Questions tagged [sls]
Space Launch System, the putative replacement for the Space Shuttle for future large missions.
73
questions
9
votes
2answers
1k views
What do the banana values mean in this tweeted plot of heavy lift vehicle capabilities?
@FreddieR's answer to What are the longest current rocket payload fairings, capable of carrying long space station sections? contains the following graphic. It's attributed to Ken Kirtland and I found ...
2
votes
1answer
122 views
Could Four SRBs Be Stacked on SLS, Thereby Generating 17.9 Million LLBs Thrust at Liftoff
I'm not sure about the total thrust of SLS Block II (Crew Stack). So the math could be wrong. Since the Atlas 5 has a version where 4 SRBs are used, is this also possible for SLS?
5
votes
1answer
242 views
RS-25E cost estimate but sentence confusing (approximately: help; maybe)?
So recently someone found out that the industry studies for SLS had been FOIAed by a site called government attic. While the other studies are interesting in their own right (check them out honestly), ...
4
votes
1answer
129 views
What specific device failed, causing engine #4 in the Core Stage Green Run to report a Failure Identification?
(See this Q&A for context if needed: What is a "Major Component Failure" referred to in news reports about the unsuccessful Space Launch System core stage test firing?)
In the post-test ...
3
votes
0answers
190 views
Likely explanation for the bottom of the SLS rocket being covered with reflective silver “muffler” tape?
NASA.gov's First Artemis Rocket Stage Moved onto NASA Barge Ahead of Green Run contains a high resolution image of the rocket. The bottom end of the rocket's cylindrical shape is closed flat and ...
24
votes
1answer
3k views
What is a “Major Component Failure” referred to in news reports about the unsuccessful Space Launch System core stage test firing?
In reporting about the unsuccessful green run of the SLS core stage, Ars Technica mentions
About 50 seconds into what was supposed to be an 8-minute test firing, the flight control center called out, ...
2
votes
1answer
140 views
Why doesn't NASA just again build the Altair LM or a modified Apollo LM for the Artemis project?
The Altair lunar module was part of the wonderful Constellation program cancelled in 2010; just the Orion spacecraft has been retained which is to deliver a crew into lunar orbit. The new carrier ...
2
votes
2answers
323 views
Why is the Orion spacecraft so big?
The Orion spacecraft which is to be used for the Artemis missions will be rated for 6 astronauts. Why so many? Given the "political" assignment is to put "a woman and another man to the ...
0
votes
2answers
170 views
“NASA's Europa Clipper has been liberated from the Space Launch System” How would the “physics” of a Starship-based mission differ from SLS?
The Hill's NASA's Europa Clipper has been liberated from the Space Launch System is quite an illuminating read about the politics of space launch. However, I noticed that it also says:
Both the ...
6
votes
1answer
130 views
Is there a G-force curve estimated for a SLS launch?
Has the G-force curve for the launch of Block 1, Block 1B, or Block 2 (crew and or cargo) Space Launch Systems been determined? If there is no published estimates for the curve, is the estimate of the ...
8
votes
1answer
515 views
How many US states receive large amounts of money due to SLS?
That NASA is spread out over so many locations across the US is history and discussed elsewhere in this site. Briefly, Congress approves funding and the funding ends up in many, many of congress' ...
18
votes
6answers
7k views
Why does the government still fund SLS while SpaceX is cheaper and has the same capabilities if not better?
Due to SpaceX's recent advancements in now proven rocket tech, why does the government still fund (what some would argue to be bloated) cost-plus contracts with Boeing and Lockheed? Am I missing ...
7
votes
0answers
65 views
Escape system of SLS vs Ares I
One of the criticism directed at the Ares I rocket was the danger during a launch termination of the solid-propellant 1st stage. As far as I understood it, a terminated Titan IV solid-propellant ...
3
votes
1answer
238 views
Is SLS capable of launching the core stage into LEO?
After watching the Hazegrayart video If Rockets were Transparent I realized that I didn't really have a clear idea what the Space Launch System (SLS) is capable of doing.
Question: Is SLS capable of ...
15
votes
2answers
2k views
Why isn't the Delta IV Heavy ever used for crewed spaceflight?
In 2014 the Orion spacecraft was launched on top of the Delta IV Heavy for the first time. Why do they build another rocket, the SLS, instead of launching the Orion on the Delta also with humans on ...
3
votes
1answer
250 views
Why is ESA developing the Vinci engine rather than buying RL10Bs?
The Vinci engine seems very very similar to the RL10B. Both are hydrolox expander-cycle engines with 465 s Isp and extendible nozzles with a ~250:1 expansion ratio. The biggest difference is that the ...
6
votes
0answers
155 views
What are these wires on the side of the SLS core stage?
I was reading about the SLS core being moved for testing and I noticed something odd on the core stage. There's several lines on the stage, which in closer inspection are wires. It's not obvious what ...
13
votes
1answer
381 views
Where are the lost RS-25D Block 2 engines?
There were 21 RS-25D Block 2 engines made. Two of them never flew. Three of them were lost with the Columbia disaster. 16 of them are tagged for SLS's use, including 14 previously flown, and the two ...
5
votes
1answer
298 views
Did the shuttle SRBs have separation motors?
Looking at a NASA fact sheet about the SLS SRBs and I noticed it has at the bottom around the nozzle, separation motors.
Watching shuttle launches It looks to me like the SRBs continue to fire ...
7
votes
1answer
1k views
What is the status of the F-1B engine development?
In this article https://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ and in several answers on this site a modernized F-1 engine is ...
4
votes
1answer
128 views
Could the SSMEs of the SLS do retro burns?
The SLS will use the main engines of the space shuttle. Are these capable of retro-burns in the upper atmosphere like SpaceX’s Merlin engines?
More broadly, could the SLS’ main engines and ...
3
votes
2answers
155 views
How does the economy of a direct launch (to the Moon) compare with two launches docking in orbit?
How much more efficient would it be to use a launcher big enough to go directly to the surface of the Moon like Apollo did, compared with using two launches with a lesser rocket, say one with the ...
5
votes
1answer
277 views
Are the APUs on the SLS SRBs planned to be hydrazine powered?
I recently read that the Space Launch System core stage, which uses renamed / slightly reworked Space Shuttle Main Engines and therefore requires a hydraulic system to service said engines, will use ...
-2
votes
2answers
510 views
Why doesn't NASA plan a manned Venus flyby first? [closed]
After America will have returned to the Moon, why won't NASA make a Venus flyby mission with the Orion/SLS before going on to manned flights to Mars?
They are planning crewed missions to Venus (...
3
votes
1answer
1k views
What exactly is a “Green Run test” for SLS that NASA is considering skipping?
The Ars Technica article Rocket Report: A new Delta 2, Blue Origin inks with NASA, a fiery Falcon Heavy says:
Boeing seeks to ship SLS core stage by the end of 2019. With a renewed emphasis from the ...
3
votes
0answers
162 views
What is holding SLS back from launching?
I'm kind of confused on this point SLS has engines, a tank, side rocket boosters, a capsule, and seemingly all of the pieces. What is the major technical issue right now that is keeping SLS from ...
1
vote
2answers
285 views
Why would an 8-minute burn result in a 6-month delay?
The Ars Technica article Vice President may tell NASA to accelerate lunar landings ends with:
And on Thursday, NASASpaceFlight.com reported that the agency is considering skipping a critical test ...
4
votes
0answers
110 views
Can Delta Heavy launch a fully fueled upper stage with no payload attached?
There is right now talk of a potential dual launch mission to fulfill EM-1, where a Delta Heavy would launch a fully fueled upper stage to LEO, to there bet met with the Orion spacecraft, likely ...
5
votes
2answers
1k views
NASA's RS-25 Engines shut down time
As a follow up to my other question about RS-25's ramp-up time, I was wondering what would be the ramp-down times for the RS-25, i.e. what would be the time that takes to go from 100% thrust to 0% ...
5
votes
1answer
274 views
NASA's RS-25 Engines
I am developing a FSX-based space flight simulator FSX SpacePort. I've been trying to get the detailed specs on NASA's RS-25 engine, namely, what were the ramp-up times for this engine? As in, how ...
6
votes
1answer
324 views
Could the SLS reach orbit without solid rocket boosters?
Could the SLS block 1 reach orbit without solid rocket boosters, and if so, how much payload could it lift?
If it couldn't reach orbit in the block 1 config, could it do so with the Exploration ...
5
votes
1answer
548 views
What are these discs on the Crawler-Transporter?
I've just watched this footage of SLS's Mobile Launcher Platform being rolled out to LC-39B for fitting tests.
On the front of the drive trucks are two rotating discs with red markings which are ...
2
votes
0answers
161 views
What is the nature of the sextant tests on the ISS for Orion cis-lunar emergency navigation?
According to the NASA Johnson video Space to Ground: A Star to Steer By: 08/10/2018:
A tool that once helped sailors cross vast oceans for centuries is now being put to the test in space. The crew ...
2
votes
0answers
88 views
What is the scheduled launch date history for SLS EM-1?
The Falcon Heavy was famous for being "6 months away" for around 6 years, seen in this chart. How has the SLS maiden launch schedule changed since its first proposed date?
P.S. If someone could ...
18
votes
2answers
5k views
Do the solid rocket boosters of the Shuttle and SLS have a self-destruct system and was it activated during the Challenger disaster?
Videos of the Challenger shuttle explosion show both solid boosters speeding on after the main tank detonated. Were they eventually self-destructed by the ground control, or why not, and why not ...
5
votes
2answers
351 views
How much will Europa Clipper weigh?
I realize that NASA will have to change Europa Clipper's loadout based on whether they are launching on the SLS 1b or the Atlas 5 backup, but does anyone know what those two mission masses will be, ...
7
votes
1answer
532 views
RS-25 Hot Fire Test
Yesterday, NASA Stennis successfully completed a hot fire test of Aerojet Rocketdyne RS-25 a.k.a SSME. It was noted in the webcast before the test started that they were testing the 'engine controller'...
12
votes
2answers
1k views
What does the software quality process for NASA's SLS look like?
What does the software quality process for NASA's SLS look like? What are the relevant standards that they have to comply to? Do they have to show that they are CMMI compliant, for example? I'm ...
9
votes
1answer
466 views
Do Orion's solar panels have adjustable sweep?
In this video overview of NASA's proposed EM-1 mission, the solar panels on the Orion spacecraft are initially shown extending perpendicular to the spacecraft (at around 3:46).
Shortly after that, as ...
5
votes
2answers
544 views
Were any Components Off The Shelf (COTS) used in the Space Shuttle?
Are there examples of Components Off The Shelf (COTS) used in the Space Transportation System?
And is NASA considering using COTS in future manned space flight systems like Orion and the SLS?
7
votes
1answer
775 views
Why will SLS Block I bring less mass to LEO than the STS shuttle system did?
The Space Transportation System (STS) could bring a fully loaded shuttle orbiter of 109 tons to orbit (or maybe empty+payload 68+25=93 tons). The Space Launch System (SLS) Block I is based on STS, but ...
4
votes
1answer
971 views
How does Exploration Mission 1 orbit differ from Apollo-era free-return? How far from Earth (and Moon) does it go?
I'm having trouble understanding the current orbit planned for NASA's Space Launch System's Exploration Mission 1. Is it possible to explain how the planned orbit works and what the maximum distance ...
4
votes
1answer
741 views
How are SLS SRBs considered man-rated?
Using solid rocket boosters on a manned launch comes with some additional risks because they can't be turned off or throttled down once lit. For the Shuttle this created some additional failures modes ...
4
votes
1answer
185 views
What naturally occurring navigational information is available for an autonomous return of SLS's EM-1?
This answer details some of the requirements that would need to be met if the Space Launch System's planned Exploration Mission 1 were to be human rated.
I've further trimmed that truncated selection ...
3
votes
1answer
191 views
Human Rate the ICPS on EM-1 of SLS
What specifically must be done to Human Rate the Interim Cryogenic Propulsion Stage (ICPS) to fly humans on Exploration Mission 1 of SLS?
1
vote
2answers
364 views
Can SLS use subcooled LOX?
The SpaceX Falcon 9 FT is using subcooled liquid oxygen. I understand that LOX gets significantly denser at lower temperatures so more propellant can be filled in the rocket's tank.
Can NASA SLS RS-...
8
votes
2answers
1k views
Why did NASA design the SLS do the job of both the Ares I and Ares V?
The design of the Constellation program called for two main launch vehicles, The Ares I and the Ares V. The Ares I was said to be human-rated and was to be used to carry the Orion vehicle and its crew ...
14
votes
3answers
6k views
What are the differences between SLS and Ares V?
SLS is to a large degree a continuation of the canceled Ares V, basically the STS without the orbiter. But what changes in design were made from Ares V to SLS? What were the reasons for those changes? ...
11
votes
4answers
3k views
Could the solid boosters of SLS be replaced by reusable Falcon 9 first stages?
Is it feasible to redesign the Space Launch System to use a pair of reusable Falcon 9 first stages instead of the five-segment solid boosters now being developed? The reason would be to lower launch ...
1
vote
1answer
209 views
Are rocket boosters insulated?
Reading about NASA testing the SLS (Space Launch System) booster and they are chilling it to 40 degrees Fahrenheit. This confused me because they are going to fill it with liquid oxygen and liquid ...
