Questions tagged [spacex]

Space Exploration Technologies Corporation, or SpaceX, is a private space exploration company. It was the world's first privately held company to successfully launch a cargo mission into space.

Filter by
Sorted by
Tagged with
6
votes
0answers
77 views

Has SpaceX made any commentary on StarLink posing a threat to astronomy?

As an amateur astronomer I've always wondered how detrimental 1,000 StarLink satellites could be to viewing the stars from an Earth-bound location. Apparently, according to this article, it is a lot ...
3
votes
2answers
172 views

How quickly can the Starlink spacecraft respond to an impending collision?

update: The word "refused" might be inaccurate: CNET: ESA's near collision with SpaceX Starlink satellite blamed on a 'bug' Ars Technica: SpaceX satellite was on “collision course” until ESA ...
6
votes
1answer
210 views

Why did August 28th, 2019 Starhopper's test roll so much to the left?

The last Starhopper test flight included a left roll of roughly 160°. It seems to have tried stopping the roll shortly after apogee using RCS thrusters, and once again shortly before touchdown. ...
17
votes
5answers
5k views

Why doesn't Starship have four landing legs?

A counterpart to the question Why doesn't the Falcon-9 first stage use three legs to land? This excellent answer states that the first stage of the Falcon-9 uses four legs because four legs are ...
35
votes
4answers
6k views

Why did Starhopper's exhaust plume become brighter just before landing?

In 2019 Aug 27's test flight, during the final 8 seconds before landing (T+00:45), Starhopper's plume was suddenly much brighter. Why? The Raptor's thrust can't ...
1
vote
1answer
105 views

When will the first Falcon-9 send something to the Moon? Will it be iSpace's HAKUTO-R?

The Teslarati article SpaceX customer iSpace updates Falcon 9-launched Moon lander, rover plans says Japanese commercial space company iSpace has provided an updated schedule for its first private ...
52
votes
5answers
12k views

Why doesn't the Falcon-9 first stage use three legs to land?

The immediate thought that would probably come into your mind would be "Because 4 legs is more stable than 3." However that is not always true. 3 legs offer the same or in some cases more stability as ...
4
votes
2answers
159 views

What is the closest distance SpaceX's Tesla Roadster (Starman) will ever be to Mars?

Elon Musk's own personal Tesla Roadster launched on the Falcon Heavy in November 2018 and unfortunately overshot the orbit of Mars. This short animation shows the trajectory of SpaceX's Roadster. It ...
2
votes
1answer
98 views

SpaceX rideshare missions: how many smallsats fit?

SpaceX has just announced their new smallsat rideshare program. Is it known how many satellites can be launched at once? Any estimates?
4
votes
1answer
400 views

Humanoid silhouette on SpaceX's Starhopper; what does it represent?

update: The silhouette now has a page in Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Hughmann_for_scale.svg The images below are from a NASA Spaceflight forum post and can be seen in @...
2
votes
1answer
161 views

What causes this diamond to appear from a single Raptor engine firing?

As seen on this video posted by Elon Musk https://twitter.com/elonmusk/status/1154629726914220032?s=19
1
vote
1answer
98 views

Could Spacex build a starhopper (starship prototype) at Vandenburg, CA launch site?

I know Spacex is building a starhopper (starship prototype) in Texas and Florida. Could they also build a starhopper prototype at the Vandenburg, CA launch complex? I know Vandenburg is better for ...
2
votes
0answers
217 views

How will SpaceX's Starship accommodate its 100 passengers from the effects of micro-gravity?

According to this Wikipedia article, Starship will take on average 115 days (3.8 months) to get to Mars and 150 days maximum (4.9 months). with an average trip time to Mars of approximately 115 ...
13
votes
8answers
4k views

How much did all the space agencies spent on rockets launching and space exploration? What are the benefits for me and you? [closed]

I thought about how much does one rocket cost to build and launch and it came up with roughly $500 million including everything. That made me pause and wonder for myself what it is that's out there ...
6
votes
1answer
103 views

Orbital insertion accuracy for SpaceX payloads

What is the orbital insertion accuracy of SpaceX for positioning its payload (for example satellites)? How close do they get to the requested or target orbital parameters? I tried to research this on ...
5
votes
0answers
144 views

What's this purple donut in the video of the Falcon 9 fairing's atmospheric reentry?

This SpaceX tweet (found in CNET's SpaceX camera captures incredible view of rocket part returning to Earth) shows a video taken by a camera in one half of the fairing on the recent STP-2 mission and ...
8
votes
1answer
1k views

Is SpaceX propulsively deorbiting a Starlink satellite already?

The plot below shows that most of the SpaceX Starlink satellites have moved from circa 450 km to circa 550 kilometers already, using their argon-based ion engines. A few, along with four unidentified ...
6
votes
1answer
176 views

Why doesn't the SpaceX web-cast show the telemetry, (altitude and speed) for the first stage during recoveries?

On the YouTube videos of SpaceX launch operations, they show altitude and velocity for the 2nd stage throughout the flight, but after stage separation I have never seen telemetry displayed for the ...
24
votes
5answers
9k views

Why doesn't SpaceX land boosters in Africa?

Apart from the obvious answer that it'd take too long to get the booster back across the Atlantic, why doesn't SpaceX leave the main or centre booster in space a little bit longer and guide it to land ...
7
votes
1answer
206 views

Did the Falcon Heavy center core miss the drone ship or abort?

On the recent Space Test Program-2 Falcon Heavy launch, the center core crashed into the ocean. Unlike the test flight, however, it was not due to running out of TEA-TEB lighter fluid. From the video ...
17
votes
5answers
5k views

Reusable spacecraft: why still have fairings detach, instead of open/close?

Why do reusable rockets (e.g. SpaceX Falcon 9) still utilize detachable fairings? SpaceX keeps trying to find a way to recover the $6M fairings for obvious cost saving reasons, why not have them ...
2
votes
2answers
123 views

Are there payload lights turning on and off in orbit on SpaceX STP-2?

In the video of the SpaceX STP-2 Mission during satellite deployment after around T+01:21:35 there are some areas that abruptly blink brightly. It's too fast and ...
8
votes
2answers
458 views

Does flying two boosters close together affect efficiency?

When returning the side boosters of the latest Falcon Heavy launch to their landing site, their trajectories keep them right next to each other, and I noticed that a "wall" of vapor is visible midway ...
4
votes
1answer
142 views

Would SpaceX's Starlink constellation contribute inordinately to space debris?

I mean they already launched a large constellation of 60 satellites and have plans to launch many more; won't all this contribute inordinately to existing space junk, which is actually becoming a real ...
7
votes
1answer
121 views

How much of the recovery system does Spacex remove from a Falcon 9 when using it in an expended manner?

Falcon 9s have a limit to how many times they can be reused, and, for the last flight of a booster they don't make it land (in one piece), and instead use all the fuel to help the payload. That way ...
6
votes
2answers
285 views

Why does the F9 second stage roll back and forth during deployment of each RADARSAT satellite?

GIF Watching the SpaceX video RADARSAT Constellation Mission after T+ 52:00 we can see at least the first two satellites deploy. In each case, the second stage ...
5
votes
0answers
190 views

What are these four “debris” objects along with the Starlink satellites?

Celestrak has an updated system of categories for retrieving lists of current TLEs, and there's already one for Starlink, yay! Currently https://www.celestrak.com/NORAD/elements/starlink.txt contains ...
3
votes
0answers
85 views

How much do SpaceX's titanium grid fin geometrical parameters measure?

Does anyone know approximately what is the width, length, thickness and depth of the titanium grid fins used in the Falcon9 v1.1? I'm trying to make a 3D model on solidworks but can't find the ...
3
votes
1answer
152 views

What are Starlink's available momentum unloading strategies?

Today's Teslarati article SpaceX wants to offer Starlink internet to consumers after just six launches talks about the new website https://www.starlink.com/ shows several images from it, and tries to ...
2
votes
1answer
249 views

Delta-V of Starlink Satellites

The recently launched Starlink satellites are designed to use their HAL Ion thrusters to seek their own independent orbits, evade collisions, and de-orbit at the end of their lives. That's a lot of ...
0
votes
0answers
116 views

What is the function of this Merlin engine's tube, and why is it getting red hot?

In the video of the recent SpaceX Starlink launch, one view of the Falcon-9 2nd stage engine shows a cane-shaped tube that glows red hot at the "handle" end and seems to get hotter over time. ...
10
votes
2answers
1k views

Is the Starlink array really visible from Earth?

I was browsing YouTube when I came across this video, recorded from a sky gazer who apparently spotted the Starlink satellites. In my lifetime, I haven't seen many satellites in the night skies (maybe ...
2
votes
0answers
120 views

What caused these strange lights around the Falcon 9 grid fins (Starlink launch)?

Early in the video of the launch of the first sixty SpaceX Starlink satellites we can see that after stage separation the first stage grid fins open. Around that time there are some phenomena I don't ...
4
votes
2answers
106 views

Shortest ever F9 2nd stage burn for the largest ever F9 payload? (Starlink Mission's SES-2 burn time of 3 seconds)

According to the SpaceX broadcast the first SpaceX Starlink launch (24-May-2019) is notable for reasons including being the heaviest ever Falcon 9 payload to date. At roughly ...
1
vote
2answers
448 views

What performance specification would be lower for Krypton than for Xenon in Hall effect thrusters?

The Ars Technica article SpaceX scrubs first attempt to launch 60 Internet satellites [Updated] (found here) discusses the use of Krypton rather than Xenon in the Starlink Hall effect ion thrusters: ...
11
votes
2answers
369 views

What does this SpaceX tweeted photo show and what causes the pure red and blue color?

This May 4, 2019 SpaceX tweet says More photos from Falcon 9’s 40th successful launch from Pad 40 in Florida and 39th first stage rocket booster landing to date → http://flickr.com/spacex and ...
7
votes
1answer
370 views

How will Starlink satellites deploy from the fairing and reach their orbits?

Elon Musk posted this picture of the first 60 Starlink satellites packed densely into the fairing of the Falcon scheduled to launch in a few hours. There doesn't appear to be a launcher or ejector to ...
7
votes
2answers
3k views

Why will Starlink satellites use krypton instead of xenon for electric propulsion?

The press kit for the first Falcon 9 Starlink launch and deployment of the first 60 satllites scheduled for May 15, 2019 says: With a flat-panel design featuring multiple high-throughput antennas ...
3
votes
1answer
186 views

How will Starlink satellites be capable of tracking on-orbit debris and autonomously avoiding collision?

The press kit for the first Falcon 9 Starlink launch and deployment of the first 60 satllites scheduled for May 15, 2019 says: Starlink satellites are capable of tracking on-orbit debris and ...
3
votes
1answer
205 views

Can we get to Mars today using current rockets/technology?

I was wondering if, using the rockets we have today (I'm guessing the most likely candidate is the Falcon Heavy), we could send at least 1 human to Mars. For arguments sake, let's ignore the fact it ...
3
votes
1answer
141 views

When Falcon 9's stage 2 engine fires up, does the flame of the engine affect stage 1 in any way?

Are there any specific design considerations that are made over nonreusable, traditional rockets to tolerate the blast from the stage 2 engine? As shown in this moment:
6
votes
2answers
323 views

Is this Falcon 9 on a drone ship in Port Canaveral really on fire?

The Teslarati article SpaceX’s latest Falcon 9 booster returns to port as NASA hints at “vested interest” shows this tweet about booster number B1056 from Jennifer Krafft Photography: #SpaceX #...
1
vote
0answers
47 views

What object is visible in the background of the Dragon view from the CRS-17 launch?

In the livestream of the CRS-17 Mission, at 28:02 into the livestream (T+13:02) there is a flashing object visible in the bottom, left third of the screen. This object moves "up" in the frame. It is ...
4
votes
0answers
112 views

Books on Vertical-Landing Vertical-Takeoff (VTVL) of Rockets? or Rocket Design in General?

I am working on a rocket control system design and I am trying to understand the the fundamental principles and concepts to design an efficient controller for recovering and landing the rocket, ...
3
votes
0answers
41 views

Is there video from the Falcon second stage of the Dragon solar panels deploying?

We get video from the second stage of the Dragon leaving the second stage. And we get video from the Dragon of its solar panels deploying. But a cool view would be of the Dragon's solar panels ...
4
votes
1answer
456 views

SpaxeX employees on the droneship when the booster lands?

SpaceX is doing a great job in recovering the boosters from its rockets. The Falcon Heavy has 3 boosters. 2 of which land at Cape Canaveral and 1 on a drone ship somewhere in the ocean. Are there ...
7
votes
2answers
1k views

Why does the Superdraco exhaust seem so under-expanded in this photo?

The Ars Technica articles From zero to 100mph in 1.2 seconds, the SuperDraco thruster delivers Dragon was destroyed just before the firing of its SuperDraco thrusters both include this "file photo" ...
0
votes
2answers
154 views

How will Mars terraforming missions really work, how do pioneers like SpaceX plan on conquering Mars? [duplicate]

We know Mars is now dead in the water (or space), it is now merely an oversized rock hurtling through space, with a bit of atmosphere. I was reading up on terraforming the planet, and learned that ...
1
vote
0answers
63 views

Most challenging aspects of a reusable satellite scheme like this?

What would be the most challenging aspects of a reusable satellite scheme similar to the one shown in this video? For the kilo-constellations (e.g. SpaceX's StarLink with 4,500 to 7,500 satellites) ...
4
votes
1answer
211 views

What does the StarLink constellation look like now? Numbers of planes and inclinations?

In the question SpaceX's 4,425 satellite constellation - what's the method to the madness? I took the orbital parameters in SpaceX's filing SpaceX non-Geostationary Satellite System Attachment A - ...