The Stack Overflow podcast is back! Listen to an interview with our new CEO.

# Tag Info

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, ...

73

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.

36

I gave an example of one a while back in this answer:

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. ...

22

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 ...

15

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

12

In shuttle parlance the "flight deck" was the upper floor of the three-story crew module, the middeck was, erm, the middle floor, and the ECLSS (or Lower Equipment) bay was the lower floor. The flight deck included both the forward facing airplane mode controls and the aft facing robot arm and rendezvous controls. If the term cockpit was used - and in my ...

10

For French and Ariane 5 Several names are used. EAP is the most common one « Étage d'Acceleration à Poudre » which could be roughly translated to « acceleration powder stage» An other more generic term used is « propulseur d’appoint » which translate to « complementary propulsion device » For Japanese and H-IIA Take this with a grain of salt my ...

9

There are two separate systems for ullage on the S-IVB (500 series only). The first one is used for the first start of the S-IVB during launch. Some information can be found in the AS-503 Saturn V Flight Manual, pages 6-31 and 6-32: ULLAGE ROCKET SYSTEM To provide propellant settling and thus ensure stable flow of lox and LH2 during J-2 engine start, ...

9

Vacuum would have a $\tau$ of zero. An opacity of $\tau$ means that the atmosphere is reducing the direct intensity of light from the Sun, if it were directly overhead, by a factor of $e^{-\tau}$. It was measured by the rovers every sol by pointing the PanCam at the Sun, or where the Sun is supposed to be, measuring the intensity, correcting for the slant ...

8

The words perigee and apogee (and their planet-specific equivalents) show it's impractical to use planet-specific names for everything. The solar system alone has far too many objects to make this practical. Try finding a specific word for 'the apoapsis of 67P-Churiymov-Cherasimenko' for instance. Geology has a sub-field called planetary geology dedicated ...

8

Boosters were in use by 21 August 1957, the first successful suborbital launch of the R-7. Definition of 'booster': A booster rocket (or engine) is either the first stage of a multistage launch vehicle, or else a shorter-burning rocket used in parallel with longer-burning sustainer rockets to augment the space vehicle's takeoff thrust and payload ...

8

Partial answer - don't know how to answer the "how often" part. It's a historical artifact - they had years of Titan documents, procedures, display and controls, etc referring to the "first stage" and the "second stage." They're not going to go back and change all that because somebody had the bright idea of airstarting it. Nope, we'll just call the ...

7

In his memoir "Liftoff", Michael Collins (Command Module pilot on Apollo 11) called it the sky. It is a quiet interval and we get a chance to examine our surroundings, this strange region called cislunar space. Is it daylight? Yes, the sun is definitely shining on us. Is it dark? Yes, if we shielded our eyes from the sun, the sky is flat black ...

7

The terminology is even less rigorous than that! Skirt, nozzle, and bell can informally refer to the same thing. Bell seems to be shorthand for bell nozzle, a common shape for a nozzle. One chapter in a book (preview) confusingly does not distinguish between skirt, skirts, and skirt structures. "Skirts" suggests Victorian hoop skirts, which indeed look ...

6

No, it's not redundant. The abbreviation GEO expands to Geosynchronous Equatorial Orbit. A geosynchronous orbit that coincided with the Earth's equatorial plane would then also be geostationary.

6

When I started at McDonnell Douglas in 1977, the term was RUDE, as in a "RUDE rocket". Rapid, Unplanned Disassembly Event. It was listed in a book full of industry acronyms I was required to read during my first two weeks. Bit was another term defined therein: Binary digIT.

5

During his tenures as Chief of the Astronaut Office and Director of Flight Crew Operations, Deke Slayton had the greatest influence over the titles of astronauts. NASA's predecessor agency -- the National Advisory Committee for Aeronautics (NACA) -- was more involved in aircraft than spacecraft. Their research resulted in the Bell X-1 supersonic aircraft ...

5

Mariner Jupiter Saturn, later named Project Voyager, initially had the Jupiter and Saturn symbols on the project logo.

5

Long time, no answer, so I'll take a stab at it...please be aware that all of my "evidence," while purely anecdotal, is first hand. I never heard the subject term, "lead head" used in this context (I was in The Office from 1996-2004, inclusive). It was frequently said, however, that, "You pay going up, or you pay coming back, nobody flies in Space for free."...

5

Terms like "correct" and "right" might imply the condition might be checked further beside the value being inside the acceptable parameters, so it’s good to stay away from that. Terms like "normal" might imply not the specific condition or even worse a comparison with some historic averages. For that reason having a less loaded term (implying you are only ...

5

It is a “Fast Mission” opportunity. These are missions that address an opportunity in the near future that would possibly be missed with the normal mission development timeline. Historically, ESA missions are classified as Large (L), Medium (M) or Small (S). The distinction is not on size of the payload, but on the technology development required for the ...

5

The technical term for them is "handrail". Image source: http://www.hunchdesign.com/uploads/2/2/0/9/22093000/restraint_and_mobility_aids.pdf IVA (IntraVehicular Activity) Handrail if you want to be formal. Table source: https://snebulos.mit.edu/projects/reference/International-Space-Station/SSP50008RC.pdf

5

If "tangential velocity" is not tangental to the orbit, what else can it be tangential to? I studied orbital mechanics in Howard Curtis' Orbital Mechanics for Engineering Students, and while I don't claim that it holds absolute truth, it uses the same definition as the diagram you posted (but less clutter): (Figure 2.8 from H. Curtis, Orbital Mechanics for ...

4

In the video Arianespace TV VS 21 Live Launch English after the spacecraft has entered "cruise" in LEO, the announcer says: Once the frigate is sent an “Engine off” we enter what we call the ballistic phase, and ballistic is probably a word I’m guessing that you’ve heard quite a lot over the years, and I believe, correct me if I’m wrong, that it means ...

4

According to the Wikipedia article on the Titan IIIC the first flight of that vehicle was on 1965 June 18. Prior to that, on 1964 August 19 a successful flight of a rocket variously known as the "Thrust Augmented Delta" (TAD) or "Delta D" or "Thor-Delta D" ushered in operational use of strap-ons for US launch systems. The TAD flew again successfully on 1965 ...

4

We're living on a planet whose name (in most languages, including both English and ancient Greek) is synonymous with "dirt", "rock" or "soil". Which, of course, is quite reasonable and descriptive, but it's bound to introduce some ambiguity in those rare instances when we're actually talking about the soil of another big ball of rock. Anyway, the point is ...

3

According to Wikipedia, "synchronous orbit" with no prefix on "synchronous" is used generically, and "geosynchronous" refers specifically to Earth. From this point of view "geo" and "Earth" do appear redundant. Maybe the nomenclature gurus wanted to make a catchy acronym ("GEO") that itself looks like it references Earth. There is also a specific term for ...

3

Moving further into the past (since you allowed suborbital flights, and this vehicle has a stated apogee of 240 miles, well above the line-whose-name-shall-not-be-spoken) there is the Sergeant-Delta aka Shotput. on October 28, 1959, NASA launched a 30-m (100-ft) inflatable sphere into a suborbital trajectory from Wallops Island as part of Project ...

3

GLOM = Gross Lift-Off Mass. This is The overall weight of a spacecraft at lift-off, including the main rocket, boosters, propellant, and payload.

Only top voted, non community-wiki answers of a minimum length are eligible