Also, NASA recently announced that the expected performance of Block 1 went up from 70 to 95 mt to LEO. I've been curious how this would change their estimate of the performance of Block 1B (currently 110 mt LEO if I remember correctly).
Figure 68 in this article seems to indicate that Block 1B is 117-123 t to LEO. I tried to run the numbers for roughly quadrupling the size of the upper stage from Block 1 and got similar numbers based on 95 t being the baseline. I did this two months ago without having seen this slide, because a 10 t boost didn't make much sense intuitively.
<snip>Also, NASA recently announced that the expected performance of Block 1 went up from 70 to 95 mt to LEO. I've been curious how this would change their estimate of the performance of Block 1B (currently 110 mt LEO if I remember correctly).<snip>
After SLS loses the weight of its first stage propulsion systems and fuel, more power is still needed to send Orion to the Moon. At this point, the upper part of the rocket and Orion are soaring almost 100 miles above Earth, accelerating at more than 17,500 miles per hour, and beginning a circular orbit around Earth. This is low-Earth orbit, often referred to as LEO. SLS can deliver more than 95 metric tons (209,439 pounds) to this orbit with a Block I configuration. However, a deep space mission requires a rocket that can travel beyond LEO with enough power and speed to overcome the pull of Earth’s gravity and send the spacecraft even farther to reach the Moon. The upper part of rocket prepares for the next big move to send Orion out of LEO without even completing a full orbit of Earth.
Quote from: BrianNH on 10/01/2018 07:36 pm<snip>Also, NASA recently announced that the expected performance of Block 1 went up from 70 to 95 mt to LEO. I've been curious how this would change their estimate of the performance of Block 1B (currently 110 mt LEO if I remember correctly).<snip>According to a NASA web page the LEO payload of 95 mT for the Block 1 that NASA is quoting is for a parking orbit of about 155 km altitude ("almost 100 miles"). QuoteAfter SLS loses the weight of its first stage propulsion systems and fuel, more power is still needed to send Orion to the Moon. At this point, the upper part of the rocket and Orion are soaring almost 100 miles above Earth, accelerating at more than 17,500 miles per hour, and beginning a circular orbit around Earth. This is low-Earth orbit, often referred to as LEO. SLS can deliver more than 95 metric tons (209,439 pounds) to this orbit with a Block I configuration. However, a deep space mission requires a rocket that can travel beyond LEO with enough power and speed to overcome the pull of Earth’s gravity and send the spacecraft even farther to reach the Moon. The upper part of rocket prepares for the next big move to send Orion out of LEO without even completing a full orbit of Earth.The quoted paragraph is after the expanded view diagram of the Block 1 on the web page.
>According to a NASA web page the LEO payload of 95 mT for the Block 1 that NASA is quoting is for a parking orbit of about 155 km altitude ("almost 100 miles"). >
The initial configuration of SLS can send more than 26 metric tons (57,000 pounds) to lunar orbits and future upgrades will enable the rocket to send at least 45 metric tons (99,000 pounds).
>Altitudes are typically given in nautical miles. 180-185 km is "almost 100" nautical miles, and is a typical parking orbit such as used by Apollo before TLI.
Quote from: envy887 on 10/03/2018 12:42 pm>Altitudes are typically given in nautical miles. 180-185 km is "almost 100" nautical miles, and is a typical parking orbit such as used by Apollo before TLI.Here in the plain-speaking Midwest "almost 100 miles" means "not quite 100 miles," and claiming it's more would receive considerable side-eye. Someone needs to work on their messaging.
Cancellation of EUS? https://twitter.com/DJSnM/status/1048001681600831488?s=20
"Development of the Exploration Upper Stage has been officially halted in that contractors have been directed to stop work immediately on it
Quote from: lucspace on 10/05/2018 12:05 pmCancellation of EUS? https://twitter.com/DJSnM/status/1048001681600831488?s=20 For those who can't see the tweet, it's from Scott Manley and is an image of these words:"Development of the Exploration Upper Stage has been officially halted in that contractors have been directed to stop work immediately on it (not even much of a tailoff phase). Officially, it's 100 day pause, but unofficially, we've been told not to expect that work to come back for minimum 1 year and likely multiple years. Core stage is in sufficient schedule/budget trouble that they're planning on just flying Block 1 a bunch of times and indefinitely postpone Block 1B and Block 2 into the farther future. Which makes the SLS project have even less of a niche than it already was clinging to, if the unofficial word's real. "
If they can't fly in 2020 this program is cooked. Also postponing EUS effectively cooks the program anyway, rocket can't really do anything useful at that point. As I have said before, at the current rate BFR will be operational before SLS, or before SLS does anything useful. So will Vulcan so will New Glenn maybe even New Armstrong.