Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [terminology]

Questions regarding special words and abbreviations used in space exploration, and their meaning in that context.

0
votes
1answer
56 views

What do you call the Apollo LEM plus CM (Command Module) when they are connected?

In the question How far away can spacecraft be seen with an optical telescope? I used ...Apollo 14 CM & LEM and the Saturn IV B..." for lack of better words. Unlike some people I (don't) ...
5
votes
2answers
167 views

Is it appropriate to use the term “geology” for Martian studies?

Jargons like geology, geophysics, geothermal has its origin in and has strong connections with Earth. Other jargons like the closet point and farthest point of an orbit to a heavenly body get ...
4
votes
1answer
60 views

What's the difference between zenith and radial?

When it comes to orbital mechanics, are zenith and radial the same? Or to put it another way, are nadir and anti-radial the same?
9
votes
1answer
227 views

Why did the S-IV-B refer to “jettison”ing its ullage?

This is based on a recent question about S-IV-B ullage motor shutoff timing, specifically something found in the Technical Information Summary AS-501, page 15: Ullage Jettison ~ 532. But why "...
3
votes
2answers
182 views

Name for point in a satellite's orbit around a planet when the satellite is furthest from the sun

When a satellite is orbiting a planet (which itself is orbiting the sun) there are periodic points when the satellite is closest to and farthest from the sun, once where it is interposed between the ...
3
votes
3answers
131 views

What's the planetary exploration word for “impact parameter” (distance of closest approach if gravity were “turned off”)?

In particle scattering there's a term called "impact parameter", which is the minimum distance a particle would pass a second particle at rest, if the attractive or repulsive force were ignored or "...
3
votes
0answers
48 views

what is the relevance of ion cyclotron and ion collision frequency ratio

On earth, the ion cyclotron and ion collision frequency ratio is 1 at roughly 118 km, and this is used as one of the definitions of the limit to space. What are ion cyclotron frequency and ion ...
3
votes
2answers
125 views

Is Dawn's upcoming low periapsis orbit for XMO7 “resonant”?

The Spaceflight Insider article Dawn will enter lowest ever orbit around Ceres says: In his Dawn Journal blog, mission director and chief engineer Marc Rayman discussed the challenges of bringing ...
7
votes
1answer
524 views

What is BECO? (Gemini) Same as MECO?

This answer links to this answer which shows the acceleration g-force envelopes experienced by early astronauts, reaching as high as almost 7.5g! Both show BECO, which is what I might call MECO or ...
15
votes
2answers
2k views

Are any “strap-on” boosters held in place by actual straps?

Have there been any strap-on boosters that are attached to the main body of a rocket with actual straps (like bands of metal or something similar), as the name implies? If not, what's the origin of ...
3
votes
2answers
100 views

What is a pickup ion?

I've been reading several publications about Titan's atmosphere and chemistry, and the term "pickup ion" kept appearing here and there (see this publication for example). I looked it up and found the ...
3
votes
1answer
101 views

What is the correct term for the exterior of a rocket or space launch system?

Would you call it the casing, cladding, exterior structure, hull, shell...?
4
votes
1answer
146 views

Why are there so many apisidal names

If we look at orbital mechanics, we can find great tables like these, demonstrating the name of the periapsis and apoapsis around various celestial bodies: Objects Periapsis Apoapsis ...
2
votes
1answer
95 views

How does one refer to the “port port” on the ISS?

Saying "port port" is clumsy. Should I refer to it as the port berthing mechanism? Is there specific terminology for what I'm referring to or are there a few options? Also, I'm specifically ...
7
votes
1answer
328 views

Injection versus insertion

I've noticed that maneuvers to leave a body's sphere of influence on the way to another body are invariably referred to as injection maneuvers, for instance, translunar injection, while maneuvers to ...
4
votes
1answer
87 views

Terminology for CubeSat telecommunications

I'm looking at a brochure for the Iris V2 Deep Space Transponder by JPL. At the end of the brochure there is some data on suggested antennas. For each antenna the bps at approximately 1 AU is shown ...
5
votes
1answer
298 views

Why do delta-v and delta-v both use the same term?

As noted in this Wikipedia article, delta-v, used in spacecraft flight dynamics, is a measure of the impulse that is needed to perform a maneuver. However, in general physics (a much longer standing ...
30
votes
3answers
7k views

Why is Jupiter called a “Gas Giant”?

Jupiter's enormous gravity would turn its atmosphere first into a liquid from a certain depth, and then into a solid further towards its centre. So Jupiter has a solid core, above which is a liquid ...
-4
votes
2answers
686 views

What precisely is downrange distance - how is it defined mathematically?

Wikipedia: Downrange is the horizontal distance traveled by a spacecraft, or the spacecraft's horizontal distance from the launch site. Spacecraft don't travel horizontally. I don't even know how ...
5
votes
0answers
210 views

Are ion thruster trajectories classified as brachistochrones?

Usually, when performing trajectory optimizations for chemical rockets, the limiting factor is the $\Delta v$ budget. That means velocity change is the optimization factor, with things like transfer ...
3
votes
2answers
714 views

What is the “specific impulse”? [duplicate]

One of the most important values when talking about rocket engines is the so-called specific impulse. I have read the Wikipedia article but still have trouble understanding what it really is and what ...
1
vote
1answer
172 views

Has every passenger been an astronaut? Will they be in the future?

There have been a number of paying passengers on orbital missions in the past, and it is likely there will be many, many more in the future, and not only on orbital missions. I'm thinking that ...
9
votes
3answers
361 views

Why don't I find the concept of cosmic velocities in western space-related materials?

One of my earliest contacts with the concept of orbital mechanics was learning about the four cosmic velocities. They were in my primary school handbook. They were referenced in amateur astronomer's ...
6
votes
1answer
261 views

What does “Q frame” means in terms of satellite coordinates?

I'm looking at some old satellite documentation which mentions the use of a "Q frame" coordinate system to keep track of the satellite attitude. What does this "Q frame" generally mean in the field of ...
0
votes
2answers
77 views

What publishing authority (and year of publishing) was the first to use the term 'occultation'?

Researching the word occultation, it is evident that it is a newly incorporated term in respect to space and eclipses. It just recently began to populate space periodicals and online articles, but ...
3
votes
1answer
301 views

Filling of LOX tanks - 'cryogenic geyser cycling'

This article about the 2016 Sept 1 Falcon 9 explosion mention 'cryogenic geyser cycling' in reference to the filling of the LOX tanks as though it were a particular method of filling tanks. In ...
5
votes
1answer
77 views

Is a coronal mass ejection (CME) synonymous with a solar particle event (SPE)?

Having read the Wiki page, this Space SE answer, and this link, I'm curious: Is a "coronal mass ejection" the same thing as (synonymous with) a "solar particle event"? If not, then what is/are the ...
7
votes
2answers
893 views

What does the abbreviation “MS” for the current Soyuz version name mean?

A quick search the meaning of the abbreviations for the previous versions of the Soyuz spacecraft easily tells me their meaning: Soyuz T. 'T' is for транспортный, ...
3
votes
3answers
325 views

Are there terms for Earth orbits with rational number multiples of 1 sidereal day?

An Earth orbit with a period of 1 sidereal day (and zero inclination) is a geosynchronous orbit, orbits slightly above and below that are supersynchronous and subsynchronous orbits, and a Molniya ...
1
vote
2answers
211 views

Why use the term “gravitational slingshot”?

I was reading about gravity assist. This maneuver is sometimes called a gravitational slingshot. But to me it seems more like a sling (like the one the Biblical David used against Goliath) The ...
4
votes
1answer
125 views

Is it still called a Van Allen radiation belt if it's around another planet?

Earth has (at least) 2 radiation belts called the Van Allen belts. Jupiter has similar radiation belt(s). Are they still called Van Allen belts around other planets? Edit: The reason I ask is every ...
16
votes
1answer
2k views

What does “in the bucket” mean?

I've heard this expression a couple of times before. It seems related to the engines, but I can't find any information on it, except in the context of testing them. Here's two videos where it occurs: ...
4
votes
2answers
1k views

Common usage of “dry-mass”

Usually, I would consider the dry-mass the mass of a vehicle without any consumables, passengers, or cargo. This NASA article however describes the Apollo 11 Eagle as: The lunar module was a two-...
5
votes
2answers
623 views

What do remotely-controlled bolts look like?

I've been reading about various components that are attached to the ISS and occasionally see references to "remotely controlled bolts". That makes sense, but I've barely been able to find more than a ...
4
votes
1answer
366 views

What does “supersonic large amplitude ID maneuver PTI” mean, and what does a tumble motor do?

In this question I linked to a YouTube video of the Ares X-1 launch. You can start listening at 02:00 for the point where these are mentioned: "Supersonic large ...
10
votes
1answer
572 views

Is this really the logo of the North Korean space program?

Reading about the North Korean space program, and its recent launch of the Kwangmyŏngsŏng-4 satellite, I stumbled upon this logo: It is referenced in quite a few news stories, like here or here, or ...
11
votes
1answer
2k views

Nuances of the terms (mean / osculating / Keplerian / orbital) elements

I've been assuming that osculating, Keplerian, and orbital elements are all synonyms, with mean orbital elements just being these averaged over some time. However occasional comments make me suspect ...
2
votes
0answers
220 views

Why does NASA use the position title “Pilot”' for crew members who are not in charge of piloting the spacecraft?

Why does NASA use the position title "Pilot"' for crew members who are not in charge of piloting the spacecraft? For example famously Buzz Aldrin's position was Lunar Module Pilot but his spacecraft ...
6
votes
3answers
176 views

Has any other term been used for a solar day on a solar system body besides “sol” on Mars?

My interest was piqued by this question and answer. For several reasons NASA needed to refer frequently and extensively to a Martian solar day, and "sol" became the nom du jour. There have been ...
4
votes
1answer
1k views

Strongbacks vs Launch towers: Difference and definition?

What's the difference between a launch tower and a strongback?
23
votes
3answers
7k views

What is the difference between docking and berthing on the ISS?

People often talk about docking and berthing. They both seem to be connecting a spacecraft to the ISS, yet seem to be very different. Why?
1
vote
4answers
942 views

Where can the term “Sol” used?

Alright, I know that "Sol" is used on Mars to count days. But is the sun called: "Sol"? And can you use that term on Earth as well? The reason for the question is that the term "sol" is used in two ...
4
votes
1answer
478 views

How were the Space Shuttle missions named?

For example, why was the 19th Shuttle mission named STS-51F instead of something more obvious like STS-19? Side note: One reason I'm asking is because in the DVD commentary of Apollo 13, Tom Hanks or ...
6
votes
2answers
224 views

Cosmonauts and Astronauts

American, Japanese and ESA space travellers are astronauts, Russian or Soviet space travellers are cosmonauts. But are there exceptions from this? Americans visiting the ISS the last years have used ...
10
votes
2answers
986 views

Is there a term to refer to a planet and its accompanying moons as a whole collection?

I am trying to find out of there is a term that can be used when referring to both a planet and any accompanying moons (if present) as a whole collection. For example if you were to refer to Mars and ...
3
votes
1answer
208 views

What is the word for the period between two Mars conjunctions?

Earth and Mars have conjunctions every 15/7 of a year, or every 26 month or every 2 years. And it varies substantially from conjunction to conjunction because of orbital precessions and eccentricities....
8
votes
1answer
381 views

What is the word for using atmosphere to dissipate kinetic energy during reentry?

Often people will use "aerobraking" in the context of landing a space ship or probe on a planet with atmosphere. This appears to be a casual and technically incorrect usage, for example from https://...
2
votes
2answers
167 views

Is “interlunar” applicable to the moons of other planets?

We have intergalactic to describe the area between galaxies. And interstellar space is between star systems. And interplanetary is between planets. Is the term "interlunar" applicable to the space ...
10
votes
2answers
625 views

Origin of term “Block I”, “Block II”, etc

In NASA spacecraft development, subsequent versions of a design are referred to as "Block 1", "Block 2", etc. What is the origin of this naming convention? Why not just call them "Version 1", "...
5
votes
1answer
1k views

What is the procedure to stop the descent engine on the Apollo 11 LEM?

What is the correct procedure to stop the descent engine on the Apollo 11 LEM? When the LEM has a contact light on Apollo 11, there is some terminology spoken that I'm assuming is important (and ...