Depot is in an earth orbit (EO). As another poster pointed out, neither NASA nor SpaceX has actually specified this orbit, hence "depot EO".
Another example: same masses and specific impulse, but as high depot orbit as you can:• Depot orbit is a high elliptic orbit with perigee in LEO and apogee somewhere around the Moon. 3.2 km/s Δv to reach from LEO, and 430 m/s Δv from NRHO.
I am not sure why NG couldn't have its own proposal and also be part of the National Team.
The HLS Starship is not practically capable of aerobraking into LEO when returning from the Moon; with no heat-shield it would need so many passes that it would probably take a year before it is down to a circular LEO.
Given the limitations of not having a heat-shield, I am pretty certain that the HLS Starship will only be used for shuttling between NRHO (or maybe EML1 or EML2) and the lunar surface; it will never return to LEO. For any other lunar missions, I suggest using a Starship with a heat-shield, so it can aerobrake, and even land back on Earth.
Quote from: DanClemmensen on 03/30/2022 06:35 pmDepot is in an earth orbit (EO). As another poster pointed out, neither NASA nor SpaceX has actually specified this orbit, hence "depot EO".While they might not have specified the exact orbit, it is fairly obvious that it is some kind of LEO. Remember the fourteen tanker launches mentioned in the GAO decision last summer? If it had been in high orbit, it would be more like fourty tankers! (Hint: you want to lift the dry mass of the numerous tankers to as low-energy orbits as possible, so the lower depot orbit, the better (while staying out of the atmosphere).)
No real news here, but LM and NG are public about the fact that they’re examining their options on HLS:https://spacenews.com/northrop-grumman-weighing-options-for-new-artemis-lunar-lander-competition/
Through Artemis missions, NASA is preparing to return humans to the Moon, including the first woman and first person of color, for long-term scientific discovery and exploration. In its work toward a regular cadence of astronaut Moon landings, the agency is pursuing two paths for sustainable lunar lander development and demonstration. One calls for additional work under an existing contract with SpaceX, and another invites other U.S. companies to provide new lander development and demonstration missions from lunar orbit to the surface of the Moon. Combined, these efforts will pave the way for multiple companies to provide recurring Moon landing services for Artemis astronauts using the Gateway as the crew staging vehicle in lunar orbit. NASA’s existing contract with SpaceX includes both a crewed and uncrewed lunar landing demonstration as part of the Artemis III mission, marking humanity’s first return to the Moon in more than 50 years. The agency will exercise an option under this contract asking the company to evolve its current Artemis III Starship Human Landing System design to meet the NASA’s sustainable requirements at the Moon and conduct another crewed demonstration landing.Separately, under a new draft solicitation released March 31, NextSTEP2 Appendix P, Human Landing System Sustaining Lunar Development, NASA has provided requirements for new companies interested in developing and demonstrating additional astronaut Moon landers. Companies selected under this contract will be required to perform one uncrewed and one crewed demonstration landing. NASA will certify any lander system prior to the crewed demonstration missions ensuring overall astronaut safety and mission success.“This approach bolsters industry readiness and competition and creates a strong plan for establishing a long-term lunar presence under Artemis with regular crewed landings,” said Lisa Watson-Morgan, program manager for the Human Landing System Program at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “NASA is committed to maintaining a flexible and resilient lunar exploration plan that will promote competition going into the future.”Together, these concurrent sustaining lander development efforts will meet NASA’s needs for recurring, long-term access to the lunar surface, such as the ability to dock with Gateway for crew transfer, accommodate an increased crew size, and deliver more mass to the surface. NASA will host a virtual Appendix P industry day April 4 to present an overview of the solicitation and to provide companies an opportunity to ask clarifying questions and provide comments. Once these have been reviewed, the agency plans to issue the final solicitation this summer.As NASA makes strides to return humans to the lunar surface under Artemis, this approach allows the agency to expedite partnerships with U.S. industry to increase the competitive pool of capable providers ahead of the solicitation for recurring lunar lander transportation services for Artemis astronauts. For more information about this procurement and industry day details, visit:https://www.nasa.gov/nextstep/humanlander4
DRAFT Broad Agency Announcement NNH19ZCQ001K_APPENDIX-P-SLDIssued: [TBD: Summer 2022]Proposals Due: [TBD: 60 days after final solicitation issued]
The purpose of this solicitation is to request proposals from industry for selection and award for the rapid development and demonstration of a Sustainable Human Landing System (HLS) from a second provider, delivering humans to the lunar surface in a subsequent Artemis mission, and with the goal of doing so by July 2027. Additionally, NASA plans to leverage crewed lander development activities to procure and certify the design of landers capable of human-class cargo delivery.
In accordance with the instructions set forth below in this Broad Agency Announcement (BAA), NASA will determine whether to award Options (see Table 1 below). It is NASA’s intent to transition between the Base period and subsequent Option periods without any break in contractor performance. The decision to award Options (formally authorize work initiation) rests solely with the Government, and no guarantee is made that an option will be awarded even though the contract will cite a value for the effort.While NASA reserves the right to change its HLS acquisition strategy at any time, NASA is currently planning to award the Base CLIN for a single contractor, pending availability of funds; and either at initial award or later, exercise Options for that contractor. Proposals shall include a firm-fixed-price (FFP) for the Option periods.
Note that while SLD [sustainable lunar development] includes HDL [human-class delivery lander] CLINs through DCR, performing a mission to deliver Human-class Cargo to the lunar surface will be procured separately via a future acquisition.
1.3.4 Sustaining Lunar Transportation (SLT) ServicesFollowing successful crewed lunar demonstrations performed pursuant to this contract, NASA intends to separately procure transportation between Gateway and the lunar surface as commercial space transportation services. NASA estimates that it will require such services approximately once per year for a period of ten years.
While NASA intends to exclude SpaceX from being a prime Contractor under the SLD procurement, SpaceX may otherwise participate (e.g., as a launch provider) on another Offeror’s team.
Quote from: TheRadicalModerate on 03/30/2022 04:43 amOne other thing that's lurking in the requirement for either Appendix P or Option B to dock at the Gateway: Option A LSS must be a passive IDSS implementation, because Orion is active only. Presumably, Gateway will also be passive only, so the docking ring has to be active. So LSS has to change its docking architecture to implement Option B.The obvious thing for LSS to do is to implement the IDSS active-active option (which, AIUI, is really an active soft-capture ring that's latched in the retracted position and has three additional passive capture latches on it), but so far there aren't any active-active implementations with any flight heritage. Presumably, the Option B/App. P uncrewed test flight would provide a live test for this, but does anybody know how much ground testing and certification hassle is required for such a docking system?As I understand it, the Option A HLS must implement both the active mode and the passive mode, because it must be able to dock with the Gateway if it is available and it must be able to dock with Orion if Gateway is not available. NASA had already announced that Gateway was optional some time ago.
One other thing that's lurking in the requirement for either Appendix P or Option B to dock at the Gateway: Option A LSS must be a passive IDSS implementation, because Orion is active only. Presumably, Gateway will also be passive only, so the docking ring has to be active. So LSS has to change its docking architecture to implement Option B.The obvious thing for LSS to do is to implement the IDSS active-active option (which, AIUI, is really an active soft-capture ring that's latched in the retracted position and has three additional passive capture latches on it), but so far there aren't any active-active implementations with any flight heritage. Presumably, the Option B/App. P uncrewed test flight would provide a live test for this, but does anybody know how much ground testing and certification hassle is required for such a docking system?
The integrated lander will provide a docking mechanism, either integrated with the vehicle or as part of an Active-Active Docking Adapter (AADA) which will be compatible with Gateway’s passive docking mechanism. In addition, for Gateway missions, the integrated lander must have the ability to dock to Orion in a contingency case for in-flight crew rescue, which requires a docking mechanism compatible with Orion’s active docking mechanism. The HLS lander may require an Active-Active Docking Adapter (AADA) or an androgynous docking adapter for docking to Gateway. This docking adapter may be disposed of at end of mission if a subsequent HLS mission does not require its use (this will be a NASA decision).
Quote from: DanClemmensen on 03/30/2022 05:03 amQuote from: TheRadicalModerate on 03/30/2022 04:43 amOne other thing that's lurking in the requirement for either Appendix P or Option B to dock at the Gateway: Option A LSS must be a passive IDSS implementation, because Orion is active only. Presumably, Gateway will also be passive only, so the docking ring has to be active. So LSS has to change its docking architecture to implement Option B.The obvious thing for LSS to do is to implement the IDSS active-active option (which, AIUI, is really an active soft-capture ring that's latched in the retracted position and has three additional passive capture latches on it), but so far there aren't any active-active implementations with any flight heritage. Presumably, the Option B/App. P uncrewed test flight would provide a live test for this, but does anybody know how much ground testing and certification hassle is required for such a docking system?As I understand it, the Option A HLS must implement both the active mode and the passive mode, because it must be able to dock with the Gateway if it is available and it must be able to dock with Orion if Gateway is not available. NASA had already announced that Gateway was optional some time ago.More info on this from the solicitation:QuoteThe integrated lander will provide a docking mechanism, either integrated with the vehicle or as part of an Active-Active Docking Adapter (AADA) which will be compatible with Gateway’s passive docking mechanism. In addition, for Gateway missions, the integrated lander must have the ability to dock to Orion in a contingency case for in-flight crew rescue, which requires a docking mechanism compatible with Orion’s active docking mechanism. The HLS lander may require an Active-Active Docking Adapter (AADA) or an androgynous docking adapter for docking to Gateway. This docking adapter may be disposed of at end of mission if a subsequent HLS mission does not require its use (this will be a NASA decision).So, as usual, I had (and still have) a terminology confusion. Presumably, "androgynous docking adapter" means a single integrated adapter that can fill both active and passive roles. (Wow, I can't wait until the Language Police find this stuff.) So an AADA must be a separate component that consists of two bi-directional passive interfaces that can glue two active systems together.Aaaaaaand now I'm confused again.We have three different docking sequences that have to be accommodated:1) HDL (Human-class Delivery Lander---aaaaarrrrrgh! Just pick a bunch of acronyms and live with them!) arrives at the Gateway. No matter what it does for self-assembly and/or refueling, the crew module has to dock with the passive Gateway IDA, so it must have an active, extended soft capture ring. So it can't have an AADA between it and the Gateway at this point.2) On nominal ascent from the lunar surface, the HDL has to dock actively with the Gateway again. Good news! No different from the assembly-phase.3) On off-nominal ascent, the HDL has to dock passively with the Orion. Now you need the AADA. But there's no way to have it in place, because the nominal docking sequence requires an active interface to do the docking. How does it get mounted so it can be used? I can only think of three possibilities, and they're all stupid at different levels:a) The HDL has two separate docking ports, one with an active IDA and one with a passive. Leaving aside the fact that this is ridiculously heavy, you wouldn't need an AADA in this scenario.b) The Orion is going to undock from the Gateway, mosey over to an AADA stowed somewhere on its exterior surface, dock with it, pull it off the Gateway, and then go do the RPOD with the HDL. Given that a bunch of the off-nominal failure modes that require direct Orion-HDL docking have to do with the Gateway losing attitude control, this appears to be as ridiculous as case #a.c) The AADA is actually not really passive on both ends, but instead has a dumb passive end that's hooked to the the HDL, and a fully androgynous end that can be either active or passive as needed. But then it's not really an AADA any more, is it? And if you have this technology, why didn't you just build it into your HDL in the first place?Unless I'm missing something or fundamentally misunderstanding the nature of an AADA, it sounds more like whoever the wrote the requirement hadn't thought it all the way through. Seems to me that the real requirement is that winning HDLs will have to implement full androgyny. More explicitly:1) The HDL IDA implementation must have a soft capture ring that works as the active system.2) That IDA must implement the full set of androgynous latches on the soft capture ring in case it has to be used in passive mode.3) I assume that also means that the soft capture ring must have a way to be latched in place in its fully retracted position so that Orion's soft capture ring can lunge, latch, and retract to bring the system to hard dock.Does this sound... right?
