Questions tagged [terminology]

Questions regarding words and abbreviations used in the fields of spaceflight and space exploration, and their meaning when used in those contexts.

Filter by
Sorted by
Tagged with
11 votes
4 answers
3k views

What is the difference between a space plane and a space shuttle?

What is the difference between a space plane and a space shuttle? It seems that they both look similar and also have a similar purpose. But what is the true difference?
user avatar
  • 119
1 vote
1 answer
78 views

What is "trade space" in the context of libration orbit mission design? (used in trade analysis, launch window analysis and trade study)

The introduction to Launch Window Trade Analysis for the James Webb Space Telescope reads: The James Webb Space Telescope (JWST) is a large-scale space telescope mission designed to study fundamental ...
user avatar
  • 148k
4 votes
1 answer
204 views

Is Ingenuity a "spacecraft?"

NASA calls its helicopter on Mars a spacecraft (status update, 2022 Jan 19). Why? Sure, Ingenuity is off Earth and it's mobile. But it can't toodle off to Phobos. It's in the same category as ...
user avatar
1 vote
2 answers
117 views

Why “super” for supersynchronous orbits? Why not “trans”?

I was just getting used to “cis” and “trans” for orbits inside and outside the Lunar orbit. “Trans” is a Latin word root meaning “across, beyond, or through”(Meriam Webster). “Trans” seems like a ...
user avatar
  • 6,758
0 votes
0 answers
135 views

Is the SS-520-5 both a floor wax and a desert topping? Can it be considered both a sounding rocket and an orbital vehicle?

The answer to If there "won't be" rockets to launch individual cubesats, then why did JAXA build exactly that? (SS-520-xx) begins The SS-520-5 launcher is not intended to be an ...
user avatar
  • 148k
24 votes
1 answer
4k views

What is "anti-geysering" and why would you turn it off 70 seconds before launch?

Today Rocket Lab launched the Electron from Launch Complex 1 Pad A in New Zealand, and there was something about ...the first time a helicopter will be stationed in the recovery zone offshore to ...
user avatar
  • 148k
2 votes
1 answer
288 views

What do "initiate dragon safe haven" and "close all centerline hatches" and "next two crossings" mean?

CNN's video Hear warning to ISS after Russia's dangerous missile test plays an audio clip of a voice communication from NASA Houston ground control to the ISS crew, with the message: ...we will need ...
user avatar
  • 148k
7 votes
5 answers
2k views

Is an orbital insertion burn part of any launch from earth

As I understand it once a spacecraft reaches low earth orbit it may have to do another burn to reach a different orbit. Would that change in orbit be considered an orbital insertion burn? Do any ...
user avatar
  • 6,747
2 votes
1 answer
268 views

How do RAAN steering increase the launch window?

In the recent ULA video by Tory Bruno Tory Talk // Atlas V Lucy: RAAN Steering (linked below) he gave some short hints about RAAN steering. What is RAAN (Right Ascension of Ascending Node) steering? ...
user avatar
  • 1,485
0 votes
0 answers
41 views

Arc length between two satellites [duplicate]

When considering two satellites in the same circular orbit, is it correct to say: The arc length between the satellites is...? Is there a more appropriate term when talking about the curved distance ...
user avatar
  • 11
16 votes
3 answers
4k views

What is an "octet" in the context of NASA's LunaNET Interoperability Standard? ("internet on the Moon")

The PDF Draft LunaNet Interoperability Specification, LN-IS Baseline V001 September 2, 2021 (found at https://esc.gsfc.nasa.gov/projects/TEMPO?tab=lunanet) has found its way to the popular press. 4.2 ...
user avatar
  • 148k
1 vote
1 answer
151 views

What are the differences (if any) between the techniques of range-rate and delay-doppler measurements?

This answer to How does an onboard atomic clock help interplanetary navigation? says: Range-Rate is the two-way measurement of signals broadcast from one location on Earth, received and retransmitted ...
user avatar
  • 148k
4 votes
0 answers
57 views

How old is the use of "L minus" to denote the number of days before launch?

In the SpaceX Inspiration4 Launch broadcast at about T-01:31:05 (91 minutes before launch) the term "L minus five" is used. While "T-minus" is a ...
user avatar
  • 148k
3 votes
1 answer
350 views

what is revisit rate

I want to understand what the revisit rate is. If the payload is required to make the revisit rate of 5 hours. The orbit is LEO (altitude less than 2000 kms). What does this mean? Revisit time - the ...
user avatar
  • 231
4 votes
1 answer
628 views

Which Falcon-9 launches were of a Falcon-9R rocket?

I have heard about Falcon 9 1.1 and Falcon 9 FT, but what is a Falcon 9R? If I understand correctly R = "reusable" which seems to apply to a lot of them. Are the Falcon 9 FT rockets launched ...
user avatar
  • 148k
4 votes
0 answers
41 views

What is the difference between these various spacecraft pyrotechnics?

The following terms have been used in various Space Exploration StackExchange questions and answers. What are the differences (if any) between these various terms? detonating cord detonating fuse (...
user avatar
  • 46.6k
19 votes
4 answers
3k views

Can "engine" and "motor" be used interchangeably in spaceflight? Are there any cases where they can't be?

Typing "rocket motor" into google returns a page full of links mostly about rocket engines. It seems that The Google has AI-synonymized them. Question: Can "engine" and "motor&...
user avatar
  • 148k
7 votes
3 answers
323 views

Term disambiguation: acceleration with/without gravity

I'm ashamed to ask this. But a free-falling accelerometer in a gravitational field will read a nice round zero. And if that accelerometer is given some thrust, it will read the acceleration produced ...
user avatar
1 vote
0 answers
36 views

Nomenclature of Interstellar Objects and Stars [closed]

I tried searching the answer to this on Google for hours and visited the IAU website as well, but it didn't really clarify my doubt. I was reading about Black Widow Pulsar, which is an "eclipsing ...
user avatar
2 votes
1 answer
198 views

What are all the kinds of electric propulsion that don't qualify as ion propulsion in standard spaceflight lingo?

Comments on the meta question We have both electric-propulsion and ion-thruster tags, are they distinct? What would be good usage guidance for electric-propulsion? indicate that the term "...
user avatar
  • 148k
4 votes
1 answer
209 views

What is the correct term for decorations on a spacecraft?

Many spacecraft have been decorated or embellished with logos, slogans, names of people or research groups, or small stowaway items. Does NASA have a term for this practice?
user avatar
  • 46.6k
2 votes
2 answers
137 views

Can we compare high microgravity to low microgravity? Can we say "what it's like to be in a significant amount of microgravity"?

In this answer to What do ISS astronauts do while the ISS gets reboosted? I wrote They strap everything down first, then make videos about what it's like to be in a significant amount of microgravity ...
user avatar
  • 148k
2 votes
0 answers
151 views

First instance of a frangible nut in space? Which space-nut was first successfully "franged"?

Wikipedia's Frangible nut begins: Not to be confused with Explosive bolt. The frangible nut is a component used in many industries, but most commonly by NASA[citation needed], to sever mechanical ...
user avatar
  • 148k
23 votes
4 answers
3k views

What is "mission design"? What do mission designers do (if such a designation exists)?

The question in meta Is the mission-design tag description wrong? Should the trajectory-design tag be somehow nixed? needs some attention, so I thought I'd turn to our "panel of experts" ...
user avatar
  • 148k
1 vote
0 answers
46 views

Are there now established classes of solar-electric powered spacecraft?

The NASA.gov press release NASA Awards Contract to Launch Initial Elements for Lunar Outpost says: NASA has selected Space Exploration Technologies (SpaceX) of Hawthorne, California, to provide ...
user avatar
  • 148k
3 votes
1 answer
200 views

What is a Beam Waveguide dish and why do deep space communications stations use them?

NASA Spaceflight.com's Deep Space Network upgrades and new antennas increase vital communication capabilities says: NASA’s Deep Space Network, commonly referred to as the DSN, has welcomed a new dish,...
user avatar
  • 148k
3 votes
1 answer
82 views

What is range angle?

In several papers on powered explicit guidance, I've come across the term "range angle." I'm familiar with inclination and azimuth angles, but range angle is new to me. A quick search gave ...
user avatar
6 votes
1 answer
481 views

Guidance vs. Navigation vs. Estimation

I'm still confused over what exactly falls under the scope of Navigation, Guidance, and Estimation systems. Say I have a bunch of IMUs and use them to determine my position and orientation and my ...
user avatar
2 votes
1 answer
133 views

What is the purpose of eccentric, parabolic and hyperbolic anomaly?

I am currently reading David Vallado's 'Fundamental of Astrodynamics and Applications' and I have this doubt on the 2nd chapter named 'Kepler's Equation and Kepler's Problems'. Although I understand ...
user avatar
2 votes
2 answers
153 views

How big is an orbit of "X by Y miles"?

While reading the NASA overview of Apollo 11, says: Apollo 11 launched from Cape Kennedy on July 16, 1969, carrying Commander Neil Armstrong, Command Module Pilot Michael Collins and Lunar Module ...
user avatar
  • 121
7 votes
1 answer
588 views

Is there an acronym for secondary engine startup? SESU?

We have acronyms for main engine cutoff (MECO) and secondary engine cutoff (SECO). Do we have an acronym for secondary engine startup---SESU maybe?
user avatar
4 votes
1 answer
175 views

Is there an established name for the regions "above" or "below" the ecliptic plane in our Solar System?

In our Solar system, all of the planets orbit the Sun along a plane known as the ecliptic. If we extend the ecliptic plane into a sphere of the same radius centred around our Sun, is there any ...
user avatar
  • 141
2 votes
2 answers
195 views

Does it count as orbital flight if one reentered the atmosphere due to its drag after about 1 revolution?

Imagine a spacecraft entered an orbit around the Earth whose perigee is low enough into the atmosphere so that it reenters and lands after a revolution, without having to perform a reentry burn. While ...
user avatar
  • 353
3 votes
1 answer
68 views

Apsis suffix for object orbiting an exoplanet

Is there already an agreed upon apsis suffix for an object orbiting an exoplanet? I don't think it's super likely that there is, as I don't think any moons have been discovered (or at least not at a ...
user avatar
  • 31
3 votes
1 answer
148 views

Is the Ceres-1 the first Chinese rocket that was given an official Romanized name?

The news feed in the The Pod Bay links to NASA Spacelfight's 2020-11-08 news item Introducing China’s new commercial rocket, Ceres-1. China’s latest commercial rocket, the Ceres-1 (Gushenxing-1) ...
user avatar
  • 148k
6 votes
4 answers
3k views

Are ECI and ECEF both frames and/or coordinate systems? Is there a difference?

I don't know really know the difference between a frame and a coordinate system. I'd proposed ECEF and ECI tags, do we need them? Frames seems to be the standard in meta but there is concern so any ...
user avatar
  • 148k
2 votes
2 answers
104 views

During an Apollo mission, were separations after dropping the S-II considered as staging events?

I would like to clarify what is a staging event. Maybe there is no definite definition. First I though it was easy as the Nasa definition is clear. Then I though of the stage-and-a-half Atlas SLV-3, ...
user avatar
  • 3,732
4 votes
0 answers
128 views

What do the RD numbers of Russian rocket engines mean?

Most Russian rocket engines have a name on the form of for example RD-107 (РД-107). But apart from different engines having different numbers, how is the number chosen? All RD-2xx engines appears to ...
user avatar
4 votes
0 answers
79 views

What is the official etymology of the term "service" module?

Are there any reputable sources about how the word "service" was chosen for the Apollo service module? (This is a question about how the term was chosen, not about what the term means. ...
user avatar
  • 46.6k
2 votes
1 answer
94 views

IMLEO orbit height

Initial Mass in Low Earth Orbit is a well defined cost metric for space missions [1]. However, this is somewhat subjective since it depends on the orbit height. My guess is that there is a ...
user avatar
  • 387
20 votes
2 answers
4k views

What is the name of the area on Earth which can be observed from a satellite?

The following image shows Earth and the trajectory of the ISS. A green line indicates which part of the earth can be observed from the ISS simultaneously. What is the name of this line or this area?
user avatar
  • 397
5 votes
1 answer
129 views

French terminology for the space industry

I am interested to know if there is some consolidated resource for matching space and satellite terminology between English and French. Examples of words to translate include: Orbital Elements, Space ...
user avatar
  • 423
17 votes
2 answers
3k views

What is a "fee area" exactly and why is it named that way?

On the map of Stennis Space Center, from the early 1960s when it was still named "Mississippi Test Facility"/"Mississippi Test Operations", part of the area is labeled "Fee ...
user avatar
  • 12.4k
4 votes
0 answers
120 views

Is there a canonical definition of the term "block" as used in "Falcon 9 block 5"?

I gather this has a meaning related to "version". However, I have seen this term used for military and commercial aircraft and other products (generally connected to government or aerospace)...
user avatar
  • 549
2 votes
1 answer
83 views

Connection between Vanguard spacecraft, Vanguard rocket, and Project Vanguard?

I think I created the vanguard tag for Why would low pump inlet pressure result in such a spectacular explosion? (Vanguard TV3) and now I'm not sure of the connection between the Vanguard spacecraft, ...
user avatar
  • 148k
17 votes
4 answers
7k views

Was "Apollo" an acronym for "America’s Program for Orbiting Lunar and Landing Operations"?

I came across this paper which, on page 9, says the following: The guidance or “shooting” algorithm is based on the Linear Peturbation Theory (Battin) developed for the America’s Program for Orbiting ...
user avatar
4 votes
1 answer
355 views

Difference between collecting satellite data and tracking its position

When people talk about "tracking" a satellite, do they generally mean receiving data / communication from it, or do they mean determining its position. When an organisation sends a satellite ...
user avatar
3 votes
3 answers
462 views

Why does NASA now call its rovers "robotic scientists?"

NASA's 2020 July 13 press release about the Mars 2020 mission calls its rover Perseverance a "robotic scientist." Is this press release, or at least this mission, the first usage of this ...
user avatar
5 votes
1 answer
203 views

What is the equivalent of Curiosity's "MSL" in the context of Perseverance? What's the official name of the mission? Are the distinctions similar?

Answers to Where does MSL end and Curiosity begin? explain the difference. There was much fanfare for the naming contest for the Perseverance rover, but I don't know what the mission is called. ...
user avatar
  • 148k
0 votes
1 answer
160 views

What is the difference between "body drag", "frictional drag" and "pressure drag" for astronaut or aerobot atmospheric locomotion in microgravity?

Complaints below my answer to Would a higher air pressure on the ISS or elsewhere make it easier to “swim” in microgravity? about my spherical-cow estimate of how fast an astronaut can accelerate by &...
user avatar
  • 148k