Questions tagged [very-low-earth-orbit]

The tag has no usage guidance, but it has a tag wiki.

Filter by
Sorted by
Tagged with
2 votes
1 answer
98 views

For using the acceleration due to drag formula, which coordinate frame should the satellite's position and velocity vectors be in?

I am working on simulating the space environment for a VLEO satellite. I am working on the atmosphere model where I am using density values from NRLMSISE00 model and plugging them into the drag ...
Anusha's user avatar
  • 85
4 votes
2 answers
252 views

Could you skim along the Karman line using a parafoil?

Imagine a person just wearing a spacesuit equipped with a parafoil returning from low orbit. Could they maintain altitude starting at 7.8 km/s above or along the Karman line slowly losing speed—maybe ...
Prototypist's user avatar
14 votes
1 answer
3k views

How dangerous is tossing equipment off the ISS?

On 2023 June 22, during an ISS spacewalk, Sergey Prokopyev and Dmitry Petelin "tossed overboard" three no longer needed devices, "off the back of the space station in a direction that ...
Camille Goudeseune's user avatar
3 votes
0 answers
133 views

How can I derive Starlink specs looking at the incident of February 2022?

I am trying to calculate and speculate the specifications of Starlink satellites (mainly related to propulsion) based on the accident on the 3rd of February 2022. There are multiple sources that ...
Playstation_waifu's user avatar
5 votes
1 answer
278 views

What factors would contribute to a spacecraft's ability to maintain a very low orbit (VLEO) or at least orbits with very low perigees?

I asked What does account for a high coffin corner of a plane? in Aviation SE. Now I wonder what factors would contribute to a spacecraft being able to maintain low circular orbits (e.g. within 200 km ...
user avatar
5 votes
1 answer
142 views

What "unique control system" modulated GOCE's thrust to compensate for variable atmospheric drag? How did it know how to modulate it?

This answer to How much time did the longest maneuver last? says: The GOCE satellite mission (Gravity Field and Steady-State Ocean Circulation Explorer) lasted 55 months (4.6 years) of largely ...
uhoh's user avatar
  • 149k
3 votes
1 answer
726 views

What technologies enable or at least help satellite operation in Very Low Earth Orbit (VLEO)?

This answer to How low is VLEO? (FCC's newest approval for SpaceX) suggests VLEO begins (or ends I guess) at 350 km. The two bad things I know about in VLEO are an enhanced rate of altitude loss due ...
uhoh's user avatar
  • 149k
3 votes
0 answers
227 views

Future trends in Earth Observation and Communications from VLEO; are there any?

Question: In order to better understand the wider market need and uses for Very Low Earth Orbit (VLEO)-enabling technologies, I'd like to ask about future trends in Earth observation imagery and ...
nhcrisp's user avatar
  • 76
1 vote
1 answer
264 views

What is Direct Simulation Monte Carlo and why is it a good method for simulating spacecraft drag in VLEO?

Reducing spacecraft drag in Very Low Earth Orbit through shape optimisation J. A. Walsh and L. Berthoud (2017) show simulations calculating drag coefficients for different "nose cone" shapes ...
uhoh's user avatar
  • 149k
2 votes
2 answers
201 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 ...
Greenhorn's user avatar
  • 363
6 votes
2 answers
2k views

Exactly how "Ferrari-like" was GOCE? Was its drag coefficient as low as the car's?

This comment mentions: This relation between drag and mass is taken to a relative (for satellites) extreme in GOCE which I think needed to be close to Earth to accurately sense the changes in gravity,...
uhoh's user avatar
  • 149k
7 votes
1 answer
355 views

How to calculate the lowest possible altitude a satellite can orbit at due to aerodynamic heating if provided with a sufficient propulsion system?

If a satellite is equipped with a propulsion system which is enough for compensating the local drag and maintaining the orbit, then aerodynamic heating would be the limiting factor for attaining the ...
Curious's user avatar
  • 71
4 votes
1 answer
464 views

How exactly does atomic oxygen cause problems for spacecraft in VLEO?

In very low Earth orbit there are (at least) two problems; aerodynamic drag, and atomic oxygen (O rather than O2). Drag can be compensated with a low thrust from an ion engine. Question: But what ...
uhoh's user avatar
  • 149k
14 votes
2 answers
635 views

How fast do optical surfaces get dirty or damaged in space?

These answers: (1, 2) to Do things get dirty in space? mention the Hubble Space Telescope but if I understand correctly refer to the outside of the telescope rather than its optical surfaces. Answers ...
uhoh's user avatar
  • 149k
4 votes
1 answer
355 views

What's the lowest altitude that an ion engine has been used for a significant orbital maneuver?

I'm thinking about trying to calculate something for Where do ion propulsion's ions go? Do they remain in the solar system or shoot out into interstellar space? Excluding low altitude tests of ion ...
uhoh's user avatar
  • 149k
8 votes
1 answer
4k views

How low is VLEO? (FCC's newest approval for SpaceX)

Engaget's SpaceX gets FCC approval to deploy thousands more internet satellites says SpaceX's plan to build a global, high-speed wireless internet network using satellites has taken another step ...
uhoh's user avatar
  • 149k
17 votes
1 answer
1k views

Have spacecraft ever dipped below the Karman line and then safely continued spaceflight?

The item in Science Alert's A Harvard Astrophysicist Says Outer Space Is Actually Closer Than We Think (see also Science; Outer space may have just gotten a bit closer) talks about the recent Acta ...
uhoh's user avatar
  • 149k