NASA prepares SLS for first crewed Artemis missions
https://www.moondaily.com/reports/NASA_ … s_999.html
As teams continue to prepare NASA's Space Launch System (SLS) rocket for its debut flight with the launch of Artemis I, NASA and its partners across the country have made great progress building the rocket for Artemis II, the first crewed Artemis mission. The team is also manufacturing and testing major parts for Artemis missions III, IV and V.
"The Space Launch System team is not just building one rocket but manufacturing several rockets for exploration missions and future SLS flights beyond the initial Artemis launch," said John Honeycutt, SLS program manager at NASA's Marshall Space Flight Center in Huntsville, Alabama. "The Artemis I mission is the first in a series of increasingly complex missions that will extend our presence on the Moon. The SLS rocket's unprecedented power and capabilities will send missions farther and faster throughout the solar system."
With its two solid rocket boosters and four RS-25 engines, SLS produces more than 8.8 million pounds of thrust to launch each Artemis mission beyond Earth's orbit and onward to the Moon. The rocket features some of the largest, most advanced, and most reliable hardware elements ever built for space exploration.
To power the agency's next-generation deep space missions, SLS delivers propulsion in phases. At liftoff, the core stage with its four RS-25 engines and the twin boosters fire to propel SLS off the launch pad into orbit. Once in orbit, the Interim Cryogenic Propulsion Stage (ICPS) provides the in-space propulsion to send NASA's Orion spacecraft and its crew on a precise trajectory toward the Moon.
The first piece of rocket hardware - the ICPS - for Artemis II arrived in Florida July 28, 2021. It is undergoing final preparations at lead contractors Boeing and United Launch Alliance's (ULA) facilities and will soon be delivered nearby to NASA's Kennedy Space Center. The ICPS fires its RL10 engine, provided by Aerojet Rocketdyne, to send the Orion spacecraft toward the Moon. ULA is already building the Artemis III ICPS in its factory in Decatur, Alabama.
"The Space Launch System is a highly capable launch vehicle purposely designed and rigorously tested to safely transport people, large cargo, and flagship science missions to deep space destinations," said John Blevins, SLS chief engineer at Marshall. "From the beginning, the SLS rocket was built to first safely send astronauts to space, and at the same time, to evolve to an even more powerful configuration that can support a variety of missions."
]]>That's the rub and the trade off between cost and capability. NASA has time to get it right as there's not enough funding to even begin preliminary design for years.
]]>Instead of giving a link to the actual source, it just rehashes & pastes parts of the report summary (PDF)
The full report is readable online here (the book PDF can be downloaded free with a simple registration)
One odd aspect of the report is that they did not have an estimate of the cost of Ares V, yet much of the report is about costs. Also the logic seems backwards: it's a disadvantage that the bigger missions enabled by Ares V will cost more, duh!
There are fantastically expensive projects there, many over $5 billion; the cost of the launcher is not going to be the biggest factor.
Ares V with a Centaur upper stage can get the Interstellar Probe Mission out to 200 AU in 23 years!
]]>At this point, the report explains, NASA doesn’t have reliable price tag info on the Ares V.
But given its development, the report spotlights a number of vision missions that might benefit from the opportunities enabled by the Constellation system, and are therefore deserving of future study, such as the Modern Universe Space Telescope, a Stellar Imager, an Interstellar Probe mission, Solar Polar Imager, Neptune Orbiter with Probes, and a Titan Explorer.
The committee believes that Ares V offers the greatest potential for an impact on science. The big launcher would be capable of hurling large-diameter, large-volume, heavy spacecraft into orbit, seemingly removing the physical — although not the financial — constraints on missions that would benefit from being able to fly large, heavy payloads to their destinations.
But the report stresses that using the Ares V could have a potentially dramatic effect on the price tags of these missions. That is, incorporating the use of an expensive launch vehicle could increase costs. But it could also possibly balance increased costs by simplifying mission design - for instance, by cutting out the requirement for on-orbit assembly or eliminating complicated deployment mechanisms.
The committee found that the greatly increased payload lift capacity promised by Ares V could lead to more costly science payloads.
Also, it was determined that the Ares 1 capabilities are not sufficiently distinct from those of Atlas V and Delta IV to enable different types or a higher quality of space science missions.
So the Ares V has great potential whereas the Ares I is limited, barring it turning out to be cheaper than Altas or Delta.
]]>payload/initial mass = e^(-DV/3500) for LOX/LH2, DV in meters/sec
]]>At a Glance
Dimensions: 6.7 meters (22 feet) high; 4 meters (13.1 feet) wide
Weight: 5,712 kilograms (12,593 pounds) with fuel, Huygens probe, adapter, etc; 2,125
kilograms (4,685 pounds) unfueled orbiter alone
Orbiter science instruments: composite infrared spectrometer, imaging system, ultraviolet imaging spectrograph, visual and infrared mapping spectrometer, imaging radar, radio science, plasma spectrometer, cosmic dust analyzer, ion and neutral mass spectrometer, magnetometer, magnetospheric imaging instrument, radio and plasma wave science
Power: 885 watts (633 watts at end of mission) from radioisotope thermoelectric generators
Cassini's ~12,600 pounds translates to 6.3 tons with a full fuel load included. And what was that lovely number your stated for TLI mass cyclops? 65 tons? So at the least something like Cassini could have been sent to Saturn with a couple extra 'toys' with ease by Ares V right? 8)
]]>Lunar and Mars missions want as much payload as possible.
Sounds right, so whether or not there's a third or fourth stage involved depends on the distance to fly and the mass of the spacecraft. I imagine the only things that might need up to a fourth stage would be a Neptune/Uranus orbiter, a TAU-Heliopause mission, a Jovian/Saturnian sample return, or a Jovian/Saturnian Prometheus-style mission.
I imagine using the EDS that'll already be part of the Ares V system pretty impressive payloads could be sent to Venus, Mars, the asteroid belt, and Jupiter for certain.
]]>Remember this? That fairing can hold a good size upper stage of around 130 MT mass. Depending on the payload mass, that would give it a big kick out of LEO. For lunar missions it's currently about 65 MT TLI, Mars would be a bit less. Beyond, well it depends how quickly you want to get there.
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