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23 votes
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How does Ingenuity measure its altitude when flying?

From multiple sites, but for the following quote, ScienceMag.org references a laser altimeter: (emphasis mine) The data began to trickle in at 6:40 a.m. ET, relayed by the Perseverance rover to ...
fred_dot_u's user avatar
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22 votes
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Radar altimeter in a space shuttle

The radar altimeter was intended only for landing, to provide a direct, precise measurement of the altitude of the vehicle above the runway. It locked on around 5000 feet altitude but was primarily ...
Organic Marble's user avatar
19 votes
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Why did the data "go wild" when Ulysses entered Hyakutake's tail?

The NASA public affairs department may have exaggerated a bit with the "went wild" quote. The encounter was not even noticed until two years after it happened! Evidence of the encounter was ...
Organic Marble's user avatar
18 votes
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What is this instrument on the ISS?

This is the Floating Potential Measurement Unit (FPMU). Specifically, the ball is the Wide Langmuir Probe. picture from here The FPMU was installed by ISS crewmembers, during an Extra Vehicular ...
Organic Marble's user avatar
16 votes
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What was the globe instrument in Vostok 1?

From russian wikipedia: Another instrument helped to the pilot to decide when to start manual operation to return to Earth - it was a small globe with a clock mechanism, which shows the (calculated, ...
Pavel Bernshtam's user avatar
14 votes
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Why is there no microscope on the Mars 2020 rover?

The MAHLI camera of Curiosity may focus from infinity down to only 18.3 mm working distance. At minimal distance the resolution is 13.9 ┬Ám per pixel. It may image objects of some tens of meters in ...
Uwe's user avatar
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12 votes
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How are physical attitude indicators actuated?

First, ignore what Wikipedia claims about attitude indicators. It shows a diagram of the inside of an airplane attitude indicator. I am not inlining this image because -- although some airplanes may ...
DrSheldon's user avatar
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9 votes
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How do ultra-stable oscillators for spacecraft work?

The material depended on the mission but was usually quartz, and the stability is insane. The development of Ultra-Stable Oscillators (USOs) is ongoing (see here and here). NASA/the ESA have used ...
Michael Stachowsky's user avatar
8 votes

Is radar & passive radar significantly different in space?

Many questions! How effective are different types of radar in space over large distances. Is radar significantly different outside of the atmosphere of Earth? The only difference between a ...
SE - stop firing the good guys's user avatar
8 votes
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Will the James Webb telescope have any visible spectrum cameras?

Two things here: The main physical processes JWST is concerned about take place in the Infrared, and JWST is not a Earth observatory It will have the NIRCam that can reach slightly into the visible ...
AtmosphericPrisonEscape's user avatar
8 votes

What could be the cause of the extraordinary high Fe counts from the PIXL instrument onboard the Perseverance rover?

To properly answer this question one would need to know what the X-ray counts signify in terms of quantities such as percent or parts per million of an element. For that, comparison with calibration ...
Fred's user avatar
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7 votes
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Rainbow Space Probe?

You don't need a laser to do this. The technique you describe is known as spectroscopy, and it can use any light source, including light from the planet's star. This is a common technique for studying ...
Hobbes's user avatar
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7 votes
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Deep space craft antenna aiming

Spacecraft use a star tracker to find their orientation (attitude). Here's a random example: Dimensions and Mass: Camera 120 by 120 by 33 mm, 1.0 kg (note: optics protrude 58 mm inside baffle) ...
Hobbes's user avatar
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7 votes
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How can rockets measure their own speed relative to the ground?

You can put measuring devices anywhere you like, but the best answers are always computed by measuring many different ways simultaneously. If you have enough independent methods, you can detect and ...
Ryan C's user avatar
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7 votes
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What do/will "quantum gyroscopes using nitro­gen-vacancy centers in diamond" for space applications actually look like, and how do they work?

(Disclaimer: I'm just a software engineer that happens to work in a quantum research center. This answer is based on my understanding of NV centers, which is limited to what I need to know for my ...
Ludo's user avatar
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6 votes
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How to make a camera survive in (near) space?

I've used a stock GoPro on a high altitude balloon that made it to 40 km, it recorded the whole way up and down (on external power). So depending on your mass and financial budget you could use this ...
PeteBlackerThe3rd's user avatar
6 votes
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Orion cockpit instrumentation

Ok - after a bit more research, I figured out what the readouts in question are: the attitude "ball", along with readouts 2, 6 and 7, are part of a spacecraft-specific instrument called Flight ...
Mitch99's user avatar
  • 513
6 votes

Earth-based microwave radiometer for the Moon

China's Chang'e 1 (CE-1) and Chang'e 2 (CE-2) lunar orbiters were both equipped with multi-channel microwave radiometers, measuring thermal emissions from the lunar surface and near-surface down to 30 ...
TildalWave's user avatar
6 votes
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Which instrument did astronauts use to measure their position?

You're remembering the Apollo Lunar Module Alignment Optical Telescope which had that spiral reticle. The alignment optical telescope is used for in-flight and lunar surface sightings. For in-flight ...
Organic Marble's user avatar
5 votes
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What technical details exist about the Soyuz TMA spacecraft and its Simvol Displays & Cockpit Controls?

There is a good manual "Soyuz Crew Operations Manual (SoyCOM) (ROP-19) (Final) , Yu. A. Gagarin Cosmonaut's Training Center, NAS15-10110, 0004AE7a (ROP-19), April 1998" which is in English, ...
Organic Marble's user avatar
5 votes

How does the Mars Ingenuity helicopter "know" where it is?

It doesn't "know" where it is. It instead estimates where it is, with the quality of the estimation degrading with time. It is using a 21st century equivalent of the "dead reckoning&...
David Hammen's user avatar
5 votes
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Will the Orion glass cockpit with CCD be tested with prospective astronauts on the ground during the upcoming Artemis 1 test flight ? If not, why?

None of what you suggest will be done because the glass cockpit won't be installed for this mission. Instead some kind of funky "tech demo" called Callisto will be flown - which sounds like ...
Organic Marble's user avatar
4 votes

Is radar & passive radar significantly different in space?

The basic problem with using radar in space is range. When you send out a radar pulse, the amount of power that returns to the transmitter is proportional to 1/range4. So double the distance means ...
Hobbes's user avatar
  • 128k
4 votes
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Calculation of V1 (orbital speed) during ascent

No, your assumptions are not correct. That's Vi, inertial velocity. NASA doesn't use the V1/"first orbital velocity" terminology, or at least didn't in Shuttle. If you zoom in on the image you can ...
Organic Marble's user avatar
4 votes

4 megapixels seems rather low, why weren't James Webb's sensors updated to higher resolution/sensitivity?

Cheap customer digital cameras are sold by the marketing using high pixel counts. More pixel than possible by the resolution of the lens, the signal noise ratio and the sensitivity. The JWST is used ...
Uwe's user avatar
  • 49k
4 votes

After one year exploring Jezero's crater floor, has there been any investigation into the presence of trace elements with PIXL?

Thanks to @asdfex for his link to PIXL data in the PDS Geosciences Node. There's a link to the Mars 2020 Analyst's Notebook tool with the PIXL instrument's data archive. In the archive I found two MSA ...
Cornelis's user avatar
  • 7,535
4 votes

What could be the cause of the extraordinary high Fe counts from the PIXL instrument onboard the Perseverance rover?

A combination of things: Iron is highly abundant in solar system matter. Except perhaps for neon, all more abundant elements are outside PIXL's sensitive band. X-ray fluorescence favors elements of ...
John Doty's user avatar
  • 3,364
3 votes

How (the heck) were Parker's sapphire elbows made?

When wires are drawn, drawing dies are used. They are typically made of a very hard material like tool steel, tungsten carbide, or diamond. To make a diamond drawing die, a small hole has to be ...
Uwe's user avatar
  • 49k
3 votes

Why does the SEIS require a bellows type wind cover?

The bellows are flexible, which means the cover will adjust itself to give a good seal on the uneven surface. the bellows can be easily folded up to take up minimum volume during flight, without ...
Hobbes's user avatar
  • 128k
3 votes
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How did Mariner 2's ridged radiometer dish focus two microwave bands but diffuse IR?

Sorry, I have no documentation. I can only offer you a physics explanation. The larger wavelength of the microwaves is too big to "see" the ridges. The wavefront is reflected by the general curve ...
BowlOfRed's user avatar
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