Space Center (KSC) is built on Merritt Island. Even ...


55

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 of the most versatile of the Greek gods. Dr. Silverstein recalls he chose the name after perusing a book of mythology at home one evening, early in 1960. He ...


53

For a powered descent to the surface of a massive body like the Moon, it turns out to be most fuel efficient to do all your deceleration at the very end of the trajectory, right before impact. (This is because if you decelerate sooner than that, you will be in flight longer; the longer you're up, the more fuel you need to spend counteracting gravity ...


48

So far as I can tell, it was first a saying used by military personnel as the phrase "Rapid Unintentional Disassembly", for a phrase when a gun broke apart if you misused it. This was used by a book for Navy Personel in 1970, so I suspect it was in use for a while before then. This seems to have evolved from that phrase somewhat over the years. The earliest ...


48

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.


46

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 mission that the rock/ice in the core account for 5–25 of these Earth masses. So the rest of about 300 Earth masses is gas. Thus Jupiter is a gas giant. It is ...


46

I gave an example of one a while back in this answer: Alternate version by Magic Octopus Urn Alternate version by Eric Duminil


45

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, specific energy means the total amount of energy you can get from one unit mass of battery. As described in the Wikipedia article, *specific impulse" is the ...


44

It has many names, depends on who you ask. In English, one name for our moon is simply the Moon. Notice the article the and the capitalization making it a proper noun. This is similar in convention as the Galaxy for our own galaxy that is otherwise also known as the Milky Way. But the word galaxy actually already implies something related to milk in Greek ...


32

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 rules are quite different for each. See this map from Wikipedia to show the different locations. Note that Kennedy (NASA) owns launch pad 39a and b, while the rest ...


28

The basic difference between docking and berthing methods is as described by @OrganicMarble and the linked article, that berthing involves the robot arm and docking does not. The reasons why one is used rather than the other was discussed by the NASA PRO in a recent webcast. Obviously, if the vehicle is not capable of docking it must be berthed; however it ...


28

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. For Mars, the terms areostationary and areosynchronous are (sometimes) used. This follows the convention of how apsides are named, so it is likely that the ...


27

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 propellant tank, it's important that the ullage volume be kept away from the inlet that leads to the engines, because you want the liquid going into the engines. ...


27

There's currently a single Google1 hit for that phrase2, so I strongly suspect this is a backronym the author thought was clever. It might be worth checking the reference given around this information "Battin, R. H., An Introduction to the Mathematics and Methods of Astrodynamics, American Insitute of Aeronautics and Astrodynamics,1987."3 -- ...


27

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, would be the green line in your image. Anything closer than the horizon will be visible to the spacecraft. area Note also that even though the area appears to have ...


24

We are "in space", in fact everything that exists and has a physical presence is. But what we usually mean by it is to describe "outer space" conditions of near (or hard) vacuum, where atmospheric pressure is already low enough to affect matter differently than under true atmospheric conditions, for example at atmospheric pressure below triple point of water....


23

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 they're held on. One of the straps, near the base of the booster, is shown highlighted in blue here: This RussianSpaceWeb page has a rendering of the boosters ...


23

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, like the Atlas V, the number of boosters can be customized per-mission. Also, in some cases the booster design is shared between launchers like the Shuttle and ...


23

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 hardly ever used in titles of scientific publications. From google scholar, there seems to be a few publications about LIBS that use the term. In conclusion, it ...


21

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 appreciate updates).


21

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 satellites and communications satellites. SE's answer about the horizon applies if the satellite is viewing the entire visible portion of the globe at once. As ...


20

The “Sailboat Island” gets its name from a Poincaré Surface-of-Section (SOS) plot of potentially stable S-type family of orbits in the Pluto-Charon system. From NASA Ames' blog post titled Playing Marbles at Pluto. Looking at the Dynamic Dust Environment. Generators, Sweepers, and Sweet-Spots by Kimberly Ennico: Othon Winter (UNESP Brazil) spoke about “On ...


20

The terms docking and berthing have a nautical origin. Smaller ships come into port under their own authority and dock. Large ships instead are berthed. They come to a stop outside of the port, relinquish control to the port authority, and are towed into port by tug boats. Docking with the International Space Station is essentially a controlled collision ...


19

Both are correct, it just depends on who/what is doing the action (sucking/blowing). Consider the following scenario. You have two large tanks, sitting in your garage (presumably on planet earth). One has a vacuum in it at 0.01 ATM, the other has some pressurized air, lets say at 10 ATM. The two tanks are connected by a sealed pipe with a valve in the ...


18

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 the certified dynamic pressure limit was not exceeded. Once the threat had passed, the engines throttled back up. If you plotted throttle level vs time on a ...


18

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 Evolution and Development EOSDIS - Earth Observation System(EOS) Data and Information System EOS - Earth Observing System NASA - EOSDIS Acronym List


18

The fee area serves to distinguish between the part of the facility that the federal government owns outright, and the surrounding area that it does not own outright, but has the right to send loud noises through. fee area - federal government owns outright restrictive easement - federal government owns a perpetual interest The 125,000-acre acoustical ...


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