23
votes
Accepted
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 ...
- 1,975
22
votes
Accepted
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 ...
- 189k
19
votes
Accepted
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 ...
- 189k
18
votes
Accepted
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
...
- 189k
16
votes
Accepted
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, ...
- 3,024
14
votes
Accepted
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 µm per pixel. It may image objects of some tens of meters in ...
- 49.5k
12
votes
Accepted
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 ...
- 48.4k
9
votes
Accepted
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 ...
- 6,300
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 ...
- 13.3k
7
votes
Accepted
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 ...
- 8,779
7
votes
Accepted
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 ...
- 131k
7
votes
Accepted
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 ...
- 14.8k
6
votes
Accepted
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 ...
6
votes
Accepted
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 ...
- 513
6
votes
Accepted
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 ...
- 189k
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&...
- 77.4k
5
votes
Accepted
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, ...
- 189k
5
votes
Accepted
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 ...
- 189k
4
votes
Accepted
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 ...
- 189k
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 ...
- 49.5k
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 ...
- 7,561
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 ...
- 4,801
4
votes
Accepted
Did the ISS CREAM experiment actually get relocated?
I finally found the answer in an EVA image iss070e015526 from November 2023 posted at images.nasa.gov.
This is cropped from there and shows CREAM mounted on the ELM-PS:
A similar-but-not-exactly-the-...
- 189k
4
votes
Accepted
What is this device on the ISS?
That's the STP-H8 payload attached to the Japanese Experiment Module External Facility. The spinning bit is the Compact Ocean Wind Vector Radiometer.
Reference: https://space.skyrocket.de/doc_sdat/stp-...
- 189k
3
votes
Accepted
Does Perseverance's SuperCam include a Martian meteorite? If so, why?
The meteorite is part of the SuperCam Calibration Target (SCCT) on Perseverance.
From the paper "SuperCam Calibration Targets: Design and Development":
As a nod to the notion of return ...
- 2,163
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 ...
- 131k
3
votes
Accepted
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 ...
- 7,129
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 ...
- 49.5k
3
votes
Are direct conversion optical receivers being looked at for future deep-space communication?
Partial, indirect answer to get the ball rollling.
This answer to What is stopping Event Horizon Telescope the size of the Earth’s orbit? in Astronomy SE elaborates on the paper cited in the question ...
- 151k
2
votes
Accepted
Why does LRO's laser altimeter telescopes use lenses instead of mirrors?
tl;dr: The 125 mm proven receiving telescope design used on the receiving telescope of the MLA laser ranger used on MESSENGER was adapted and enlarged to 150 mm for the LOLA of LRO. I am guessing that ...
- 151k
Only top scored, non community-wiki answers of a minimum length are eligible