A bigger service module for Orion

[Eric Hedman]

I have read plenty about the the shortfall in performance of the Orion Service Module.  I don't remember any discussion about boosting the performance of the service module.  The service module has a smaller diameter then Orion.  Is it possible to expand the diameter to store more propellant and give the service module enough extra delta V to be useful while maintaining the same height of the rocket?  Or would you have to stretch the service module to accomplish this?  The bottom line, would this give you anything useful such as entering low lunar orbit while still able to return to Earth?  Is this a practical idea?

[arthuroMo]

I'm late to the party, so do you have any synthetic article/post/debate on Orion's shortfalls ?
Or a non-synthetic one 

[jstrotha0975]

Orion will probably need a bigger service module if they use it for Mars. Other than that I don't see the need.

[Pipess]

The planned lunar architecture uses the existing service module, so a more capable version would be superfluous (even a waste of resources if you want to be cynical) unless, as stated above, Orion goes to Mars or performs some other mission outside of being a ferry to Gateway.

[spacenut]

Is there any way to cut Orion's mass?  It is way overweight. 

[DanClemmensen]

The planned lunar architecture uses the existing service module, so a more capable version would be superfluous (even a waste of resources if you want to be cynical) unless, as stated above, Orion goes to Mars or performs some other mission outside of being a ferry to Gateway.

How long can Orion loiter in NRHO without Gateway? If a bigger service module extends the loiter time, then it is insurance against unavailability of Gateway for longer lunar missions. Of course, this assumes the bigger service module could be delivered before Gateway can be delivered.

[pochimax]

ESA could provide a bigger service module if it is requested by NASA.

It is impossible to have a bigger ESM before Gateway is in lunar orbit.

For missions to asteroids, you can pre-position Gateway as an outpost around the asteroid, but then you will need this bigger service module to reach the orbit of Gateway/asteroid. Then, Gateway returns to NRHO or whatever, Orion to reentry on Earth.

[pathfinder_01]

The planned lunar architecture uses the existing service module, so a more capable version would be superfluous (even a waste of resources if you want to be cynical) unless, as stated above, Orion goes to Mars or performs some other mission outside of being a ferry to Gateway.

How long can Orion loiter in NRHO without Gateway? If a bigger service module extends the loiter time, then it is insurance against unavailability of Gateway for longer lunar missions. Of course, this assumes the bigger service module could be delivered before Gateway can be delivered.

The limit would likely not be the service module. I don't know the current spec. but Orion was supposed to be able to support itself 3 months without a crew and 6 months when docked to a station when the program began.

[pochimax]

3 months inside Orion and the crew will begin to killing each other 

You need more space, for privacy and psychological health, for missions longer than a few days. Gateway is the right thing to solve it. The other possibility would be an expendable orbital module for Orion, which is undesirable. Better to have a reusable orbital module => Gateway.

[DanClemmensen]

3 months inside Orion and the crew will begin to killing each other 

You need more space, for privacy and psychological health, for missions longer than a few days. Gateway is the right thing to solve it. The other possibility would be an expendable orbital module for Orion, which is undesirable. Better to have a reusable orbital module => Gateway.

The initial Gateway (PPE+HALO) is tiny even compared to Orion. Even with I-HAB it's not huge. However, the 30-day mission probably only has two crew in NRHO while the others are in HLS.  If you want a bigger space in NRHO, just keep a Starship HLS up there. It's huge. However, I don't think Starship HLS is designed to sustain the Orion.

[TrevorMonty]

Only benefit more DV would provide is option for Orion to enter and return from LLO. So reducing lander's DV requirements.
If SLS EUS had few days of endurance it could  place Orion in LLO. Existing service module has enough DV to return from LLO.

[pochimax]

3 months inside Orion and the crew will begin to killing each other 

You need more space, for privacy and psychological health, for missions longer than a few days. Gateway is the right thing to solve it. The other possibility would be an expendable orbital module for Orion, which is undesirable. Better to have a reusable orbital module => Gateway.

The initial Gateway (PPE+HALO) is tiny even compared to Orion. Even with I-HAB it's not huge. However, the 30-day mission probably only has two crew in NRHO while the others are in HLS.  If you want a bigger space in NRHO, just keep a Starship HLS up there. It's huge. However, I don't think Starship HLS is designed to sustain the Orion.

It is enough space. The important thing is the separte departments (Orion / Gateway). Not currently possible in Orion.

On the other hand, Gateway is far cheaper than an expendable Starship HLS mission for missions not landing on the Moon or for the whole lunar surface program. Remember I expect Gateway lifetime on the order of 30 years.

I expect in the future NASA will ask Europe for this bigger ESM+, for missions different than lunar landings (asteroids, lagrange points, etc.). Not all will be lunar surface. Moreover, as it will be possible to do lunar surface missions without Gateway NASA could do a lunar surface mission and, at the same time, move Gateway to an interesting destination (asteroid) for a rendezvous with Orion with ESM+.

[Jim]

Remember I expect Gateway lifetime on the order of 30 years.

I expect in the future NASA will ask Europe for this bigger ESM+, for missions different than lunar landings (asteroids, lagrange points, etc.).

neither are going to happen.  Artemis (SLS/Orion) is only going to last a few missions.

[DanClemmensen]

3 months inside Orion and the crew will begin to killing each other 

You need more space, for privacy and psychological health, for missions longer than a few days. Gateway is the right thing to solve it. The other possibility would be an expendable orbital module for Orion, which is undesirable. Better to have a reusable orbital module => Gateway.

The initial Gateway (PPE+HALO) is tiny even compared to Orion. Even with I-HAB it's not huge. However, the 30-day mission probably only has two crew in NRHO while the others are in HLS.  If you want a bigger space in NRHO, just keep a Starship HLS up there. It's huge. However, I don't think Starship HLS is designed to sustain the Orion.

On the other hand, Gateway is far cheaper than an expendable Starship HLS mission for missions not landing on the Moon or for the whole lunar surface program. Remember I expect Gateway lifetime on the order of 30 years.

The first three Starship  HLS (unncrewed demo, Option A lander, Option B lander)  are already paid for and will end up in NRHO, so Gateway cannot be "cheaper".  Added stuff to convert any of them into a long term station might be expensive, but maybe less expensive than I-HAB.

Thiis thread is about Orion. An extended Orion SM might allow Orion to operate for an extended period in conjunction wil one of thee HLSs.

[pochimax]

The first three Starship  HLS (unncrewed demo, Option A lander, Option B lander)  are already paid for and will end up in NRHO, so Gateway cannot be "cheaper".  Added stuff to convert any of them into a long term station might be expensive, but maybe less expensive than I-HAB.

Thiis thread is about Orion. An extended Orion SM might allow Orion to operate for an extended period in conjunction wil one of thee HLSs.

The thread is about a more powerful Orion service module and its possible uses.

It is unlikely that it can be used for lunar low orbit missions. The ESMs are already being built for this decade, so if the decision is made to expand said module it will be in the 30s, for missions starting in 2030 or further in time.
By then the Gateway and lunar landers will be around a long time ago. The lunar landers will be designed to go up and down from NRHO orbit and billions will have been spent on their development with that capacity. It doesn't make sense to spend more money to make the Orion more powerful but the lunar landers less capable.

It doesn't make sense for the trip to Mars either, since that's what the Martian manned transfer vehicle is used for and the Orion just has to go to and from the parking orbit of the Martian transfer ship.

Therefore, only a more powerful Orion makes sense to move through cislunar space and Lagrangian points. Given the very small volume of the ship for long missions of this type, they only make sense with an orbital module for Orion. Such a expendable module does not make economic sense as NASA could be able to move the existing Gateway for such a mission. The only cost would be refuelling and this will be probably routinely do at the expenses of european o japonese colaboration in the program.

I think will be far cheaper to move Gateway for the mission than to made a new Lunaship specific for supporting such a mission.

[Jim]

Therefore, only a more powerful Orion makes sense to move through cislunar space and Lagrangian points.\

No, there is no reason for such a mission for NASA

[yg1968]

Remember I expect Gateway lifetime on the order of 30 years.

I expect in the future NASA will ask Europe for this bigger ESM+, for missions different than lunar landings (asteroids, lagrange points, etc.).

neither are going to happen.  Artemis (SLS/Orion) is only going to last a few missions.

SLS and Orion will last as long as Congress continues to fund them. I expect SLS and Orion to last as long as there is no other BLEO alternatives such as crewed Starship.

[Zed_Noir]

IF someone wants a "bigger" Orion service module. There always the option of docking the current Orion stack to a pre-positioned stripped down SpaceX HLS lander variant with no landing hardware and full tanks in LEO. Plus the bonus of the pressurized volume and pre-positioned cargo that will be available in the lander variant.

Of course getting the Orion to LEO with the SLS will be optional. 

[pochimax]

IF someone wants a "bigger" Orion service module. There always the option of docking the current Orion stack to a pre-positioned stripped down SpaceX HLS lander variant with no landing hardware and full tanks in LEO. Plus the bonus of the pressurized volume and pre-positioned cargo that will be available in the lander variant.

Of course getting the Orion to LEO with the SLS will be optional. 

You need to connect that kind of Moonship with Orion with all the requirements... At that point, will be far cheaper to modify the ESM instead of making that "Moonshipstein". Moreover if it is the eurpeans who pay for it as a contribution for Artemis or whatever the name of the NASA cislunar / mars space program in the '30s, '40s, etc.

[Zed_Noir]

IF someone wants a "bigger" Orion service module. There always the option of docking the current Orion stack to a pre-positioned stripped down SpaceX HLS lander variant with no landing hardware and full tanks in LEO. Plus the bonus of the pressurized volume and pre-positioned cargo that will be available in the lander variant.

Of course getting the Orion to LEO with the SLS will be optional. 

You need to connect that kind of Moonship with Orion with all the requirements... At that point, will be far cheaper to modify the ESM instead of making that "Moonshipstein". Moreover if it is the eurpeans who pay for it as a contribution for Artemis or whatever the name of the NASA cislunar / mars space program in the '30s, '40s, etc.

You do realize that the SpaceX HLS lander is supposed to docked with Orion and act as a mothership, prior to the Gateway platform being available.

IIRC, the length of the Orion ESM is limited by roof ceiling in the VAB. Could make the ESM wider. But that is basically developing a new spacecraft. The European ESM derived from the ATV is the form factor it is because it cost too much change from it's previous form factor.

The Europeans should be considering something else to contributed in the future instead of more Orion ESM to the Artemis program.