Artemis Dragon lunar lander
SpaceX has been unusually quiet about its proposals for Artemis and Gateway Logistics Services, unlike Boeing, Blue Origin or Northrop Grumann. Publicly they did not seem very interested to pursue such a contract, and some have considered it to be more focused on Starship and Starlink. The Dragon XL announcement (again, extremely thin on details and announced by NASA only) puts a different light on it. SpaceX does not want to draw attention to its proposals. That is very strange, when being led by only celebrity that launched his own car into space. Interplanetary space. So they seem to be extremely secretive about Artemis.
For a long time, Dragon 2 was considered as possible precursor for SpaceX moon lander. It has flight heritage (soon followed up with first manned mission), fully functional and tested docking adapter, proven GNC, heat shield, solar power and propulsion elements. Dragon 2 was envisioned with having landing legs and capability to land on any firm surface (including Earth, Moon and Mars). Red Dragon was discontinued. Grey Dragon was not addressed.
Other possible lander designs will miss most of these elements, especially in integrated form. Blue moon lander proposal includes several different vendors who would need to integrate three different elements (Transfer, Descent and Ascent Element) from five different vendors in just four years. Most of these elements would utilize new designs or designs transferred from other vehicles and/or applications.
There are four main drawbacks of selecting lunar lander based on SpaceX Dragon platform. First is political. NASA is a governmental entity whose funding is approved by people with primary interest to distribute funding among their electorates. Thus SpaceX faces significant disadvantage with its vertical integration focused on just three federal states (California, Texas and Florida).
Second, although it is highly likely that SpaceX proposal would be the most cost effective, they are already the major (or even main) CRS-2, CCP and GLS provider. This raises concerns whether they would have enough talent and resources to provide the most complex part of the Artemis program - lunar landing vehicles. In just four years.
Third, selection of SpaceX for lunar landing would position them as the main NASA transportation supplier for a whole spectrum of human spaceflight efforts, providing them with de-facto monopoly and restricting other major suppliers in space industry (Boeing, Lockheed Martin, Northrop Grumman, Sierra Nevada and possibly Blue Origin).
Lastly, any proposal built around Dragon would not be considered mass efficient. Dragon 2 is quite heavy vehicle, optimized for reentry in Earth Atmosphere. Thus any Dragon derived lunar lander would be based on Dragon XL.
Transfer element would probably be based on Dragon XL itself, where the "cargo" would be replaced with fuel tanks used for transferring the whole stack from the lunar gateway near rectilinear high orbit down to low lunar orbit and back. This can use existing low-thrust Draco engines, so the transfer element would be very similar to XL variant (if they provide enough propellant capacity).
Descent and ascent elements based on Dragon XL would require a lot of delta-V budget (over 3.7km/s) using MMH/NTO propellant with specific impulse.
With SpaceX attitude towards reuse, most likely design would use the same element for both ascent and descent with MMH/NTO propellant. It is storable and could be reused-transferred using fuel transfer from Dragon XL. This approach would require significantly more propellant than hydrolox based proposals. But Falcon Heavy and Dragon XL can be sized to maximize the in-space fuel transfer, which would make it easy for SpaceX to provide all necessary propellant using rather cheap Dragon XL/Falcon Heavy flights.
Let us assume that the dry mass of Lunar Dragon together with astronauts and cargo would be 4000 kg (which is probably an overestimate). With ISP of 320 and transfer element based on Dragon XL with the same mass (4000 kg), such configuration would require two Falcon Heavy flights and have total mass of 23000 kg in EML1 (which I used as approximation for NRHO delta-V budget). Falcon Heavy could easily launch both vehicles to EML1 or NRHO with booster reuse. Assuming that development cost for ascent/descent element would be the same as Dragon 2 with two flights (2.6 billion), and that Dragon XL as transfer element would be simple modification (total mission cost of 400 million), that would enable cost for first Artemis lunar landing of just 3 billion USD. With additional cost of Orion/SLS.
There is additional technical obstacle here, and that is design of the engine for lunar descent and ascent. The total ascent/descent thrust would be in the range of 30kN, which is not suitable for SuperDraco engine. Furthermore, there would likely need to be multiple engines that would be positioned on the upper edge of the vehicle, in order to minimize risk of debris damaging the engines during landing or ascent. That engine placement would make lunar Dragon quite different in external appearance from other Dragon vehicles.
As both vehicles (ascent/descent and transfer element) would return to the staging point near the gateway, both could be refueled and reused. Especially if the future missions could use spare capacity to transfer fuel to the landing stack.
Beside new MMH/NTO engine (to cover the range of thrust between Draco and SuperDraco), location of the descent/ascent engine, landing legs, ingress/egress hatch design to access the lunar surface, most other elements could be directly applied from Dragon XL and Dragon 2 vehicle designs.
With this architecture and assumed pricing, SpaceX would be uniquely positioned to provide the landing element(s) of the Artemis program, with minimum timeline risk and cost. But the political and economic aspects of the US space program could (again) force NASA to select other provider(s).
For a long time, Dragon 2 was considered as possible precursor for SpaceX moon lander. It has flight heritage (soon followed up with first manned mission), fully functional and tested docking adapter, proven GNC, heat shield, solar power and propulsion elements. Dragon 2 was envisioned with having landing legs and capability to land on any firm surface (including Earth, Moon and Mars). Red Dragon was discontinued. Grey Dragon was not addressed.
Other possible lander designs will miss most of these elements, especially in integrated form. Blue moon lander proposal includes several different vendors who would need to integrate three different elements (Transfer, Descent and Ascent Element) from five different vendors in just four years. Most of these elements would utilize new designs or designs transferred from other vehicles and/or applications.
There are four main drawbacks of selecting lunar lander based on SpaceX Dragon platform. First is political. NASA is a governmental entity whose funding is approved by people with primary interest to distribute funding among their electorates. Thus SpaceX faces significant disadvantage with its vertical integration focused on just three federal states (California, Texas and Florida).
Second, although it is highly likely that SpaceX proposal would be the most cost effective, they are already the major (or even main) CRS-2, CCP and GLS provider. This raises concerns whether they would have enough talent and resources to provide the most complex part of the Artemis program - lunar landing vehicles. In just four years.
Third, selection of SpaceX for lunar landing would position them as the main NASA transportation supplier for a whole spectrum of human spaceflight efforts, providing them with de-facto monopoly and restricting other major suppliers in space industry (Boeing, Lockheed Martin, Northrop Grumman, Sierra Nevada and possibly Blue Origin).
Lastly, any proposal built around Dragon would not be considered mass efficient. Dragon 2 is quite heavy vehicle, optimized for reentry in Earth Atmosphere. Thus any Dragon derived lunar lander would be based on Dragon XL.
Transfer element would probably be based on Dragon XL itself, where the "cargo" would be replaced with fuel tanks used for transferring the whole stack from the lunar gateway near rectilinear high orbit down to low lunar orbit and back. This can use existing low-thrust Draco engines, so the transfer element would be very similar to XL variant (if they provide enough propellant capacity).
Descent and ascent elements based on Dragon XL would require a lot of delta-V budget (over 3.7km/s) using MMH/NTO propellant with specific impulse.
With SpaceX attitude towards reuse, most likely design would use the same element for both ascent and descent with MMH/NTO propellant. It is storable and could be reused-transferred using fuel transfer from Dragon XL. This approach would require significantly more propellant than hydrolox based proposals. But Falcon Heavy and Dragon XL can be sized to maximize the in-space fuel transfer, which would make it easy for SpaceX to provide all necessary propellant using rather cheap Dragon XL/Falcon Heavy flights.
Let us assume that the dry mass of Lunar Dragon together with astronauts and cargo would be 4000 kg (which is probably an overestimate). With ISP of 320 and transfer element based on Dragon XL with the same mass (4000 kg), such configuration would require two Falcon Heavy flights and have total mass of 23000 kg in EML1 (which I used as approximation for NRHO delta-V budget). Falcon Heavy could easily launch both vehicles to EML1 or NRHO with booster reuse. Assuming that development cost for ascent/descent element would be the same as Dragon 2 with two flights (2.6 billion), and that Dragon XL as transfer element would be simple modification (total mission cost of 400 million), that would enable cost for first Artemis lunar landing of just 3 billion USD. With additional cost of Orion/SLS.
There is additional technical obstacle here, and that is design of the engine for lunar descent and ascent. The total ascent/descent thrust would be in the range of 30kN, which is not suitable for SuperDraco engine. Furthermore, there would likely need to be multiple engines that would be positioned on the upper edge of the vehicle, in order to minimize risk of debris damaging the engines during landing or ascent. That engine placement would make lunar Dragon quite different in external appearance from other Dragon vehicles.
As both vehicles (ascent/descent and transfer element) would return to the staging point near the gateway, both could be refueled and reused. Especially if the future missions could use spare capacity to transfer fuel to the landing stack.
Beside new MMH/NTO engine (to cover the range of thrust between Draco and SuperDraco), location of the descent/ascent engine, landing legs, ingress/egress hatch design to access the lunar surface, most other elements could be directly applied from Dragon XL and Dragon 2 vehicle designs.
With this architecture and assumed pricing, SpaceX would be uniquely positioned to provide the landing element(s) of the Artemis program, with minimum timeline risk and cost. But the political and economic aspects of the US space program could (again) force NASA to select other provider(s).
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